Indian Society of Genetics & Plant Breeding

Molecular validation and screening of Triticum dicoccoides Korn. accessions for stripe rust résistance gene Yr15 with SSR marker

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Biotic Stresses in wheat are a major constraint that limits
the production. Among several diseases, which attack
wheat, the most common are those caused by fungal
pathogens. Besides other two rusts, stripe rust or yellow
rust, (Puccinia striiformis Westend f. sp. tritici Eriks.) of
wheat is more destructive particularly in temperate,
cooler and humid regions than the tropics. It is most
devastating disease of wheat throughout the world.
China is the largest epidemic region in the world [1]. In
India, stripe rust is confined to northern hills, foot hills
of Himalayas and north western region of the country.
Stripe rust also appears in southern hill zone. Because
of its early appearance it can cause severe damage
resulting into poor tillering and shriveled grain. The most
effective, efficient and economical mean for control of
stripe rust is the use of genetic resistance. There are
about 40 resistance genes (Yr1-Yr40), which have so
far been identified and assigned to specific
chromosomal location, while 23 are provisional [2]. Most
of the cultivars grown in northern Indian plains are
susceptible to stripe rust and only a few genes namely,
YrA, Yr2, Yr2Ks, Yr9, Yr18 and Yr27 have been
postulated in the present day cultivars, which are not
effective against one or more pathotypes. Gene Yr9 is
most frequently occurring among the varieties released
after 1995. Of the 40 Yr genes designated so far, only
five have been transferred from wild relatives of wheat.
One such resistance gene Yr15, located on 1BS has
been transferred from wild emmer, Triticum dicoccoides
(2n=4x=28, genome AABB) into common wheat [3] and
it is effective against virulent Indian pathotypes of stripe
rust [4] in seedling and adult stage. Yr15 has been
introgressed into Sunstar*6/C80-1 and HD2329 a
popular Indian cultivar. To confirm the introgressed
gene, genetic analysis through test of allelism or
comparison of the infection type with differentials is
necessary. However, with the development of DNA
markers, the confirmation of a target gene can be
authenticated, provided molecular marker (s) closely
linked with the gene are available. Wild emmer provides
extensive and promising genetic resources for disease
resistance in wheat. In addition to, Yr15, another gene
conferring resistance to stripe rust Yr35 has also been
transferred into wheat [5]. About 35 accessions of T.
dicoccoides received from ICARDA have been
evaluated for stripe rust resistance [4]. Twenty one
randomly chosen amongst them were screened with
the Yr15 linked molecular marker to study DNA
polymorphism. The results on validation of Yr15 linked
molecular marker and screening

Keywords: N/A


Year: 2009
Volume: 69
Issue: 1
Article DOI: N/A
Print ISSN: 0019-5200
Online ISSN: 0975-6906


N. K. Singh info_circle
Suresh Chand info_circle

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