scholarly journals Rice Blast Disease in India: Present Status and Future Challenges

2021 ◽  
Author(s):  
Deepak Chikkaballi Annegowda ◽  
Mothukapalli Krishnareddy Prasannakumar ◽  
Hirehally Basavarajegowda Mahesh ◽  
Chethana Bangera Siddabasappa ◽  
Pramesh Devanna ◽  
...  

Rice (Oryza sativa L.) is the staple food of the majority of Indians, and India is both the major producer and consumer of rice. Rice cultivation in India is confronted with diverse agro-climatic conditions, varying soil types, and several biotic and abiotic constraints. Among major fungal diseases of Rice in India, the blast caused by Magnaporthe oryzae is the most devastating disease, with the neck blast being the most destructive form. Most of the blast epidemic areas in India have been identified with a mixture of races blast fungus resulting in the resistance breakdown in a short period. At present, a more significant number of the rice varieties cultivated in India were bred by conventional breeding methods with blast resistance conferred by a single resistance gene. Therefore, the blast disease in India is predominantly addressed by the use of ecologically toxic fungicides. In line with the rest of the world, the Indian scientific community has proven its role by identifying several blast resistance genes and successfully pyramiding multiple blast resistance genes. Despite the wealth of information on resistance genes and the availability of biotechnology tools, not a great number of rice varieties in India harbor multiple resistance genes. In the recent past, a shift in the management of blast disease in India has been witnessed with a greater focus on basic research and modern breeding tools such as marker-assisted selection, marker-assisted backcross breeding, and gene pyramiding.

Plant Disease ◽  
2021 ◽  
Author(s):  
Yulin Jia ◽  
Melissa H Jia ◽  
Zongbu Yan

Rice blast disease caused by the fungus Magnaporthe oryzae (syn. M. grisea) is one of the most lethal diseases for sustainable rice production worldwide. Blast resistance mediated by major resistance genes are often broken-down after a short period of deployment, while minor blast resistance genes, each providing a small effect on disease reactions, are more durable. In the present study, we first evaluated disease reactions of two rice breeding parents ‘Minghui 63’ and ‘M-202’ with 11 US blast races, IA45, IB1, IB45, IB49, IB54, IC1, IC17, ID1, IE1, IG1, and IH1 commonly found under greenhouse conditions using a category disease rating resembling infection types under field conditions. ‘Minghui 63’ exhibited differential resistance responses in comparison with that of ‘M-202’ to the tested blast races. A recombinant inbred line (RIL) population of 275 lines from a cross between ‘Minghui 63’ and ‘M-202’ was also evaluated with the above mentioned blast races. The population was genotyped with 156 simple sequence repeat (SSR) and insertion and deletion (Indel) markers. A linkage map with a genetic distance of 1022.84 cM was constructed using inclusive composite interval mapping (ICIM) software. A total of 10 resistance QTLs, eight from ‘Minghui 63’ and two from ‘M-202’, were identified. One major QTL, qBLAST2 on chr 2, was identified by seven races/isolates. The remaining nine minor resistance QTLs were mapped on chromosome 1, 3, 6, 9, 10, 11 and 12. These findings provide useful genetic markers and resources to tag minor blast resistance genes for marker assisted selection in rice breeding program and for further studies of underlying genes.


2018 ◽  
Vol 108 (7) ◽  
pp. 878-884 ◽  
Author(s):  
W. W. Fang ◽  
C. C. Liu ◽  
H. W. Zhang ◽  
H. Xu ◽  
S. Zhou ◽  
...  

A set of differential isolates of Magnaporthe oryzae is needed for the postulation of blast resistance genes in numerous rice varieties and breeding materials. In this study, the pathotypes of 1,377 M. oryzae isolates from different regions of China were determined by inoculating detached rice leaves of 24 monogenic lines. Among them, 25 isolates were selected as differential isolates based on the following characteristics: they had distinct responses on the monogenic lines, contained the minimum number of avirulence genes, were stable in pathogenicity and conidiation during consecutive culture, were consistent colony growth rate, and, together, could differentiate combinations of the 24 major blast resistance genes. Seedlings of rice cultivars were inoculated with this differential set of isolates to postulate whether they contain 1 or more than 1 of the 24 blast resistance genes. The results were consistent with those from polymerase chain reaction analysis of target resistance genes. Establishment of a standard set of differential isolates will facilitate breeding for blast resistance and improved management of rice blast disease.


2020 ◽  
Vol 56 (No. 3) ◽  
pp. 93-101
Author(s):  
Bo Lan ◽  
Ying-Qing Yang ◽  
Qiang Sun ◽  
Hong-Fan Chen ◽  
Jian Chen ◽  
...  

To understand the cause of loss of rice blast resistance, we studied the pathogenicity of Magnaporthe oryzae strains isolated from rice hybrid Wuyou 308 and evaluated its resistance genes. A total of 62 M. oryzae strains were isolated and tested in 7 Chinese rice varieties with varying degrees of resistance to rice blast and 30 blast-resistant monogenic lines. Fourteen physiological races of M. oryzae were identified: 8.55% belonging to the ZA group, 86.67% to the ZB group, and 5.00% to the ZC group. ZB15 was the most abundant race (45.00%). Five resistance genes, Pi-3(1), Pi-z5, Pi-k, Pi-kp(C), and Pi-k(C), conferred good resistance to the 62 strains, with resistance frequencies of 95.56, 91.11, 88.89, 82.22, and 82.22%, respectively. In contrast, Pi-a(2) had a resistance frequency of 0%. The hybrid combination Wuyou 308 was found to carry Pi-ta and Pi-b genes. Because Pi-ta and Pi-b both showed low resistance frequencies to M. oryzae isolated from Jiangxi, the hybrid rice variety Wuyou 308 could be infected by most of the 62 M. oryzae strains. The emergence and spread of rice blast disease in Wuyou 308 may thus be difficult to avoid when climatic conditions are favourable.


2011 ◽  
Vol 123 (1) ◽  
pp. 19-27 ◽  
Author(s):  
Yohei Koide ◽  
Leodegario A. Ebron ◽  
Hiroshi Kato ◽  
Hiroshi Tsunematsu ◽  
Mary Jeanie Telebanco-Yanoria ◽  
...  

2020 ◽  
Vol 175 ◽  
pp. 01008
Author(s):  
Nataliya Vozhzhova ◽  
Elena Krasnova ◽  
Elena Ionova

The current paper has considered the challenge of breeding of rice lines adapted to the climatic conditions of the Southern Federal District of Russia by pyramiding a complex of Pi-1, Pi-2, Pi-33, Pi-ta and Pi-b rice blast resistance genes which is efficient in the southern part of Russia. The control of the resistance genes present in the breeding material was carried out using a marker-associated selection (MAS). The purpose of the current study was to identify the Pi-1, Pi-2, Pi-33, Pi-ta, and Pi-b rice blast resistance genes in the rice samples developed in the laboratory of rice breeding and seed production of the FSBSI “Agricultural Research Center “Donskoy” to identify valuable genotypes. The screening of 689 breeding samples of rice resulted in identification of the allelic state of the Pi-1, Pi-2, Pi-33, Pi-ta and Pi-b rice blast resistance genes, and the genotypes with functional alleles of these genes and their combinations. There were identified 19 breeding samples of rice possessing a combination of 4 functional alleles of rice blast resistance genes in various combinations. The identified rice samples are valuable genetic material and are recommended to use as the sources of rice blast resistance in the breeding process.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1580
Author(s):  
Elena Dubina ◽  
Pavel Kostylev ◽  
Margarita Ruban ◽  
Sergey Lesnyak ◽  
Elena Krasnova ◽  
...  

The article concentrates on studying tolerance to soil salinization, water flooding, and blast in Russian and Asian rice varieties, as well as hybrids of the second and third generations from their crossing in order to obtain sustainable paddy crops based on domestic varieties using DNA markers. Samples IR 52713-2B-8-2B-1-2, IR 74099-3R-3-3, and NSIC Rc 106 were used as donors of the SalTol tolerance gene. Varieties with the Sub1A locus were used as donors of the flood resistance gene: Br-11, CR-1009, Inbara-3, TDK-1, and Khan Dan. The lines C101-A-51 (Pi-2), C101-Lac (Pi-1, Pi-33), IR-58 (Pi-ta), and Moroberekan (Pi-b) were used to transfer blast resistance genes. Hybridization of the stress-sensitive domestic varieties Novator, Flagman, Virazh, and Boyarin with donor lines of the genes of interest was carried out. As a result of the studies carried out using molecular marking based on PCR in combination with traditional breeding, early-maturing rice lines with genes for resistance to salinity (SalTol) and flooding (Sub1A), suitable for cultivation in southern Russia, were obtained. Introgression and pyramiding of the blast resistance genes Pi-1, Pi-2, Pi-33, Pi-ta, and Pi-b into the genotypes of domestic rice varieties were carried out. DNA marker analysis revealed disease-resistant rice samples carrying 5 target genes in a homozygous state. The created rice varieties that carry the genes for blast resistance (Pentagen, Magnate, Pirouette, Argamac, Kapitan, and Lenaris) were submitted for state variety testing. The introduction of such varieties into production will allow us to avoid epiphytotic development of the disease, preserving the biological productivity of rice and obtaining environmentally friendly agricultural products.


2019 ◽  
Author(s):  
Ying Zhou ◽  
Fang Lei ◽  
Qiong Wang ◽  
Weicong He ◽  
Yuan Bin ◽  
...  

Abstract Background: As rice ( Oryza sativa ) is the staple food of more than half the world’s population, rice production contributes greatly to global food security. Rice blast caused by the fungus M agnaporthe oryzae is a devastating fungal disease of rice, affecting yield and grain quality and resulting in substantial annual economic losses. Because the fungus evolves rapidly,, resistance conferred by most of the single blast race resistance genes is often broken after a few years of intensive agricultural use. Effective resistance breeding in rice therefore requires continual enrichment of the reservoir of resistance genes and alleles. Seed banks represent a rich source of genetic diversity; however, they have not been extensively used to identify novel genes and alleles. Results: We carried out a large-scale screen for novel blast resistance alleles in 1883 rice varieties from major rice producing areas across China. Of these, 107 varieties showed at least moderate resistance to natural infection by rice blast at rice blast nurseries in Enshi and Yichang, Hubei Province. Using sequence-based allele mining to amplify and clone the allelic variants of major rice blast resistance genes at the Pi2/9/gm/zt locus of chromosome 6 from the 107 blast-resistant varieties, we identified 13 novel blast resistance alleles. We then used controlled infections to assess the resistance of rice varieties carrying the novel alleles to 34 single rice blast isolates from Hubei, Guangdong, Jiangsu, Hunan, Jangxi, Sichuan, Heilongjiang, and Fujin Provinces. The varieties identified as being resistant in the nursery trials showed varied disease responses when infected with the single blast isolates, suggesting that the novel Pi2/9/gm/zt alleles vary in their blast resistance spectra. Some of the newly identified alleles have unique single nucleotide polymorphisms (SNPs), insertions, or deletions, in addition to polymorphic residues that are shared between the different alleles. Conclusions: These alleles expand the allelic series of blast resistance genes, enriching the genetic resource for rice blast resistance breeding programs and for studies aimed at deciphering rice–rice blast molecular interactions. Key words : Pi9 , R-genes, Nucleotide diversity, Gene conversion, Resistance gene alleles, Rice blast


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