小麦×冰草属间杂种F_1的植株再生及其变异

Plant Regeneration and Variation of a Wheat X Agropyron Gaertn Intergeneric Hybrid

在对0.5—40.cm长幼穗培养4周后诱导出愈伤组织的基础上,获得了88株普通小麦(Triticum aestivum cv.Chinese Spring,2n=6x=42,AABBDD)×沙生冰草(Agropyron desertorum Fisch.> Schult.,2n=4x=28,PPPP)杂种F_1的再生植株。不同长度的幼穗在培养时,其愈伤组织发生的部位及其增殖速度不同。再生植株的产生主要是通过直接器官发生途径。所有的再生植株染色体数目全与杂种F_1相同,为2n=35。与杂种F_1相比,再生植株的减数分裂行为是相当复杂的,证明有染色体结构变异的发生。每茎穗数、叶片失绿斑等形态上的变异是由环境效应引起的;而株高、每穗轴节上小穗数和育性是由遗传效应决定的。特别值得注意的是,再生植株的自交结实率高达5.49%,共获得自交种子484粒,这对利用P染色体组中的期望基因有着极为重要的意义。

Plants of the hybrid Triticum aestivum × Agropyron desenorum were directly regenerated from callus induced on 0.5-4.0 cm immature inflorescence cultured for four weeks. There were apparent differences in response of callus induction and proliferation to immature inflorescences ranging in different lengths. The plant regeneration occured mainly by means of direct organogenesis. The somatic chromosome number of regenerants was invariable, 2n = 35. Compared with the donor hybrid plants, the meiotic behaviour of pollen mother cells in regenerants was rather complex, indicating that chromosomal structural changes were produced in the regenerants. The morphological variation such as more than one spike on a single culrr and chlorophyll aberration were caused by the environmental effects, but the plant height and the additional spikelets in some rachis nodes as well as the increased fertility by a genotypical effect. It is particularly worthwhile to note that the regenerants had rather high self-fertility, self set being 5.49%. The 484 selfed seeds were obtained from all regenerated plants. These seeds would provide a potential possibility for use of the expected gene(s) from P genome.