Genetic analysis and gene detection of fructan content using DArT molecular markers in spring bread wheat (Triticum aestivum L.) grain

Abstract

Fructans (fructo-oligosaccharides) is one of the most important carbohydrates in wheat vegetative tissues and plays a vital role in wheat grain development. One hundred and forty 'Avocet'× 'Chilero' wheat (Triticum aestivum L.) recombinant inbred lines (RILs) were phenotyped for grain fructans at Luoyang and Langzhou field sites in the 2015-2016 and 2016-2017 growing seasons and 2090 Diversity Arrays Technology (DArT) molecular marker data were used to determine genomic regions controlling fructan content. Eleven significant quantitative trait loci (QTL) for wheat fructan content were identified on chromosomes 1B, 2A, 2B, 2D, 3D, 4B, 6B, 6D, 7A, and 7B using the inclusive composite interval mapping (ICIM) method, explaining 4.08% to 27.40% of the phenotypic variance, with seven exceeding 10%. The single environment analysis identified QF.haust-6D.1 and QF.haust-7B in Luoyang, QF.haust-1B, QF.haust-2D, QF.haust-3D, and QF.haust-7B in Lanzhou, and QF.haust-1B, QF.haust-7A, and QF.haust-7B in average phenotypic performance. The multi-environment analysis identified QF.haust-2B and QF.haust-7B, which explained 21.01% and 17.39% of the phenotypic variance, respectively. The positive allele of QF.haust-2B and QF.haust-7B were all originated from Chilero. QF.haust-2B was flanked by the 3957031 and SNP1203021 markers; candidate genes for QF.haust-2B were identified by anchoring marker sequences in the IGWSC wheat genome sequence, involving a variety of biological processes, such as the regulation of ribosomes metabolism in wheat. We also constructed the physical map for wheat grain fructan QF.haust-2B and QF.haust-7B, QF.haust-7B with a physical length of 11.47 Mb between marker SNP3026392 and 3954877 and 103 genes within the segment, in which ten were related to glucose metabolism. This study provides a theoretical basis and technical support for wheat grain fructan content-related genes and molecular marker-assisted breeding.