scholarly journals Selection of Differential Isolates of Magnaporthe oryzae for Postulation of Blast Resistance Genes

2018 ◽  
Vol 108 (7) ◽  
pp. 878-884 ◽  
Author(s):  
W. W. Fang ◽  
C. C. Liu ◽  
H. W. Zhang ◽  
H. Xu ◽  
S. Zhou ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Magnaporthe Oryzae ◽  
Blast Resistance ◽  
Polymerase Chain Reaction Analysis ◽  
Colony Growth ◽  
Blast Disease ◽  
Avirulence Genes ◽  
Rice Varieties ◽  
Minimum Number ◽  
Blast Resistance Genes

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.

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 ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Oryza Sativa L ◽  
Blast Resistance ◽  
Gene Pyramiding ◽  
Climatic Conditions ◽  
Blast Disease ◽  
Selection Marker ◽  
Rice Varieties ◽  
Future Challenges ◽  
Blast Resistance Genes

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.

Mapping Blast Resistance Genes in Rice Varieties ‘Minghui 63’ and ‘M-202’

Plant Disease ◽  
2021 ◽  
Author(s):  
Yulin Jia ◽  
Melissa H Jia ◽  
Zongbu Yan
Keyword(s):  
Resistance Genes ◽  
Blast Resistance ◽  
Interval Mapping ◽  
Blast Disease ◽  
Chromosome 1 ◽  
Rice Breeding ◽  
Resistance Qtls ◽  
Rice Varieties ◽  
Short Period ◽  
Blast Resistance Genes

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.

scholarly journals Study of pathogenicity and genetic diversity of Magnaporthe oryzae isolated from rice hybrid Wuyou 308 and detection of resistance genes

2020 ◽  
Vol 56 (No. 3) ◽  
pp. 93-101
Author(s):  
Bo Lan ◽  
Ying-Qing Yang ◽  
Qiang Sun ◽  
Hong-Fan Chen ◽  
Jian Chen ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Blast Resistance ◽  
Rice Variety ◽  
Climatic Conditions ◽  
Blast Disease ◽  
Rice Varieties ◽  
Rice Blast Resistance ◽  
Rice Hybrid

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.

scholarly journals Rice Breeding in Russia Using Genetic Markers

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1580
Author(s):  
Elena Dubina ◽  
Pavel Kostylev ◽  
Margarita Ruban ◽  
Sergey Lesnyak ◽  
Elena Krasnova ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Target Genes ◽  
Blast Resistance ◽  
Soil Salinization ◽  
Water Flooding ◽  
Rice Varieties ◽  
Asian Rice ◽  
Southern Russia ◽  
Tolerance Gene ◽  
Blast Resistance Genes

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.

scholarly journals Identification of novel rice blast resistance alleles through sequence-based allele mining

2019 ◽  
Author(s):  
Ying Zhou ◽  
Fang Lei ◽  
Qiong Wang ◽  
Weicong He ◽  
Yuan Bin ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Rice Blast ◽  
Blast Resistance ◽  
Resistance Breeding ◽  
Economic Losses ◽  
The Novel ◽  
Allele Mining ◽  
Rice Varieties ◽  
Rice Blast Resistance ◽  
Blast Resistance Genes

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

scholarly journals A Genome-Wide Meta-Analysis of Rice Blast Resistance Genes and Quantitative Trait Loci Provides New Insights into Partial and Complete Resistance

2008 ◽  
Vol 21 (7) ◽  
pp. 859-868 ◽  
Author(s):  
Elsa Ballini ◽  
Jean-Benoît Morel ◽  
Gaétan Droc ◽  
Adam Price ◽  
Brigitte Courtois ◽  
...  
Keyword(s):  
Quantitative Trait Loci ◽  
Resistance Genes ◽  
Quantitative Trait ◽  
Rice Blast ◽  
Blast Resistance ◽  
Durable Resistance ◽  
Rice Genome ◽  
Blast Disease ◽  
Trait Loci ◽  
Blast Resistance Genes

The completion of the genome sequences of both rice and Magnaporthe oryzae has strengthened the position of rice blast disease as a model to study plant–pathogen interactions in monocotyledons. Genetic studies of blast resistance in rice were established in Japan as early as 1917. Despite such long-term study, examples of cultivars with durable resistance are rare, partly due to our limited knowledge of resistance mechanisms. A rising number of blast resistance genes and quantitative trait loci (QTL) have been genetically described, and some have been characterized during the last 20 years. Using the rice genome sequence, can we now go a step further toward a better understanding of the genetics of blast resistance by combining all these results? Is such knowledge appropriate and sufficient to improve breeding for durable resistance? A review of bibliographic references identified 85 blast resistance genes and approximately 350 QTL, which we mapped on the rice genome. These data provide a useful update on blast resistance genes as well as new insights to help formulate hypotheses about the molecular function of blast QTL, with special emphasis on QTL for partial resistance. All these data are available from the OrygenesDB database.

Frequencies and Variations of Magnaporthe oryzae Avirulence Genes in Hunan Province, China

Plant Disease ◽  
2021 ◽  
Author(s):  
Zhirong Peng ◽  
Ling Li ◽  
Shenghai Wu ◽  
Xiaolin Chen ◽  
Yinfeng Shi ◽  
...  
Keyword(s):  
Magnaporthe Oryzae ◽  
Blast Resistance ◽  
Hunan Province ◽  
Start Codon ◽  
Nucleotide Polymorphisms ◽  
Avirulence Genes ◽  
Rice Varieties ◽  
Synonymous Mutations ◽  
Pathogen Populations ◽  
Avr Genes

Rice blast caused by Magnaporthe oryzae poses significant threaten to rice production. For breeding and deploying resistant rice varieties, it is essential to understand the frequencies and genetic variations of avirulence (AVR) genes in the pathogen populations. In this study, 444 isolates were collected from Hunan Province, China in 2012, 2015, and 2016, and their pathogenicity was evaluated by testing them on monogenic rice lines carrying resistance (R) genes Pita, Pizt, Pikm, Pib, or Pi9. The frequencies of corresponding AVR genes AVRPizt, AVRPikm, AVRPib, AVRPi9, and AVRPita were characterized by amplification and sequencing these genes in the isolates. Both Pi9 and Pikm conferred resistance to over 75% of the tested isolates, while Pizt, Pita, and Pib were effective against 55.63%, 15.31%, and 3.15% of the isolates, respectively. AVRPikm and AVRPi9 were detected in 90% of the isolates and AVRPita, AVRPizt, and AVRPib were present in 26.12%, 66.22%, and 79% of the isolates, respectively. Sequencing of AVR genes showed that most mutations were single nucleotide polymorphisms (SNPs), transposon insertions, and insertion mutations. The variable sites of AVRPikm and AVRPita were mainly located in the coding sequence (CDS) regions, and most were synonymous mutations. A 494 bp Pot2 transposon sequence insertion was found at the 87 bp upstream of the start codon in AVRPib. Noteworthy, although no mutations were found in CDS of AVRPi9, a GC-rich inserted sequence of ~200 bp was found at the 1272 bp upstream of the start codon in three virulent isolates. As AVRPikm and AVRPi9 were widely distributed with low genetic variation in the pathogen population, Pikm and Pi9 should be promising genes for breeding rice cultivars with blast resistance in Hunan.

scholarly journals Combination of rice blast resistance genes in the genotypes of russian rice varieties with the use of marker assisted selection

2017 ◽  
Vol 15 (3) ◽  
pp. 54-63
Author(s):  
Pavel I. Kostylev ◽  
Elena V. Krasnova ◽  
Aleksandr A. Redkin ◽  
Elena V. Dubina ◽  
Zhanna M. Mukhina
Keyword(s):  
Resistance Genes ◽  
Marker Assisted Selection ◽  
Blast Resistance ◽  
Pcr Analysis ◽  
Rice Varieties ◽  
Rice Blast Resistance ◽  
Second Stage ◽  
Grain Productivity ◽  
Third Stage ◽  
Blast Resistance Genes

Grain productivity of rice is significantly reduced by dangerous disease – blast. Therefore, the development of resistant high yielding rice varieties with the Pi group of genes is important. Use of molecular markers linked with the loci of resistance significantly optimizes the breeding process. The purpose of the research is to develop rice lines combining 2-6 loci of resistance to blast: Pi-1, Pi-2, Pi-33, Pi-ta, Pi-b, Pi-40 by molecular marking. Materials and Methods. As donors of resistance genes foreign samples were used, recipient – Russian varieties. In the studies we used micro-satellites markers and PCR analysis. Results. In the first stage of the research as a result of hybridization domestic lines with genes Pi-l, Pi-2, Pi-33 were obtained. At the second stage – hybrids with all 3 genes were developed. In the third stage genes Pi-b and Pi-ta and on the fourth – Pi-40 were introduced. Conclusion. As a result, rice genotypes, combining 6 loci of blast resistance were developed with use of marker assisted selection.

Sign in / Sign up

Export Citation Format

Share Document