陆地棉愈伤诱导及胚胎发生能力的遗传分析

 在特定培养条件下对62个陆地棉（Gossypium hirsutum L.）品种进行了离体培养研究。结果表明，基因型对愈伤组织的诱导率没有明显影响，但对体细胞胚胎发生能力影响很大。仅27.4%的品种有体细胞胚胎发生能力，其中胚胎发生能力较强的品种占11.3%,多数品种(72.6%)在本试验中未观察到胚状体形成。在含有IAA及KT的培养条件下，基因型对愈伤组织的生长速度有明显影响。双列杂交结果表明，基因型间愈伤组织生长速度和体细胞胚胎发生能力存在显著差异。愈伤组织生长速度的一般配合力、特殊配合力和反交效应都达到极显著水平。无胚胎发生能力的品种与有胚胎发生能力的品种杂交所得20个组合都不能形成胚状体，且F#-2代呈3:1的分离比例，表明体细胞胚胎发生受一对隐性主效基因控制。在有胚胎发生能力的基因型中，胚胎发生能力还存在量的差异，这种差异可能受一些修饰基因的控制。

Genetic Analysis of Callus Induction and Somatic Embryogenesis in Upland Cotton

Explants of 62 cultivars of upland cotton (Gossypium hirsutum L.) were cultured on the IK and DK media. The results indicated that genotype (cultivars) did not have significant effect on the inducing rate of callus, but greatly affected the embryogenesis on both IK and DK media. Only 16 cultivars were embryogenic, out of which 7 were highly embryogenic, 4 were moderate and 5 were low, the other cultivars were non embryogenic. The growing speed of callus was also influenced by genotype on the IK media, but it was not influenced on the DK media. Positive correlation between the growing speed of callus and the embryogenic ability was observed on the IK media, but it was not confirmed on the DK media. Complete diallel crossing was used in the genetic analysis. Thirty six genotypes were obtained and inoculated on the IK media. Remarkable general combining ability, special combining ability and reciprocal crossing effect on the growth rate of callus were noted. Two types of variation of the embryogenenic ability were observed, one was quality type variation, and the other was quantitative type. All the hybrid combinations of non embryogenic and embryogenic showed non embryogenic phenotype, and the segregation ratio of non embryogenic to embryogenic in F 2 offsprings was 3 to 1, suggesting that the somatic embryogenesis was mainly controlled by one pair of recessive genes which accounted for the quality type variation of the somatic embryogenesis. The quantitative variation of the somatic embryogenesis may be caused by some modification genes.