Query (optional)   in Class  All Allele Author Colleague Collection Assembly Gene Gene Class Gene Product Germplasm Image Journal Keyword Library Locus Map Map Data Marker Pathology Polymorphism Probe Protein QTL Rearrangement Reference Sequence Species Trait Trait Study Two Point Data  

---

GrainGenes Reference Report: TAG-102-511

[Submit comment/correction]

Reference	TAG-102-511
Title	Molecular markers linked to stem rot resistance in rice
Journal	Theoretical and Applied Genetics
Year	2001
Volume	102
Pages	511-516
Author	Ni J Colowit PM Oster JJ Xu K Mackill DJ
Abstract	Summary: Stem rot (Sclerotium oryzae) is an important disease constraint in Californian rice production. Measurement of resistance is laborious, and the low heritability of the trait limits the effectiveness of selection in breeding programs. Molecular markers linked to the trait would therefore provide a superior selection screen to assist in transferring resistance into improved cultivars. The genetics of resistance to stem rot was studied in the germplasm line 87-Y-550 (PI566666), which inherited its resistance from the wild species Oryza rufipogon. Four crosses of 87-Y-550 with susceptible lines were made and recombinant inbred lines of only the most-resistant and most-susceptible progeny within each cross were advanced for late-generation testing. Approximately 900 AFLP (amplified fragment length polymorphism) primer combinations were applied to resistant and susceptible bulks within each cross. One AFLP marker showed significant association with stem rot resistance and accounted for approximately 45.0% of the phenotypic variation in 59 progenies. This marker was mapped on rice chromosome 2 between the RFLP markers RZ166 and RG139 by using F2-reference population information. The accuracy of AFLP marker mapping was validated by size and sequence comparison of AFLP bands from 87-Y-550 and the reference population. With the strategy of selective genotyping combined with a parental survey, two microsatellite markers, RM232 and RM251, on chromosome 3 were also found associated with stem rot resistance and accounted for 41.1% and 37.9% of the phenotypic variation, respectively. The multiple linear regression model included TAA/GTA167 on chromosome 2 and RM232 on chromosome 3 and cumulatively explained 49.3% of total variation. The molecular markers linked to stem rot resistance should facilitate selection for this recalcitrant trait in rice breeding programs by eliminating the need for early generation screening
Keyword	[ Hide all but 1 of 66 ] aflp aflp marker amplified fragment length polymorphism breeding breeding programs chromosome chromosome maps cross crossing cultivar disease disease resistance fragment length polymorphism fungal diseases generation genetic mapping genetic markers genotyping germplasm germplasm line heritability inbred lines length polymorphism limits magnaporthe salvinii mapping marker measurement microsatellite microsatellite marker model molecular marker multiple oryza oryza rufipogon oryza sativa phenotypic variation polymorphism population primer production progeny program programs recombinant inbred line regression resistance resistant rflp rflp marker rice rice breeding rot rufipogon sclerotium oryzae screen screening segregation selection sequence stem strategies strategy trait wild wild species

GrainGenes is a product of the Agricultural Research Service of the US Department of Agriculture.