Detection of Bacterial Leaf Blight Resistance Genes in Indigenous Glutinous Rice Landraces

T Thanh,P.H Ton,K.H Trung,L.T Nghia,P.B Hien,N.T Duong,T.V Hai,Tran Dang Khanh,V.D Hai,D.M Trung,N.T Luong

doi:10.18052/www.scipress.com/jhpr.2.1

Abstract

Bacterial leaf blight disease (BLB) caused by Xanthomonas oryzae pv is one of the most widespread devastating diseases of rice worldwide. In this study, a total of 86 indigenous glutinous rice landraces were examined for BLB resistant genes included Xa4, xa5, and Xa7 by using molecular markers. The results indicated that 37 samples carrying resistant genes, in which Xa4 was found in 11 samples, xa5 determined in 6 samples, Xa7 was in 19 samples, respectively. However, both of Xa7 and Xa4 were observed in only one sample. The resistant level against 10 bacterial strains carrying the resistant genes was also evaluated. We found that the number 6, 9, and 8 out of the 10 bacterial strains were resistant to the landraces which carried the Xa4, xa5, and Xa7. The bacterial strain number 5 was revealed highly toxic, causing infection of all samples. The agronomical traits, yield and yield components of 37 rice landraces included the resistant genes (Xa4, xa5 and Xa7) were evaluated. Our findings may provide useful genetic sources in indigenous glutinous rice landraces to further develop BLB resistant rice lines via molecular breeding program.

Highlights

Bacterial leaf blights (BLB) disease in rice caused by Xanthomonas oryzae pv.oryzae bacterial, and is one of the most widespread devastating diseases in all rice-cultivating areas of the world
In order to exploit them for rice breeding, it is initially examine for BLB resistant genes
According to report of Ton et al [5], Xa4 gene was determined the resistance to 6/10 leaf blight bacterial strains in the nothern Vietnam

Summary

Introduction

Bacterial leaf blights (BLB) disease in rice caused by Xanthomonas oryzae pv.oryzae bacterial, and is one of the most widespread devastating diseases in all rice-cultivating areas of the world. If the disease becomes serious, rice yield can be totally lost. In rice producing countries in Asia, millions of hectares of rice paddies have seriously influenced yearly by infestation of BLB. According to the report of MARD (2015) [1] BLB was caused severe infestation across the country up to 11.921 ha in both Mekong and Red River Deltas. Total BLB affected areas in south provinces were 7.069 ha, increased 2.129 ha comparing in 2016 and 110 ha were severely lost [2] (MARD, 2017). Using the resistant varieties are considered as the most feasible solution, which could help for environmentalfriendly and possibly produce safety products instead of using agrochemical pesticides. In order to successfully improve BLB resistant rice varieties, the genetic sources of rice landraces play a key role in controlling this disease

Objectives

Methods

Results

Conclusion