Molecular marker assisted development of chromosome aneuploid lines of durum wheat lacking Gli-A1 or Gli-A2 loci harbouring immunogenic epitopes for celiac disease

Abstract

The study aimed to develop aneuploid lines of tetraploid wheat (Triticum turgidum var durum, AABB) to provide genetic materials to immunologists in our project for understanding the precise role of gliadins in the induction of Celiac disease occurring in genetically susceptible individuals. The genes for gliadins are coded at gli loci located on the short arms of chromosome group 1 (1AS, 1BS and 1DS) and 6 (6AS, 6BS and 6DS) in hexaploid wheat. An interspecific crossing program was implemented with four hexaploid cytogenetic stocks as female parents crossed with the Indian durum wheat variety HI8663 as the male parent. Molecular marker (EST-SSR) based screening was employed to identify plants in BC₁F₂ lacking specific chromosomes. The identified plants were selfed and the progenies were reconfirmed for the absence of 1A/1AS or 6A/6AS. Multiplex SSR and gene based markers were employed to ascertain the presence of D chromosomes. The study resulted in the development of nine durum aneuploid lines lacking whole chromosome 1A, three lacking short arm of chromosome 1A, five lacking whole chromosome 6A and four aneuploid lines lacking short arm of chromosome 6A. Interestingly, all the developed lines lacking chromosome 1A or its short arm possessed chromosome 1D. In a few aneuploid lines, one or more chromosomes of D genome were retained. The aneuploid cytogenetic stocks lacking specific chromosomes developed in the present study can be used for further investigation into the role of celiac epitopes present on chromosomes 1A and 6A.