Characterization and genetic analysis of OguCMS and doubled haploid based large genetic arsenal of Indian cauliflowers (Brassica oleracea var. botrytis L.) for morphological, reproductive and seed yield traits revealed their breeding potential

Cytoplasmic male sterile (CMS) lines along with homozygous doubled haploid (DH) inbreds are the foundation of present-day cauliflower hybrid breeding. However, successful utilization of crop genetic arsenal depends on their extensive characterization for agro-morphological and reproductive traits. In this context, a large genetic stock of cauliflower encompassing 76 CMS and DH lines were characterized extensively for the first time in India. The variance analysis accompanied with k-means clustering revealed high genetic variability among these 76 genetic stocks of cauliflower under study. The CMS lines, Ogu402-6A, Ogu76-33A and Ogu76-4A were identified for development of early maturing hybrids. While the CMS lines, Ogu13-85-6A, Ogu309-2A and Ogu2A were selected as parents for generation of the hybrids with highly compact curds. Superior agronomic traits, abundant pollen production and good seed setting in the DH lines DH-53-1 and DH-53-10 revealed their potential for genetic and genomic studies in cauliflowers. The k-means clustering grouped them into four distinct clusters and clustering was validated by Silhouette coefficient. The slightly higher magnitude of phenotypic coefficient of variation than corresponding genotypic coefficient of variation for majority of traits indicated influence of environment in expression of these traits to lesser extent. High estimates of heritability (> 80%) accompanied with high genetic advance for total yield and earliness traits indicated the scope of reliable selection in the present germplasm. The PCA analysis revealed the maximum contribution of numbers of silique per plant and seed yield in total variation. This study will be instrumental in formulating strategy in developing new age F₁ hybrids through effective utilization of CMS and DH lines in cauliflowers.