Divergence and association studies in sunflower (Helianthus annuus L.)

Abstract

In the present study we report the genetic diversity among 18 sunflower inberd lines involving alloplasmic cms lines, conventional cms and restorer lines (petiolaris source) using twenty traits. Efforts were also made to correlate various morphological and physiological traits with seed yield and oil content. The study was performed at Oil Seed Section, Department of Plant Breeding and Genetics, Punjab Agricultural University (PAU), Ludhiana, India. The analysis of variance recorded persence of significant variability among the garmplasm lines. Mahalanobis D2 statistic indicated presence of substantial genetic diversity and genotypes were grouped into five clusters. ARG-3A and cms-XA were designated as the most diverse cms sources. Grain yield an important character showed highly significant positive correlation with days to 50% flowering, days to maturity, plant height, chlorophyll content, oil content, and biological yield at both genotypic and phenotypic levels. Path coefficient analysis revealed direct positive effect of no. of leaves per plant, 100 seed weight, chlorophyll content, leaf area, leaf area index, oil content, biological yield and harvest index on grain yield. Plant height, seed size, number of leaves per plant, chlorophyll content, leaf traits, and oil content were identified as important traits for selection criteria to improve seed yield in sunflower. It was also observed that different cytoplasmic sources used in the present study did not show any deviations from the previously established correlations between important morphophysiological and seed yield traits and can be exploited in heterosis breeding programme.