普通小麦–大赖草易位系T6DL·7LrS的分子细胞遗传学鉴定

Molecular and cytogenetic identification of Triticum aestivum–Leymus racemosus translocation line T6DL·7LrS

摘要:

大赖草高抗小麦赤霉病, 将大赖草抗性基因导入普通小麦, 对创新小麦赤霉病抗性种质有重要意义。为了获得普通小麦-大赖草抗赤霉病易位系，采用12 00 R 60Co-γ射线处理小麦-大赖草二体附加系 DA7Lr花粉, 授予已去雄的普通小麦中国春，对其后代 (M1) 种子根尖细胞有丝分裂中期染色体进行GISH分析，获得了1株具有1条普通小麦-大赖草易位染色体的植株，让其自交，对自交后代中具有2条易位染色体植株的花粉母细胞减数分裂中期I进行观察，发现2条易位染色体形成了稳定的棒状二价体，表明该植株为纯合体。利用顺序GISH-双色FISH分析，结合小麦D组专化探针Oligo-pAs1-2和B组专化探针Oligo-pSc119.2-2，进一步鉴定出该普通小麦-大赖草易位系为T6DL·7LrS，该易位系的育成也为小麦赤霉病遗传改良提供了新种质。

Abstract:

Leymus racemosus had a high resistant capacity to wheat scab (Fusarum head blight). The transfer of scab resistant gene from L. racemosus to Triticum aestivum is of great significance for broadening the germplasm of wheat resistance. To obtain Triticum aestivum–Leymus racemosus translocation line with scab resistance, we irradiated the pollen of T. aestivum-L. racemosus disomic addition line DA7Lr by 60Co-γ-rays 1 200 R (100 R/min) prior to pollinating to emasculation T. aestivum cv. Chinese Spring. One plant with one translocation chromosome was detected in the M1 by GISH. The plant with one translocation chromosome was self-pollinated, and at meiotic metaphase I its progenies with two translocation chromosomes were analyzed for chromosome pairing behavior in their pollen mother cells (PMCs). One rod bivalent was observed at meiotic metaphase I, indicating that the plant with two translocation chromosomes was one translocation homozygote. Sequential GISH-FISH analysis, using Oligo-pAs1-2 and Oligo-pSc119.2-2 as probe, translocation line was confirmed as T6DL·7LrS. The translocation line had higher resistance to wheat scab and feasibility to be used as a new source in wheat breeding resistant to scab disease.