Phenotypic variation Research Papers - Academia.edu (original) (raw)

The ocelot, Leopardus pardalis, is a medium-sized Neotropical felid with a relatively wide geographical distribution. Across their range, ocelots exhibit clinal variation in pattern and color of pelage. Despite this variation, few... more

The ocelot, Leopardus pardalis, is a medium-sized Neotropical felid with a relatively wide geographical distribution. Across their range, ocelots exhibit clinal variation in pattern and color of pelage. Despite this variation, few aberrant genetic morphs have been documented. This record describes the first apparent leucistic variant for the ocelot: a white female with black markings that was treed on three occasions over a 3-year period in the transitional Chaco of western Paraguay.

Research was conducted to study interrelationships between agronomic and seed characters and their direct and indirect effects on seed yield per plant under normal and limited irrigation regimes. Two field experiments were conducted in... more

Research was conducted to study interrelationships between agronomic and seed characters and their direct and indirect effects on seed yield per plant under normal and limited irrigation regimes. Two field experiments were conducted in 1996 at the Experimental Station of College of Agriculture, Shiraz University at Badjgah. Fourteen sunflower (Helianthus annuus L.) cultivars consisting of eight hybrids and six open

SUMMARY - Gluten strength is the main determinant of the end-use quality in durum. Wheat gluten strength is affected by genetic variation at genes coding for gliadins and glutenins, and by environmental factors. We grew 110 recombinant... more

SUMMARY - Gluten strength is the main determinant of the end-use quality in durum. Wheat gluten strength is affected by genetic variation at genes coding for gliadins and glutenins, and by environmental factors. We grew 110 recombinant inbred lines of the cross Jennah Khetifa x Cham1 in 13 environments (sites and years), and analyzed gluten strength in the resulting grain

Primate socioecological studies have attempted to derive general frameworks using the average behavioural traits of species or genera to place them into categories. However, with the accumulation of primate studies, it is timely to place... more

Primate socioecological studies have attempted to derive general frameworks using the average behavioural traits of species or genera to place them into categories. However, with the accumulation of primate studies, it is timely to place more emphasis on understanding within-species variation in social structure. In this review we have four objectives. First, we examine within-species variation in the potential determinants of social structure, including diet, demography, predation and infanticide, and document considerable variation. Second, we present case studies of within-species variation in social structure to illustrate the potential magnitude of this variation. For example, there are cases within a single interbreeding population where multi-male, uni-male, fission–fusion and monogamous groups are found. Third, by examining widespread primate lineages that occur in a variety of habitats, we note that there are differences in the magnitude of variation in social structures across different lineages and as a result we consider phylogenetic constraints on phenotypic variation in social structure. Finally, we reflect on the implications of extensive variation in social structure. We suggest that primate social structure will represent a combination of adaptation to present-day environment and phylogenetic inertia. To advance our understanding of the relative contribution of phylogeny versus ecology we propose two approaches. One approach is to compare groups in the same interbreeding population that inhabit different ecological conditions. Any differences that are found can be attributed to ecological differences, since phylogeny should not play a role within a single population. The second approach is to study distantly related species that have similar social structures to illustrate how similar ecological pressures might be operating to select for parallel social structures.

Categorization of locations with similar environments helps breeders to efficiently utilize resources and effectively target germplasm. This study was conducted to determine the relationship among winter wheat (Triticum aestivum L.) yield... more

Categorization of locations with similar environments helps breeders to efficiently utilize resources and effectively target germplasm. This study was conducted to determine the relationship among winter wheat (Triticum aestivum L.) yield testing locations in South Dakota. Yield trial data containing 14 locations and 38 genotypes from 8 year were analyzed for crossover genotype (G) × environment (E) interactions according to the Azzalini-Cox test. G × E was significant (P < 0.05) and contributed a small proportion of variation over the total phenotypic variation. This suggested that for efficient resource utilization, locations should be clustered. The data were further analyzed using the Shifted Multiplicative Model (SHMM), Spearman’s rank correlation and GGE biplot to group testing locations based on yield. SHMM analysis revealed four major cluster groups in which the first and third had three locations, with four locations in each of the second and fourth groups. Spearman rank correlations between locations within groups were significant and positive. GGE biplot analysis revealed two major mega-environments of winter wheat testing locations in South Dakota. Oelrichs was the best testing location and XH1888 was the highest yielding genotype. SHMM, rank correlation and GGE biplot analyses showed that the locations of Martin and Winner in the second group and Highmore, Oelrichs and Wall in the third group were similar. This indicated that the number of testing locations could be reduced without much loss of grain yield information. GGE biplot provided additional information on the performance of entries and locations. SHMM clustered locations with reduced cross-over interaction of genotype × location. The combined methods used in this study provided valuable information on categorization of locations with similar environments for efficient resource allocation. This information should facilitate efficient targeting of breeding and testing efforts, especially in large breeding programs.

The brown planthopper (BPH) is one of the most serious insect pests of rice throughout Asia. In this study, we constructed a linkage map to determine the locus for BPH resistance gene, using an F2 population from a cross between a... more

The brown planthopper (BPH) is one of the most serious insect pests of rice throughout Asia. In this study, we constructed a linkage map to determine the locus for BPH resistance gene, using an F2 population from a cross between a resistant indica cultivar, ‘Col.5 Thailand’, and a susceptible cultivar ‘02428’. Insect resistance was evaluated using 147 F3 families and the genotype of each F2 plant was inferred from the phenotype of corresponding F3 families. Two QTLs was detected on chromosome 2 (explains 29.4% phenotypic variation) and 6 (46.2% variation explained) associated with resistance to BPH in the mapping population. Comparison of the chromosomal locations and reactions to BPH biotypes indicated that the gene on chromosome 6 is different from at least 18 of the 19 previously identified BPH resistance genes. These two genes have large effects on BPH resistance and may be a useful BPH resistance resource for rice breeding programs.

... initiated to assess variation in fruits, nuts and kernels of some important indigenous tree species such as Adansonia digitata ([Assogbadjo et al., 2005], [Assogbadjo et al., 2006] and [Assogbadjo et al., 2011]), Tamarindus indica... more

... initiated to assess variation in fruits, nuts and kernels of some important indigenous tree species such as Adansonia digitata ([Assogbadjo et al., 2005], [Assogbadjo et al., 2006] and [Assogbadjo et al., 2011]), Tamarindus indica (Fandohan et al., 2011), Balanites aegyptiaca ...

Plant acclimation to stress is associated with profound changes in proteome composition. Since proteins are directly involved in plant stress response, proteomics studies can significantly contribute to unravel the possible relationships... more

Plant acclimation to stress is associated with profound changes in proteome composition. Since proteins are directly involved in plant stress response, proteomics studies can significantly contribute to unravel the possible relationships between protein abundance and plant stress acclimation. In this review, proteomics studies dealing with plant response to a broad range of abiotic stress factors — cold, heat, drought, waterlogging, salinity, ozone treatment, hypoxia and anoxia, herbicide treatments, inadequate or excessive light conditions, disbalances in mineral nutrition, enhanced concentrations of heavy metals, radioactivity and mechanical wounding are discussed. Most studies have been carried out on model plants Arabidopsis thaliana and rice due to large protein sequence databases available; however, the variety of plant species used for proteomics analyses is rapidly increasing. Protein response pathways shared by different plant species under various stress conditions (glycolytic pathway, enzymes of ascorbate–glutathione cycle, accumulation of LEA proteins) as well as pathways unique to a given stress are discussed. Results from proteomics studies are interpreted with respect to physiological factors determining plant stress response. In conclusion, examples of application of proteomics studies in search for protein markers underlying phenotypic variation in physiological parameters associated with plant stress tolerance are given.

The West African sub-region is indisputably the region of greatest diversity of Okra (Abelmoschus spp L.) germplasm as it currently hosts some 1,769 accessions of Okra (representing 77.49%) out of the 2, 283 reported world-wide. These are... more

The West African sub-region is indisputably the region of greatest diversity of Okra (Abelmoschus spp L.) germplasm as it currently hosts some 1,769 accessions of Okra (representing 77.49%) out of the 2, 283 reported world-wide. These are largely uncharacterised, making it practically impossible to ascribe specific attributes to known accessions to facilitate breeding for further improvement to meet specific demands by end-users or industrial-scale production. Twenty six (26) local accessions and three (3) exotic lines of Okra were collected
from eight geographic regions of Ghana. Their agro-morphological traits were evaluated under field conditions
on the research farm of the Biotechnology and Nuclear Agriculture Research Institute. Hierarchical cluster analysis of results grouped the accessions into two major clusters and subsequently into five sub-clusters based on the qualitative characters studied. The pattern of clustering did not indicate any relationship with geographic origin of collection. The two most divergent accessions were Cs-Legon (local accession) and Clemson spineless (exotic line). There were no duplicates among the accessions which exhibited great variability with respect to all vegetative as well as reproductive characters, except one.

Geochemical cycling and industrial pollution have made toxic metal ions a pervasive environmental pressure throughout the world. Biofilm formation is a strategy that microorganisms might use to survive a toxic flux in these inorganic... more

Geochemical cycling and industrial pollution have made toxic metal ions a pervasive environmental pressure throughout the world. Biofilm formation is a strategy that microorganisms might use to survive a toxic flux in these inorganic compounds. Evidence in the literature suggests that biofilm populations are protected from toxic metals by the combined action of chemical, physical and physiological phenomena that are, in some instances, linked to phenotypic variation among the constituent biofilm cells. Here, we propose a multifactorial model by which biofilm populations can withstand metal toxicity by a process of cellular diversification.

Rapid and uniform seed germination under diverse environmental conditions is a desirable characteristic for most crop plants, such as rice, wheat, and maize. However, the genetic base of the variations in the rate of germination is not... more

Rapid and uniform seed germination under diverse environmental conditions is a desirable characteristic for most crop plants, such as rice, wheat, and maize. However, the genetic base of the variations in the rate of germination is not well understood. In this study, quantitative trait loci (QTL) for germination rate were mapped with a set of 143 chromosome segment substitution lines (CSSL) each contains a small genomic fragment from a japonica variety Nipponbare in the uniform genetic background of an indica variety Zhenshan97. Nine CSSL showed significantly lower germination rate than that in Zhenshan97. Four germination-related QTL were identified located on chromosomes 2, 5, 6 and 10, at which all japonica alleles decreased germination rate. By using the CSSL-derived F2 population, a major QTL (qGR2) on chromosome 2 was confirmed, and delimited to a 10.4 kb interval containing three putative candidate genes, of which OsMADS29 was only expressed preferentially in the seed. These results would facilitate cloning of the major gene that affects germination rate, and provide an insight into the genetic basis of germination.

The inheritance and genetic linkage analysis for seed dormancy and preharvest sprouting (PHS) resistance were carried out in an F8 recombinant inbred lines (RILs) derived from the cross between “CN19055” (white-grained, PHS-resistant)... more

The inheritance and genetic linkage analysis for seed dormancy and preharvest sprouting (PHS) resistance were carried out in an F8 recombinant inbred lines (RILs) derived from the cross between “CN19055” (white-grained, PHS-resistant) with locally adapted Australian cultivar “Annuello” (white-grained, PHS-susceptible). Seed dormancy was assessed as germination index (GI7) while assessment for preharvest sprouting resistance was based on whole head assay (sprouting index, SI) and visibly sprouted seeds (VI). Segregation analysis of the F2, F3 data from the glasshouse and the RIL population in 2004 and 2005 field data sets indicated that seed dormancy and PHS resistance in CN19055 is controlled by at least two genes. Heritabilities for GI7 and VI were high and moderate for SI. The most accurate method for assessing PHS resistance was achieved using VI and GI7 while SI exhibited large genotype by environment interaction. Two quantitative trait loci (QTLs) QPhs.dpivic.4A.1 and QPhs.dpivic.4A.2 were identified. On pooled data across four environments, the major QTL, QPhs.dpivic.4A.2, explained 45% of phenotypic variation for GI7, 43% for VI and 20% for SI, respectively. On the other hand, QPhs.dpivic.4A.1 which accounted for 31% of the phenotypic variation in GI7 in 2004 Horsham field trial, was not stable across environments. Physical mapping of two SSR markers, Xgwm937 and Xgwm894 linked to the major QTL for PHS resistance, using Chinese Spring deletions lines for chromosome 4AS and 4AL revealed that the markers were located in the deletion bins 4AL-12 and 4AL-13. The newly identified SSR markers (Xgwm937/Xgwm894) showed strong association with seed dormancy and PHS resistance in a range of wheat lines reputed to possess PHS resistance. The results suggest that Xgwm937/Xgwm894 could be used in marker-assisted selection (MAS) for incorporating preharvest sprouting resistance into elite wheat cultivars susceptible to PHS.