人工合成新小麦的细胞学与农艺性状研究

人工合成小麦被广泛应用于小麦遗传育种及进化研究。本实验对四倍体野生二粒小麦、圆锥小麦、硬粒小麦与节节麦杂交,经染色体自动加倍形成的23个人工六倍体小麦第一代(S1代)的细胞学及农艺性状进行研究。结果表明,不同人工合成小麦的细胞学存在显著差异。四倍体供体母本对减数分裂影响很大。其中,由野生二粒小麦AS285合成的人工小麦的减数分裂很不正常,这可能由于控制减数分裂"二倍体"化的Ph1位点变异所致。减数分裂不正常,会导致其细胞学不稳定。因此,在用人工合成六倍体小麦构建遗传群体或作遗传研究之前,有必要先观察其减数分裂,选择出减数分裂正常的材料用于研究工作。根据本研究,单价体可作为判断减数分裂是否正常的依据。同时,不同人工合成小麦的农艺性状存在显著差异,它们为育种提供了新的资源。

Cytological and Agronomic Traits of Newly Synthetic Hexaploid Wheat

Synthetic hexaploid wheat(SHW) has been widely used in studies on evolution,genetics and breeding.Cytological and agronomic traits of the first generation(S1) in 23 SHWs,derived from the spontaneous chromosome doubling of the hybrid between Triticum turgidum ssp.dicoccoides,ssp.turgidum,and ssp.durum and Aegilops tauschii were observed in this study.There were significant variances on meiotic behaviours,largely depending on the female donor of tetraploid wheat(T.turgidum).Three SHWs derived from T.turgidum ssp.dicoccoides AS285 were very abnormal in meiosis,which may be related to the variation in Ph1 allele,responsible for the meiotic diploidization in wheat.The irregular meiosis may lead to the cytological instability of SHWs.Therefore,it is necessary to observe meiosis of newly-synthesized SHWs in order to avoid the applications of SHWs with irregular meiosis in studies on genetics.Based on the present study,the number of univalents can be used as an indicator for the irregularity of meiosis.Moreover,there were high variations on agronomic traits in SHWs,indicating their value on wheat breeding.