Morphological and Molecular Characterization of a New Self-Compatible Almond Variety (original) (raw)
Related papers
International journal of horticultural science, 2012
Almond [Prunus dulcis (Mill.) D. A. Webb.] as one of the oldest domesticated plants is thought to have originated in central Asia. Gametophytic self-incompatibility of almond is controlled by the highly polymorphic S-locus. The S-locus encodes for an S-ribonuclease (S-RNase) protein in the pistils, which degrades RNA in self-pollen tubes and hence stops their growing. This study was carried out to detect S-RNase allelic variants in Hungarian and Eastern European almond cultivars and Turkish wild growing seedlings, and characterize their S-allele pool. Five new alleles were identifi ed, S 31H , S 36-S 39 in Eastern European local cultivars. The village Bademli and Akdamar island are two distinct places of almond natural occurrence in Turkey. Trees growing wild around Bademli city showed greater genetic diversity than those originated on Akdamar island. Many of the previously described 45 S-RNase alleles have been also detected in these regions. Homology searches revealed that Turkish almonds carried some P. webbii alleles indicating hybridization between the two cultivars and massive introgression events. Our results supply long-awaited information on almond S-allele diversity from regions between the main cultivation centres and the centre of origin of this species; and are discussed from the aspect of methodological developments and evolution of the cultivated almond.
Challenges for Self-Compatibility Identification in Almond
V International Symposium on Pistachios and Almonds, 2011
Several approaches have been utilised to assess the level of self-compatibility in almond, such as fruit set after self-pollination and bagging, pollen tube growth, and the more recent S f allele identification by molecular markers and gene sequencing. However, none of these methods has given fully reliable results as all of them show advantages and limitations. An active S f allele, not conferring selfcompatibility in spite of its fully identity with the inactive S f allele conferring selfcompatibility, has been recently identified, showing that the presence of the S f allele is not the only requirement for self-compatibility expression in almond and that the coding region of the S f allele may not be involved in that expression. Missequencing of alleles has also created confusion for allele identification. Thus, a better knowledge of the plant material as a whole, and not only of its genotype, is fundamental for the understanding of self-compatibility in almond and for the evaluation of the new selections in a breeding programme.
Journal of Nuts, 2015
The almond, Prunus dulcis Miller which belongs to Rosaceae family, is one of the most important commercial and oldest cultivated tree nut crops. Almonds are classified as a 'nut' in which the edible seed is the commercial product. Therefore, pollination and fertilization are necessary in almond. The characteristic of cultivated almond to express gametophytic self-incompatibility discourages self-fertilization and favors cross pollination. Genetic control of pollen-pistil self-incompatibility is through a single gene (S) which exists in a series of alleles S 1 to S x. Compatibility of pollen-pistil in almond is an important consideration in planning crosses in breeding program and in choosing pollinizers for orchard planting. Identification of self-(in) compatibility in almond carried out by molecular and controlled pollination methods. In this study, identification of S-alleles in 37 Iranian almond cultivars and genotypes was carried out by PCR method with using degenerate primers of EM-PC3consRDEMPC2cons FD, PaconsI-Fand EM-PC1consRD. In this way the size of S-alleles were estimated based on bands which amplified with second intron. The results confirmed self-incompatibility in cultivars and most genotypes. However, the S f-like allele (in size) was observed in A 9 and A 36 genotypes. If these results are confirmed by sequencing the S f allele, it will be first time to identify self-compatible genotype in Iranian almond genotypes.
2017
The evaluation of an almond collection using morphological variables and identification of self-incompatibility genotype is useful for selecting pollinizers and for the design of crossing in almond breeding programs. In this study, important morphological traits and self-incompatibilities in 71 almond cultivars and genotypes were studied. Simple and multiplex specific PCR analyses were used in order to identify self-incompatibility alleles. Based on the results, cultivars and genotypes including ‘Dir Ras–e-Savojbolagh’, ‘D-124’, ‘D-99’, ‘Shahrood 12’, ‘Tuono’, ‘Nonpareil’, ‘Price’, ‘Mirpanj-e-Tehran’, ‘Pakotahe-e- Taleghan’, ‘V-13-34’, ‘V-16-8, ‘V-11-10’, ‘Zarghan 10’, ‘Uromiyeh 68’, ‘Barg dorosht-e-Hamedan’ and ‘Yazd 60’ were late flowering and had the highest quality of nut and kernel characters. The result of the PCR method using combined primers AS1II and AmyC5R showed amplification of ten self-incompatibility alleles (S1, S2, S3, S5, S6, S7, S8, S10, S12,and S unknown allele) ...
Identification of Self-Incompatibility Alleles in Almond and Related Prunus Species Using PCR
Acta horticulturae, 2003
The almond, Prunus dulcis Miller which belongs to Rosaceae family, is one of the most important commercial and oldest cultivated tree nut crops. Almonds are classified as a 'nut' in which the edible seed is the commercial product. Therefore, pollination and fertilization are necessary in almond. The characteristic of cultivated almond to express gametophytic self-incompatibility discourages self-fertilization and favors cross pollination. Genetic control of pollen-pistil self-incompatibility is through a single gene (S) which exists in a series of alleles S 1 to S x. Compatibility of pollen-pistil in almond is an important consideration in planning crosses in breeding program and in choosing pollinizers for orchard planting. Identification of self-(in) compatibility in almond carried out by molecular and controlled pollination methods. In this study, identification of S-alleles in 37 Iranian almond cultivars and genotypes was carried out by PCR method with using degenerate primers of EM-PC3consRDEMPC2cons FD, PaconsI-Fand EM-PC1consRD. In this way the size of S-alleles were estimated based on bands which amplified with second intron. The results confirmed self-incompatibility in cultivars and most genotypes. However, the S f-like allele (in size) was observed in A 9 and A 36 genotypes. If these results are confirmed by sequencing the S f allele, it will be first time to identify self-compatible genotype in Iranian almond genotypes.
Identification of self-incompatibility genotypes of almond by allele-specific PCR analysis
TAG Theoretical and Applied Genetics, 2000
In almond, gametophytic self-incompatibility is controlled by a single multiallelic locus (S-locus). In styles, the products of S-alleles are ribonucleases, the S-RNases. Cultivated almond in California have four predominant S-alleles (S a , S b , S c , S d ). We previously reported the cDNA cloning of three of these alleles, namely S b , S c and S d . In this paper we report the cloning and DNA sequence analysis of the S a allele. The S a -RNase displays approximately 55% similarity at the amino-acid level with other almond S-RNases (S b , S c , and S d ) and this similarity was lower than that observed among the S b , S c and S d -RNases. Using the cDNA sequence, a PCR-based identification system using genomic DNA was developed for each of the S-RNase alleles. Five almond cultivars with known self-incompatibility (SI) geno-types were analyzed. Common sequences among four S-alleles were used to create four primers, which, when used as sets, amplify DNA bands of unique size that corresponded to each of the four almond S-alleles; S a (602 bp), S b (1083 bp), S c (221 bp) and S d (343 bp). All PCR products obtained from genomic DNA isolated from the five almond cultivars were cloned and their DNA sequence obtained. The nucleotide sequence of these genomic DNA fragments matched the corresponding S-allele cDNA sequence in every case. The amplified products obtained for the S a -and S b -alleles were both longer than that expected for the coding region, revealing the presence of an intron of 84 bp in the S a -allele and 556 bp in the S b -allele. Both introns are present within the site of the hypervariable region common in S-RNases from the Rosaceae family and which may be important for S specificity. The exon portions of the genomic DNA sequences were completely consistent with the cDNA sequence of the corresponding S-allele. A useful application of these primers would be to identify the S-genotype of progeny in a breeding program, new varieties in an almond nursery, or new grower selections at the seedling stage.
2016
Almond [Prunus amygdalus Batsch syn. Prunus dulcis (Mill.) D.A.Webb] trees are either self- or cross-incompatible, which results in lower fruit set and yields. Flower bagging, fluorescence microscopy, and polymerase chain reaction (PCR) were used to discriminate between selfcompatible genotypes obtained from crosses of the self-incompatible female parents (‘121’ and ‘4’) with the self-compatible male parent (‘Tuono’). This study was performed on 80 almond genotypes. The results of this study showed that, in the first cross (‘121’ × ‘Tuono’), genotypes 5, 11, 13, 14, 17, 20, 27, 29, 31, 35, and 38 were identified as being self-compatible and, in the second cross (‘4’ × ‘Tuono’), genotypes 1, 2, 10, 11, 12, 15, 21, 23, 25, 32, 37, 38,and 40 were found to be self-compatible. There were some promising genotypes based on self-compatibility and nut and kernel characteristics; for example, genotype 40 had the highest mean fruit and kernel weights at 2.9 and 1.3 g, respectively. PCR can be used to identify self-compatible genotypes at the juvenile stage. Flower bagging under favourable climatic conditions not only discriminated between self-compatible almond genotypes, but can also be used to measure fruit set percentages. Flower bagging and fluorescence microscopy can be used to determine the level of self-incompatibility. Fluorescence microscopy identified self-incompatible genotypes, even under unfavourable conditions. In general, a combination of all three methods is recommended to increase the accuracy of detecting selfcompatible genotypes of almond.
Preliminary identification of self-incompatibility genotypes of Sicilian almond landraces
Acta horticulturae, 2018
Sicily is the main almond producer in Italy. The almond tree is one of the main protagonists of the Sicilian agrarian landscape, especially in the winter, when the bare branches are covered by white or pinkish flowers. Its presence is particularly significant in the province of Agrigento, in Syracuse and in Ragusa areas, where the almond nut is used for fresh consumption and for the preparation of typical sweets. The extremely rich Sicilian almond germplasm can be useful for genetic improvement, since many local landraces possess aromatic characteristics of the nuts of high value. Self-incompatibility in this species is gametophytic and controlled by a multi-allelic S locus, coding for the stylar RNases and the SFBox protein, expressed in the pollen. In commercial almond orchards, cross-compatible cultivars with overlapping flowering time are usually planted together to ensure fruit set. In this study S-genotypes of Sicilian landraces were investigated for the first time with consensus primers designed for the S locus. Knowledge of the S-genotypes of Sicilian almond germplasm can be helpful for planning pollinators in the orchards and for choosing parents and starting a breeding program focusing on the improvement of local resources.
The almond Sf haplotype shows a double expression despite its comprehensive genetic identity
Scientia Horticulturae, 2010
Since self-compatibility has become the primary objective of most almond breeding programmes, search for new self-compatibility sources has acquired a great importance in almond research. The local Spanish cultivar 'Vivot', identified as showing the genotype S 23 S f , thus presumably self-compatible, was found to be unexpectedly self-incompatible in spite of the presence of the S f allele, as also observed in other almond cultivars. However, not only the coding sequences of both the S f -RNase and the SFB f of 'Vivot' and 'Blanquerna', a confirmed self-compatible cultivar, were identical, but also the 5 regulatory sequence of the S f -RNase of both. Thus, the reason for the different expression of the S f is independent of the complete genetic identity found in the whole chromosome region bordering the S-locus in the almond cultivars sharing the S f allele.