Genetic analysis and molecular mapping of QTLs for resistance to rice black-streaked dwarf disease in rice.

Tong Zhou,Linlin Du,Guoliang Wang,Yongjian Fan,Lijiao Wang,Ying Lan,Yijun Zhou,Ying Wang,Cunyi Gao,Feng Sun

doi:10.1038/srep10509

Abstract

Rice black-streaked dwarf disease, caused by rice black-streaked dwarf virus (RBSDV), is transmitted by small brown planthoppers (Laodelphax striatellus Fallén, SBPH) and causes severe yield loss in epidemic years in China and other East Asian countries. Breeding for resistance to RBSDV is a promising strategy to control the disease. We identified Tetep that showed resistance to RBSDV using a field test and artificial inoculation test. An evaluation of the resistance mechanism revealed that Tetep was resistant to RBSDV but not to SBPH. Genetic analysis showed that the resistance of Tetep to RBSDV was controlled by quantitative trait loci (QTLs). Three new QTLs for RBSDV resistance were identified in this study, i.e., qRBSDV-3, qRBSDV-10 and qRBSDV-11. The LOD scores of qRBSDV-3, qRBSDV-10 and qRBSDV-11 were 4.07, 2.24 and 2.21, accounting for 17.5%, 0.3% and 12.4% of the total phenotypic variation, respectively. All the resistance loci identified in this study were associated with virus resistance genes. The alleles for enhancing resistance on chromosomes 3 and 11 originated from Tetep, whereas the other allele on chromosome 10 originated from a susceptible parent. The identified new resistance QTLs in this study are useful resources for efficiently breeding resistant rice cultivars to RBSDV.

Highlights

Non-preference 4.16 ± 0.943a 3.93 ± 0.617ab 2.59 ± 0.320bc 1.23 ± 0.039c resistance mechanisms to rival diseases, the mechanisms underlying the resistance have not yet been revealed to date
Researchers have tried to identify the genetic factors that control the resistance to rice black-streaked dwarf disease for a long time
These results suggested that rice might have developed multiple mechanisms of resistance to rice black-streaked dwarf disease during the long-term co-evolution among the virus, the plant and the vector

Summary

Introduction

Non-preference 4.16 ± 0.943a 3.93 ± 0.617ab 2.59 ± 0.320bc 1.23 ± 0.039c resistance mechanisms to rival diseases, the mechanisms underlying the resistance have not yet been revealed to date. We attempted to understand the mechanism and inheritance mode of resistance to rice black-streaked dwarf disease in the resistant cultivar Tetep. We performed a QTL analysis to map the resistance to the virus by generating a genetic linkage map and collecting resistance phenotypes in the progenies of a genetic cross between Tetep and the susceptible cultivar Huaidao No.[5].

Methods

Results

Conclusion