Singh, Dhirendra KumarGaur, Geeta2016-10-222016-10-222014-01http://krishikosh.egranth.ac.in/handle/1/81407Thesis-PhdThe present investigation was carried out at vegetable research centre (VRC),G.B.Pant Uuniversity of Agriculture and Technology, Pantnagar, Uttarakhnad during cropping season of 2011 and 2012. The major objectives of the study were to estimate the extent of genetic variability, correlation, path analysis, manifestation of heterosis, general and specific combining ability effects. The experiment was laid down in randomized block design with 3 replications, fifty one crosses were evolved in line x tester mating design with 17 genotypes as a female parents (lines) and 3 genotypes as a male parents (testers). The analysis of varience revealed highly significant differences among genotypes for all the attributes under study. Plant diameter showed high amount of heritability and high genetic advance as percentage of mean showed in curd size index. The F1 cross PCF 103 x PG-6 found best hetrotic combination for number of leaf per plant, lamina length, marketable curd weight, curd size index and curd yield (q/ha) over better parents. Inb 9-5 x PG-6 was best heterotic cross over standard parent. The other combination showing significant value for all types of heterosis were Inb-9 -5 x PG-3, Inb 20-3 x PG-6, PCF 103 x PG-3, PCF 102 x PG-6, Inb 9-5 x PG-6 and Inb 20-3 x PG-5. For the development of early curd, negative heterosis is desirable for days to curd initiation, and days to curd maturity. The hybrids, for days to curd initiation were PCF-103 x PG-3, Inb 20-3 x PG-6, PCF-103 x PG-5, Inb DC-5-3 x PG-6, PEC1x PG-5 and for days to curd maturity was PCF-103 x PG-5, PCF-103 x PG-3, PCF-79 x PG-5, PCF-79 x PG-6, Inb 20-3 x PG-6, were most promising hybrids. The findings of present investigation revealed that the parent, Inb-5-2 (plant gross weight, marketable curd weight , net curd weight, curd size index, harvest index, curd yield), Inb- DC 5-3 ( plant height, number of leaf per plant, plant gross weight, stalk length, net curd weight, curd size index), Inb-9-5( plant height, plant diameter, leaf length, leaf width, lamina length, petiole length, plant gross weight), PCF-92 ( plant height, plant diameter, leaf length, leaf width, lamina length, plant gross weight, curd size index ), Inb-20-3 ( plant height, leaf length, stalk length, marketable curd weight , net curd weight, harvest index, curd yield ), PCF-79 ( plant height, petiole length, plant gross weight, marketable curd weight , net curd weight, curd diameter, curd size index, curd yield), Inb 10-1 ( plant diameter, leaf length, leaf width, lamina length, marketable curd weight , net curd weight, days to curd initiation, days to curd maturity, harvest index, curd yield), PCF-103 (plant height, plant diameter, number of leaf per plant, leaf length, leaf width, lamina length, petiole length, plant gross weight, marketable curd weight , net curd weight, days to curd initiation, days to curd maturity, curd size index curd yield ).,while among the testers PG-3( plant height, leaf length, petiole length, plant gross weight, marketable curd weight), PG-5 (plant diameter, leaf width, lamina length, plant gross weight, marketable curd weight, net curd weight), PG-6 ( number of leaf per plant, stalk length, curd depth, curd diameter, days to curd initiation, days to curd maturity, curd size index, harvest index, curd yield),were promising donor based on general combining ability. The cross PCF-1 X PG-6 and PCF 92 x PG-5 showed maximum sca effects hence, these crosses may be advanced to recover desirable segregants for the improvement of yield and yield contributing characters.enhorticulture, heterosis, combining ability, cauliflowers, Brassica oleracea var. botrytisThesis