普通小麦与粗山羊草属间杂种的染色体构型及其后代的育性特征

利用3个推广品种(莱州953、山农辐63、陕7859)分别与原产地不同的抗白粉病的6份粗山羊草Aegilops tauschii(Coss.)Schmal.]杂交,得到63个无胚乳的种子,将56枚幼胚接种到N6 0.5mg/L IBA 0.2 mg/L NAA的培养基上进行褓姆培养,得到37个植株。其中莱州953与粗山羊草的杂交结实率和成苗率较高,分别平均为8.58%和4.82%。粗山羊草对白粉病的抗性基因在不同的杂交组合中受到不同程度的改变或抑制。以莱州953为父本,分别与不同组合的杂种F_1回交,大多数组合均得到回交种子,回交结实率平均为1.70%;以莱州953作母本,与莱州953/Y225 F _1回交得到2粒种子,说明普通小麦与粗山羊草的杂种F_1也能产生少量有授精能力的花粉。以山农辐63为父本与山农辐63/Y219 F_1回交亦得到回交种子。通过对普通小麦与粗山羊草6个杂交组合的杂种F_1PMCMI染色体构型的分析,一般多出现14个左右单价体和一定频率的多价体,并观察到可能为A、B组染色体形成的异形二价体;粗山羊草的D组染色体和普通小麦的D组染色体联会正常,可发生自由重组,从而为将粗山羊草的有益基因导入普通小麦提供了细胞学依据。

CHROMOSOME CONFIGURATIONS ANDFERTILITY CHARACTERISTICS OF HYBRIDS BETWEEN TRITICUM AESTIVUM L.AND AEGILOPS TAUSCHII (COSS.) SCHMAL.

Three cultivers (Laizhou 953, Shan-nongfu 63. Shan 7859) of Triticum aesti-vum L. were used to cross 6 different accessions of Ae. tauschii (Coss.) Schmal., which were resistant to powdery mildew and 63 seeds obtained without endosperm. Out of them, 56 immature embryoes were cultured on N6 0.5mg/L IBA 0.2mg/ L NAA, and 37 hybrid plants obtained. The seed sets and the percentages of seedlings established of hybrids between Laizhou 953 and Ae. tauschii were higher (8.58% and 4.82% on an average respectively). It had been shown that the expression of powdery mildew resistance genes from Ae. tauschii may be altered or suppressed to some extent in different common wheat backgrounds. Laizhou 953, as male, was backcrossed to Laizhou 953/ Ae. tauschii F1, and backcrossing seeds were harvested in most of the combinations. The backcrossing seed set was 1.70 % on an average. Laizhou 953, as female, was backcrossed to Laizhou 953/Y 225 F1, and 2 seeds were harvested, showing that the hybrid between T. aestivum and A. etauschii could produce a few functional pollens. Sannongfu 63, as male, was backcrossed to Shannongfu 63/Y219 F1, and backcrossing seeds were produced also. Analyses of the chromosome configurations at PMC MI from 6 different hybrids showed that not only were about 14 uni-valents and some frequencies of multiva-lents observed, but also abnormal bivale-nts, which might be formed by pairings of chromosome from A and B genomes of common wheat. Complete pairings and free recombinations could occur between the chromosomes from Ae.tauschii and the ones from D genome of T. aestivum. So the transfer of desirable genes from Ae. tauschii into common wheat is possible.