High or low temperature deviations from the optimum can adversely affect the growth and development of plants and they respond to such changes through several mechanisms (Stone 2001, Maestri et al. 2002). The situation gets more aggravated by limitingsoil moisture, where heat and drought stresses frequently occur simultaneously. In pearl millet (Pennisetum glaucum), grown during the rainy season, high temperature in certain regions adversely affects seedling establishment and plant population (Rai and Anand Kumar 1994), while in summer low temperature during germination (Joshi et al. 1997) and high temperature during flowering and grain development adversely affect the respective processes (Norman et al. 1995). Although, molecular bases of thermotolerance, including the roles of phytohormones, antioxidants, membrane lipids and heat shock proteins, apart from the thermotolerance of translation and thermostability of key enzymes, have been discussed (Maestri et al. 2002), the significance of the morphophys ological consequences in identifying the thermotolerance are very vital for a good crop establishment. In view of the above, this investigation was done to understand the effects of high temperature and receding soil moisture on seedling growth characters of some commercial pearl millet hybrids.
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机译：最佳温度的高低偏差可能会对植物的生长和发育产生不利影响，并且它们会通过多种机制对这种变化做出响应（Stone 2001，Maestri et al。2002）。限制土壤水分会加剧这种情况，在这种情况下，高温和干旱经常同时发生。在雨季生长的珍珠粟（Pennisetum glaucum）中，某些地区的高温会对幼苗的生长和植物种群产生不利影响（Rai and Anand Kumar 1994），而在夏季，发芽期间的低温（Joshi等，1997）和高温开花和籽粒发育过程中的温度不利地影响了各自的过程（Norman等，1995）。尽管已经讨论了耐热性的分子基础，包括植物激素，抗氧化剂，膜脂和热休克蛋白的作用，除了翻译的耐热性和关键酶的热稳定性以外（Maestri et al。2002），形态学的重要性。鉴定耐热性的生物学后果对于作物的良好生长至关重要。有鉴于此，本研究旨在了解高温和土壤水分减少对某些商品小米杂种的幼苗生长特性的影响。
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