小麦体细胞多个性状变异特点的研究

STUDIES ON INHERITANT PATTERNS OF MULTIPLE TRAITS IN WHEAT SOMACLONAL VARIANTS

用１２个基因型的幼胚和８个基因型的幼穗作外植体，研究了Ｒ２代多个性状的变异方向及平均表现，结果表明，（１）Ｒ２代各数量性状的变异在幼胚（或幼穗）间的平均表现呈连续变异，为提高试验基础水平，应有较大的外植体群体，使较优外植体个体能参与试验；（２）各性状变异趋势为：抗赤霉病性多向感病方向变异，病小穗数约增加０．５～８．０个，抗病株出现机率较小。抽穗期一般提早０．３～５．０ｄ。大部分幼胚系株高变异趋高，幼穗系株高趋矮，基因型间具很大随意性，降矮幅度一般为２～５ｃｍ。穗部性状变优，平均穗长增加１ｃｍ左右，平均每穗小穗数增加１．５～２．０个，平均单株穗数增加０．５～１．０个；（３）超亲优株普遍存在，具有获得优良突变体的可能；

Immature embryoes of 12 genotypes and young inflorescences of 8 genotypes of wheat were used as explants to explore the direction and mean appearance of somaclonal variation. The results could be used to guide the utilization on inducing somaclonai variation. 1) All traits studied were quantitative traits. The mean appearances of variation in R 2 generation of two explants used were continous. In order to pick out the desirable plants from the regenerated groups, large group of explants were necessary. 2) Tendency of variation in each trait variation of resistance to scab was tended to reduce, approximately 0.5～3.0 more infected spikelets were observed. The probability to obtain resistant variant was relatively low. Heading stage could be moved up generally 3 to 5 days. Height variation was random, the range of variation is around 5 cm. Length of spike, number of spikelet and number of spike per plant were tended to increase. Mean length of spike was increased about 1 cm, mean number of spikelet 1.5～2.0, mean number of spike per plant 0.5～1.0. 3) Excellent individuals which were better than the good parents were widely existed in regenerated group, it was possible to gain desirable variant. 4) To some extent, the features of variation between the regenerated groups from the two explants were different in some genotypes and some traits.