Selective fertilization in plants in relation to plant breeding. I. Chinese cabbage (Brassica pekinensis RUPR.) 5. Some Schemes of F₁ seed production utilizing selective fertilization.

Abstract

( 1 ) Size of seed resulting from inter-varietal hybridization (F₁ seed) tended to be larger than that of intra-varietal hybridization (seed of female plant), but this tendency was not distinct (Table 1). Therefore, seed size seems to be not always effective in screening F₁ seeds. However, since germination of F₁ seeds was apparently faster (Table 2) and growth of F₁ seedlings was more vigorous than those of intra-varietal ones, F₁ Plants may remain in a field only through thinning out weak seedlings. ( 2 ) It was found that F₁ plants were distinctly more resistant to virus and Bacillus aroidae than those of female parent (Table 3). ( 3 ) Frequency (%) of F₁ seeds in the case of mixpollination was higher in crosses utilizing selfcompatible plants than in self-incompatible ones as female parent (Table 4).