Development and identification of four new synthetic hexaploid wheat lines with solid stems

Abstract

Stem solidness is an important agronomic trait for increasing the ability of wheat to resist lodging. In this study, four new synthetic hexaploid wheat with solid stems were developed from natural chromosome doubling of F1 hybrids between a solid-stemmed durum wheat (Triticum turgidum ssp. durum, 2n = 4x = 28, AABB) and four Aegilops tauschii (2n = 2x = 14, DD) accessions. The solid expression of the second internode at the base of the stem was stable for two synthetic hexalpoid wheat Syn-SAU-117 and Syn-SAU-119 grown in both the greenhouse and field. The lodging resistance of four synthetic solid-stem wheats is stronger than that of CS, and Syn-SAU-116 has the strongest lodging resistance, followed by Syn-SAU-119. The paraffin sections of the second internode showed that four synthetic wheat lines had large outer diameters, well-developed mechanical tissues, large number of vascular bundles, and similar anatomical characteristics with solid-stemmed durum wheat. The chromosomal composition of four synthetic hexaploid wheat was identified by FISH (fluorescence in situ hybridization) using Oligo-pSc119.2-1 and Oligo-pTa535-1. At adult stage, all four synthetic hexaploid wheat showed high resistance to mixed physiological races of stripe rust pathogen (CYR31, CYR32, CYR33, CYR34). These synthetic hexaploid wheat lines provide new materials for the improvement of common wheat.

Impact of “Green Revolution” gene Rht-B1b on coleoptile length of wheat

“…Thus, improving lodging resistance of tall wheat has become an important research direction. Besides of reducing the height of plants, an alternative way is to breed wheat varieties with solid-stemmed stems to enhance lodging resistance in wheat (Liang et al, 2022). Wheat with tall plant height Rht-B1a/Rht-D1a allele combined with solid-stemmed stems alleles of TdDof might have high lodging and drought tolerances, long coleoptile and produce higher yield in drought field (Jatayev et al, 2020;Nilsen et al, 2020).…”

A “solid” solution for wheat stem sawfly (Hymenoptera: Cephidae) resistance: Genetics, breeding and development of solid stem wheat

“…Rescue, Chinook, and Cypress are the cultivars that are derived from S‐615 (Larson & MacDonald, 1966) with Rescue being the first SS bread wheat cultivar that was developed and grown widely over the Northern great plains of North America in early 1950s (Larson & Macdonald, 1962). Golden Ball (Clark et al., 1922) and Biodur (Kemp, 1934) are the main sources of SS in durum wheat among many SS cultivars and landraces (Damania et al., 1997; Liang et al., 2022) with Biodur being the source of SS for the existing SS durum wheat varieties in Western Canada such as CDC Fortitude, AAC Raymore, AAC Cabri (Lanning et al., 2006; Liang et al., 2022; Pozniak et al., 2015; Singh et al., 2014, 2017). Among the members of Canadian Western Extra Strong cultivars, a haplotype was discovered that has alleles for hollow and solid stems in the same quantitative trait loci (QTL) (Nilsen et al., 2017).…”

“…Additionally, they also have larger sclerenchyma girders and higher elasticity when compared to hollow varieties (Bainsla et al., 2018; Biffen, 1905; Engledow & Hutchinson, 1925; Karim & Jahan, 2013). Higher stem wall thickness also confers increased stalk strength and lodging resistance by avoiding ovalization and collapse of the stem in SS varieties (Kong et al., 2013; Liang et al., 2022). Therefore, solid pith parenchyma and the thicker walls of mechanical tissue of the stem are crucial factors for lodging resistance as well (Kong et al., 2013).…”

“…Although SS is under genetic control, the phenotype is highly influenced by non‐genetic components like environmental conditions, nitrogen (N) application, and sowing density (Beres et al., 2012). However, the impact of non‐genetic factors is stronger in bread wheat than in durum wheat (Liang et al., 2022; Platt & Farstad, 1949). Environmental factors such as cold temperatures, low light intensity, moisture, and precipitation reduce SS (Holmes, 1984; Platt & Farstad, 1949).…”

“…In durum wheat, the association of Sst 1 locus, Qss.msub‐ 3BL (Houshmand et al., 2007) and the secondary QTLs on chromosomes 2A and 2D caused a greater increase in stem solidness when compared to Sst1 acting alone (Cook et al., 2004; Nilsen et al., 2017). Durum cultivars have a consistent expression of SS, are genetically more stable, and less affected by non‐genetic factors compared to the SS bread wheat (Liang et al., 2022; Platt & Farstad, 1949). Additionally, the yield losses due to WSS damage in durum cultivars were comparatively lesser than bread wheat varieties (Özberk et al., 2005).…”