Alberto Leon - Academia.edu (original) (raw)

Papers by Alberto Leon

Research paper thumbnail of Agronomic Aspects of the Sunflower 7-HYDROXYLATED Simple Coumarins / Aspectos Agronómicos De Las Cumarinas Simples 7- Hidroxiladas en Girasol / Aspects Agronomiques De 7 Coumarines Hydroxyles Simples Chez Le Tournesol

helia, 2000

SUMMARY Sunflower and other Helianthus ssp. produced, among other secondary metabolites, the coum... more SUMMARY Sunflower and other Helianthus ssp. produced, among other secondary metabolites, the coumarins scopoletin, scopolin and ayapin. In the most general sense they can be defined as stress metabolites, their synthesis being induced in response to adverse environmental condition, both biotic and abiotic. The pattern of coumarin synthesis and accumulation depends on plant variety, it is tissue dependent and developmentally regulated. Coumarin synthesis in sunflower seems to be part of the defence strategy against microorganisms, insect and parasitic plants. From an agricultural point of view the defensive potential of these compounds can be exploited in order to develop resistant varieties (either by classical plant breeding or by biotechnology) or crop protection strategies involving the use of chemicals which induced coumarin synthesis.

Research paper thumbnail of Mapping a novel fertility restoration gene in sunflower

A novel fertility restoration factor for the PET1 cytoplasm, coming from the public line RHA340, ... more A novel fertility restoration factor for the PET1 cytoplasm, coming from the public line RHA340, was evaluated together with resistance genes to downy mildew (Plasmopara halstedii) Pl8 and black rust (Puccinia helianthi) in a mapping population segregating for the three characters. Linkage between the resistance genes and the fertility restoration was not detected, showing that the restoration factor present in the line RHA340 is different from Rf1. Bulk segregant analysis with microsatellite markers allowed to detect markers corresponding to linkage group 7, and this location was confirmed in the mapping population. A map was built showing the order and the distance of these loci.

Research paper thumbnail of EFFECT OF SUNFLOWER CHLOROTIC MOTTLE VIRUS INFECTION ON SUNFLOWER YIELD PARAMETERS / EFECTOS DE LA INFECCIÓN CON EL VIRUS DEL MOTEADO CLORÓTICO DEL GIRASOL SOBRE PARÁMETROS DE LA PRODUCCIÓN DEL GIRASOL / EFFET DE L´INFECTION AVEC LE VIRUS "SUNFLOWER CHLOROTIC MOTTLE VIRUS" (SuCMoV) SUR LES PARAME...

HELIA, 2001

SUMMARYSunflower chlorotic mottle virus (SuCMoV) was detected in several sunflower (Helianthus an... more SUMMARYSunflower chlorotic mottle virus (SuCMoV) was detected in several sunflower (Helianthus annuus L.) growing areas, causing a disease characterized by systemic chlorotic mottling. Symptom severity depended on several factors, including the ontogenetic stage at which infections occur. The objective of this study was to determine the effects of artificial infections with SuCMoV at different ontogenetic stages on agronomic yield characters (plant height, stem and capitulum diameters, achene yield, seed width and length, weight of 1000 seeds and oil content). Sunflower seeds of commercial hybrids Dekalb 4030, Contiflor 3N, and ACA 884 were sown in a split plot design with four replications, which were mechanically inoculated with SuCMoV at four growth stages. A negative (non-inoculated) control was included in the experiment. Virus infection was detected by symptoms and by double antibody sandwich enzymelinked immunosorbent assay (DAS-ELISA). Virus infections at all stages signific...

Research paper thumbnail of Accumulation of soluble phenolic compounds in sunflower capitula correlates with resistance to Sclerotinia sclerotiorum

Euphytica, 2003

Disease symptoms and total soluble phenolics content have been analysed in four sunflower (Helian... more Disease symptoms and total soluble phenolics content have been analysed in four sunflower (Helianthus annuus L.)lines with different resistance levels(from highly susceptible to resistant) to head rot caused by Sclerotinia sclerotiorum (Lib.) de Bary. At the beginning of the flowering stage, capitula were inoculated by spraying with a water suspension of ascospores, and disease symptoms were evaluated from day 6 to day14 after inoculation. The most susceptible genotypes showed all their ovaries to be necrosed and abundant lesions in corollas, bracts and receptacle. In the resistant line, the ovary and corolla were only partially necrosed with no symptoms in the bracts or the receptacle. Total soluble phenolics were extracted and quantified from different parts of the capitulum in both inoculated and non-inoculated plants. The amount of phenolic compounds depended on the sunflower line, the time after inoculation, and the tissue. Higher constitutive and induced phenolic content as we...

Research paper thumbnail of Molecular marker analysis of Helianthus annuus L. 1. Restriction fragment length polymorphism between inbred lines of cultivated sunflower

Theoretical and Applied Genetics, 1994

A detailed linkage map of Helianthus annuus was constructed based on segregation at 234 RFLP loci... more A detailed linkage map of Helianthus annuus was constructed based on segregation at 234 RFLP loci, detected by 213 probes, in an F 2 population of 289 individuals (derived from a cross between the inbred lines HA89 and ZENB8). The genetic markers covered 1380 centiMorgans (cM) of the sunflower genome and were arranged in 17 linkage groups, corresponding to the haploid number of chromosomes in this species. One locus was found to be unlinked. Although the average interval size was 5.9 cM, there were a number of regions larger than 20 cM that were devoid of markers. Genotypic classes at 23 loci deviated significantly from the expected ratios (1:2:1 or 3:1), all showing a reduction in the ZENB8 homozygous class. The majority of these loci were found to map to four regions on linkage groups G, L and P.

Research paper thumbnail of Single Nucleotide Polymorphisms and Linkage Disequilibrium in Sunflower

Genetics, 2007

Genetic diversity in modern sunflower (Helianthus annuus L.) cultivars (elite oilseed inbred line... more Genetic diversity in modern sunflower (Helianthus annuus L.) cultivars (elite oilseed inbred lines) has been shaped by domestication and breeding bottlenecks and wild and exotic allele introgression−the former narrowing and the latter broadening genetic diversity. To assess single nucleotide polymorphism (SNP) frequencies, nucleotide diversity, and linkage disequilibrium (LD) in modern cultivars, alleles were resequenced from 81 genic loci distributed throughout the sunflower genome. DNA polymorphisms were abundant; 1078 SNPs (1/45.7 bp) and 178 insertions-deletions (INDELs) (1/277.0 bp) were identified in 49.4 kbp of DNA/genotype. SNPs were twofold more frequent in noncoding (1/32.1 bp) than coding (1/62.8 bp) sequences. Nucleotide diversity was only slightly lower in inbred lines (θ = 0.0094) than wild populations (θ = 0.0128). Mean haplotype diversity was 0.74. When extraploted across the genome (∼3500 Mbp), sunflower was predicted to harbor at least 76.4 million common SNPs amon...

Research paper thumbnail of Use of RFLP Markers for Genetic Linkage Analysis of Oil Percentage in Sunflower Seed

Crop Science, 1995

Increased seed oil percentage is an important objective when breeding for high oil yield in sunfl... more Increased seed oil percentage is an important objective when breeding for high oil yield in sunflower (Helianthus annuus L.). Although some researchers have investigated the genetics and heritability of sunflower oil percentage, most analyses were conducted on the oil percentage in the whole seed through conventional breeding and biometric procedures. The primary objective of this research was to identify restriction fragment length polymorphisms (RFLPs) linked to quantitative trait loci affecting seed oil percentage, kernel oil percentage, and kernel percentage. An F2 population consisting of 289 individuals was produced by crossing two inbred lines that differ for the traits. The RFLP and trait data were obtained directly from seif-pollinated F2 plants. The RFLP markers (identifying 201 codominant loci) located six regions representing 57% of the genetic variation of seed oil percentage. Two of these regions were associated with kernel oil percentage, two with kernel percentage, and two with both components. Additive gene action was predominant for seed oil percentage and its components.

Research paper thumbnail of Genetic study of recessive broomrape resistance in sunflower

Euphytica, 2016

Genetic resistance to broomrape (Orobanche cumana Wallr.) in sunflower is mainly monogenic and do... more Genetic resistance to broomrape (Orobanche cumana Wallr.) in sunflower is mainly monogenic and dominant. Massive use of vertical resistance has led to the progressive extension of increasingly virulent races of the parasite. Additional introduction of horizontal resistance genes is crucial to develop more durable resistance. The objective of this research was to study the inheritance of resistance to broomrape race F in sunflower line K-96 and to identify QTL of potential value for marker assisted pyramiding of resistance genes. The inheritance of broomrape resistance was studied in crosses with the susceptible line P-21 and the line P-96, with oligogenic recessive resistance. Crosses with P-96 revealed broad transgressive segregation for susceptibility in the F 2 , indicating that both lines possess different resistance alleles. Crosses with P-21 suggested that the trait is mainly controlled by a dominant-recessive epistasis at two loci. Additionally, segregation for plant height was identified and measured in a non-inoculated F 2 population. Five QTL on LG 2, 3, 4, 5, and 6 were associated with broomrape resistance traits. Two of them at LG 4 and 5 were also associated with plant height, suggesting an alleged pleiotropic effect of plant height on broomrape resistance. The latter two QTL had been previously identified in the cross P-21 9 P-96, whereas the other QTL seem to be involved in K-96 but not in P-96 resistance. This study concluded that K-96 and P-96 have complementary QTL with minor effect on broomrape resistance. They are, therefore, good donor sources for marker-assisted pyramiding programs.

Research paper thumbnail of The genetic map position of the locus encoding the 2S albumin seed storage proteins in cultivated sunflower ( Helianthus annuus L.)

Euphytica, 2001

Sunflower contains two classes of seed proteins: the 11S globulins (helianthinins) and the 2S alb... more Sunflower contains two classes of seed proteins: the 11S globulins (helianthinins) and the 2S albumins. Polymorphisms have been detected within both classes and therefore they have been proposed as genetic markers. The objectives of the present study were to identify sunflower seed protein polymorphisms and locate them on an RFLP linkage map. Seed proteins of 68 inbred lines and four

Research paper thumbnail of Selection of a Sunflower Line with Multiple Herbicide Tolerance That Is Reversed by the P450 Inhibitor Malathion

Selection of a Sunflower Line with Multiple Herbicide Tolerance That Is Reversed by the P450 Inhibitor Malathion

Weed Science, 2011

Ninety-seven inbred lines of sunflower were screened in the field by treatment with a combination... more Ninety-seven inbred lines of sunflower were screened in the field by treatment with a combination of imazamox and malathion, an inhibitor of cytochrome P450 monooxygenases (P450s), to identify sunflower lines with natural tolerance to the herbicide reversed by malathion. One tolerant line, named TolP450-1, was selected and characterized in the field and in the greenhouse to evaluate its response to the herbicides imazamox, prosulfuron, and atrazine at different plant development stages (germination, emergence, and third difoliate) with and without malathion. For all herbicides and all development stages analyzed, TolP450-1 showed significantly higher tolerance compared with the susceptible line RHA266. In all cases, the tolerance was reversed by malathion. This sunflower line, tolerant to multiple herbicides, may be useful in helping to manage herbicide-resistant weeds by allowing additional herbicides to be used in this oilseed crop.

Research paper thumbnail of Acetohydroxyacid synthase mutations conferring resistance to imidazolinone or sulfonylurea herbicides in sunflower

Theoretical and Applied Genetics, 2004

Wild biotypes of cultivated sunflower (Helianthus annuus L.) are weeds in corn (Zea mays L.), soy... more Wild biotypes of cultivated sunflower (Helianthus annuus L.) are weeds in corn (Zea mays L.), soybean (Glycine max L.), and other crops in North America, and are commonly controlled by applying acetohydroxyacid synthase (AHAS)-inhibiting herbicides. Biotypes resistant to two classes of AHAS-inhibiting herbicides-imidazolinones (IMIs) or sulfonylureas (SUs)-have been discovered in wild sunflower populations (ANN-PUR and ANN-KAN) treated with imazethapyr or chlorsulfuron, respectively. The goals of the present study were to isolate AHAS genes from sunflower, identify mutations in AHAS genes conferring herbicide resistance in ANN-PUR and ANN-KAN, and develop tools for marker-assisted selection (MAS) of herbicide resistance genes in sunflower. Three AHAS genes (AHAS1, AHAS2, and AHAS3) were identified, cloned, and sequenced from herbicide-resistant (mutant) and-susceptible (wild type) genotypes. We identified 48 single-nucleotide polymorphisms (SNPs) in AHAS1, a single six-base pair insertiondeletion in AHAS2, and a single SNP in AHAS3. No DNA polymorphisms were found in AHAS2 among elite inbred lines. AHAS1 from imazethapyr-resistant inbreds harbored a C-toT mutation in codon 205 (Arabidopsis thaliana codon nomenclature), conferring resistance to IMI herbicides, whereas AHAS1 from chlorsulfuron-resistant inbreds harbored a C-toT mutation in codon 197, conferring resistance to SU herbicides. SNP and single-strand conformational polymorphism markers for AHAS1, AHAS2, and AHAS3 were developed and genetically mapped. AHAS1, AHAS2, and AHAS3 mapped to linkage groups 2 (AHAS3), 6 (AHAS2), and 9 (AHAS1). The C/T SNP in codon 205 of AHAS1 cosegregated with a partially dominant gene for resistance to IMI herbicides in two mutant × wild-type populations. The molecular breeding tools described herein create the basis for rapidly identifying new mutations in AHAS and performing MAS for herbicide resistance genes in sunflower.

Research paper thumbnail of Quantitative trait loci for growing degree days to flowering and photoperiod response in Sunflower (Helianthus annuus L.)

Theoretical and Applied Genetics, 2001

The number of days from seedling emergence to flowering (DTF) is a major consideration in sunflow... more The number of days from seedling emergence to flowering (DTF) is a major consideration in sunflower breeding programs. This is a complex trait determined by the genotype, environmental conditions and interactions. Photoperiod and temperature have major effects on DTF and could be important sources of genotype× environment interaction. The objectives of this study were to locate quantitative trait loci (QTLs) associated with growing degree days (GDD) to flowering and photoperiod (PP) response in an elite sunflower population. Two hundred and thirty five F 2-generation plants and their F 2:3 and F 2:4 progenies of a single-cross population of two divergent inbred lines were evaluated in six environments (locations, years and sowing dates) with photoperiods known to elicit a PP response between the inbred lines. Detection of QTLs was facilitated with a genetic linkage map of 205 RFLP loci and composite interval mapping. The 205 restriction fragment length polymorphism (RFLP) loci covered 1380 cM and were arranged in 17 linkage groups, which is the haploid number of chromosomes in this species. The average interval size was 5.9 cM. Six QTLs in linkage groups A, B, F, I, J and L were associated with GDD to flowering and accounted for 76% of the genotypic variation in the mean environment. QTLs in linkage groups A and B accounted for 72% of the genetic variation. QTL×environment (QTL×E) interactions were highly significant for linkage groups A, B, F and J (P<0.01). QTLs in linkage groups A and B were highly dependent on PP. Also, QTL mapping of the ratio of the GDD required by a progeny to flower at a PP of 12.1 and 15.0 h, defined as the photoperiod response (PPR), suggested that alleles at QTLs in linkage groups A and B were responsive to PP. QTLs in linkage groups F and J showed QTL×E interaction but the LOD values were not associated with PP. QTL×E interactions for additive effects were highly significant (P<0.01) for linkage groups A, B and F. QTL×E interactions for QTLs with dominant effects were significant (P<0.01) for linkage groups A, B and J. The dominant effect of QTLs in linkage group B increased in environments with a longer PP. The knowledge of how these QTLs influence the GDD for flowering and how they interact with the environment will facilitate marker-assisted selection and backcross conversion of photoperiodsensitive germplasm.

Research paper thumbnail of cDNA cloning, expression levels and gene mapping of photosynthetic and non-photosynthetic ferredoxin genes in sunflower (Helianthus annuus L.)

Theoretical and Applied Genetics, 2009

Fatty acid desaturation in plastids and chloroplasts depends on the electron-donor activity of fe... more Fatty acid desaturation in plastids and chloroplasts depends on the electron-donor activity of ferredoxins. Using degenerate oligonucleotides designed from known photosynthetic and heterotrophic plant ferredoxin sequences, two full-length ferredoxin cDNAs were cloned from sunflower (Helianthus annuus L.) leaves and developing seeds, HaFd1 and HaFd2, homologous to photosynthetic and non-photosynthetic ferredoxins, respectively. Based on these cDNAs, the respective genomic sequences were obtained and the presence of DNA polymorphisms was investigated. Complete sequencing of the HaFd1 and HaFd2 genes in different lines indicated the presence of two haplotypes for HaFd2 and their alignment showed that sequence polymorphisms are restricted to the 5 0-NTR intron. In addition, specific DNA markers for the HaFd1 and HaFd2 genes were developed that enabled the genes to be mapped. Accordingly, the HaFd1 locus maps to linkage group 10 of the public sunflower map, while the HaFd2 locus maps to linkage group 11. Both ferredoxins display different spatial-temporal patterns of expression. While HaFd2 is expressed at similar levels in all tissues tested (leaves, stem, roots, cotyledons and developing seeds), HaFd1 is more strongly expressed in green tissues than in all the other tissues tested. Both photosynthetic-and heterotrophic-ferredoxins are present in sunflower seeds and may contribute to fatty acid desaturation during oil accumulation. Nevertheless, the levels of HaFd2 expression during seed formation are distinct in lines that only varied in the HaFd2 haplotypes they expressed. Communicated by A. Bervillé.

Research paper thumbnail of Molecular analysis of the high stearic acid content in sunflower mutant CAS-14

Molecular analysis of the high stearic acid content in sunflower mutant CAS-14

Theoretical and Applied Genetics, 2005

Increasing the stearic acid content to improve sunflower (Helianthus annuus L.) oil quality is a ... more Increasing the stearic acid content to improve sunflower (Helianthus annuus L.) oil quality is a desirable breeding objective for food-processing applications. CAS-14 is a sunflower mutant line with a high stearic acid content in its seed oil (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;35% vs. &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;6% in currently grown sunflower hybrids), which is controlled by the Es3 gene. However, the expression of the high stearic acid character in CAS-14 is strongly influenced by temperature during seed maturation and it is not uniform along the seed. The objectives of this study were (1) to identify PCR-based molecular markers linked to the Es3 gene from CAS-14, (2) to map this gene on the sunflower genetic map, and (3) to characterize the interaction between CAS-14 and CAS-3, a sunflower high stearic acid (about 26%) mutant line with the Es1 and Es2 genes determining this trait. Two F2 mapping populations were developed from crosses between CAS-14 and P21, a nuclear male sterile line with the Ms11 gene controlling this character, and between CAS-14 and CAS-3. One hundred and thirty-three individuals from P21xCAS-14, and 164 individuals from CAS-3xCAS-14 were phenotyped in F2 and F3 seed generations for fatty acid composition using gas-liquid chromatography, and they were then genotyped with microsatellite [simple sequence repeat (SSR)] and insertion-deletion (INDEL) markers. Bulk segregant analysis in the P21xCAS-14 population identified two markers on LG 8 putatively linked to Es3. A large linkage group was identified using additional markers mapping to LG 8. Es3 mapped to the distal half of LG 8 and was flanked by the SSR markers ORS243 and ORS1161 at genetic distances of 0.5, and 3.9 cM, respectively. The Ms11 gene was also mapped to LG 8 and genetic distance between this gene and Es3 was found to be 7.4 cM. In the CAS-3xCAS-14 population, two QTLs were identified on LG 1 and LG 8, which underlie the Es1 gene from CAS-3 and the Es3 gene from CAS-14, respectively. A significant epistatic interaction between these two QTLs was found. Results from this study provided a basis for determining CAS-14 efficient breeding strategies.

Research paper thumbnail of An integrated restriction fragment length polymorphism - amplified fragment length polymorphism linkage map for cultivated sunflower

Genome, 2001

Restriction fragment length polymorphism (RFLP) maps have been constructed for cultivated sunflow... more Restriction fragment length polymorphism (RFLP) maps have been constructed for cultivated sunflower (Helianthus annuus L.) using three independent sets of RFLP probes. The aim of this research was to integrate RFLP markers from two sets with RFLP markers for resistance gene candidate (RGC) and amplified fragment length polymorphism (AFLP) markers. Genomic DNA samples of HA370 and HA372, the parents of the F 2 population used to build the map, were screened for AFLPs using 42 primer combinations and RFLPs using 136 cDNA probes (RFLP analyses were performed on DNA digested with EcoRI, HindIII, EcoRV, or DraI). The AFLP primers produced 446 polymorphic and 1101 monomorphic bands between HA370 and HA372. The integrated map was built by genotyping 296 AFLP and 104 RFLP markers on 180 HA370 × HA372 F 2 progeny (the AFLP marker assays were performed using 18 primer combinations). The HA370 × HA372 map comprised 17 linkage groups, presumably corresponding to the 17 haploid chromosomes of sunflower, had a mean density of 3.3 cM, and was 1326 cM long. Six RGC RFLP loci were polymorphic and mapped to three linkage groups (LG8, LG13, and LG15). AFLP markers were densely clustered on several linkage groups, and presumably reside in centromeric regions where recombination is reduced and the ratio of genetic to physical distance is low. Strategies for targeting markers to euchromatic DNA need to be tested in sunflower. The HA370 × HA372 map integrated 14 of 17 linkage groups from two independent RFLP maps. Three linkage groups were devoid of RFLP markers from one of the two maps.

Research paper thumbnail of Variability among inbred lines and RFLP mapping of sunflower isozymes

Genetics and Molecular Biology, 2002

Eight isozyme systems were used in this study: acid phosphatase (ACP), alcohol dehydrogenase (ADH... more Eight isozyme systems were used in this study: acid phosphatase (ACP), alcohol dehydrogenase (ADH), esterase (EST), glutamate dehydrogenase (GDH), malate dehydrogenase (MDH), phosphoglucoisomerase (PGI), 6-phosphogluconate dehydrogenase (PGD), and phosphoglucomutase (PGM). The polymorphism of these enzyme systems was studied in 25 elite inbred lines. A total of 19 loci were identified, but only eight of them were polymorphic in the germplasm tested. The polymorphic index for the eight informative markers ranged from 0.08 to 0.57, with a mean value of 0.36. Five isozyme loci were mapped in F 2:3 populations with existing RFLP data. Est-1, Gdh-2 and Pgi-2 were mapped to linkage groups 3, 14 and 9, respectively. As in previous reports, an ACP locus and a PGD locus were found to be linked, both located in linkage group 2 of the public sunflower map.

Research paper thumbnail of Molecular Mapping of Nuclear Male Sterility Genes in Sunflower

Crop Science, 2005

Nuclear male sterility (NMS) is a useful tool for sunflower (Helianthus annuus L.) breeding and g... more Nuclear male sterility (NMS) is a useful tool for sunflower (Helianthus annuus L.) breeding and genetics programs. A clear understanding of the genetics of NMS at the molecular level and the identification of linked molecular markers will greatly facilitate breeding for this trait. P21 is an inbred line carrying the single gene Ms11 controlling NMS, and NMS801 and NMS373 are two inbred lines with the NMS gene Ms10 The objectives of this study were to (i) identify molecular markers linked with the Ms10 and the Ms11 NMS genes, and (ii) place these genes on the genetic map of sunflower. Three F2 and a BC1F1 mapping populations developed from crosses between the male‐sterile (MS) lines P21, NMS801, and NMS373, and male‐fertile (MF) (wild‐type) lines were scored for fertility/sterility. The NMS801 and NMS373 populations segregated for Ms10 and T, a tightly linked anthocyanin pigment locus. The P21 populations segregated for Ms11 These populations were then genotyped with restriction frag...

Research paper thumbnail of Quantitative Trait Loci for Genetically Correlated Seed Traits are Tightly Linked to Branching and Pericarp Pigment Loci in Sunflower

Crop Science, 2006

The seed oil concentrations of large‐seeded, low‐oil and small‐seeded, high‐oil sunflower (Helian... more The seed oil concentrations of large‐seeded, low‐oil and small‐seeded, high‐oil sunflower (Helianthus annuus L.; x = 17) cultivars differ by 180 to 280 g kg−1 We identified quantitative trait loci (QTL) for seed oil and other seed traits in a low‐ × high‐oil (RHA280 × RHA801) recombinant inbred line (RIL) mapping population segregating for apical branching (B), phytomelanin pigment (P), and hypodermal pigment (Hyp) loci. B, Hyp, and P mapped to linkage groups 10, 16, and 17, respectively. The seed oil concentrations of RHA280 and RHA801 were 254 and 481 g kg−1, respectively. Composite interval mapping (CIM) identified 40 QTL for seed oil concentration, 100‐seed weight, seed length, width and depth, kernel and pericarp weight, and kernel‐to‐pericarp weight ratio in 14 DNA marker intervals on 10 of 17 linkage groups. Twenty‐four of the QTL were tightly linked to B, P, and Hyp and may have been partly or wholly caused by the pleiotropic effects of B, P, and Hyp Multilocus QTL analyses ...

Research paper thumbnail of Genetic Mapping of a Locus ( hyp ) Affecting Seed Hypodermis Color in Sunflower

Crop Science, 1996

Sunflower (Helianthus annuus L.) seed color is determined by pigmentation of three layers of the ... more Sunflower (Helianthus annuus L.) seed color is determined by pigmentation of three layers of the pericarp (hull): epidermis, hypodermis, and phytomelanin layer. A gene with major effects on hypodermis color was reported previously. However, genetic factors that determine the presence or absence of pigment in the hypodermis have not been reported. We identified RFLP markers linked to factor(s) affecting hypodermis pigmentation and assessed the relationship between this trait and oil percentage in sunflower seed. An F 2 single-cross population was produced from homozygous and homogeneous inbred parents ZENB8 and HA89, with pigmented and unpigmented hypodermis, respectively. Two hundred sixty-seven F 2 plants and their Fs families were evaluated. A dominant factor (Hyp) determining the presence of white pigments in the hypodermis was located to linkage group 'G'. Seeds with white hypodermis had lower oil percentage than those with unpigmented hypodermis. The Hyp factor was located in the same map interval as one QTL with major effects on seed oil percentage in this population. Knowledge of genetic linkage among DNA markers, hypodermis pigmentation, and oil percentage should enhance breeding programs.

Research paper thumbnail of SMART – Sunflower Mutant population And Reverse genetic Tool for crop improvement

BMC Plant Biology, 2013

Background Sunflower (Helianthus annuus L.) is an important oilseed crop grown widely in various ... more Background Sunflower (Helianthus annuus L.) is an important oilseed crop grown widely in various areas of the world. Classical genetic studies have been extensively undertaken for the improvement of this particular oilseed crop. Pertaining to this endeavor, we developed a “chemically induced mutated genetic resource for detecting SNP by TILLING” in sunflower to create new traits. Results To optimize the EMS mutagenesis, we first conducted a “kill curve” analysis with a range of EMS dose from 0.5% to 3%. Based on the observed germination rate, a 50% survival rate i.e. LD50, treatment with 0.6% EMS for 8 hours was chosen to generate 5,000 M2 populations, out of which, 4,763 M3 plants with fertile seed set. Phenotypic characterization of the 5,000 M2 mutagenised lines were undertaken to assess the mutagenesis quality and to identify traits of interest. In the M2 population, about 1.1% of the plants showed phenotypic variations. The sunflower TILLING platform was setup using Endo-1-nucl...

Research paper thumbnail of Agronomic Aspects of the Sunflower 7-HYDROXYLATED Simple Coumarins / Aspectos Agronómicos De Las Cumarinas Simples 7- Hidroxiladas en Girasol / Aspects Agronomiques De 7 Coumarines Hydroxyles Simples Chez Le Tournesol

helia, 2000

SUMMARY Sunflower and other Helianthus ssp. produced, among other secondary metabolites, the coum... more SUMMARY Sunflower and other Helianthus ssp. produced, among other secondary metabolites, the coumarins scopoletin, scopolin and ayapin. In the most general sense they can be defined as stress metabolites, their synthesis being induced in response to adverse environmental condition, both biotic and abiotic. The pattern of coumarin synthesis and accumulation depends on plant variety, it is tissue dependent and developmentally regulated. Coumarin synthesis in sunflower seems to be part of the defence strategy against microorganisms, insect and parasitic plants. From an agricultural point of view the defensive potential of these compounds can be exploited in order to develop resistant varieties (either by classical plant breeding or by biotechnology) or crop protection strategies involving the use of chemicals which induced coumarin synthesis.

Research paper thumbnail of Mapping a novel fertility restoration gene in sunflower

A novel fertility restoration factor for the PET1 cytoplasm, coming from the public line RHA340, ... more A novel fertility restoration factor for the PET1 cytoplasm, coming from the public line RHA340, was evaluated together with resistance genes to downy mildew (Plasmopara halstedii) Pl8 and black rust (Puccinia helianthi) in a mapping population segregating for the three characters. Linkage between the resistance genes and the fertility restoration was not detected, showing that the restoration factor present in the line RHA340 is different from Rf1. Bulk segregant analysis with microsatellite markers allowed to detect markers corresponding to linkage group 7, and this location was confirmed in the mapping population. A map was built showing the order and the distance of these loci.

Research paper thumbnail of EFFECT OF SUNFLOWER CHLOROTIC MOTTLE VIRUS INFECTION ON SUNFLOWER YIELD PARAMETERS / EFECTOS DE LA INFECCIÓN CON EL VIRUS DEL MOTEADO CLORÓTICO DEL GIRASOL SOBRE PARÁMETROS DE LA PRODUCCIÓN DEL GIRASOL / EFFET DE L´INFECTION AVEC LE VIRUS "SUNFLOWER CHLOROTIC MOTTLE VIRUS" (SuCMoV) SUR LES PARAME...

HELIA, 2001

SUMMARYSunflower chlorotic mottle virus (SuCMoV) was detected in several sunflower (Helianthus an... more SUMMARYSunflower chlorotic mottle virus (SuCMoV) was detected in several sunflower (Helianthus annuus L.) growing areas, causing a disease characterized by systemic chlorotic mottling. Symptom severity depended on several factors, including the ontogenetic stage at which infections occur. The objective of this study was to determine the effects of artificial infections with SuCMoV at different ontogenetic stages on agronomic yield characters (plant height, stem and capitulum diameters, achene yield, seed width and length, weight of 1000 seeds and oil content). Sunflower seeds of commercial hybrids Dekalb 4030, Contiflor 3N, and ACA 884 were sown in a split plot design with four replications, which were mechanically inoculated with SuCMoV at four growth stages. A negative (non-inoculated) control was included in the experiment. Virus infection was detected by symptoms and by double antibody sandwich enzymelinked immunosorbent assay (DAS-ELISA). Virus infections at all stages signific...

Research paper thumbnail of Accumulation of soluble phenolic compounds in sunflower capitula correlates with resistance to Sclerotinia sclerotiorum

Euphytica, 2003

Disease symptoms and total soluble phenolics content have been analysed in four sunflower (Helian... more Disease symptoms and total soluble phenolics content have been analysed in four sunflower (Helianthus annuus L.)lines with different resistance levels(from highly susceptible to resistant) to head rot caused by Sclerotinia sclerotiorum (Lib.) de Bary. At the beginning of the flowering stage, capitula were inoculated by spraying with a water suspension of ascospores, and disease symptoms were evaluated from day 6 to day14 after inoculation. The most susceptible genotypes showed all their ovaries to be necrosed and abundant lesions in corollas, bracts and receptacle. In the resistant line, the ovary and corolla were only partially necrosed with no symptoms in the bracts or the receptacle. Total soluble phenolics were extracted and quantified from different parts of the capitulum in both inoculated and non-inoculated plants. The amount of phenolic compounds depended on the sunflower line, the time after inoculation, and the tissue. Higher constitutive and induced phenolic content as we...

Research paper thumbnail of Molecular marker analysis of Helianthus annuus L. 1. Restriction fragment length polymorphism between inbred lines of cultivated sunflower

Theoretical and Applied Genetics, 1994

A detailed linkage map of Helianthus annuus was constructed based on segregation at 234 RFLP loci... more A detailed linkage map of Helianthus annuus was constructed based on segregation at 234 RFLP loci, detected by 213 probes, in an F 2 population of 289 individuals (derived from a cross between the inbred lines HA89 and ZENB8). The genetic markers covered 1380 centiMorgans (cM) of the sunflower genome and were arranged in 17 linkage groups, corresponding to the haploid number of chromosomes in this species. One locus was found to be unlinked. Although the average interval size was 5.9 cM, there were a number of regions larger than 20 cM that were devoid of markers. Genotypic classes at 23 loci deviated significantly from the expected ratios (1:2:1 or 3:1), all showing a reduction in the ZENB8 homozygous class. The majority of these loci were found to map to four regions on linkage groups G, L and P.

Research paper thumbnail of Single Nucleotide Polymorphisms and Linkage Disequilibrium in Sunflower

Genetics, 2007

Genetic diversity in modern sunflower (Helianthus annuus L.) cultivars (elite oilseed inbred line... more Genetic diversity in modern sunflower (Helianthus annuus L.) cultivars (elite oilseed inbred lines) has been shaped by domestication and breeding bottlenecks and wild and exotic allele introgression−the former narrowing and the latter broadening genetic diversity. To assess single nucleotide polymorphism (SNP) frequencies, nucleotide diversity, and linkage disequilibrium (LD) in modern cultivars, alleles were resequenced from 81 genic loci distributed throughout the sunflower genome. DNA polymorphisms were abundant; 1078 SNPs (1/45.7 bp) and 178 insertions-deletions (INDELs) (1/277.0 bp) were identified in 49.4 kbp of DNA/genotype. SNPs were twofold more frequent in noncoding (1/32.1 bp) than coding (1/62.8 bp) sequences. Nucleotide diversity was only slightly lower in inbred lines (θ = 0.0094) than wild populations (θ = 0.0128). Mean haplotype diversity was 0.74. When extraploted across the genome (∼3500 Mbp), sunflower was predicted to harbor at least 76.4 million common SNPs amon...

Research paper thumbnail of Use of RFLP Markers for Genetic Linkage Analysis of Oil Percentage in Sunflower Seed

Crop Science, 1995

Increased seed oil percentage is an important objective when breeding for high oil yield in sunfl... more Increased seed oil percentage is an important objective when breeding for high oil yield in sunflower (Helianthus annuus L.). Although some researchers have investigated the genetics and heritability of sunflower oil percentage, most analyses were conducted on the oil percentage in the whole seed through conventional breeding and biometric procedures. The primary objective of this research was to identify restriction fragment length polymorphisms (RFLPs) linked to quantitative trait loci affecting seed oil percentage, kernel oil percentage, and kernel percentage. An F2 population consisting of 289 individuals was produced by crossing two inbred lines that differ for the traits. The RFLP and trait data were obtained directly from seif-pollinated F2 plants. The RFLP markers (identifying 201 codominant loci) located six regions representing 57% of the genetic variation of seed oil percentage. Two of these regions were associated with kernel oil percentage, two with kernel percentage, and two with both components. Additive gene action was predominant for seed oil percentage and its components.

Research paper thumbnail of Genetic study of recessive broomrape resistance in sunflower

Euphytica, 2016

Genetic resistance to broomrape (Orobanche cumana Wallr.) in sunflower is mainly monogenic and do... more Genetic resistance to broomrape (Orobanche cumana Wallr.) in sunflower is mainly monogenic and dominant. Massive use of vertical resistance has led to the progressive extension of increasingly virulent races of the parasite. Additional introduction of horizontal resistance genes is crucial to develop more durable resistance. The objective of this research was to study the inheritance of resistance to broomrape race F in sunflower line K-96 and to identify QTL of potential value for marker assisted pyramiding of resistance genes. The inheritance of broomrape resistance was studied in crosses with the susceptible line P-21 and the line P-96, with oligogenic recessive resistance. Crosses with P-96 revealed broad transgressive segregation for susceptibility in the F 2 , indicating that both lines possess different resistance alleles. Crosses with P-21 suggested that the trait is mainly controlled by a dominant-recessive epistasis at two loci. Additionally, segregation for plant height was identified and measured in a non-inoculated F 2 population. Five QTL on LG 2, 3, 4, 5, and 6 were associated with broomrape resistance traits. Two of them at LG 4 and 5 were also associated with plant height, suggesting an alleged pleiotropic effect of plant height on broomrape resistance. The latter two QTL had been previously identified in the cross P-21 9 P-96, whereas the other QTL seem to be involved in K-96 but not in P-96 resistance. This study concluded that K-96 and P-96 have complementary QTL with minor effect on broomrape resistance. They are, therefore, good donor sources for marker-assisted pyramiding programs.

Research paper thumbnail of The genetic map position of the locus encoding the 2S albumin seed storage proteins in cultivated sunflower ( Helianthus annuus L.)

Euphytica, 2001

Sunflower contains two classes of seed proteins: the 11S globulins (helianthinins) and the 2S alb... more Sunflower contains two classes of seed proteins: the 11S globulins (helianthinins) and the 2S albumins. Polymorphisms have been detected within both classes and therefore they have been proposed as genetic markers. The objectives of the present study were to identify sunflower seed protein polymorphisms and locate them on an RFLP linkage map. Seed proteins of 68 inbred lines and four

Research paper thumbnail of Selection of a Sunflower Line with Multiple Herbicide Tolerance That Is Reversed by the P450 Inhibitor Malathion

Selection of a Sunflower Line with Multiple Herbicide Tolerance That Is Reversed by the P450 Inhibitor Malathion

Weed Science, 2011

Ninety-seven inbred lines of sunflower were screened in the field by treatment with a combination... more Ninety-seven inbred lines of sunflower were screened in the field by treatment with a combination of imazamox and malathion, an inhibitor of cytochrome P450 monooxygenases (P450s), to identify sunflower lines with natural tolerance to the herbicide reversed by malathion. One tolerant line, named TolP450-1, was selected and characterized in the field and in the greenhouse to evaluate its response to the herbicides imazamox, prosulfuron, and atrazine at different plant development stages (germination, emergence, and third difoliate) with and without malathion. For all herbicides and all development stages analyzed, TolP450-1 showed significantly higher tolerance compared with the susceptible line RHA266. In all cases, the tolerance was reversed by malathion. This sunflower line, tolerant to multiple herbicides, may be useful in helping to manage herbicide-resistant weeds by allowing additional herbicides to be used in this oilseed crop.

Research paper thumbnail of Acetohydroxyacid synthase mutations conferring resistance to imidazolinone or sulfonylurea herbicides in sunflower

Theoretical and Applied Genetics, 2004

Wild biotypes of cultivated sunflower (Helianthus annuus L.) are weeds in corn (Zea mays L.), soy... more Wild biotypes of cultivated sunflower (Helianthus annuus L.) are weeds in corn (Zea mays L.), soybean (Glycine max L.), and other crops in North America, and are commonly controlled by applying acetohydroxyacid synthase (AHAS)-inhibiting herbicides. Biotypes resistant to two classes of AHAS-inhibiting herbicides-imidazolinones (IMIs) or sulfonylureas (SUs)-have been discovered in wild sunflower populations (ANN-PUR and ANN-KAN) treated with imazethapyr or chlorsulfuron, respectively. The goals of the present study were to isolate AHAS genes from sunflower, identify mutations in AHAS genes conferring herbicide resistance in ANN-PUR and ANN-KAN, and develop tools for marker-assisted selection (MAS) of herbicide resistance genes in sunflower. Three AHAS genes (AHAS1, AHAS2, and AHAS3) were identified, cloned, and sequenced from herbicide-resistant (mutant) and-susceptible (wild type) genotypes. We identified 48 single-nucleotide polymorphisms (SNPs) in AHAS1, a single six-base pair insertiondeletion in AHAS2, and a single SNP in AHAS3. No DNA polymorphisms were found in AHAS2 among elite inbred lines. AHAS1 from imazethapyr-resistant inbreds harbored a C-toT mutation in codon 205 (Arabidopsis thaliana codon nomenclature), conferring resistance to IMI herbicides, whereas AHAS1 from chlorsulfuron-resistant inbreds harbored a C-toT mutation in codon 197, conferring resistance to SU herbicides. SNP and single-strand conformational polymorphism markers for AHAS1, AHAS2, and AHAS3 were developed and genetically mapped. AHAS1, AHAS2, and AHAS3 mapped to linkage groups 2 (AHAS3), 6 (AHAS2), and 9 (AHAS1). The C/T SNP in codon 205 of AHAS1 cosegregated with a partially dominant gene for resistance to IMI herbicides in two mutant × wild-type populations. The molecular breeding tools described herein create the basis for rapidly identifying new mutations in AHAS and performing MAS for herbicide resistance genes in sunflower.

Research paper thumbnail of Quantitative trait loci for growing degree days to flowering and photoperiod response in Sunflower (Helianthus annuus L.)

Theoretical and Applied Genetics, 2001

The number of days from seedling emergence to flowering (DTF) is a major consideration in sunflow... more The number of days from seedling emergence to flowering (DTF) is a major consideration in sunflower breeding programs. This is a complex trait determined by the genotype, environmental conditions and interactions. Photoperiod and temperature have major effects on DTF and could be important sources of genotype× environment interaction. The objectives of this study were to locate quantitative trait loci (QTLs) associated with growing degree days (GDD) to flowering and photoperiod (PP) response in an elite sunflower population. Two hundred and thirty five F 2-generation plants and their F 2:3 and F 2:4 progenies of a single-cross population of two divergent inbred lines were evaluated in six environments (locations, years and sowing dates) with photoperiods known to elicit a PP response between the inbred lines. Detection of QTLs was facilitated with a genetic linkage map of 205 RFLP loci and composite interval mapping. The 205 restriction fragment length polymorphism (RFLP) loci covered 1380 cM and were arranged in 17 linkage groups, which is the haploid number of chromosomes in this species. The average interval size was 5.9 cM. Six QTLs in linkage groups A, B, F, I, J and L were associated with GDD to flowering and accounted for 76% of the genotypic variation in the mean environment. QTLs in linkage groups A and B accounted for 72% of the genetic variation. QTL×environment (QTL×E) interactions were highly significant for linkage groups A, B, F and J (P<0.01). QTLs in linkage groups A and B were highly dependent on PP. Also, QTL mapping of the ratio of the GDD required by a progeny to flower at a PP of 12.1 and 15.0 h, defined as the photoperiod response (PPR), suggested that alleles at QTLs in linkage groups A and B were responsive to PP. QTLs in linkage groups F and J showed QTL×E interaction but the LOD values were not associated with PP. QTL×E interactions for additive effects were highly significant (P<0.01) for linkage groups A, B and F. QTL×E interactions for QTLs with dominant effects were significant (P<0.01) for linkage groups A, B and J. The dominant effect of QTLs in linkage group B increased in environments with a longer PP. The knowledge of how these QTLs influence the GDD for flowering and how they interact with the environment will facilitate marker-assisted selection and backcross conversion of photoperiodsensitive germplasm.

Research paper thumbnail of cDNA cloning, expression levels and gene mapping of photosynthetic and non-photosynthetic ferredoxin genes in sunflower (Helianthus annuus L.)

Theoretical and Applied Genetics, 2009

Fatty acid desaturation in plastids and chloroplasts depends on the electron-donor activity of fe... more Fatty acid desaturation in plastids and chloroplasts depends on the electron-donor activity of ferredoxins. Using degenerate oligonucleotides designed from known photosynthetic and heterotrophic plant ferredoxin sequences, two full-length ferredoxin cDNAs were cloned from sunflower (Helianthus annuus L.) leaves and developing seeds, HaFd1 and HaFd2, homologous to photosynthetic and non-photosynthetic ferredoxins, respectively. Based on these cDNAs, the respective genomic sequences were obtained and the presence of DNA polymorphisms was investigated. Complete sequencing of the HaFd1 and HaFd2 genes in different lines indicated the presence of two haplotypes for HaFd2 and their alignment showed that sequence polymorphisms are restricted to the 5 0-NTR intron. In addition, specific DNA markers for the HaFd1 and HaFd2 genes were developed that enabled the genes to be mapped. Accordingly, the HaFd1 locus maps to linkage group 10 of the public sunflower map, while the HaFd2 locus maps to linkage group 11. Both ferredoxins display different spatial-temporal patterns of expression. While HaFd2 is expressed at similar levels in all tissues tested (leaves, stem, roots, cotyledons and developing seeds), HaFd1 is more strongly expressed in green tissues than in all the other tissues tested. Both photosynthetic-and heterotrophic-ferredoxins are present in sunflower seeds and may contribute to fatty acid desaturation during oil accumulation. Nevertheless, the levels of HaFd2 expression during seed formation are distinct in lines that only varied in the HaFd2 haplotypes they expressed. Communicated by A. Bervillé.

Research paper thumbnail of Molecular analysis of the high stearic acid content in sunflower mutant CAS-14

Molecular analysis of the high stearic acid content in sunflower mutant CAS-14

Theoretical and Applied Genetics, 2005

Increasing the stearic acid content to improve sunflower (Helianthus annuus L.) oil quality is a ... more Increasing the stearic acid content to improve sunflower (Helianthus annuus L.) oil quality is a desirable breeding objective for food-processing applications. CAS-14 is a sunflower mutant line with a high stearic acid content in its seed oil (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;35% vs. &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;6% in currently grown sunflower hybrids), which is controlled by the Es3 gene. However, the expression of the high stearic acid character in CAS-14 is strongly influenced by temperature during seed maturation and it is not uniform along the seed. The objectives of this study were (1) to identify PCR-based molecular markers linked to the Es3 gene from CAS-14, (2) to map this gene on the sunflower genetic map, and (3) to characterize the interaction between CAS-14 and CAS-3, a sunflower high stearic acid (about 26%) mutant line with the Es1 and Es2 genes determining this trait. Two F2 mapping populations were developed from crosses between CAS-14 and P21, a nuclear male sterile line with the Ms11 gene controlling this character, and between CAS-14 and CAS-3. One hundred and thirty-three individuals from P21xCAS-14, and 164 individuals from CAS-3xCAS-14 were phenotyped in F2 and F3 seed generations for fatty acid composition using gas-liquid chromatography, and they were then genotyped with microsatellite [simple sequence repeat (SSR)] and insertion-deletion (INDEL) markers. Bulk segregant analysis in the P21xCAS-14 population identified two markers on LG 8 putatively linked to Es3. A large linkage group was identified using additional markers mapping to LG 8. Es3 mapped to the distal half of LG 8 and was flanked by the SSR markers ORS243 and ORS1161 at genetic distances of 0.5, and 3.9 cM, respectively. The Ms11 gene was also mapped to LG 8 and genetic distance between this gene and Es3 was found to be 7.4 cM. In the CAS-3xCAS-14 population, two QTLs were identified on LG 1 and LG 8, which underlie the Es1 gene from CAS-3 and the Es3 gene from CAS-14, respectively. A significant epistatic interaction between these two QTLs was found. Results from this study provided a basis for determining CAS-14 efficient breeding strategies.

Research paper thumbnail of An integrated restriction fragment length polymorphism - amplified fragment length polymorphism linkage map for cultivated sunflower

Genome, 2001

Restriction fragment length polymorphism (RFLP) maps have been constructed for cultivated sunflow... more Restriction fragment length polymorphism (RFLP) maps have been constructed for cultivated sunflower (Helianthus annuus L.) using three independent sets of RFLP probes. The aim of this research was to integrate RFLP markers from two sets with RFLP markers for resistance gene candidate (RGC) and amplified fragment length polymorphism (AFLP) markers. Genomic DNA samples of HA370 and HA372, the parents of the F 2 population used to build the map, were screened for AFLPs using 42 primer combinations and RFLPs using 136 cDNA probes (RFLP analyses were performed on DNA digested with EcoRI, HindIII, EcoRV, or DraI). The AFLP primers produced 446 polymorphic and 1101 monomorphic bands between HA370 and HA372. The integrated map was built by genotyping 296 AFLP and 104 RFLP markers on 180 HA370 × HA372 F 2 progeny (the AFLP marker assays were performed using 18 primer combinations). The HA370 × HA372 map comprised 17 linkage groups, presumably corresponding to the 17 haploid chromosomes of sunflower, had a mean density of 3.3 cM, and was 1326 cM long. Six RGC RFLP loci were polymorphic and mapped to three linkage groups (LG8, LG13, and LG15). AFLP markers were densely clustered on several linkage groups, and presumably reside in centromeric regions where recombination is reduced and the ratio of genetic to physical distance is low. Strategies for targeting markers to euchromatic DNA need to be tested in sunflower. The HA370 × HA372 map integrated 14 of 17 linkage groups from two independent RFLP maps. Three linkage groups were devoid of RFLP markers from one of the two maps.

Research paper thumbnail of Variability among inbred lines and RFLP mapping of sunflower isozymes

Genetics and Molecular Biology, 2002

Eight isozyme systems were used in this study: acid phosphatase (ACP), alcohol dehydrogenase (ADH... more Eight isozyme systems were used in this study: acid phosphatase (ACP), alcohol dehydrogenase (ADH), esterase (EST), glutamate dehydrogenase (GDH), malate dehydrogenase (MDH), phosphoglucoisomerase (PGI), 6-phosphogluconate dehydrogenase (PGD), and phosphoglucomutase (PGM). The polymorphism of these enzyme systems was studied in 25 elite inbred lines. A total of 19 loci were identified, but only eight of them were polymorphic in the germplasm tested. The polymorphic index for the eight informative markers ranged from 0.08 to 0.57, with a mean value of 0.36. Five isozyme loci were mapped in F 2:3 populations with existing RFLP data. Est-1, Gdh-2 and Pgi-2 were mapped to linkage groups 3, 14 and 9, respectively. As in previous reports, an ACP locus and a PGD locus were found to be linked, both located in linkage group 2 of the public sunflower map.

Research paper thumbnail of Molecular Mapping of Nuclear Male Sterility Genes in Sunflower

Crop Science, 2005

Nuclear male sterility (NMS) is a useful tool for sunflower (Helianthus annuus L.) breeding and g... more Nuclear male sterility (NMS) is a useful tool for sunflower (Helianthus annuus L.) breeding and genetics programs. A clear understanding of the genetics of NMS at the molecular level and the identification of linked molecular markers will greatly facilitate breeding for this trait. P21 is an inbred line carrying the single gene Ms11 controlling NMS, and NMS801 and NMS373 are two inbred lines with the NMS gene Ms10 The objectives of this study were to (i) identify molecular markers linked with the Ms10 and the Ms11 NMS genes, and (ii) place these genes on the genetic map of sunflower. Three F2 and a BC1F1 mapping populations developed from crosses between the male‐sterile (MS) lines P21, NMS801, and NMS373, and male‐fertile (MF) (wild‐type) lines were scored for fertility/sterility. The NMS801 and NMS373 populations segregated for Ms10 and T, a tightly linked anthocyanin pigment locus. The P21 populations segregated for Ms11 These populations were then genotyped with restriction frag...

Research paper thumbnail of Quantitative Trait Loci for Genetically Correlated Seed Traits are Tightly Linked to Branching and Pericarp Pigment Loci in Sunflower

Crop Science, 2006

The seed oil concentrations of large‐seeded, low‐oil and small‐seeded, high‐oil sunflower (Helian... more The seed oil concentrations of large‐seeded, low‐oil and small‐seeded, high‐oil sunflower (Helianthus annuus L.; x = 17) cultivars differ by 180 to 280 g kg−1 We identified quantitative trait loci (QTL) for seed oil and other seed traits in a low‐ × high‐oil (RHA280 × RHA801) recombinant inbred line (RIL) mapping population segregating for apical branching (B), phytomelanin pigment (P), and hypodermal pigment (Hyp) loci. B, Hyp, and P mapped to linkage groups 10, 16, and 17, respectively. The seed oil concentrations of RHA280 and RHA801 were 254 and 481 g kg−1, respectively. Composite interval mapping (CIM) identified 40 QTL for seed oil concentration, 100‐seed weight, seed length, width and depth, kernel and pericarp weight, and kernel‐to‐pericarp weight ratio in 14 DNA marker intervals on 10 of 17 linkage groups. Twenty‐four of the QTL were tightly linked to B, P, and Hyp and may have been partly or wholly caused by the pleiotropic effects of B, P, and Hyp Multilocus QTL analyses ...

Research paper thumbnail of Genetic Mapping of a Locus ( hyp ) Affecting Seed Hypodermis Color in Sunflower

Crop Science, 1996

Sunflower (Helianthus annuus L.) seed color is determined by pigmentation of three layers of the ... more Sunflower (Helianthus annuus L.) seed color is determined by pigmentation of three layers of the pericarp (hull): epidermis, hypodermis, and phytomelanin layer. A gene with major effects on hypodermis color was reported previously. However, genetic factors that determine the presence or absence of pigment in the hypodermis have not been reported. We identified RFLP markers linked to factor(s) affecting hypodermis pigmentation and assessed the relationship between this trait and oil percentage in sunflower seed. An F 2 single-cross population was produced from homozygous and homogeneous inbred parents ZENB8 and HA89, with pigmented and unpigmented hypodermis, respectively. Two hundred sixty-seven F 2 plants and their Fs families were evaluated. A dominant factor (Hyp) determining the presence of white pigments in the hypodermis was located to linkage group 'G'. Seeds with white hypodermis had lower oil percentage than those with unpigmented hypodermis. The Hyp factor was located in the same map interval as one QTL with major effects on seed oil percentage in this population. Knowledge of genetic linkage among DNA markers, hypodermis pigmentation, and oil percentage should enhance breeding programs.

Research paper thumbnail of SMART – Sunflower Mutant population And Reverse genetic Tool for crop improvement

BMC Plant Biology, 2013

Background Sunflower (Helianthus annuus L.) is an important oilseed crop grown widely in various ... more Background Sunflower (Helianthus annuus L.) is an important oilseed crop grown widely in various areas of the world. Classical genetic studies have been extensively undertaken for the improvement of this particular oilseed crop. Pertaining to this endeavor, we developed a “chemically induced mutated genetic resource for detecting SNP by TILLING” in sunflower to create new traits. Results To optimize the EMS mutagenesis, we first conducted a “kill curve” analysis with a range of EMS dose from 0.5% to 3%. Based on the observed germination rate, a 50% survival rate i.e. LD50, treatment with 0.6% EMS for 8 hours was chosen to generate 5,000 M2 populations, out of which, 4,763 M3 plants with fertile seed set. Phenotypic characterization of the 5,000 M2 mutagenised lines were undertaken to assess the mutagenesis quality and to identify traits of interest. In the M2 population, about 1.1% of the plants showed phenotypic variations. The sunflower TILLING platform was setup using Endo-1-nucl...