Improving rice blast resistance of Feng39S through molecular marker-assisted backcrossing

Abstract

Background Rice blast caused by Magnaporthe oryzae is one of the most widespread biotic constraints that threaten rice production. Using major resistance genes for rice blast resistance improvement is considered to be an efficient and technically feasible approach to achieve optimal grain yield. Results We report here the introgression of the broad-spectrum blast resistance gene Pi2 into the genetic background of an elite PTGMS line, Feng39S, for enhancing it and its derived hybrid blast resistance through marker-assisted backcrossing (MABC) coupled with genomics-based background selection. Two PTGMS lines, designated as DB16206–34 and DB16206–38, stacking homozygous Pi2 were selected, and their genetic background had recurrent parent genome recovery of 99.67% detected by the SNP array RICE6K. DB16206–34 and DB16206–38 had high resistance frequency, with an average of 94.7%, when infected with 57 blast isolates over 2 years, and the resistance frequency of their derived hybrids ranged from 68.2% to 95.5% under inoculation of 22 blast isolates. The evaluation of results under natural blast epidemic field conditions showed that the selected PTGMS lines and their derived hybrids were resistant against leaf and neck blast. The characterizations of the critical temperature point of fertility-sterility alternation of the selected PTGMS lines, yield, main agronomic traits, and rice quality of the selected PTGMS lines and their hybrids were identical to those of the recurrent parent and its hybrids. DB16206–34/9311 or DB16206–38/9311 can be used as a blast-resistant version to replace the popular hybrid Fengliangyou 4. Likewise, DB16206–34/FXH No.1 or DB16206–38/FXH No.1 can also be used as a blast-resistant version to replace another popular hybrid Fengliangyou Xiang 1. Conclusions Our evaluation is the first successful case to apply MABC with genomics-based background selection to improve the blast resistance of PTGMS lines for two-line hybrid rice breeding.

Breeding and biotechnological interventions for trait improvement: status and prospects

“…For instance, NILs of drought-tolerant rice have been developed through introgression of root QTLs derived from a drought-tolerant japonica upland cultivar CT9993 into a lowland susceptible indica cultivar IR20 (Suji et al 2012 ). Yang et al ( 2019 ) had introgressed the blast resistance gene, Pi2 , into an elite line by coupling MABC with genomics-based background selection. Kang et al ( 2019 ) exploited the rapid generation advance system for expedited development of near-isogenic lines (NIL) from rice stripe virus resistant and susceptible parents, followed by MABC to develop a virus-resistant line in a short duration.…”

Superior japonica rice variety YJ144 with improved rice blast resistance, yield, and quality achieved using molecular design and multiple breeding strategies

“…Single resistance genes, though, cannot effectively deal with multiple pathotype infections simultaneously; thus, multiple studies used polymerized rice blast genes to improve the blast resistance of susceptible varieties (Jiang et al 2012;Zhao et al 2018), including enhanced Jin 23B and Kongyu 131 through Pi1 and Pi2 pyramiding, pyramiding blast resistance genes Piz5 and Pi54 into the elite Basmati rice restorer line PRR 78, and breeding the high-yielding and durable resistance rice variety Longliangyou 3189 by using Pigm (Koide et al 2010;Singh et al 2013;Deng et al 2017;Yang et al 2019;Yin et al 2021). However, it is challenging to pyramid multiple favorable genes because of the laborious molecular detection techniques and long breeding periods involved (Yang et al 2019). Anther culture technology produces haploid plants from pollen microspores that can become diploid either naturally or via treatment with active mitotic substances.…”

Superior japonica rice variety YJ144 with improved rice blast resistance, yield, and quality achieved using molecular design and multiple breeding strategies

“…Single resistance genes, though, cannot effectively deal with multiple pathotype infections simultaneously; thus, multiple studies used polymerized rice blast genes to improve the blast resistance of susceptible varieties (Jiang et al 2012 Yin et al 2021). However, it is challenging to pyramid multiple favorable genes because of the laborious molecular detection techniques and long breeding periods involved (Yang et al 2019). Anther culture technology produces haploid plants from pollen microspores that can become diploid either naturally or via treatment with active mitotic substances.…”