Location: Hard Winter Wheat Genetics Research Unit
Title: Dissection of Genetic Componenets of Preharvest Sprouting Resistance in White Wheat. Authors
|Liu, Shubing -|
|Cai, Shibin -|
|Chen, Cuixia -|
Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 19, 2010
Publication Date: May 11, 2010
Citation: Liu, S., Bai, G., Cai, S., Chen, C. 2010. Dissection of Genetic Componenets of Preharvest Sprouting Resistance in White Wheat.. Molecular Breeding. DOI:10.1007/s11032-010-9448-7. Interpretive Summary: Pre-harvesting sprouting (PHS) refers to rain-induced seed germination in a physiologically mature wheat head prior to harvest. Sprouted wheat grain usually has poor flour quality and may receive discounts when sold. White wheat varieties are often more susceptible to PHS due to low levels of seed dormancy compared to red wheat varieties. Using DNA marker technology, four genes that control delayed seed germination, were identified from a white-seeded Chinese wheat landrace named Tutoumai A. A gene on chromosome 4A consistently showed a major effect while the other three genes only showed a minor effect in some experiments. The sprouting tolerance gene in the Chinese landrace should be useful to improve PHS resistance in US white wheat varieties.
Technical Abstract: Preharvest sprouting (PHS) in rain-affected wheat (Triticum aestivum) is a major constraint to the production of high-quality wheat, especially in regions where white grain wheat cultivars are preferred. To characterize quantitative trait loci (QTLs) for PHS resistance and seed dormancy (SD), we evaluated 162 recombinant inbred lines developed from the cross between PHS-resistant white wheat landrace Tutoumai A and PHS-susceptible white wheat cultivar ‘Siyang 936’ for PHS resistance and SD in field and greenhouse experiments. Composite interval mapping (CIM) identified four QTLs for PHS resistance and long SD that explained up to 45 and 40.8% of the phenotypic variation in five PHS and four SD experiments, respectively. Qphs.pseru-4A.1 was detected in three of the five PHS experiments, and Qphs.pseru-5B.1, Qphs.pseru-5B.2, and Qphs.pseru-4B.1 were detected in two of the five PHS experiments, respectively. All four QTLs for PHS resistance also affected SD. Qphs.pseru-4A.1 was significant in all four SD experiments; the other three QTLs were detected only in one experiment. Additive and epistatic effects were observed for PHS resistance and SD. Besides three additive QTLs for PHS resistance and two for long SD, an additional 11 and 10 QTLs were detected with epistatic effects on PHS resistance and SD, respectively. The major genetic component of PHS resistance was SD, and other genetic factors may also contribute to PHS resistance in this population.