N_Ali_et al 2016 Multiple Alien Introgressions in Wheat.pdf (1.43 MB)
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Introgression of chromosome segments from multiple alien species in wheat breeding lines with wheat streak mosaic virus resistance

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posted on 30.08.2016, 15:21 by N. Ali, John Seymour Heslop-Harrison, H. Ahmad, R. A. Graybosch, G. L. Hein, T. Schwarzacher
Pyramiding of alien-derived Wheat streak mosaic virus (WSMV) resistance and resistance enhancing genes in wheat is a cost-effective and environmentally safe strategy for disease control. PCR-based markers and cytogenetic analysis with genomic in situ hybridisation were applied to identify alien chromatin in four genetically diverse populations of wheat (Triticum aestivum) lines incorporating chromosome segments from Thinopyrum intermedium and Secale cereale (rye). Out of 20 experimental lines, 10 carried Th. intermedium chromatin as T4DL*4Ai#2S translocations, while, unexpectedly, 7 lines were positive for alien chromatin (Th. intermedium or rye) on chromosome 1B. The newly described rye 1RS chromatin, transmitted from early in the pedigree, was associated with enhanced WSMV resistance. Under field conditions, the 1RS chromatin alone showed some resistance, while together with the Th. intermedium 4Ai#2S offered superior resistance to that demonstrated by the known resistant cultivar Mace. Most alien wheat lines carry whole chromosome arms, and it is notable that these lines showed intra-arm recombination within the 1BS arm. The translocation breakpoints between 1BS and alien chromatin fell in three categories: (i) at or near to the centromere, (ii) intercalary between markers UL-Thin5 and Xgwm1130 and (iii) towards the telomere between Xgwm0911 and Xbarc194. Labelled genomic Th. intermedium DNA hybridised to the rye 1RS chromatin under high stringency conditions, indicating the presence of shared tandem repeats among the cereals. The novel small alien fragments may explain the difficulty in developing well-adapted lines carrying Wsm1 despite improved tolerance to the virus. The results will facilitate directed chromosome engineering producing agronomically desirable WSMV-resistant germplasm.

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Citation

Heredity, 2016, 7, pp. 114-123

Author affiliation

/Organisation/COLLEGE OF MEDICINE, BIOLOGICAL SCIENCES AND PSYCHOLOGY/MBSP Non-Medical Departments/Department of Genetics

Version

AM (Accepted Manuscript)

Published in

Heredity

Publisher

Nature Publishing Group on behalf of The Genetics Society

issn

0018-067X

eissn

1365-2540

Copyright date

2016

Available date

01/12/2016

Publisher version

http://www.nature.com/hdy/journal/v117/n2/full/hdy201636a.html

Language

en

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