Confirming and Identifying New Loci for Rice Blast Disease Resistance using Magnaporthe oryzae Field Isolates in the US

Abstract

Quantitative trait loci (QTL) play important roles in controlling rice blast disease. In the present study, 10 field isolates of the races IA1, IB1, IB17, and IC1 of US rice blast fungus Magnaporthe oryzae collected in 1996 and 2009 were used to identify blast resistance QTL with a recombinant inbred line (RIL) population consisting of 227 F7 individuals derived from the cross of rice (Oryza sativa L.) cultivars Lemont and Jasmine 85. Jasmine 85 is an indica cultivar that is moderately resistant, and Lemont is a tropical japonica cultivar susceptible to rice blast in greenhouse inoculation. Disease reactions of the parents and RILs were evaluated under greenhouse conditions. A total of six resistance QTL, qBLR8, qBLR10‐1, qBLR10‐2, qBLR10‐3, qBLR12‐1, and qBLR12‐2, were identified on chromosomes 8, 10, and 12, respectively. Phenotypic variation, conditioned by these six resistance QTL, ranged from 5.37 to 39.18%. Among them, qBLR12‐1 and qBLR12‐2 provided the strongest resistance to the newest isolates of the most virulent race IA1 of M. oryzae. Three of these resistance QTL have been identified using different blast isolates in a previous study. qBLR10‐1, qBLR10‐2, and qBLR10‐3 have not been previously found in this cross. These confirmed and new resistance QTL will be useful for the development of rice cultivars with improved effective resistance to rice blast via a marker‐assisted selection (MAS) approach.

Genome-wide association mapping revealed numerous novel genomic loci for grain nutritional and yield-related traits in rice (Oryza sativa L.) landraces

“…Ying et al (2012) identified a QTL qOle8 for oleic acid in the proximity of RM1148 on chromosome-8 by analyzing an F 2 population. Later close linkage (4.4 cM) of RM25 and RM1148 was established by Xing et al (2015) during the tagging of a new rice blast resistance gene in a RIL population. Thus, identification of RM25 as a significantly associated marker for oleic acid content in these rice landrace has immense opportunity to use this marker for the MAS program in the future breeding for high oleic acid content in rice bran.…”

Conventional Breeding and Molecular Markers for Blast Disease Resistance in Rice (Oryza sativa L.)

“…6). Except for the population Sakha 104 × IRBL9-W the ratio was 3 positive: 1 negative with all the primers [51][52][53][54][55][56]. However, the data for F 2 generations were categorized into two groups according to segregation ratios.…”

Genetic Diversity Analysis and Molecular Characterization of Elite Rice Promising Lines for Yield, Blast Disease Resistance and Rice Stem Borer تحليل التنوع الوراثى والتوصيف الجزيئي لمحصول سلالات الارز المبشرة، ومقاومتها لمرض اللفحة وثاقبة ساق الارز

“…RM289, RM590 and RM202 related for (R-genes Pi 26(t), Piz (the most effective genes under this study) and R-gene Piy(t), respectively). The same markers were related for R-genes (Goncharova, et al,2020, Eizenga, et al,2009, Xing, et al, 2015and Wang, et al, 2014, RM163 and RM3394 related for identified blast resistance to blast genotype (Hasan, et al, 2018 andWang, et al, 2015), as show in Table ( 7). Six SSR markers (RM3392, RM289, RM6467, RM23001, RM205 and RM5313) were determined for grain yield of thirteen promising lines.…”