Rice blast: strategies and challenges for improving genetic resistance

Abstract

Rice blast, caused by the fungus Pyricularia oryzae L., is considered one of the main threats to world rice production. The development of resistant cultivars is one of the best and sustainable control alternatives. Plant breeding efforts have been accelerated by genetic mapping (linkage and associative) and marker assisted selection. On the other hand, genomic editing techniques, such as meganucleases (MNs), Zinc-finger nucleases (ZFNs), Transcription Activator-like Effector Nucleases (TALENs) and Clustered Regularly Interspaced Short Palindrome Repeats/CRISPR-associated protein 9 (CRISPR/Cas9), can be used to promote specific genetic modifications. Likewise, transgenics can also be used to manipulate specific genes. In this sense, this work aims to characterize rice blast and elucidate available biotechnological alternatives to accelerate the development of improved rice cultivars resistant to rice blast.

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

“…Note: 1-2 = resistant (R), 3 = moderately resistant (MR), 4-6 = susceptible (S) and 7-9 = highly susceptible (HS). In addition, it has become necessary to know and identify these genes, to be used in hybridization to transfer the resistance trait into new varieties [3,11]. In another context, the modern or new varieties are better to carry multiple resistance genes to display broad-spectrum and durable resistance in the field or gene accumulation and gene pyramiding.…”

“…Many pathogens attack the rice crop, causing diseases with different symptoms that vary from species to species [1,2]. However, the most devastating one is blast disease, caused by Magnaporthe oryzae, which infects the leaves and panicles results in a huge loss in yield [3]. The estimation of the yield losses was recorded from 5% to 70%, according to the severity of infection [4][5][6].…”

Understanding the Dynamics of Blast Resistance in Rice-Magnaporthe oryzae Interactions

“…The introgression of R and QTLs genes in rice is considered to be one of the best ways to control blast disease [ 305 ]. Therefore, deploying single or multiple QTLs that impart the partial resistance and non-race specificity is a priority in rice breeding nowadays [ 306 , 307 ]. Though there are more than 500 reported QTLs for blast resistance, only few of them have been deployed under field conditions.…”

Investigating Rice Blast Resistance Gene Distribution among Landrace Rice Varieties in Lower Northern Thailand for Improving Rice Cultivars

“…Pyricularia oryzae (Ascomycota, syn. Magnaporthe oryzae) [1] is one of the major fungal pathogens causing rice blast disease (RBD) worldwide [2]. Symptomatic RBD is appeared in many parts of rice seedlings (Oryza sativa L.), such as leaf, stem, and node, resulting in a severe reduction of growth development and yield of rice [3].…”