Quantitative evaluation of protective effect of Pb1 gene, conferring field resistance to rice panicle blast, using near-isogenic lines.
Quantitative evaluation of protective effect of Pb1 gene, conferring field resistance to rice panicle blast, using near-isogenic lines.
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DOI：
10.1270/jsbbr.7.75
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发表时间：
2005-01-01
期刊：
影响因子：
--
通讯作者：
Iwasaki, M.
中科院分区：
文献类型：
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作者：
Fujii, K.;Hayano-Saito, Y.;Iwasaki, M.
为定量评价从籼稻品种“莫丹”中提取的抗稻穗瘟病基因Pb1的保护作用。在2个试验点的稻田中，用3对Pb1基因位点的近等基因系（NILs）进行了2年的抗性试验，这些基因系是由日本水稻品种“Koganebare”（对不含Pb1基因的稻瘟病敏感）和“Tsukinohikari”（对含Pb1基因的稻瘟病具有抗性）杂交而成的约2000个重组自交系（RILs）。用Pb1基因与水稻条纹病毒抗性基因Stvb-i对“光光”（Koshihikari）进行评价，其保护效果为：保护效果=（不含Pb1的侵染部分率-含Pb1的侵染部分率）/（不含Pb1的侵染部分率）* 100。Pb1基因对稻瘟病的保护作用随着水稻植株生长阶段的推进而增强；叶（营养生长期）期<旗叶期<穗（生殖生长期）期。Pb1基因对患病粒率的年均保护值非常高（93），表明与不含Pb1基因的兄弟姐妹系相比，Pb1基因可将患病粒率降低至1/10以下。在稻瘟病有利条件下，含Pb1的NILs与不含Pb1的兄弟系的糙米穗产量之比为2.40:1-16.2:1，表明在稻瘟病不利条件下，NILs对稻瘟病相关的产量损失具有很高的保护作用，而在稻瘟病不利条件下，NILs的穗产量之比为0.78:1-1.29:1（(1.070.18):1）。在有利条件下，添加Pb1的亲本糙米头/毛率和千粒重显著高于未添加Pb1的亲本，蛋白质含量显著低于未添加Pb1的亲本。由此可见，在稻瘟病菌有利环境下，Pb1基因对稻米品质也表现出二级保护作用。
To evaluate quantitatively the protective effects of the Pb1 gene which is derived from an Indica rice variety "Modan" and confers field resistance to rice panicle blast, tests for blast resistance were conducted in paddy fields over a period of two years at two testing sites using three pairs of near-isogenic lines (NILs) for the Pb1 locus selected from about 2,000 recombinant inbred lines (RILs) which were developed from the cross between the Japanese rice cultivars "Koganebare" (susceptible to rice blast without Pb1 gene) and "Tsukinohikari" (resistant to the disease with Pb1). A NIL pair of cultivar "Koshihikari" for Pb1 and Stvb-i, a gene conferring resistance to rice stripe virus, was also used for the evaluation, in which the protective effect was given as follows: Protective effect=(rate of infected part without Pb1-rate of infected part with Pb1)/(rate of infected part without Pb1) * 100 The protective effect of the Pb1 gene against rice blast increased with the progression of the growth stages of the rice plants; leaf (vegetative growth) stage < flag leaf stage < panicle (reproductive growth) stage. The average protective value of the Pb1 gene for the percentage of diseased grains was very high (93) for each year, which showed that Pb1 could reduce the percentage of diseased grains to less than 1/10, compared with sib-lines without Pb1 gene. The head brown rice yield ratios of NILs with Pb1 to the sib-lines without Pb1 were 2.40:1-16.2:1 under conducive conditions for blast disease, revealing a very high protective effect on yield loss associated with panicle blast infection, while 0.78:1-1.29:1 ((1.070.18):1) under conditions less conducive to the disease. The values of the head/gross brown rice rate and thousand kernel weight in brown rice of the NILs with Pb1 under disease-conducive conditions, were significantly higher, while the protein content was significantly lower than the values of the sib-lines without Pb1, respectively. Thus, the Pb1 gene also showed a secondary protective effect on rice quality under the blast fungus-conducive environment.