Evaluation of Resistance of US Rice Breeding Lines to the Rice Blast Pathogen

The objective of this work was to evaluate the resistance spectra of six elite breeding lines of rice, developed for improved yield and grain quality, in inoculation tests in the greenhouse and in the field. Forty-six isolates of Pyricularia grisea collected from the cultivar Primavera, 31 from the cultivar Maravilha and 19 from six elite breeding lines, totaling 96 were utilized for inoculations. Out of 11 international and 15 Brazilian pathotypes, IC-1, IB-9, and BD-16, respectively, were identified as most frequent isolates collected from the cultivar Primavera. The isolates retrieved from Maravilha belong to four international and 11 Brazilian pathotypes, the predominant ones being IB-9 and IB-49 and BB-1 and BB-21, respectively. Lines CNAs 8711 and CNAs 8983 showed resistant reaction to all test isolates from Maravilha, while CNAs 8983 was susceptible to three isolates of Primavera pertaining to the pathotype IC-1. A majority of isolates exhibiting compatible reaction to Primavera were incompatible to Maravilha and vice-versa.Field assessment of rice blast utilizing the area under disease progress curve as a criterion for measuring disease severity showed significant differences among the six breeding lines. The isolates of P. grisea exhibiting differential reaction on breeding lines can be utilized in pyramiding resistance genes in new upland rice cultivars.

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Drought tolerant rice breeding lines developed for rainfed lowland areas

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/423/1/012019 ◽

2020 ◽

Vol 423 ◽

pp. 012019

Author(s):

A Hairmansis ◽

Yullianida ◽

R Hermanasari ◽

A P Lestari ◽

P Sasmita ◽

...

Keyword(s):

Rice Breeding ◽

Breeding Lines ◽

Drought Tolerant ◽

Rainfed Lowland

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Genotyping-by-Sequencing-Based Genetic Analysis of African Rice Cultivars and Association Mapping of Blast Resistance Genes Against Magnaporthe oryzae Populations in Africa

Phytopathology ◽

10.1094/phyto-12-16-0421-r ◽

2017 ◽

Vol 107 (9) ◽

pp. 1039-1046 ◽

Cited By ~ 4

Author(s):

Emmanuel M. Mgonja ◽

Chan Ho Park ◽

Houxiang Kang ◽

Elias G. Balimponya ◽

Stephen Opiyo ◽

...

Keyword(s):

Genetic Diversity ◽

Association Mapping ◽

Magnaporthe Oryzae ◽

Rice Blast ◽

Blast Resistance ◽

Genotyping By Sequencing ◽

Rice Breeding ◽

Rice Cultivars ◽

R Genes ◽

African Rice

Understanding the genetic diversity of rice germplasm is important for the sustainable use of genetic materials in rice breeding and production. Africa is rich in rice genetic resources that can be utilized to boost rice productivity on the continent. A major constraint to rice production in Africa is rice blast, caused by the hemibiotrophic fungal pathogen Magnaporthe oryzae. In this report, we present the results of a genotyping-by-sequencing (GBS)-based diversity analysis of 190 African rice cultivars and an association mapping of blast resistance (R) genes and quantitative trait loci (QTLs). The 190 African cultivars were clustered into three groups based on the 184K single nucleotide polymorphisms generated by GBS. We inoculated the rice cultivars with six African M. oryzae isolates. Association mapping identified 25 genomic regions associated with blast resistance (RABRs) in the rice genome. Moreover, PCR analysis indicated that RABR_23 is associated with the Pi-ta gene on chromosome 12. Our study demonstrates that the combination of GBS-based genetic diversity population analysis and association mapping is effective in identifying rice blast R genes/QTLs that contribute to resistance against African populations of M. oryzae. The identified markers linked to the RABRs and 14 highly resistant cultivars in this study will be useful for rice breeding in Africa.

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Irrigated and Rain-Fed Lowland Rice Breeding in Uganda: A Review

10.5772/intechopen.97157 ◽

2021 ◽

Author(s):

Jimmy Lamo ◽

David Ochan ◽

Desta Abebe ◽

Zelalem Zewdu Ayalew ◽

Anna Mlaki ◽

...

Keyword(s):

Rice Blast ◽

Amylose Content ◽

Second Phase ◽

Rice Yellow Mottle Virus ◽

Rice Varieties ◽

Breeding Lines ◽

Third Phase ◽

Yellow Mottle ◽

Breeding Efficiency ◽

Selection Of

Since introduction of rice into Uganda in 1904, improvement of the irrigated and rain-fed lowland types was undertaken to address a number of production and quality constraints in three consecutive and overlapping phases. The initial phase was achieved through evaluation of introduction, selection of promising lines and subsequent release of the selected lines for production by the farmers. In the second phase, genetic potential of traits and characteristics of interest were analyzed and used to guide selection of suitable parents for hybridization and the third phase employed genotyping approach in screening and selection of the parental lines and the segregating populations to enhance the breeding efficiency for the traits of importance. Simultaneously, the key production constraints addressed included resistance to rice yellow mottle virus (RYMV), rice blast, bacterial leaf blight and narrow leaf spot diseases as well as submergence tolerance and cold tolerance. The quality traits considered for the improvement alongside the grain yield parameters were the grain aroma, amylose content, shape and size. These interventions have resulted into release and wide adoption of seven rice varieties in Uganda besides several breeding lines which have informally diffused into different major rice production agro-ecology. Subsequently, it can be concluded that a substantially strong and functional breeding platform for rice in Uganda has been established.

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Resistance in Rice Breeding Lines to the Blast Fungus in Nepal

Nepal Agriculture Research Journal ◽

10.3126/narj.v6i0.3344 ◽

1970 ◽

Vol 6 ◽

pp. 49-56 ◽

Cited By ~ 2

Author(s):

Bedanand Chaudhary ◽

Sundar M Shrestha ◽

Ram C Sharma

Keyword(s):

Field Condition ◽

Blast Resistance ◽

Quantitative Resistance ◽

Rice Breeding ◽

Breeding Lines ◽

Research Journal ◽

Neck Blast ◽

Upland Field ◽

Major Resistance Genes ◽

Greenhouse Assay

A total of 36 rice breeding lines including checks were evaluated for resistance to blast atRampur during 2000-2001. The experiments were conducted under both field condition andgreenhouse inoculated condition. Qualitative resistance in rice to blast was assessed based onlesion type, whereas quantitative resistance was assessed based on area under disease progresscurve (AUDPC) in the upland field condition. The number of sporulating lesions and the numberof leaves with at least one sporulating lesion per plant were considered as measures forevaluation of quantitative resistance in the greenhouse assay. The lesion type, neck blastpercentage and AUDPC data suggest that most of the rice lines possess higher level of resistanceto leaf and neck blast. The rice lines varied for the number of sporulating lesions and the numberof leaves with sporulating lesion per plant. Some lines were incompatible to virulent blastisolates, showing major resistance genes. NR 1558, NR 601-1-1-9, BW306-2 and CN 836-3-10were promising lines for quantitative resistance to both leaf and neck blast. Radha 12, Sabitri,Janaki possess higher level of quantitative resistance to blast, hence these could be promoted forcultivation in blast-prone environments. These genotypes could also be utilized as donor parentsfor breeding durable blast resistant varieties. The most virulent blast isolate could be used forevaluation of both qualitative and quantitative resistance to blast in early generation in thegreenhouse so that workload could be cut down in future works.Key words: Blast resistance; field condition; greenhouse assay; Pyricularia grisea; rice linesDOI: 10.3126/narj.v6i0.3344Nepal Agriculture Research Journal Vol.6 2005 pp.49-56

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