การถ่ายทอดลักษณะยีน Ogura CMS และความดีเด่นของลูกผสมในผักกาดขาวปลี

Abstract

The cytoplasmic-genic male sterility trait was transferred from Chinese cabbage of Chinese variety to common Chinese cabbage variety vie backcrossing of BC1, BC2, and BC3 yielding 18 hybrid lines that showed small sized flower, short style, and indehiscent pollen compared to the normal plant. The SSR (Simple sequence repeat) result showed all backcross generations had inherited cytoplasmic genic male sterility at the genetic level. The hybrids were evaluated for both summer and winter cropping. In the summer season, all 18 hybrids formed heading with three cross hybrids, 23-9-3 ×27-8-7, 23-9-3 ×142-7-12, and 27-8-7 × 23-6 having a high head shape quality while the commercial varieties and the parental line would not form heads. In the winter season, all these three hybrids also showed good head shape quite comparable to the commercial varieties which usually have a head shape index of more than 1. Note that, for the summer crop, the head shape index of the hybrids would have a higher value than that of the commercial varieties that do not form a head in the warm season. The mean trimming percentage of the hybrids grown in the winter and summer seasons was 57.75 Heterosis evaluation of hybrids 23-9-3 × 27-8-7, 23-9-3 × 142-7-12, and 27-8-7 × 23-6 showed positive over the mid-parent heterosis, which was significantly different from zero for all characteristics: head height, canopy width, leaf number, leaf width, leaf length, head weight, head diameter, and head length. The combining ability evaluation result showed that 23-6 had good general combining ability, which was significantly different from zero for leaf width and head weight. The 23-8-7 had good general combining ability, which was significantly different from zero for head weight and head length. The 23-9-3 showed good general combining ability, which was significantly different from zero for leaf number, and the 142-7-12 performed good general combining ability, which was significantly different from zero for head height. The good specific combining ability results of 23-6 ×142-6-5, 23-6 ×142-7-12, and 23-9-3 ×27-8-7 favored the good horticultural characteristics of the hybrids studied. Moreover, the interaction between combining ability and season was found to have effects on all characteristics. The combining ability analysis showed that the 23-6 and 23-9-3 have a potential to be maternal lines and the 142-6-5 and 142-7-12 have the potential to be a male line for a heat-tolerant hybrid.