Understanding the genetic control of adaptation and yield for Kazakh bread wheat

Yermekbayev, Kanat (2022) Understanding the genetic control of adaptation and yield for Kazakh bread wheat. Doctoral thesis, University of East Anglia.

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Abstract

Kazakhstan is a major wheat exporter in the region. However, an average wheat grain yield has not changed since 1960’s in the country and plant breeding is mainly based on conventional breeding methods. Here, we developed the first segregating population for Kazakhstan with the cross of UK and KZ wheats. Thus, the crossing of two wheat varieties adapted and bred for diverse climatic conditions allows the discovery of variations that might be important for adaptation to Kazakh conditions. Several adaptation and yield related QTL were discovered among which are two plant height QTL with large additive effects. NILs and NIL combinations were developed for the loci. These new resources were used to study how height increasing QTL affect agronomic performance in Kazakhstan. The NIL analysis validated the effect of the two height QTL in the UK and showed that the chromosome 6A effect was the most stable. The height increases conferred by Pamyati Azieva (Kazakh wheat) on chromosomes 5A and 6A did not result in significant changes in yield or stress tolerance in Kazakh field trials. Recombinants from both QTL regions were used for finemapping leading to the identification of candidate genes and molecular markers for the loci. A large Central-Asian wheat panel was established. The panel was genetically fingerprinted with Axiom 35K genotyping platform revealing detailed population structure of Central-Asian germplasm and it’s relationship with other global germplasm collections. The haplotype led approach in this population helped us to further refine the two target loci and haplotype analysis suggested that diversity for both loci is very low in Kazakh germplasm. Taking into account the yield data and the beneficial effect of reduced height for standing power it is proposed that these haplotypes are used to select against the common Pamyati Azieva alleles and introduce height reducing alleles, exemplifying a haplotype led pre-breeding strategy for Central-Asia. The new resources developed here can help with similar approaches to address the numerous trait targets of Central-Asian wheat breeders.

Item Type:	Thesis (Doctoral)
Faculty \ School:	Faculty of Science > School of Biological Sciences
Depositing User:	James Tweddle
Date Deposited:	15 Nov 2022 10:22
Last Modified:	15 Nov 2022 10:22
URI:	https://ueaeprints.uea.ac.uk/id/eprint/89861
DOI:

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