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用中国春ph2b突变体(Triticumaestivum L.cv.Chinese Spring)与华山新麦草(Psathyrostachys huashani-caKeng)杂种F1的部分进行自交,而另一部分与3个不同的普通小麦品种以及中国春ph2b突变体进行回交,并对自交和回交一代的形态学和细胞学进行研究。结果表明:(1)含有AABBDDNs的自交F2的花粉母细胞减数分裂中期Ⅰ平均单价体数都在7以上,说明来自华山新麦草的Ns基因组可引起普通小麦ABD基因组中某一个(几个)同源组发生不联会或联会消失;(2)在回交一代(F1×CS、F1×CSph2b)中,平均单价体数都在7以下,说明其中的ph2b基因起到了促进染色体配对的作用;而在回交一代(F1×J-11、F1×郑麦-9023)中,则表现正常,与理论一致;(3)在所有自交和回交一代中,减数分裂期间均出现染色体桥、落后染色体、三分孢子体、多分孢子体以及微核等各种染色体异常行为,说明Ns基因组引起了所得材料细胞学上的不稳定性。从总体上讲,回交比自交能更快地恢复ph2b基因促进部分同源染色体配对的作用,为染色体重组提供更多的机会,期望在后代中获得新种质。
Inbred lines were obtained from the hybrid F1 of Chinese Spring ph2b mutant (Triticum pestivum L.cv.Chinese Spring) and Psathyrostachys huashani-caKeng, while the other part was crossed with three different common wheat varieties and the Chinese Spring ph2b mutant Backcrossed, and studied the morphology and cytology of the selfing and backcross generation. The results showed that: (1) The average number of meiotic metaphase Ⅰ in meiotic metaphase of pollen mother cells with AABBDDNs was more than 7, indicating that the Ns genome from P. huashanica could cause one of ABD genomes in wheat (several (2) In the backcrossed generation (F1 × CS, F1 × CSph2b), the average number of unit price is below 7, indicating that the ph2b gene plays a role in promoting chromosome pairing (F1 × J-11, F1 × Zhengmai -9023), which was normal and consistent with the theory. (3) In all the selfing and backcross generations, Chromosome bridges, backward chromosomes, triple sporozoites, pollenosomal and micronuclei, and other chromosomal abnormalities, showed that the Ns genome caused cytological instability of the resulting material. In general, backcross restored the ph2b gene more quickly than the self-cross and promoted the pairing of homologous chromosomes, providing more opportunities for chromosomal recombination and expecting to obtain new germplasm in future generations.