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Rice resistance (R) genes have been effectively deployed to prevent blast disease caused by the fungal pathogen Magnaporthe oryzae, one of the most serious threats for stable rice production worldwide. Weedy rice competing with cultivated rice may carry novel or lost R genes. The quantitative trait locus qBR12.3b was previously mapped between two single nucleotide polymorphism markers at the 10,633,942-bp and 10,820,033-bp genomic positions in a black-hull-awned (BHA) weed strain using a weed-crop-mapping population under greenhouse conditions. In this study, we found a portion of the known resistance gene Ptr encoding a protein with four armadillo repeats and confers a broad spectrum of blast resistance. We then analyzed the sequences of the Ptr gene from weedy rice, PtrBHA, and identified a unique amino acid glutamine at protein position 874. Minor changes of protein conformation of the PtrBHAgene were predicted through structural analysis of PtrBHA, suggesting that the product of PtrBHAis involved in disease resistance. A gene-specific codominant marker HJ17-13 from PtrBHAwas then developed to distinguish alleles in weeds and crops. The PtrBHAgene existed in 207 individuals of the same mapping population, where qBR12.3b was mapped using this gene-specific marker. Disease reactions of 207 individuals and their parents to IB-33 were evaluated. The resistant individuals had PtrBHAwhereas the susceptible individuals did not, suggesting that HJ17-13 is reliable to predict qBR12.3b. Taken together, this newly developed marker, and weedy rice genotypes carrying qBR12.3b, are useful for blast improvement using marker assisted selection.
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Registration of two rice mapping populations using weedy rice ecotypes as a novel germplasm resource
Abstract Two mapping populations were developed from crosses of the Asianindicarice (Oryza sativaL.) cultivar ‘Dee Geo Woo Gen’ (DGWG; PI 699210 Parent, PI 699212 Parent) and two weedy rice ecotypes, an early‐flowering straw hull (SH) biotype AR‐2000‐1135‐01 (PI 699209 Parent) collected in Arkansas and a late‐flowering black hull (BHA) biotype MS‐1996‐9 (PI 699211 Parent) collected in Mississippi. The weed and crop‐based rice recombinant inbred line (RIL) mapping populations have been used to identify genomic regions associated with weedy traits as well as resistance to sheath blight and rice blast diseases. The mapping population consists of 185 (DGWG/SH; Reg. no. MP‐9, NSL 541035 MAP) and 234 (BHA/DGWG; Reg. no. MP‐10, NSL 541036 MAP) F8RILs, of which 175 (DGWG/SH) and 224 (BHA/DGWG) were used to construct two linkage maps using single nucleotide polymorphic markers to identify weedy traits, sheath blight, and blast resistance loci. These mapping populations and related datasets represent a valuable resource for basic rice evolutionary genomic research and applied marker‐assisted breeding efforts in disease resistance.
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- Award ID(s):
- 1947609
- PAR ID:
- 10361296
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Journal of Plant Registrations
- Volume:
- 16
- Issue:
- 1
- ISSN:
- 1936-5209
- Format(s):
- Medium: X Size: p. 162-175
- Size(s):
- p. 162-175
- Sponsoring Org:
- National Science Foundation
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