Genomic regions influencing resistance to the parasitic weed Striga hermonthica in two recombinant inbred populations of sorghum

Haussmann, B I G and Omanya, G O and Welz, H G and Geiger, H H and Hess, D E and Folkertsma, R T and Reddy, B V S and Kayentao, M (2004) Genomic regions influencing resistance to the parasitic weed Striga hermonthica in two recombinant inbred populations of sorghum. TAG Theoretical and Applied Genetics, 109 (5). pp. 1005-1016. ISSN 1432-2242

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Abstract

Molecular markers for resistance of sorghum to the hemi-parasitic weed Striga hermonthica were mapped in two recombinant inbred populations (RIP-1, -2) of F3:5 lines developed from the crosses IS9830 × E36-1 (1) and N13 × E36-1 (2). The resistant parental lines were IS9830 and N13; the former is characterized by a low stimulation of striga seed germination, the latter by “mechanical” resistance. The genetic maps of RIP-1 and RIP-2 spanned 1,498 cM and 1,599 cM, respectively, with 137 and 157 markers distributed over 11 linkage groups. To evaluate striga resistance, we divided each RIP into set 1 (116 lines tested in 1997) and set 2 (110 lines evaluated in 1998). Field trials were conducted in five environments per year in Mali and Kenya. Heritability estimates for area under the striga number progress curve (ASNPC) in sets 1 and 2 were respectively 0.66 and 0.74 in RIP-1 and 0.81 and 0.82 in RIP-2. Across sites, composite interval mapping detected 11 QTL (quantitative trait loci) and nine QTL in sets 1 and 2 of RIP-1, explaining 77% and 80% of the genetic variance for ASNPC, respectively. The most significant RIP-1 QTL corresponded to the major-gene locus lgs (low stimulation of striga seed germination) in linkage group I. In RIP-2, 11 QTL and nine QTL explained 79% and 82% of the genetic variance for ASNPC in sets 1 and 2, respectively. Five QTL were common to both sets of each RIP, with the resistance alleles deriving from IS9830 or N13. Since their effects were validated across environments, years and independent RIP samples, these QTL are excellent candidates for marker-assisted selection.

Item Type:	Article
Divisions:	UNSPECIFIED
CRP:	UNSPECIFIED
Subjects:	Mandate crops > Sorghum
Depositing User:	Library ICRISAT
Date Deposited:	08 Dec 2011 09:34
Last Modified:	14 Sep 2013 09:05
URI:	http://oar.icrisat.org/id/eprint/4825
Official URL:	Http://dx.doi.org/10.1007/s00122-004-1706-9
Projects:	UNSPECIFIED
Funders:	UNSPECIFIED
Acknowledgement:	UNSPECIFIED
Links:	Author

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