Evaluation of Guangxi common wild rice for resistance to brown planthopper using a new stem evaluation method

Abstract

AbstractBrown planthopper [BPH, Nilaparvata lugens (Stål)] is considered one of the most important pests of rice (Oryza sativa L.), which poses a serious threat to rice production. Identifying resistant Oryza germplasm can provide reliable accessions for breeding BPH resistant rice cultivars. In this study, the stem evaluation method (SEM) was first applied to identify the BPH resistance of 1,221 accessions of common wild rice (O. rufipogon Griff.) collected from three different regions of Guangxi Province, China. From this screening, 58 BPH resistant accessions were screened a second time, with 33 accessions ultimately identified as stable, highly resistant germplasm as confirmed by a third identification at the adult‐plant stage. The distribution of the 58 BPH‐resistant common wild rice accessions varies significantly from region to region. Genotypic analyses based on 42 simple sequence repeat (SSR) markers revealed that these 58 BPH‐resistant accessions were genetically diverse, reflecting the rich genetic diversity reported in Guangxi common wild rice. Furthermore, results verified that the SEM is efficient for rapid and accurate screening of BPH‐resistant germplasm, especially when a limited number of seeds are available or elite breeding lines need to be screened immediately. Also, SEM is the best method for evaluating BPH resistance at the adult stage because fewer insects are needed, and it is possible to repeat the evaluation in the same crop season. The 33 resistant rice accessions are a potential source of novel BPH resistance genes for developing cultivars with improved BPH resistance.