جستجوی مقالات مرتبط با کلیدواژه « genotypic coefficient of variation » در نشریات گروه « کشاورزی »

Genetic diversity is key to breeding programs and increasing selection efficiency. In this study, 19 promising advanced lines (F7 generation) along with two cultivars, Dalgan and, RGS003 were evaluated in a randomized complete block design with three replications in three experimental field stations (Gorgan, Sari and, Zabol) during the 2020–2021 growing season. The highest phenotypic and genotypic coefficient of variations was found for number of lateral branches and number of pods per plant, respectively. The highest broad sense heritability was estimated for days to end of flowering, and days to start of flowering and the lowest broad sense heritability was estimated for the plant height. The genotypes G16, G18, G15, G1, G2, G5, and G20 with a higher SIIG values as well as a higher seed yield above average were introduced as superior genotypes with respect to yield and other agronomic traits. Therefore, these genotypes can be used for further testing, including adaptation tests. Also, the results of factor analysis and genetic correlation coefficients indicated a positive relationship between number of lateral branches, number of pods per plant and number of seeds per pod with seed yield and seed yield. Generally, it can be concluded that number of lateral branches, number of pods per plant and number of seeds per pod traits could be used as the appropriate criteria to select for increasing seed yield in rapeseed breeding programs.

The study of genetic diversity is an important step in planning crop breeding programs. According to researchers, diversity of the population under selection ensures the desired results in breeding programs. In this regard, using the capacity of local populations to create new cultivars and achieve maximum diversity is very efficient. Therefore, the purpose of this study is to investigate the agro-morphological traits of pepper populations to identify the breeding potential of local populations for producing hybrid cultivars.

In the present study, 30 populations of Iranian peppers were planted in five replications in the research greenhouse of Department of Plant Production and Genetics of Urmia University, in order to study the genetic variability in terms of some agro-morphological traits. The experiment was conducted in a completely randomized design (CRD) in pot conditions in  2016-2017. In this study, variance analysis (ANOVA) and mean comparison of traits by Duncan's multiple range test, estimation of phenotypic correlation by Pearson method and principal component analysis on correlation coefficient and also cluster analysis by Ward method has done and realized. Also, the variance components, heritability (h2), phenotypic coefficient of variation (PCV), genotypic coefficient of variation (GCV), and environmental coefficient of variation (ECV) were calculated.

The results showed significant difference among the populations for all studied traits. The highest phenotypic coefficient of variation (PCV) (88.36) was observed for single fruit weight and also the highest genotypic coefficient of variation (GCV) (83.63) was observed for the same trait (single fruit weight). The pulp weight and fruit yield (0.950) had the highest significant positive correlation coefficient and the single fruit weight and fruit number (-0.558) had the highest significant negative correlation coefficient. According to the results of hierarchical cluster analysis, the studied populations were divided into five clusters based on the studied traits. The Tabriz population in the first cluster and the Gharah Bagh-Urmia population in the fourth cluster were superior in the fruit number trait.

In this study based on the results of mean comparisons Bash Ghala (from Urmia), Nakhchivan (from Urmia) and Keshtiban (from Urmia) populations were superior in terms of most of the studied traits. Also, Bash Ghala (from Urmia), Nakhchivan (from Urmia) and Keshtiban (from Urmia) populations were in the same cluster had higher fruit yield than other studied populations. Therefore, these populations can be used as one of the top parents in the intersection with other populations to create desirable genetic compounds.

Strawberry (Fragaria × ananassa Duch.) is one of the important and commercial small fruits that are planted in temperate regions which contain high amount of natural antioxidants. Study of genetic diversity is very important for distinguish the genotypes relationships and evaluation and exploitation of genetic resources for breeding programs. To evaluate the physiological and phenological characteristics of strawberries genotypes, an experiment was carried out using a randomized complete block design with 3 replications in the Agricultural Research Center of Kurdistan, Iran. Physiological parameters (amount of chlorophyll a, b and ab, soluble solids, titratable acidity and anthocyanin) and phenological characters (appearance of first stolon, first flower and first fruit, flowering and fruiting period) and yield of genotypes were evaluated. Results of analysis of variance showed significant differences among genotypes for all traits at the 1% level of probability, indicating the existence of genetic diversity among genotypes. The results of mean comparison showed significant differences among genotypes for all traits, indicating existence of wide diversity among the studied strawberry genotypes. The highest chlorophyll content belonged to Paros genotype and the highest yield recorded from Queen Eliza and Gaviota genotypes, respectively. The highest anthocyanin and soluble solids content was belonged to Gaviota and lowest amount of these parameters belonged to Paros and Chandler genotypes and Chandler genotype also had the highest amount of chlorophyll a. There were little difference between phenotypic and genotypic coefficient of variation, indicating the low effect of environment on these characters. All traits had high common heritability with range of 82-99 %. Data were analyzed using principal factor analysis. The factor analysis technique extracted four factors. Four factors explained about 74.05% of the total variation, and 50.84% of the variance was accounted for by the two first factors. Factors I and II were identified as photosynthetic, and fertility Index, respectively. According to results of factor analysis and other analysis, Paros genotype was identified as suitable cultivar.