Genome-wide design to breed high-yield, high-quality, disease-resistant japonica rice

Recently, Li Aihong's team from the Lixiahe Regional Agricultural Science Research Institute in Jiangsu, together with Ning Joseph's team from the Institute of Plant Protection of the Chinese Academy of Agricultural Sciences, and Yangzhou University's Yang Zefeng team published a research paper in "Genome Biology"
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The study collected 198 japonica rice varieties promoted on a large scale in Jiangsu, Zhejiang, and Shandong provinces and performed genome resequencing analysis to analyze the genomic information of excellent japonica rice varieties in central China and the genetic law of dominant gene loci; And on this basis, through genomic design and breeding strategies, excellent rice lines with high yield, high quality and disease resistance have been created
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Rice blast caused by rice blast infection infecting rice is the most serious fungal disease affecting rice production in China.
Global climate change and frequent extreme climates have exacerbated the occurrence of rice blast and seriously affected food security
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Cultivating disease-resistant varieties is the most economical, effective and environmentally friendly strategy for the prevention and control of rice blast, and is of great significance for ensuring food production, people's needs, and safe production

Yield, quality, and rice blast resistance are complex traits controlled by multiple genes and have modular characteristics.
In breeding practice, strengthening the selection of a trait will often lead to the loss of other traits' molecular modules, resulting in "high yield and no disease resistance.
" "The phenomenon of "high-quality but not high-yield" is widespread
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Therefore, how to achieve high-yield, high-quality, disease-resistant and multi-character aggregation is a key scientific problem to be solved urgently in molecular design breeding

Central China is one of the most important main producing areas of japonica rice in China, with an annual japonica rice planting area of ​​nearly 3 million hectares, which is of great significance for ensuring China’s food security
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However, the rules of genetic improvement and the use of favorable genotypes in this region are still unclear

At the same time, the study found that the amylose content of high-yield rice varieties bred in the past ten years showed a significant decline, and the resistance level of rice blast showed a downward trend, indicating that there is a significant negative correlation between rice quality and resistance to rice blast
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Through the construction of a genome-wide linkage map, it was found that the susceptible allele linkage (Hap1 type) of the Piz locus on chromosome 6 is a key point that restricts the balance of yield, quality, and disease resistance

To sum up, the research system excavated the breeding selection imprints of the improvement of japonica rice varieties in Central China, analyzed the genetic rules of the key genes for yield, quality and disease resistance in the process of variety selection, in order to achieve the selection of high-yield, high-quality, disease-resistant rice varieties.

The study also shows that the comprehensive use of genomics technology to analyze modern variety improvement laws and key gene/allele utilization is an effective method to achieve precise and efficient molecular design breeding.

Related paper information: https://doi.