Quantitative trait loci (QTL) of stem strength and related traits in a doubled-haploid population of wheat (Triticum aestivum L.)

Abstract

Scoring for lodging resistance is difficult under natural field conditions. The stem strength of wheat has been used as an index of lodging resistance. However, this is a complex trait comprised of two characters, i.e. stem mechanical elasticity and rigidity. Therefore it is closely associated with stem morphological and anatomical features. A study of the genetics of stem strength and related traits of basal stem internodes is very important for genetic improvement of lodging resistance in wheat. In this study, a doubled-haploid (DH) population derived from anther culture of the cross CA9613/H1488 was used. Stem strength and related basal internode traits were measured at the milk stage. A molecular map of the DH population was constructed using 189 SSR markers, and quantitative trait loci (QTL) for each trait were analyzed based on this molecular linkage map. A total of six QTL for stem strength, culm wall thickness, pith diameter and stem diameter were identified: 1) Two QTL (QSs-3A and QSs-3B) for stem strength were detected on chromosomes 3A and 3B, exhibiting 10.6 and 16.6% phenotypic variance, respectively. 2) Two QTL (QPd-1A and QPd-2D) associated with pith diameter were detected on chromosomes 1A and 2D, respectively, jointly explaining about 30% of phenotypic variance. 3) As far as stem diameter and culm wall thickness were concerned, one QTL was detected on chromosomes 3B and 2D, respectively; QSd-3B explained 8.7% of the phenotypic variance of stem diameter, whereas QCwt-2D explained 9.6% of the phenotypic variance of culm wall thickness. In addition, among the QTLs detected, two with pleiotropic effects were observed. Correlated traits are usually associated with the pleiotropic effects of the same QTL(s) or linkage of different QTLs. But this was not true in some cases. The results of QTL mapping showed that stem strength can be improved by breeding for wider stems with a higher stem diameter/pith diameter ratio. This can be facilitated by using the markers linked to QSd-3B and QCwt-2D. Combining stem strength, stem diameter and culm wall thickness may be used as a selection index for lodging resistance with marker-assisted selection (MAS) to improve lodging resistance in this population.

Quantitative trait loci analysis of stem strength and related traits in soybean

“…However, extreme dwarfism is also associated with decreased biomass, shrunken seeds, premature senescence, and increased susceptibility to diseases, resulting in reduced yield (Allan 1986;Islam et al 2007). Furthermore, even after dwarfing, lodging may still occur if stem strength is weak (Hai et al 2005;Ma 2009), therefore increasing stem strength will be a very promising strategy to breed soybean with high lodging resistance. As one of the key influencing factors of lodging, stem strength (resiliency of stem) is significantly correlated with lodging resistance in soybean (Mancuso and Caviness 1991;Supplementary Table S1).…”

“…SS was measured using a prostrate tester made in Japan (DIK-7400, Daiki Soil and Moisture). The prostrate tester was set perpendicularly to the plants at 20 cm height, when plants inclined to 45°from the vertical, pushing resistance was measured, and estimated using the following formula: SS (gram per stem) = test value/40 9 1,000 (Kashiwagi and Ishimaru 2004;Hai et al 2005). At maturity stage, lodging (LD) was recorded according to the methods described by Lee et al (1996).…”

“…Plant height has been the main target for improvement of lodging resistance, however, the susceptibility to lodging differs among cultivars with similar plant heights, thus plant height is not necessarily the most important factor and there might be others determining lodging resistance (Kashiwagi and Ishimaru 2004). Stem strength (pushing resistance) has been proposed as one of the key influencing factors of lodging in recent years (Kashiwagi and Ishimaru 2004;Hai et al 2005;Ma 2009), some advances of genetic studies for stem strength have been achieved in wheat (Hai et al 2005), barley (Berry et al 2006), rice (Dunca 2008), pea (Beeck et al 2006(Beeck et al , 2008 and soybean (Mancuso and Caviness 1991). Furthermore, stem strength has been used as an important index of lodging resistance in wheat and rice, and plays an important role in breeding for lodging resistance (Islam et al 2007).…”

The Pattern of Lignin Deposition in The Cell Walls of Internodes During Barley (Hordeum vulgare L.) Development

“…Previous research has shown that lignin synthesis and accumulation might be related to stem strength (Jones et al, 2001;Pedersen et al, 2005;Ma, 2009). This creates a major problem in monocotyledonous crop plants in which poor culm strength leads to a lodging phenotype (Hai et al, 2005;Ma, 2009). The selection and breeding processes, which aim to prevent plant lodging, lead to the creation of dwarf and semi-dwarf phenotypes of barley cultivars.…”

Factors Related to Physical Strength of Banana Pseudostem

“…Some researchers found that plants' lodging-resistances were positively correlated with stem's diameter [16]. After a wheat double haploid line was gotten by hybridizing the line CA9613 and H1488, the physical strength of the stem and the characters of the basic stem were measured at milk stage [17]. Six QTLs are responsible for physical strength of stem, thickness of stem wall, pore diameter and stem diameter were found in 1A, 2D, 3A, and 3B [17].…”