QTLs for Resistance to Major Rice Diseases Exacerbated by Global Warming: Brown Spot, Bacterial Seedling Rot, and Bacterial Grain Rot.

Ritsuko Mizobuchi,Hiroyuki Sato,Masahiro Yano,Shuichi Fukuoka,Seiya Tsushima

doi:10.1186/s12284-016-0095-4

Abstract

In rice (Oryza sativa L.), damage from diseases such as brown spot, caused by Bipolaris oryzae, and bacterial seedling rot and bacterial grain rot, caused by Burkholderia glumae, has increased under global warming because the optimal temperature ranges for growth of these pathogens are relatively high (around 30 °C). Therefore, the need for cultivars carrying genes for resistance to these diseases is increasing to ensure sustainable rice production. In contrast to the situation for other important rice diseases such as blast and bacterial blight, no genes for complete resistance to brown spot, bacterial seedling rot or bacterial grain rot have yet been discovered. Thus, rice breeders have to use partial resistance, which is largely influenced by environmental conditions. Recent progress in molecular genetics and improvement of evaluation methods for disease resistance have facilitated detection of quantitative trait loci (QTLs) associated with resistance. In this review, we summarize the results of worldwide screening for cultivars with resistance to brown spot, bacterial seedling rot and bacterial grain rot and we discuss the identification of QTLs conferring resistance to these diseases in order to provide useful information for rice breeding programs.

Highlights

Climate changes have widespread impacts on human life
Among these are pathogens that cause agriculturally important diseases such as sheath blight, caused by Rhizoctonia solani, brown spot (BS), caused by Bipolaris oryzae, and bacterial seedling rot (BSR) and bacterial grain rot (BGR), both caused by Burkholderia glumae, because the optimal temperature ranges for growth of these pathogens are relatively high
We focus on host plant resistance to BS, BSR and BGR

Summary

Introduction

Climate changes have widespread impacts on human life. The Intergovernmental Panel on Climate Change (IPCC) published the Fifth Assessment Report (AR5) in 2014 which provided a clear and up-to-date view of the current state of scientific knowledge relevant to climate change. By field observation without artificial inoculation during 3 years in different districts in Punjab state of North India, three cultivars were categorized as susceptible (Pannu et al 2006). A set of recombinant inbred lines (RILs) derived from a cross between ‘Tadukan’ (resistant) and ‘Hinohikari’ (susceptible) was used to identify QTLs conferring resistance to BS at the seedling stage in a greenhouse screen.

Results

Conclusion