Association mapping for quality traits in a durum wheat collection

ASTIZ VALENTINA; MIRANDA RUBEN; RONCALLO PABLO F.; GONZÁLEZ LISARDO; ECHENIQUE VIVIANA C.; LARSEN ADELINA OLGA; MOLFESE ELENA; DREISIGACKER SUSANNE

Bologna

Conferencia; International Conference: From Seed To Pasta 3; 2018

UNIBO, CREA, CNR, CIMMYT

Grain protein content and gluten strength are major targets in durum wheat breeding programs (Triticum turgidum L. var. durum). Six experiments were conducted in the south of the province of Buenos Aires (Argentina) using a world-wide durum wheat germplasm collection (170 entries) in order to analyzed grain protein content, thousand kernel weight and gluten strength. This collection was genotyped with the Breeders' 35K Axiom® array and four major genes markers. The population structure was assessed by using a subset of 1,000 SNPs in low linkage disequilibrium and association mapping (AM) was performed using 3,745 markers for all the phenotypic traits. It was possible to find associations between the three phenotypic traits and the molecular markers used, confirming previously reported chromosomal regions and in some cases, novel QTLs. Seven SNPs located on 2A, 2B, 3B and 7B chromosomes were associated with thousand kernel weight in three environments, some previously reported in similar genome regions in bread and durum wheat. Six markers located on chromosomes 2B and 4A were associated with grain protein content in two environments. Additional marker-trait associations (MTA) for protein content were considered unsatisfactory showing low environmental stability. Several MTA were detected on 1B (7.46 - 36.42 cM) for gluten strength. AM was effective to detect several of the QTLs previously reported in the same chromosomal regions through biparental mapping. These results suggest that AM is a suitable tool to identify genomic regions for traits that are routinely measured in wheat breeding programs.