Indian Society of Genetics & Plant Breeding

Marker assisted selection to pyramid seedling resistance gene Lr24 and adult plant resistance gene Lr48 for leaf rust resistance in wheat

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One Agropyron elongatum derived dominant seedling
resistance gene (Lr24) and one recessive adult plant
resistance (APR) gene (Lr48) for leaf rust resistance, were
pyramided together employing marker assisted selection
(MAS) with sequence characterized amplified region
(SCAR) marker SCS1302607 tagged to the gene Lr24 and
two random amplified polymorphic DNA (RAPD) markers
flanking the gene Lr48, S3450 and S336775 in wheat. The
RAPD marker S3
450, linked in repulsion phase amplified a
450 bp marker fragment corresponding to the recessive
resistance allele and the other marker S336
775 linked in
coupling phase amplified a 775 bp marker fragment
corresponding to the dominant susceptibility allele of the
Lr48 locus. Parental genotypes comprised of the near
isogenic line (NIL) of the most widely grown cultivar
PBW343 possessing Lr24 and an Australian cultivar CSP44
possessing APR gene Lr48. Phenotyping was done after
inoculating with pathotype 77-5 of Puccinia triticina and
integrated with MAS under controlled conditions of
Phytotron (for F1 and F3 generations) and natural field
conditions (for selection in F2 and F4 generations).
Agronomic suitability of the marker positive plants was
integrated for generating the F3 families and selecting the
4 subfamilies. MAS facilitated the identification of 26 F4
subfamilies fixed for both the genes with desirable plant
type from three F3families homozygous for dominant gene
Lr24 selected from 38 F
2 single plants homozygous for
APR Lr48. The selected F
4 subfamilies were furthered for
seed bulking and yield performance in F5 generation.

Keywords: Marker assisted selection, adult plant resistance, pyramiding, leaf rust resistance; Lr48, Lr24, RAPD, SCAR


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


A. Singh, J. K. Pallavi,K. V. Prabhu info_circle

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