QTL Mapping Of Lodging Related Traits In Wheat

Lodging is an important factor affecting high and stable yield in wheat. A double haploid population contain 168 lines derived from the HP3 (Huapei3) and YM57 (Yumai57) was used to detect the gene that controlled the lodging related traits. The lodging related traits about anatomical characteristics, mechanical properties, length and fresh weight of the basal internode, and the awn related traits were analysised and identified in nine environments in two years. The main contents and results of this work are as follows:1. 34 QTL were detected for the anatomical traits of the second basal internode, which located on the chromosome 1A, 1B, 2A, 2D, 3D, 4B, 4D, 5B, 5D, 6A, 7A and 7D. The Qlvb.sdau-5D control the large vascular bundle was found in three environments in 2008-2009 cropping seasons, which account for 10.39-13.69% of the phenotypic variance. The Qsvb.sdau-1B and Qsvb.sdau-6A affected small vascular bundle were detected in two environments, which explained 8.54-17.2% and 3.48-9.28% of the phenotypic variance. The Qsd.sdau-1B control the stem diameter was stable in all the three environments in two years study, accounting for 4.95-11.37% of the phenotypic variance. The QTL control the pith diameter was different in each environment.2. 23 QTL were detected for the external mechanical properties, which located on the chromosome 1B, 2A, 2D, 3D, 5B, 5D and 7D. The Qsh.sdau-3D coincide control the stem hardness, stem chewiness and the stem resilience, may be a result of pleiotropy, and explain 9.26-14.93% of the phenotypic variance.3. The analysis result of the plant height, spike length, internode length in the mapping population showed that the Qph.sdau-4D was stable expression in all the environments in two years, less affected by environments. The Qph.sdau-4D from the pollen parents YM57 could reduce the plant height of 5.22cm, which explain 9.42-14.1% of the phenotypic variance. This QTL is useful for choose dwarf beneficial traits to improve lodging resistance in the molecular wheat breeding program.4. Conditional QTL analysis results on the internode length showed that the conditional QTL can detect more QTLs than traditional QTL analysis. The QTL control the spike length and the plant height was different. These results provide us useful information to cultivate wheat varieties with shorter plant height and longer spike length.5. Combined with the results in two years showed that the basal internode of plant height is mainly affected by the QTL in chromosome 4D, 4B and 3A, the upper internode was mainly controlled by the QTL in chromosome 4D, 1B and 7D, and the QTL affect the spike length was located on chromosome 2D.6. 17 QTL were detected in the DH population for the plant fresh weight, which located on the chromosome 1B, 2D, 3A, 4B, 4D, 5B, 5D and 6A. The Qsbifw.sdau-3A which affected the second internode fresh weight was detected in the year 2009-2010 under all the environmental conditions, accounting for 5.47-10.25% of the phenotypic variance.7. 38 QTL were detected for the awn traits, which located on the chromosome 1B, 1D, 2A, 2B, 2D, 3D, 4D, 5D and 6D, and 21 of 38 QTL were identified on the chromosome 2B. The major gene Qal.sdau-2B was determined to affect the AL, TAL, TASA, and TAV in nine environments for two years, and explained 9.42-18.5% of the phenotypic variance. Qal.sdau-1D was found to affect the AL in five environments, and explained 7.04-13.06% of the phenotypic variance.8. In summary, the QTL identified for a trait or several related traits often detected in a similar site on the chromosome in nine environments in two years. The phenomenon of cluster distribution is beneficial to pyramiding good characters in molecular marker-assisted selection breeding practice.