Association mapping of dynamic developmental plant height in common wheat

Abstract

Drought as a major abiotic stress often occurs from stem elongation to the grain filling stage of wheat in northern China. Plant height (PH) is a suitable trait to model the dissection of drought tolerance. The purposes of the present study were to validate molecular markers for PH developmental behavior and identify elite alleles of molecular markers. After the phenotyping of 154 accessions for PH dynamic development under well-watered (WW) and drought stressed (DS) conditions, and the genotyping of 60 SSR markers from six candidate chromosome regions related to PH found in our previous linkage mapping studies, both parameters PH and drought tolerance coefficient (DTC) calculated by the conditional analysis were used for association mapping. A total of 46 significant association signals (P < 0.01) were identified in 23 markers, and phenotypic variation ranged from 7 to 50%. Among them, four markers Xgwm261-2D, Xgwm495-4B, Xbarc109-4B and Xcfd23-4D were detected under both water regimes. Furthermore, 10 markers were associated with DTC, and four with both parameters PH and DTC at the same plant development stage. The results revealed different allelic effects of associated markers; for example, the 155 bp Xgwm495-4B allele was associated with a reduced height of -11.2 cm under DS and -15.3 cm under WW, whereas the 167 bp allele exhibited increased height effects of 3.9 and 8.1 cm, respectively. This study demonstrates a strong power of joint association analysis and linkage mapping for the identification of important genes in wheat.

Single-nucleotide polymorphisms and association analysis of drought-resistance gene TaSnRK2.8 in common wheat

“…A limited water supply often inhibits plant height development. As it is very easily measured and remains constant after flowering, PH usually serves as a suitable agronomic trait for evaluating drought tolerance in crop plants [29,30]. In addition, seedling biomass is an effective criterion for identifying drought tolerance in plants [31,32], and other traits, such as flag leaf width and water-soluble carbohydrates, were proposed as key traits supporting grain yield under stress conditions in wheat [33,34].…”

Association Mapping and Haplotype Analysis of a 3.1-Mb Genomic Region Involved in Fusarium Head Blight Resistance on Wheat Chromosome 3BS

“…For example, Zhang et al [44] found that allele Xgwm130 132 underwent very strong positive selection for 1,000 kernel weight during modern breeding. Through association mapping of dynamic development of plant height in common wheat, Zhang et al [53] exposed different allelic effects of associated markers; gwm495-4B 155 was associated with reduced height of −11.2 cm under drought stressed and −15.3 cm under well watered conditions, whereas the 167 bp allele exhibited increased height effects of 3.9 and 8.1 cm, respectively. In the present study, different allelic effects of significant loci were also found for FHB response (Figure 4, Figure S3).…”

Mixed linear model association mapping for low chloride accumulation rate in oriental-type tobacco (Nicotiana tabaccum L.) germplasm

“…However, current gene mapping efforts in plants are shifting from conventional biparental QTL mapping to LD-based association mapping (Sorkheh et al 2008), which is the most effective approach to utilize natural variation in the form of ex situ conserved crop genetic resources. Some successful reports on association mapping in plants such as rice (Yan et al 2009), barley (Kraakman et al 2006), wheat (Ghavami et al 2011;Zhang et al 2011Zhang et al ), potato (D'hoop et al 2008, soybean (Jun et al 2007), maize (Andersen et al 2007), chickpea (Saeed et al 2013), and forage grasses (Dobrowolski & Forster 2007) are available. To our knowledge, this is the first report on the identification of responsible locus for chloride accumulation rate via association mapping in tobacco.…”