Genome-wide association study and linkage analysis on resistance to rice black-streaked dwarf virus disease

Abstract As one of the most important part of the ideal plant type of japonica rice, leaf shape affects the photosynthesis and carbohydrate accumulation directly. Mining and using new leaf shape related genes/QTLs can further enrich the theory of molecular breeding and accelerate the breeding process of japonica rice. In the present study, 2 RILs and a natural population with 295 japonica rice varieties were used to map QTLs for flag leaf length (FL), flag leaf width (FW) and flag leaf area (FLA) by linkage analysis and genome-wide association study (GWAS) through 2 years. A total of 64 QTLs were detected by 2 ways, and pleiotropic QTLs qFL2 (Chr2_33,332,579) and qFL10 (Chr10_10,107,835; Chr10_10,230,100) consisted of overlapping QTLs mapped by linkage analysis and GWAS through 2 years were identified. The candidate genes LOC_Os02g54254, LOC_Os02g54550, LOC_Os10g20160, LOC_Os10g20240, LOC_Os10g20260 were obtained, filtered by linkage disequilibrium (LD), and haplotype analysis. LOC_Os10g20160 (SD-RLK-45) showed outstanding characteristics in quantitative real-time PCR (qRT-PCR) analysis in leaf development period, belongs to S-domain receptor-like protein kinases gene and probably to be a main gene regulating flag leaf width of japonica rice. The results of this study provide valuable resources for mining the main genes/QTLs of japonica rice leaf development and molecular breeding of japonica rice ideal leaf shape.

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Genome-wide Association Study on Resistance to Rice Black-streaked Dwarf Disease Caused by Rice Black-streaked Dwarf Virus

Plant Disease ◽

10.1094/pdis-10-19-2263-re ◽

2020 ◽

Author(s):

Qing Liu ◽

Guofang Lan ◽

Yajun Zhu ◽

Kai Chen ◽

Congcong Shen ◽

...

Keyword(s):

Association Study ◽

Genome Wide Association Study ◽

Genome Wide Association ◽

Dwarf Virus ◽

Nucleotide Polymorphisms ◽

Genome Wide ◽

Resistant Varieties ◽

Close Phylogenetic Relationship ◽

The Difference ◽

Dwarf Disease

Rice black-streaked dwarf disease (RBSDD) caused by rice black-streaked dwarf virus (RBSDV) is one of the most destructive viral diseases of rice. Thus, it is imperative that resistant rice germplasms are screened for novel RBSDV-resistant genes. The RBSDV resistance of a diverse global collection comprising 1,953 rice accessions was evaluated under natural conditions across 3 years. The average disease incidences of the Xian/indica (XI) subgroup were significantly lower than those of the Geng/japonica (GJ) subgroup. Interestingly, most XI-1A accessions in the Xian subgroup were significantly more susceptible than XI-1B accessions, even though XI-1A and XI-1B have a close phylogenetic relationship. Four Xian accessions stably and highly resistant to RBSDV were consistently identified in 2 years. Ten genomic regions (GRs) with 147 single nucleotide polymorphisms associated with RBSDV resistance were detected by a single-locus genome-wide association study (GWAS), of which five were repeatedly identified in a multi-locus GWAS. Two previously reported GRs, grRBSDV-6.1 and grRBSDV-6.3, which were repeatedly detected as stably and highly associated with RBSDV resistance, contained 17 and 7 genes, respectively, with significant differences of resistance among haplotypes. Haplotype analyses of the candidate genes LOC_Os06g03150 in grRBSDV-6.1 and LOC_Os06g31190 in grRBSDV-6.3 suggested that the former gene is mainly associated with the differentiation of resistance within the Xian subgroup and the latter gene mainly explains the difference in the resistance between Xian and Geng. Another three novel resistance GRs (grRBSDV-1.1, grRBSDV-7.1, and grRBSDV-9.1) were identified. Our findings may enhance the application of disease-resistant rice germplasms for breeding RBSDV-resistant varieties.

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Combined Linkage Analysis and Genome-wide Association Study Reveal QTLs and Candidate Genes Conferring Genetic Control of Prolificacy Trait in Maize

10.20944/preprints202101.0185.v1 ◽

2021 ◽

Author(s):

Zhao Wang ◽

Jingyang Gao ◽

Yunmeng Li ◽

Jemim Razia sultana ◽

Yifan Luan ◽

...

Keyword(s):

Linkage Analysis ◽

Association Study ◽

Candidate Genes ◽

Genome Wide Association Study ◽

Genetic Research ◽

Significant Snps ◽

Genome Wide Association ◽

Pcr Analysis ◽

Genome Wide ◽

Ethylene Signaling Pathway

For the different harvest targets, the requirement for the prolificacy trait of maize was also different, so prolificacy is of great significance for modern production. Although some QTLs and genes associated with prolificacy in teosinte have been reported, the genetic mechanism of prolificacy in maize has not been fully elucidated. In this study, two RIL populations and GWAS population were used to genetic research of prolificacy trait in maize, with multi-environment. Combine linkage analysis and Genome-wide association study has identified a total of 13 QTLs and 8 significant SNPs. There were two genes related to tissue differentiation in the stable QTL qP9-2, and two significant SNPs corresponding to three genes were in QTL qP5-1 and QTL qP7-1, respectively. Four candidate genes GRMZM2G317262, GRMZM2G317584, GRMZM5G882364 and GRMZM2G141679 were finally screened out by qRT-PCR analysis. Based on the function of candidate genes, ethylene signaling pathway plays an important role in the formation of prolificacy in maize. It has deepened our understanding of the formation mechanism of prolificacy and laid a foundation for breeding new varieties with various prolificacy in maize.

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