Pollination and variability studies in cauliflower

Abstract

The present investigation was taken up to study the level of self-incompatibility and genetic variability among the selected fifteen genotypes of early cauliflower. Fertility index was estimated by seed set as well as fluorescence microscopic methods. By seed set method, out of 15 genotypes, seven genotypes namely IIHR-223, IIHR-217-19-6-12, IIHR-263, IIHR-73-5, IIHR-318, IIHR-351 and IIHR-266-16 were found to be selfincompatible as the fertility index was very high and more than one. This high fertility index might be due to the fact that self-incompatible genotypes possess highly expressive S-alleles. Due to these S-alleles action in self-incompatible genotypes seed set was very less under self pollination (bagging and manual selfing of open flowers). Genotypes IIHR-250-4-1-11-28, IIHR-272, IIHR-217-3-14, IIHR-352, IIHR-316-17, IIHR-73-3, IIHR-305 and IIHR-73-24 were self compatible because their fertility index was less than one. The ultimate categorization of all the fifteen genotypes into self-incompatible and self-compatible based on fertility indices remained the same under both the methods. The analysis of variance revealed highly significant differences among the genotypes for days to curd initiation, day to curd maturity, leaf number, plant weight, leaf weight and curd weight. It was observed that high heritability values were associated with moderate value of genetic advance or gain for days to curd initiation and days to curd maturity. Moderate heritability with moderate genetic advance has been observed for characters like leaf weight, curd weight, curd diameter, low heritability with low genetic advance was observed for characters like total plant weight, leaf number, curd size, stalk length and stalk weight indicating that these characters are governed by non additive gene components and the selection based on phenotypic appearance will not be effective and hence they can be exploited by heterosis breeding