棉纤维发育相关基因时空表达与纤维品质的关联分析

以14个纤维品质差异的棉花品种(或品系)为材料，研究10个纤维发育相关基因时空表达变化与纤维品质的关系，为阐明棉纤维发育相关基因与纤维品质形成关系提供理论基础。利用实时荧光定量PCR技术检测10个基因在14个供试品种(或品系)不同纤维发育时期的相对表达量，结果表明，虽然遗传背景完全不同，但它们具有某些共同表达特征。GhExp1、GhCIPK1、GhSus1、GhSusA1和GhPL这5个基因都是在纤维伸长期优势表达；GhACT1、GhRacA和GhRacB是在纤维伸长前期和次生壁加厚期高表达；而GhCelA1和GhcelA3是在纤维伸长后期和次生壁加厚期优势表达。这些基因表达谱与纤维品质关联分析显示，GhRacA在23DPA高表达且表达量与纤维品质显著正相关，其余基因在低表达时其表达量与纤维品质呈显著性相关，而在高表达时其表达量与纤维品质无相关性。GhExp1在20DPA的表达量与纤维比强度和整齐度呈显著负相关，与伸长率呈极显著正相关；GhPL在23DPA的表达量与纤维长度呈显著负相关；GhRacA在5DPA和23DPA的表达量均与伸长率呈极显著正相关；GhRacB在10DPA的表达量与长度和整齐度呈显著负相关；GhCelA1基因在5DPA的表达量与纤维长度呈显著正相关，与马克隆值呈显著负相关，在10DPA的表达量与马克隆值呈显著正相关，与伸长率达到极显著正相关，与比强度呈显著负相关，与长度和整齐度呈极显著负相关；GhCIPK1、GhACT1、GhSus1、GhSusA1和GhCelA3 这5个基因在纤维发育各时期的表达量与纤维品质各指标未检测到相关性。

Associated Analysis between Temporal and Spatial Expression of Fiber Development Genes and Fiber Quality

Ten genes expressed preferentially in fiber development period reported previously and 14 cotton cultivars (strains) with distinctly different fiber quality were selected in this paper. To test the relative expression values of the genes in six different fiber developmental stages, 0 day post anthesis (DPA), 5 DPA, 10 DPA, 15 DPA, 20 DPA, 23 DPA, by real-time quantitative RT-PCR (qRT-PCR), and the data of fiber qualities from 14 cotton varieties (strains). The expression profile showed that GhExp1, GhCIPK1,GhSus1, GhSusA1 and GhPL genes were expressed preferentially during fiber elongation; GhACT1、GhRacA and GhRacB genes all had high expression level in earlier stage of fiber elongation and the thickening period of secondary cell wall. Two cellulose synthase genes (GhCelA1 and GhCelA3) were expressed predominantly during late stage of fiber elongation and the thickening period of secondary cell wall. For most genes, the expression value in low expression level period had significant correlation with fiber quality, while no significant correlation was detected in preferential expression stage of these genes with an exception of GhRacA gene. The expression level of GhExp1 in 20DPA fiber of 14 cotton varieties (strains) had a significant negative correlation with fiber strength and uniformity and a significant positive correlation with fiber elongation percentage; the expression level of GhPL gene in 23DPA had a significant negative correlation with fiber length; the expression level of GhRacA gene in 5DPA and 23DPA both had a high significant positive correlation with fiber elongation percentage; the expression level of GhRacB gene in 10DPA had a significant negative correlation with fiber length and uniformity; the expression level of GhCelA1 gene in 5DPA had a significant positive correlation with fiber length and a significant negative correlation with micronaire value; the expression level of GhCelA1 gene in 10DPA had a significant negative correlation with fiber length, a significant positive correlation with micronaire value, and a high significant correlation with fiber elongation percentage; the correlation between the expression levels of GhCIPK1, GhACT1, GhSus1, GhSusA1and GhCelA3 gene and fiber quality indexes had not been detected.