陆地棉GhbHLH4基因的克隆与功能分析

bHLH是一类存在于真核生物中的转录因子家族,其成员广泛参与到植物生长发育及抗逆过程之中。但是,在棉花中有关bHLH基因功能的研究报道不多。以陆地棉为材料分离克隆了GhbHLH4基因并对其功能进行了初步分析。结果表明：GhbHLH4基因启动子中含有大量与抗逆相关的顺式作用元件;转GhbHLH4基因的拟南芥植株与野生型相比叶片宽大、根系发达,转GhbHLH4基因植株能够耐受150 mmol/L NaCl并完成整个生长过程。研究结果为深入了解GhbHLH4基因耐盐的分子机理奠定了基础。     

芙蓉葵的黄萎病抗性鉴定

为挖掘抗棉花黄萎病菌新种质,进而为棉花抗黄萎病育种提供有益基因资源。以芙蓉葵(Hibiscus moscheutos L.)、‘中棉所8号’和Pima90-53为材料,采用蛭石育苗和无菌育苗2种方法,对其黄萎病抗性进行了鉴定。结果表明,采用蛭石育苗,芙蓉葵表现出高抗黄萎病,病情指数为7.69,其抗性优于抗病的海岛棉品种Pima90-53。陆地棉品种‘中棉所8号’表现出感病性状。采用无菌育苗,芙蓉葵黄萎病抗性优于海岛棉品种Pima90-53。2种抗性鉴定方法中,均不能从接菌培养的芙蓉葵分离出黄萎病菌。说明芙蓉葵具有高抗棉花黄萎病的特性。     

半野生棉与亚洲棉对草甘膦抗性评价及比较分析

采用叶片棉球定位鉴定法,初步鉴定并评价了半野生棉和亚洲棉对草甘膦的自然抗性,结果表明:参试材料抗性水平从高抗至高感分6级,极端抗性水平相差33.3倍(0.2%对0.006%)。其中,半野生棉对草甘膦的自然抗性分级丰富,抗性水平分布自高抗至高感;但大部分半野生棉不耐草甘膦,近86%(346份)的材料抗性水平处于低耐级别以下。而亚洲棉抗性水平都处于高抗至低耐的4个级别,抗性多样性较差,但整体抗性水平较高,70.3%(71份)表现为耐或以上级别。从半野生棉和亚洲棉中分别筛选到2份和5份高抗材料,半野生棉中有1份高感材料,亚洲棉中无对草甘膦敏感材料。本研究报道的极端材料为棉花草甘膦抗性遗传机制研究、新品种的培育、内源抗性基因的挖掘和感抗机理研究,奠定了良好的材料基础。     

亚洲棉和雷蒙德氏棉MATE基因家族生物信息学及其同源基因在陆地棉中的表达分析

多药和有毒化合物排出(MATE)蛋白家族是1个次级转运蛋白家族。为了更好地了解亚洲棉和雷蒙德氏棉中MATE蛋白的种类和数量,利用2种二倍体棉花基因组的氨基酸和c DNA数据库对MATE基因家族进行筛选,并分析亚洲棉和雷蒙德氏棉全基因组中MATE基因的种类和进化关系。结果显示,在亚洲棉基因组中初步鉴定了34个MATE基因,而在雷蒙德氏棉中筛选出42个MATE基因。基因结构和系统进化的比较分析表明,进化关系近的MATE基因在结构上基本是一致的。同时对陆地棉中克隆的Gh TT12及与其同一族的部分MATE基因进行荧光定量分析,推测其所在同一族的MATE基因功能可能与转运原花青素有关。这些结果为进一步深入分析棉花MATE基因的功能以及在原花青素转运中的作用提供了理论基础。     

海岛棉DELLA蛋白编码基因GbGAI的克隆与功能初步分析

赤霉素在棉花纤维发育过程中起着重要作用。DELLA蛋白是赤霉素信号传导通路中的一类重要负调节因子。通过同源克隆的方法,克隆了新疆特有棉花栽培种海岛棉中DELLA蛋白的同源基因GbGAI。序列比对分析表明GbGAI编码的氨基酸序列具有DELLA蛋白的典型结构域。构建其过量表达载体,通过农杆菌侵染花序的方法转入野生型拟南芥中,观察表型。转基因株系表现出晚花,株高变矮等赤霉素不敏感突变体的表型。     

Breeding high-yield upland cotton (Gossypium hirsutum) lines with high-quality fibre by mutation

The yield and fibre quality of upland cotton (Gossypium hirsutum) cultivars are very difficult to improve simultaneously. Attempts to breed upland cotton cultivars with high-quality fibre that can spin more than 40 yarn count (Ne) and present yields equal to those of commercial cultivars have not been successful. The seeds of the high-yield upland cotton line Tai 8033 were mutagenized in a Chinese Practice No. 8 recoverable satellite, and the mutated line was selected to produce high-quality and high-yield lines by pedigree selection. The eight mutated lines fit the Chinese standard of high-quality cotton class I, were suitable for spinning more than 40 Ne and had yields that were 12.7%, 7.1% and 3.5% higher than the current control cultivar yield in the cotton cultivation area tested in Jiangsu Province. The fibre of one line successfully spun 80 Ne that fit the high-quality yarn standards. After seeds were mutagenized by exposure to a space environment in a satellite, the fibre quality of upland cotton cultivars was improved through pedigree selection.     

Two-year study on combining ability and heterotic potential in functional traits under salt stress in upland cotton (Gossypium hirsutum)

Salt tolerance is a physiologically and genetically complex trait controlled by multiple genes. To analyze the genetic basis of salt tolerance we evaluated 18 F₁ along with their nine parents under three salt stress levels i.e. control, 10 dS m⁻¹ and 15 dS m⁻¹ in the summer of 2017 and 2018. Data were recorded for the number of bolls, seed cotton yield, boll weight, Na⁺, K⁺, K⁺/Na⁺ ratio, H₂O₂, SOD, POD, CAT and TSP. Line × tester analysis indicated that the contribution of lines was greater than testers. Except for Na⁺, most of the traits were controlled by non-additive genes. With the rise of salt stress, SCA variances increased and were higher than GCA variances for most of the traits indicating the traits were controlled by a few largely dominant genes. KEHKSHAN, FH-118 and FH-114 were found good general combiner whereas the cross KEHKSHAN × FH-114 was a good specific combiner and also indicated significant better parent heterosis for most traits during two years under salt stress and can be utilized in a breeding programme for salt tolerance.     

不同棉花基因型种子萌发响应铜胁迫的差异

在铜污染耕地种植棉花对提高耕地利用效率和棉农收入具有重要意义,但铜胁迫对棉花种子萌发的影响仍不清楚。以7个陆地棉品种（系）为试验材料,设置0、10、100和2 000μmol/L 4个Cu²⁺浓度处理进行发芽试验,记录10d后棉花种子的发芽率和幼苗的鲜重、根长和芽长。以幼苗鲜重、根长和芽长为指标,采用耐性指数和隶属函数对不同品种（系）种子的耐受性进行综合评价。结果表明,在Cu²⁺浓度10~2 000μmol/L范围内随着浓度的升高,幼苗鲜重、根长和芽长所受抑制增强,且根长的受抑制程度高于芽长。在中低浓度下（10~100μmol/L）能将不同基因型种子萌发对铜胁迫的耐受性较好地区分开来,鄂抗棉10号的耐性指数和隶属函数平均值均居首位,而SGK321均居末位。研究结果初步表明,鄂抗棉10号为铜胁迫钝感基因型,而SGK321为敏感基因型。     

陆地棉BGLU基因家族成员的全基因组鉴定与表达分析

植物BGLU基因在生物和非生物胁迫防御中起着重要作用,利用生物信息学手段对陆地棉（Gossypium hirsutum） BGLU家族成员进行全基因组鉴定,对序列特征、保守域结构、染色体定位、启动子元件等家族特征进行了分析,并进一步结合转录组数据和qRT-PCR分析了BGLU基因家族的病菌胁迫响应模式。结果表明,共鉴定出53个陆地棉BGLU基因,根据系统发育进化关系分为6个亚族,部分基因在病菌胁迫下特异性表达。荧光定量和转录组测序结果表明,GhBGLU5、GhBGLU14、GhBGLU18、GhBGLU26、GhBGLU34在抗病棉花中的表达水平显著高于感病品种,推测这些基因正向调控棉花黄萎病抗性。上述结果为进一步分析棉花BGLU家族基因的功能以及分子机制提供一定的理论基础。