Heterosis and Genetic Diversity of Yield and Its Some Components in F1 of Sunflower Inbred Lines

Abstract

Fall season 2020, six inbred lines of sunflower were crossed by half-diallel crosses to obtain 15 single hybrids. The genotypes (parents and first-generation hybrids -F1) were planted in randomized comlete block design (RCBD) with three replications in a field/Babylon Governorate during the spring season 2021. The study aimed to estimate Heterosis of the first generation hybrids from the mean of the parents for the traits; stem diameter, head diameter, number of seeds per head, weight of 100 seeds, seed yield and oil yield per plant. Furthermore, estimation of genetic distance among genotypes using cluster analysis. The results of the analysis of variance showed that there were significant differences at the probability level (0.01) for all the studied traits of the parents and the first generation hybrids. The two hybrids (I×Q) and (Q×C) were distinguished a high significant positive heterosis for most of the traits measured. The cluster analysis showed that the two genotypes that include hybrids (Q×C) and (Q×F) had the highest Euclidean distance (175.92 and 183.66) respectively. This indicated to high degree of genetic diversity between the two hybrids and the rest of the studied hybrids, which it positively reflected on the performance of the hybrids for the studied traits. The results of Principal Component Analysis (PCA) and Dendrogram showed that (Q) genotype was far from the rest of the genotypes and isolated to a single group, whereas the remaining genotypes separated into groups to two separed branches, especially the two genotypes (C( and )Q). The reason may be due to the distinguish genetic difference of these interested genotypes which have the ablility to transfer from parents to the its progenies, which resulted from a presence of the clear genetic distance between them, while, other genotypes lacks the of this genetic variation case.