应用DNA标记定位水稻的抗稻瘟病基因

 从水稻分子遗传图谱选取177个RFLP标记,比较以红脚占为抗源,感病品种IR24为轮回亲本所构建的近等基因对K80R和K79S之间的多态性表现。发现了一些可能与稻瘟病抗性基因连锁的阳性标记。在(K80R×K79S)的F₂群体中,经稻瘟病菌ZB₁小种接种,110株为抗病,33株为感病,用总共10个阳性标记与F₂群体中每个单株的DNA杂交,发现抗病基因与第12染色体上的标记RG81、RG869和RZ397共分离;检测F₃株系的抗病性分离情况,确定F₂植株的抗病性基因型,计算出抗病基因与分子标记的遗传距离,将该基因定位在第12连锁群上。应用近等基因池DNA和随机引物,经PCR扩增和共分离分析,建立了二个RAPD片段与抗病基因紧密连锁。

TAGGING RICE BLAST RESISTANCE GENES VIA DNA MARKERS

K80R and K79S were a pair of near iso-genie lines with blast resistance genes. They were derived from progenies of three backcrossing followed by nine self-crossing of Hong-Jiao-Zhan as the donor of blast resistance genes and IR24 as the recurrent parent. One hundred and seventy-seven RFLP probes were screened among these four varieties and 10 positive probes were isolated. Plants of F2 population of K80RX K79S were inoculated with Pyricularia aryzae Cav. race ZB, and were scored 110 resistant: 33 susceptible. RFLPs of each F2 plants were tested by the positive probes. RG81, RG869 and RZ397 on chromosome 12 were found to be linked with a blast resistance gene, which was named Pi-h-1 (t). Genotypes of each F2 plants were monitored by investigating the reaction to P. aryzae of each F3 lines and genetic distances between Pi-h-1 (t) and RFLP markers were calculated. Two PCR amplified fragments were found to be tightly linked to Pi-h-1 (t) by RAPD analysis.of near isogenic pools of DNA from F2 plants.