Are 'multiple cross-multiple pollen hybrids' an answer for productive populations in Brassica campestris (var.) Brown Sarson? Part 2: Evolution of 'Mucromphs'

Abstract

A set of 167 'mucromphs' was evaluated in their F₁ generation for seven 'plant', four 'plot' and five 'ratio' characters. Methods of characterizing the parents and the hybrids on the basis of combining ability effects described in the first part were found to be efficient in identifying desirable cross combinations for pedigree breeding or generating composite populations. Order effects of multiple-pollen combinations were found to be potent for a number of character components. High x Low cross-combinations were found to produce a high frequency of heterotic crosses followed by High x High. Selected biparental progenies, single crosses, three-way crosses and elite varieties were successful female parents and combinations of pollen from two varieties, one variety and three varieties were successful male parents, in that order, in producing significant heterosis in mucromphs. The relationship between general and specific combining ability on the one hand and realised heterosis on the other was discussed.