جستجوی مقالات مرتبط با کلیدواژه « genotypic correlation » در نشریات گروه « بیوتکنولوژی و ژنتیک گیاهی »

Eggplant is a highly nutritious vegetable that is widely consumed. The aim of this study was to evaluate the genetic diversity between eggplant accessions from the National Plant Gene-Bank of Iran. In the first year, a preliminary evaluation was conducted using 168 accessions. Based on preliminary evaluation results, 40 accessions were selected for complementary evaluation in the second year. The evaluation was based on 23 quantitative and qualitative traits. The results of the preliminary evaluation showed statistically significant (P<0.01) differences between accessions for all traits. Fruit shape frequencies were rounded (35.89 percent), elongated (32.18 percent), oval (13.67 percent), Semi-elongated (13.15 percent), and mace-shaped (5.11 percent). In the complementary evaluation, there were significant differences between accessions for all traits. Qualitative traits such as flower color (1.56) and fruit shape (1.53) exhibited the highest genetic variation, while fruit color (0.5) showed the lowest. Cluster analysis analysis results revealed four groups for accessions and the highest (22.34) and least (0.12) genetic distances between 1 and 2 and between 7 and 21accessions, respectively. Factor analysis showed that the first three factors explained 68.06 percent of total variation in data. The first and second factors were related to yield and yield components, respectively. Also, fruit yield traits showed high heritability and there was significant genetic correlation between these traits. Therefore, high heritable and high-scoring traits in these factors should be considered when selecting progenies in segregating populations for improvement in terms of fruit yield and shape.

Identifying selection indices is the most important step of a breeding project that aims to improve grain yield. The definition of the selection index is usually done by evaluating the variables in multivariate statistical methods. In the present study, the relationship between grain yield and its components in bread wheat genotypes was determined by multivariate statistical methods. The experiment was conducted in a randomized complete block design with 3 replications in the research farm of Gorgan University of Agricultural Sciences and Natural Resources in the 2018-19 crop years. Ten commercial cultivars of bread wheat along with their offspring from direct and inverse crosses in a dialysis arrangement were evaluated for morphological and phenological traits, especially grain yield and its components. The results of genotypic and phenotypic correlation coefficients showed a positive and significant correlation (at 1% probability level) between grain yield and spike length, spike weight, number of fertile tillers, number of seeds per spike, number of spikes per spike, 1000-seed weight, biological yield and harvest index. Based on the results of stepwise regression analysis, biological yield, harvest index, number of grains per main spike and main spike weight were entered into the regression model, respectively, and explained a total of 98% of the variation in grain yield. Based on the results of path analysis, biological yield had the highest direct effect on grain yield. After biological yield, the most direct effect on grain yield was related to the weight of main spike. Also, by considering eigenvalues greater than one in factor analysis, 8 hidden factors were identified that explained a total of 75.18% of the data changes. In general, it can be concluded that biological yield, harvest index, number of seeds per spike and weight of spike compared to other traits can be used as appropriate indicators in breeding programs to select high-yield genotypes in field conditions. Genotypes Alo, Ehsan♂ × Gonbad♀ and Ehsan had the highest value for the studied traits, which can be used in future breeding researches.

Anise is an annual plant belonging to Apiaceae family and fruit essential oil of this herb is used in various pharmaceutical, cosmetic and beverage industries. Drought stress is one of the most critical limiting factors for anise production in worldwide. In this research, to finding interrelationships among different traits and performance, some anise genotypes were evaluated using the biplot method. In this study, 18 anise genotypes were evaluated in normal irrigation regime and drought stress conditions according to a randomized complete block design with three replications at the field of the Western Australia University (UWA), Australia. Fifteen phonological, morphological and physiological traits were measured. Results indicated the positive and significant correlations between yield and fruit number and fruit thousand weight in both conditions. Due to the negative correlation between phonological features with fruit yield in two different irrigation conditions, it could be concluded that to have genotypes with high fruit yield, selection for early ripening genotypes should be done in anise. In this study, a significant correlation was observed between fruit yield and relative water content in the stress condition. Therefore, this trait can be used as a physiological index to evaluate drought tolerance in anise. According to cluster analysis based on the measured traits, genotypes were divided into 3 groups in both non-stress and stress conditions. According to the results of the comparison of the means of the groups in non-stress and drought stress conditions, genotypes No. 1, 5, 6, 11, 12, 14, 15 and 16 were identified as the most drought-tolerant genotypes. These genotypes could be utilized in breeding programs for further improvement of drought tolerance in anise germplasm.

To study the genetic diversity of soybean inbred lines, grain yield modeling and selection of superior genotypes, 80 lines of soybean obtained from crosses of Karbin × Fora cultivars along with L.17 soybean cultivar as control were studied in research farm of Agriculture Khorram Abad Sarab Chenghaey in 9 ×9lattice design. Significant differences were observed between control and studied soybean lines.  There was a positive and significant correlation between seed yield and most of the traits evaluated, including the number of pods per plant, percentage of germination, plant height, number of seeds per pod, and number of seeds per plant. Stepwise regression analysis showed that plant height, number of pods per plant, number of seeds per pod and 100-seed weight explained 82% of yield. Using factor analysis, 17 traits in four components explained about 62% of the total variation. Therefore, plant height trait, number of pods per plant, number of seeds per pod, 100-seed weight can be considered as criteria for selection of superior lines to improve grain yield in soybean.