Sundaram Raman M, Vishnupriya M R, Laha Gouri S, Rani N Shobha, Rao P Srinivasa, Balachandran Sena M, Reddy Gajjala Ashok, Sarma Nukala P, Sonti Ramesh V
Directorate of Rice Research, Rajendranagar, Hyderabad, India.
Biotechnol J. 2009 Mar;4(3):400-7. doi: 10.1002/biot.200800310.
Bacterial blight (BB) is a serious disease of rice in India. We have used molecular marker-assisted selection in a backcross breeding program to introgress three genes (Xa21, xa13, and xa5) for BB resistance into Triguna, a mid-early duration, high yielding rice variety that is susceptible to BB. At each generation in the backcross program, molecular markers were used to select plants possessing these resistance genes and to select plants that have maximum contribution from the Triguna genome. A selected BC3F1 plant was selfed to generate homozygous BC(3)F(2) plants with different combinations of BB resistance genes. Plants containing the two-gene combination, Xa21 and xa13, were found to exhibit excellent resistance against BB. Single plant selections for superior agronomic characteristics were performed on the progeny of these plants, from BC(3)F(3) generation onwards. The selected plants were subjected to yield trials at the BC(3)F(8) generation and were found to have a significant yield advantage over Triguna. The newly developed lines are being entered into national multi-location field trials. This work represents a successful example of the application of molecular marker-assisted selection for BB resistance breeding in rice.
细菌性条斑病（BB）是印度水稻的一种严重病害。我们在回交育种计划中利用分子标记辅助选择，将三个抗BB基因（Xa21、xa13和xa5）导入Triguna，Triguna是一个生育期适中偏早、高产但易感BB的水稻品种。在回交计划的每一代中，使用分子标记来选择携带这些抗性基因的植株，并选择来自Triguna基因组贡献最大的植株。选择的一株BC3F1植株进行自交，以产生具有不同BB抗性基因组合的纯合BC(3)F(2)植株。发现含有Xa21和xa13这两个基因组合的植株对BB表现出优异的抗性。从BC(3)F(3)代开始，对这些植株的后代进行单株选择以获得优良农艺性状。在BC(3)F(8)代对所选植株进行产量试验，发现它们比Triguna具有显著的产量优势。新培育的品系正在进入全国多点田间试验。这项工作是分子标记辅助选择在水稻抗BB育种中应用的一个成功范例。
