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Genetics and Molecular Mapping of Rust Resistance in Wheat

KrishiKosh

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Title Genetics and Molecular Mapping of Rust Resistance in Wheat
Ph.D.
 
Creator GIREESH C.
 
Contributor Vinod
 
Subject diseases, wheats, genes, genetics, planting, chromosomes, crossing over, genotypes, segregation, dna
 
Description The present investigation was undertaken to study the inheritance and molecular mapping of
stem rust resistance in bread wheat genotype WR95 and leaf rust resistance in durum wheat
genotype Trinakria. WR95 showed resistance to stem rust races, 11, 11A, 15-1, 21A-2, 40A,
117-6 and 295. Genetic analysis of stem rust resistance in F2 and F3 populations from the cross
NI5439/WR95 showed a single recessive gene against races 40A whereas a dominant gene
was observed to control resistance against races 11 and 11A in F2 population derived from
Agra Local/WR95. The recessive gene was mapped to 5DL chromosome with markers Xcfd3
and Xwmc215 flanking the gene with a distance of 8.6cM and 12.8cM respectively. The
recessive gene in WR95 present on 5DL chromosome was located in the same region as
recessive stem rust resistance gene Sr30. Since, WR95 showed a recessive resistance gene
against race 21A-2 while the genotype Webster which carries Sr30 was susceptible, it was
concluded that the recessive gene in WR95 is different from Sr30. The recessive stem rust
resistance gene in WR95 was tentatively named as SrWR1. The second stem rust resistance
gene in WR95, dominant in nature and conferring resistance against races 11 and 11A was
mapped near the telomeric region of long arm of chromosome 2B. Xwmc317 was the closest
marker at the distance of 8.2cM. Stem rust resistance genes Sr9, Sr16 and Sr28 have also been
mapped to chromosome arm 2BL. Since, WR95 is resistant to virulent races of Sr28 and Sr9,
therefore, the dominant gene in WR95 may be either Sr16 or a novel gene tentatively named
as SrWR2. Durum wheat genotype Trinakria showed high degree of resistance to 18 races of
leaf rust tested at seedling stage. Genetic analysis at seedling stage in F2 population derived
from the cross A-9-30-1/Trinakria against race 77-5 revealed a dominant gene governing leaf
rust resistance in Trinakria. The F2 results were further validated in BC1 population. Molecular
mapping of leaf rust resistance using SSR markers in F2 from the cross A-9-30-1/Trinakria
identified Xgwm234 as closely linked to leaf rust resistance gene at the distance of 6.3cM on
5BL chromosome. The leaf rust resistance gene identified in Trinakria is proposed to be
tentatively named as LrTrk. The only other gene mapped on chromosome 5BS is Lr52.
However, the identity of LrTrk different from Lr52 needs to be determined. The marker
Xgwm234 closely linked to leaf rust resistance gene LrTrk can be used in marker assisted
breeding for transfer of leaf rust resistance from Trinakria to commercial durum cultivars.
 
Date 2016-03-09T18:03:23Z
2016-03-09T18:03:23Z
2014-01-12
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/65027
 
Language en_US
 
Format application/pdf
 
Publisher IARI, DIVISION OF GENETICS, NEW DELHI