Water stress is a serious global issue regarding growth of agricultural crops and sustainable food production for the large population. In the present situation due to low rainfall and unavailability of advanced irrigation methods, water deficit stress is the most limiting factor decreasing crop production in many regions of the world. In this study, to assess the drought tolerance mechanism in cotton cultivars was monitored by drought- induced physio-biochemical changes. To assess the tolerance in cotton cultivars, a field experiment was conducted in split plot design in which the main plot consists of irrigated and complete rainfed conditions as a stress and cotton cultivars arranged in the main plot as a subplot. The overall comparative analysis revealed that hybrid was superior over their parents under well-watered as well as in water deficit conditions in terms of chlorophyll content, wax content, accumulation of compatible solutes, photosynthesis rate, stomatal conductance, transpiration rate and yield parameters. The findings from the results indicate that under water deficit conditions plants having a different adaptive mechanisms for coping with the stress situation. So, some of the adaptive mechanisms such as accumulation of sugars, polyphenols, amino acids, non-enzymatic antioxidants, and wax deposition helps to maintain osmotic balance, to protect cellular macromolecules, to detoxify the cells, and to scavenge free radicals under water deficit condition.

中文翻译：

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缺水胁迫-棉花（Gossypium hirsutum L.）品种的生理生化变化

缺水问题是一个严重的全球性问题，涉及农业作物的增长和大量人口的可持续粮食生产。在目前的情况下，由于降雨量少和无法采用先进的灌溉方法，缺水胁迫是世界许多地区减产的最大限制因素。在这项研究中，通过干旱诱导的生理生化变化监测棉花品种的干旱耐受机制。为了评估棉花品种的耐受性，在分田设计中进行了田间试验，在该试验中，主田由灌溉和完全的雨水条件作为胁迫，而棉田作为副田布置在主田中。总体比较分析表明，在水量充足和缺水条件下，杂种在叶绿素含量，蜡含量，相容性溶质的积累，光合作用率，气孔导度，蒸腾速率和产量参数方面均优于其亲本。结果的发现表明，在缺水条件下，植物具有不同的适应机制来应对胁迫状况。因此，一些适应性机制，例如糖，多酚，氨基酸，非酶类抗氧化剂和蜡沉积的积累，有助于维持渗透平衡，保护细胞大分子，使细胞解毒以及在缺水情况下清除自由基健康）状况。光合作用速率，气孔导度，蒸腾速率和产量参数。结果的发现表明，在缺水条件下，植物具有不同的适应机制来应对胁迫状况。因此，一些适应性机制，例如糖，多酚，氨基酸，非酶类抗氧化剂和蜡沉积的积累，有助于维持渗透平衡，保护细胞大分子，使细胞解毒以及在缺水情况下清除自由基健康）状况。光合作用速率，气孔导度，蒸腾速率和产量参数。结果的发现表明，在缺水条件下，植物具有不同的适应机制来应对胁迫状况。因此，一些适应性机制，例如糖，多酚，氨基酸，非酶类抗氧化剂和蜡沉积的积累，有助于维持渗透平衡，保护细胞大分子，使细胞解毒以及在缺水情况下清除自由基健康）状况。