Development of Male and Female Parents of F1 Hybrid in Chinese Cabbage

Abstract

Male and female parents were improved to produce good hybrid progenies of Chinese cabbage, a highly self-incompatible vegetable crop. Hybrid seed production using bees was also studied. Inbred seeds of 4 Chinese cabbage lines were produced using bud pollination which is a conventional technique for inbred lines. Results showed that line 40-9 gave the highest seed weight of 0.165 g/plant. Using seed set analysis technique to check self-incompatibility, lines 23-3-4, 27, 27-3-7, and 40-9 were found to be self-incompatible among the 9 Chinese cabbage lines evaluated. However, when fluorescent microscope technique was used, the self-incompatible lines were 23-3-4, 27, 27-3-7, 40-9, and 142. Four inbred lines with self-incompatibility were selected to produce seeds. When line 40-9 was used as female parent in reciprocal crosses by bee pollination, the progenies gave the highest seed yield, an indication of maternal effect. Crosses 40-9 x 142-5, 40-9 x 27-3-7 and 40-9 x 23-3-4 gave high seed weight of 4.8, 3.9 and 2.7 kg/rai, respectively. Comparison of 11 Chinese cabbage hybrids with 3 commercial varieties showed that hybrid 142-5 x 40-9 gave the highest head yield with 6,170 kg/rai, 36.3% higher than commercial varieties. Other crosses such as hybrids 23 x 27, 23 x 142, 27-3-7 x 23-”.-4, 27-3-7 x 142-5 and 40-9 x 23-3-4 had good horticultural characteristics. These results indicate that improvement of parental lines is necessary to enhance good F1 hybrid.