稻瘟病对常香粳1813产量和大米品质的影响

Effects of Rice Blast Disease on the Yield and Rice Quality of Changxiangjing 1813

稻瘟病菌Magnaporthe oryzae引起的稻瘟病可导致水稻大幅度减产,严重时减产40%~50%,威胁着全球的水稻生产和粮食安全。然而,目前稻瘟病菌对大米品质的影响鲜有报道。采用抗病香软米品种常香粳1813,鉴定其基因组中抗稻瘟病基因的分布情况,通过开展稻瘟病菌接种以及成熟期种子观察和千粒重、长宽比检测,进一步分析了大米的出糙率、精米率、垩白度、垩白率等加工品质参数和主要物质成分总蛋白、总脂肪、总淀粉和直链淀粉含量变化。结果表明:常香粳1813基因组含有Pid2、Pid3和Pib稻瘟病抗性基因,感染稻瘟病菌后,常香粳1813穗顶端出现瘪粒,中下部谷粒表面有明显的褐色病斑,千粒重显著下降,长宽比显著上升。感染稻瘟病菌后加工的大米色泽暗黄,出糙率、精米率显著下降,垩白率上升,且总蛋白含量显著上升,总脂肪、总淀粉和直链淀粉含量显著下降。这些结果表明稻瘟病菌对常香粳1813的种子、大米的产量和质量都有明显影响。

The rice blast disease caused by Magnaporthe oryzae could lead to the significant reduction in rice production,by 40%-50%in severe cases,which threatened the global rice production and food security.However,there were few reports about the effect of Magnaporthe oryzae on rice quality.The distribution of rice blast resistance genes in the genome of Changxiangjing 1813,a disease-resistant fragrant and soft rice variety,was identified.After the inoculation of Magnaporthe oryzae,the observation of seeds at the maturation period and the detection of thousand-grain weight and the ratio of length to width,the processing quality parameters of rice,such as the brown rice rate,milled rice rate,chalkiness degree and chalky percentage,as well as the changes of total protein,total fat,total starch and amylose contents were further analyzed.The results showed that the genome of Changxiangjing 1813 contained the rice blast resistance genes of Pid2,Pid3 and Pib.After being infected by Magnaporthe oryzae,the shriveled grains appeared at the top of the panicle of Changxiangjing 1813,and there were obvious brown spots on the surface of the grains in the middle and lower parts.The thousand-grain weight decreased significantly,and the ratio of length to width increased significantly.After the infection with Magnaporthe oryzae,the rice was dark and yellow in color,and the brown rice rate and milled rice rate was significantly decreased,while the chalky percentage was increased.Moreover,the content of total protein was significantly increased,and the contents of total fat,total starch and amylose were significantly decreased.These results indicated that the Magnaporthe oryzae had significant effect on the seed/rice yield and quality of Changxiangjing 1813.