ICAR-Indian Institute of Rice Research (ICAR-IIRR), Hyderabad 500 030, India.
J Genet. 2022;101.
To combat the dreaded diseases in rice like bacterial blight (BB) and blast, host plant resistance has been advocated as the most suitable and sustainable method. Through the present study, we have successfully incorporated three major BB resistance genes, namely , and into NLR3449, a high yielding, blast resistant, fine-grain type, popular rice variety through marker-assisted backcross breeding. Foreground selection was carried out using polymerase chain reaction based, gene-specific markers, namely pTA248 (), xa13prom () and xa5FM () at each generation of backcrossing, while 127 polymorphic SSR markers spanning on 12 chromosomes were used for background selection and backcrossing was limited to two rounds. At BCF generation, a single plant (NLR-87-10) with 89.9% recovery, possessing all the three BB resistance genes was forwarded to BCF generation. A solitary BCF plant, namely NLR-87- 10-106 possessing all the three resistance genes and 96% genome recovery was identified and advanced through selfing until BCF generation by adopting pedigree-method of selection. Three best BCF lines, possessing high level of resistance against BB and blast, and equivalent or superior to NLR 34449 in terms of yield, grain quality and agro-morphological traits were identified and advanced for multilocation trials.
为了防治水稻上的细菌性条斑病（BB）和稻瘟病等可怕疾病，人们提倡利用寄主植物抗性作为最合适和最可持续的方法。通过本研究，我们成功地将三个主要的 BB 抗性基因、和 导入 NLR3449，这是一种高产、抗稻瘟病、细粒型、广受欢迎的水稻品种，通过标记辅助回交育种。在回交的每一代中，我们使用基于聚合酶链反应的基因特异性标记物 pTA248（）、xa13prom（）和 xa5FM（）进行前景选择，同时使用覆盖 12 条染色体的 127 个多态性 SSR 标记进行背景选择，并将回交限制在两轮。在 BCF 代，我们选择了一个单株（NLR-87-10），该单株具有 89.9%的恢复率，携带所有三个 BB 抗性基因，并被推进到 BCF 代。我们选择了一个单独的 BCF 植株，即 NLR-87-10-106，它携带所有三个抗性基因，基因组恢复率达到 96%，并通过自交被鉴定和推进到 BCF 代，采用系谱法进行选择。我们还鉴定和推进了三个最好的 BCF 系，它们具有高水平的 BB 和稻瘟病抗性，在产量、谷物品质和农艺形态特征方面与 NLR34449 相当或优于 NLR34449，并进行了多点试验。
