Institute of Biotechnology, Professor Jayashanker Telangana State Agriculture University, Hyderabad, 500030, India.
Department of Biotechnology, ICAR-Indian Institute of Rice Research, Hyderabad, 500030, India.
Mol Biol Rep. 2024 May 6;51(1):619. doi: 10.1007/s11033-024-09549-8.
Rice blast and bacterial leaf blight (BLB) are the most limiting factors for rice production in the world which cause yield losses typically ranging from 20 to 30% and can be as high as 50% in some areas of Asia especially India under severe infection conditions.
An improved line of Tellahamsa, TH-625-491 having two BLB resistance genes (xa13 and Xa21) and two blast resistance genes (Pi54 and Pi1) with 95% Tellahamsa genome was used in the present study. TH-625-491 was validated for all four target genes and was used for backcrossing with Tellahamsa. Seventeen IBCF plants heterozygous for all four target genes, 19 IBCF plants homozygous for four, three and two gene combinations and 19 IBCF plants also homozygous for four, three and two gene combinations were observed. Among seventeen IBCF plants, IBCF-62 plant recorded highest recurrent parent genome (97.5%) covering 75 polymorphic markers. Out of the total of 920 IBCF plants screened, 19 homozygous plants were homozygous for four, three and two target genes along with bacterial blight resistance. Background analysis was done in all 19 homozygous IBCF plants possessing BLB resistance (possessing xa13, Xa21, Pi54 and Pi1 in different combinations) with five parental polymorphic SSR markers. IBCF-62-515 recovered 98.5% recurrent parent genome. The four, three and two gene pyramided lines of Tellahamsa exhibited varying resistance to blast.
Results show that there might be presence of antagonistic effect between bacterial blight and blast resistance genes since the lines with Pi54 and Pi1 combination are showing better resistance than the combinations with both bacterial blight and blast resistance genes.
稻瘟病和细菌性条斑病（BLB）是全球范围内限制水稻生产的最主要因素，通常会导致 20%至 30%的产量损失，在某些地区，特别是印度，在严重感染的情况下，损失甚至高达 50%。
本研究使用了经过改良的 Tellahamsa 品系 TH-625-491，该品系含有两个 BLB 抗性基因（xa13 和 Xa21）和两个稻瘟病抗性基因（Pi54 和 Pi1），其 Tellahamsa 基因组的 95%得到了保留。TH-625-491 经过了所有四个目标基因的验证，并被用于与 Tellahamsa 的回交。观察到 17 株 IBCF 植株在所有四个目标基因上均为杂合子，19 株 IBCF 植株在四个、三个和两个基因组合上均为纯合子，19 株 IBCF 植株也在四个、三个和两个基因组合上均为纯合子。在 17 株 IBCF 植株中，IBCF-62 植株记录的轮回亲本基因组最高（97.5%），涵盖了 75 个多态性标记。在总共筛选的 920 株 IBCF 植株中，有 19 株纯合植株同时携带四个、三个和两个目标基因以及细菌性条斑病抗性。对所有携带 BLB 抗性（xa13、Xa21、Pi54 和 Pi1 不同组合）的 19 株纯合 IBCF 植株进行了背景分析，使用了五个亲本多态性 SSR 标记。IBCF-62-515 恢复了 98.5%的轮回亲本基因组。Tellahamsa 的四个、三个和两个基因叠加系表现出对稻瘟病的不同抗性。
结果表明，细菌性条斑病和稻瘟病抗性基因之间可能存在拮抗作用，因为含有 Pi54 和 Pi1 组合的系比同时含有细菌性条斑病和稻瘟病抗性基因的组合表现出更好的抗性。
