小麦体细胞无性系矮秆变异体AS34株高构成和育种潜力探讨

创制和利用矮秆资源对于小麦品种改良具有重要意义。到目前为止,在小麦属中虽然已鉴定了多个矮秆资源,但多数矮秆资源在小麦中的利用价值有限。本研究对利用无性系变异途径获得的小麦矮秆材料AS34及其与模式小麦品种中国春杂交F1、F2材料进行了株高构成和主要农艺性状分析。结果发现,AS34共有4个节间,比其野生型豫麦66少了1个节间,各个节间长度按相似比例缩短,穗下节长度短于第2节长度;F1株高、节间长度指数介于2个亲本之间,节数与AS34相同,穗长、小穗数、穗粒数超过2个亲本;F2株高、穗长、穗粒数、小穗数变异范围广泛,约70%植株株高为60~89 cm,穗长6.0~9.9 cm、穗粒数50~79粒、小穗数20~24个。结果表明,AS34的矮秆变异由多基因控制,表现为数量性状,其矮秆性状对杂交后代穗长、小穗数、穗粒数等主要农艺性状有正向遗传效应,F2选择穗大、粒多、株高适中优良单株的机率较大,具有很好的育种利用价值。

Investigation on the Plant Height Constitution and Breeding Potential of a Dwarfing Somatic Variation Line AS34 in Wheat

It is very important to create, characterize, and use wheat dwarfing resources for wheat breeding. Even though many dwarfing materials have been excavated in Triticum genera so far, most of them are less employed valuable in wheat variety improvement. In this study, a dwarfing somatic variation line AS34 developed recently and its F1 and F2 generation plants with Chinese Spring (C.S) were investigated for plant height constitution and several main agronomic traits related to yield potential. Results revealed that the stem of AS34 is consisted of four internodes, which is one less than its wild type of Yumai66. The length of each internode in AS34 was shortening by a similar ration with the plant height to Yumai66, and the first internode was less than the second internode in length of this dwarfing line. The plant height and internode length of the F1 plants were almost the average values of their two parents, containing the same internodes as AS34. Especially, the F1 plants appeared superiority over their two parents in spike length, spikelets per spike and grains per spike. In the F2 generation plants, plant height, spike length, grains per spike, and spikelets per spike varied broadly, and about 70 % of the F2 plants had 60-90 cm in plant height, 6.0-10.0 cm in spike length, 50-79 grains per spike, 20-24 spikelets per spike. Results suggested that the dwarfing trait of AS34 was controlled by multiple genes, and appeared positive genetic effects on the above main agronomic characteristics in the segregated population when crossed with other wheat varieties, in which the ideal plants with moderate plant height, longer spike, and more grains per spike could be selected with more chance, assuming that AS34 would be potentially used in wheat breeding.