Development of soft kernel durum wheat

Abstract

Kernel texture (grain hardness) is a fundamental and determining factor related to wheat (Triticum spp.) milling, baking and flour utilization. There are three kernel texture classes in wheat: soft and hard hexaploid (T. aestivum), and very hard durum (T. turgidum subsp. durum). The genetic basis for these three classes lies with the Puroindoline genes. Phenotypically, the easiest means of quantifying kernel texture is with the Single Kernel Characterization System (SKCS), although other means are valid and can provide fundamental material properties. Typical SKCS values for soft wheat would be around 25 and for durum wheat≥80. Soft kernel durum wheat was created via homeologous recombination using the ph1b mutation, which facilitated the transfer of ca. 28 Mbp of 5DS that replaced ca. 21 Mbp of 5BS. The 5DS translocation contained a complete and intact Hardness locus and both Puroindoline genes. Expression of the Puroindoline genes in durum grain resulted in kernel texture and flour milling characteristics nearly identical to that of soft wheat, with high yields of break and straightgrade flours, which had small particle size and low starch damage. Dough water absorption was markedly reduced compared to durum flour and semolina. Dough strength was essentially unchanged and reflected the inherent gluten properties of the durum background. Pasta quality was essentially equal-to-or-better than pasta made from semolina. Agronomically, soft durum germplasm showed good potential with moderate grain yield and resistance to a number of fungal pathogens and insects. Future breeding efforts will no doubt further improve the quality and competitiveness of soft durum cultivars.

Quality evaluation of near isogenic lines of wheat developed through marker assisted backcross breeding for grain softness

“…Hard wheat requires greater force during milling and produces higher mean particle size than soft wheat (Morris. 2019).…”

“…Grain texture is under genetic control and more than 70% of the variation in grain hardness results due to the action of two extremely closely linked genes PinaD1 and PinbD1 that code for puroindoline polypeptides called as PINA and PINB proteins, respectively (Morris et al 2019). The pair of these genes was transferred from Australian soft wheat variety Barham into Indian hard wheat variety DBW14, which possesses weak and extensible gluten (Rai et al 2019a).…”

Novel quality features to expand durum wheat applications

“…The typical yellow endosperm color is determined mainly by two loci: Psy1 and Psy2. 34 Psy1 was located on chromosomes 7A and 7B of durum wheat, while Psy2 is located on group 5 chromosomes of durum wheat. 35 The yellow color is related to the presence of lutein, zeaxanthin and ⊎-cryptoxanthin, providing health benefits due to their antioxidant capacity.…”

“…Durum wheat owes its amber yellow color to carotenoids. The typical yellow endosperm color is determined mainly by two loci: Psy1 and Psy2 34 . Psy1 was located on chromosomes 7A and 7B of durum wheat, while Psy2 is located on group 5 chromosomes of durum wheat 35 .…”

Breeding Soft Durum Wheat through Introgression of the T5AL·5VS Translocated Chromosome

“…A small portion of the distal tip of a chromosome 5D short arm (5DS) of the Chinese Spring (CS), carrying genes Pina and Pinb, has been transferred to chromosome 5B, forming a 5BL•5BS-5DS translocation by nonhomologous chromosomes recombination in the ph1b mutation [2,5,6]. Subsequently, a soft durum line Svevo was developed through introgression of the 5BL•5BS-5DS translocated chromosome [7]. In addition, overexpression of the Pina gene in transgenic durum wheat led to a medium-hard kernel texture [8].…”