Dynamics of Race Structures of the Rice Blast Pathogen Population in Heilongjiang Province, China From 2006 Through 2015

Abstract

Rice blast caused by the fungus Magnaporthe oryzae is one of the most destructive diseases of rice. Its control through the deployment of host resistance genes would be facilitated by understanding the pathogen’s race structure. Here, dynamics of race structures in this decade in Heilongjiang province were characterized by Chinese differential cultivars. Two patterns of dynamics of the race structures emerged: both race diversity and population-specific races increased gradually between 2006 and 2011, but they increased much more sharply between 2011 and 2015, with concomitant falls in both the population-common races and dominant races. Four races (ZD1, ZD3, ZD5, and ZE1) were among the top three dominant races over the whole period, indicating that the core of the race structure remained stable through this decade. On the host side, the composition of resistance in the cultivar differential set could be divided in two: the three indica-type entries of the differential set expressed a higher level of resistance to the population of M. oryzae isolates tested than did the four japonica-type entries. The cultivars Tetep and Zhenlong 13 as well as two additional resistance genes α and ε were confirmed as the most promising donors of blast resistance for the local rice improvement programs. [Formula: see text]Copyright © 2019 The Author(s). This is an open-access article distributed under the CC BY-NC-ND 4.0 International license .

The Rice Blast Resistance Gene Pid Family has been Strictly Diverged into Indica and Japonica Subspecies

“…That is, the unique allelic structures of the three members of the Pid family have been mainly constructed by the genotype, d2-d3, exactly, Pid2-ZS_ Pid3-ZS, carried by the lineage in rice breeding programs in China since the 1960s. It was, again, concerned that updating the lineage would be the key to enlarge genetic diversities of rice cultivars in the next generation in China A further priority will be to identify the functional speci cities of the various Pid alleles by challenging near isogenic lines with a set of both indica and japonica races of the pathogen (Zhang et al 2017(Zhang et al , 2019Huang et al 2021).…”

“…The test was based on the formula where a and b represent the number of indica type entries scored as, respectively, harbouring or not harbouring a given allele or genotype, while c and d represent the same for the japonica type entries. N denotes the total number of alleles or genotypes detected for each Pid gene or genotype (Fernando et al 2018;Zhang et al 2019;Huang et al 2021). If all alleles derived from a given resistance gene, which was extremely diverged into indica group, then the resistance gene was de ned as indica type one, and that in turn called as japonica type one.…”

“…Magnaporthe oryzae Couch), the causative agent of the damaging disease rice blast (Dean et al 2012;Liu and Wang 2016;Zhang et al 2017Zhang et al , 2019Zhao et al 2018;Huang et al 2021). A wealth of genes determining resistance to this pathogen has supported the success of using breeding to provide a sustainable means of mitigating the damage caused by blast (He et al 2012;Zhai et al 2014;Deng et al 2017;Zhang et al 2017Zhang et al , 2019. The genetics of resistance largely follows the gene-for-gene principle, involving an interaction between a host's resistance gene and a matching avirulence gene in the pathogen (Flor 1971 Huang et al 2021).…”

“…As a result, following the mutation of matching avirulence genes, major gene-based resistances are prone to rapid breakdown. That in turn enable it to create a new genotype of resistance gene to overcome the emerged new race with its new resistance speci city(Zeigler et al 1995;Wu et al 2014;Wang et al 2017;Zhang et al 2017Zhang et al , 2019Zhao et al 2018; …”

Pathogenicity and population structure analysis of Pyricularia oryzae in different districts of Jiangsu province, China

“…The complexity of the genetic diversity of rice blast poses a great challenge in minimizing crop losses, which largely relies on the use of host resistance genes. Host resistance tends to be broken down due to high levels of genetic instability and diversity in pathogenic fungal populations (Zeigler et al, 1995;Mekwatanakarn et al, 2000;Wu et al, 2014;Wang et al, 2017;Zhang et al, , 2019 known that the R genes Piz, Pi2,Pi9,Pi40, and Pigm are localized at the Piz locus of the rice genome, and that alleles of the Piz locus play a key role in conferring resistance to P. oryzae (Zhou et al, 2006;Wu et al, 2015).…”