Bhatt, LalitThapliyal, Vivek2024-08-212024-08-212023-05Theses of Ph.Dhttps://krishikosh.egranth.ac.in/handle/1/5810213516The present investigation entitled „Study on heterosis and combining ability in cauliflower (Brassica oleracea var. botrytis L.)‟ was conducted at Vegetable Research Centre, Govind Ballabh Pant University of Agriculture and Technology, Pantnagar, Uttarakhand during cropping season of 2019 and 2020. The major objectives of the study were to estimate heterobeltiosis and standard heterosis for yield and component characters, combining abilities of parents and crosses and to determine the correlation as well as the gene action involved in the expression of traits. The experiment was laid down in Randomized Complete Block Design with three replications. Thirty cross combinations were evolved from 13 cauliflower genotypes by following line × tester mating design with 10 lines and 3 testers. The parents and crosses were evaluated for 15 metric and 8 visual/quality characters. Analysis of variance for all the traits revealed highly significant differences indicating that there was considerable variability for these traits among the genotypes. Cross combinations namely COMP-3 × Pant Gobhi-3, PCF-120 × Pant Gobhi-3, PC-77 × Pusa Meghna, INB-9-2 × Pusa Meghna and PCF-120 × Pusa Meghna exhibited significant heterobeltiosis for curd yield along with most of the yield attributing characters. PC-100 × Pusa Meghna and PCF-65 × Pusa Meghna also exhibited significant desirable heterobeltiosis for a number of traits like plant height, lamina length, leaf length, leaf width, etc. In case of standard heterosis, cross combination COMP-3 × Pant Gobhi-3 exhibited high significant value for almost all the characters except plant spread, number of leaves per plant, leaf length, stalk length and days to harvest. Other cross combinations exhibiting significant standard heterosis for curd yield along with other yield attributing traits were COMP-3 × Sabour Agrim, INB- 9-2 × Pusa Meghna, PC-77 × Pusa Meghna and PCF-120 × Pant Gobhi-3. Lines namely COMP-3, DC-54-15 and INB-9-2 were found as the best general combiners for most of the traits. Among testers, Pant Gobhi-3 was found to best general combiner for most of the traits followed by Pusa Meghna whereas Sabour Agrim was observed to be poor general combiner for all the traits. Cross combination PC-77 × Pusa Meghna exhibited significant high SCA effect for all the characters except days to harvest, whereas PC-98 × Sabour Agrim exhibited highly significant SCA effect for curd yield along with most of the yield attributing traits. The cross combinations showing high heterosis coupled with high SCA effects for curd yield were PCF-120 × Pant Gobhi-3, PC-77 × Pusa Meghna and INB-9-2 × Pusa Meghna and can be further used in crop improvement programme.EnglishThesis