干旱胁迫对生长产生不利影响,发展,生产力,棉花(陆地棉)的纤维品质。提高耐旱性的育种策略需要提高对植物干旱反应的认识,需要正确鉴定作物的耐旱性基因型。包括棉花。这项研究的目的是使用分层Ward的聚类分析,根据形态生理生化性状对所选棉花基因型的耐旱性进行分类。选择棉花的五个基因型(Takfa3,Takfa6,Takfa7,Takfa84-4和Takfa86-5)作为植物材料,在开花阶段,在充分浇水(WW;98±2%田间容量)和缺水(WD;50±2%田间容量)的条件下生长16天。收集了有关形态生理生化参数和这些参数的基因表达水平的数据,随后将基因型分类为耐旱性或易感干旱的基因型。GhPRP(富含脯氨酸的蛋白)的上调,GhP5CS(Δ1-吡咯啉-5-羧酸合成酶),在WD条件下,在Takfa3基因型中观察到GhP5CR(Δ1-吡咯啉-5-羧酸还原酶)与游离脯氨酸富集有关。游离脯氨酸的积累,总可溶性糖,在WD条件下检测到植物中的钾,作为控制细胞渗透势的主要渗透压物质发挥了关键作用。在WD条件下,叶片中的镁和钙浓度也得到了富集,作为基本要素和调节光合能力。叶绿色,净光合速率,气孔导度,在WD条件下,蒸腾速率也有所下降,导致生长迟缓,特别是Takfa6,Takfa7,Takfa84-4和Takfa86-5基因型的地上性状。与WW条件相比,WD条件下棉花基因型的叶片温度(1.1-4.0°C)和作物水分胁迫指数(CWSI>0.75)与气孔关闭和蒸腾速率降低有关。基于游离脯氨酸的增加,可溶性糖,叶片温度,和CWSI,以及地上生长性状和生理属性的下降,五种基因型分为两个类群:耐旱性(Takfa3)和干旱敏感性(Takfa6,Takfa7,Takfa84-4和Takfa86-5)。确定的耐旱棉基因型,即,Takfa3可能生长在干旱条件下的地区。建议在干旱易发环境下,在旱田条件下进一步验证Takfa3的产量性状。
Drought stress adversely affects growth, development, productivity, and fiber quality of cotton (Gossypium hirsutum L). Breeding strategies to enhance drought tolerance require an improved knowledge of plant drought responses necessitating proper identification of drought-tolerant genotypes of crops, including cotton. The objective of this study was to classify the selected cotton genotypes for their drought tolerance ability based on morpho-physio-biochemical traits using Hierarchical Ward\'s cluster analysis. Five genotypes of cotton (Takfa 3, Takfa 6, Takfa 7, Takfa 84-4, and Takfa 86-5) were selected as plant materials, and were grown under well-watered (WW; 98 ± 2% field capacity) and water-deficit (WD; 50 ± 2% field capacity) conditions for 16 days during the flower initiation stage. Data on morpho-physio-biochemical parameters and gene expression levels for these parameters were collected, and subsequently genotypes were classified either as a drought tolerant or drought susceptible one. Upregulation of GhPRP (proline-rich protein), GhP5CS (Δ1-pyrroline-5-carboxylate synthetase), and GhP5CR (Δ1-pyrroline-5-carboxylate reductase) in relation to free proline enrichment was observed in Takfa 3 genotype under WD condition. An accumulation of free proline, total soluble sugar, and potassium in plants under WD conditions was detected, which played a key role as major osmolytes controlling cellular osmotic potential. Magnesium and calcium concentrations were also enriched in leaves under WD conditions, functioning as essential elements and regulating photosynthetic abilities. Leaf greenness, net photosynthetic rate, stomatal conductance, and transpiration rate were also declined under WD conditions, leading to growth retardation, especially aboveground traits of Takfa 6, Takfa 7, Takfa 84-4, and Takfa 86-5 genotypes. An increase in leaf temperature (1.1 - 4.0 °C) and crop water stress index (CWSI > 0.75) in relation to stomatal closure and reduced transpiration rate was recorded in cotton genotypes under WD conditions compared with WW conditions. Based on the increase of free proline, soluble sugar, leaf temperature, and CWSI, as well as the decrease of aboveground growth traits and physiological attributes, five genotypes were categorized into two cluster groups: drought tolerant (Takfa 3) and drought susceptible (Takfa 6, Takfa 7, Takfa 84-4, and Takfa 86-5). The identified drought-tolerant cotton genotype, namely, Takfa 3, may be grown in areas experiencing drought conditions. It is recommended to further validate the yield traits of Takfa 3 under rainfed field conditions in drought-prone environments.