中文摘要：

【目的】研究膜下滴灌条件下土壤水分对棉花光合物质生产、分配的调节效应,揭示不同土壤水分对棉花对产量形成的影响机制,为干旱区发展节水高产高效农业提供依据。【方法】在新疆气候生态条件下,选用对水分反应敏感性不同的新陆早10号和新陆早13号为试验材料。控制0～60cm土壤相对含水量滴水下限分别为田间持水量55%、70%和85%,滴水上限均为田间持水量,采用气体交换和同位素示踪技术,研究花铃期不同土壤水分对叶片光合速率、14C光合产物运转和分配及产量的影响。【结果】滴水下限为55%处理土壤轻度水分亏缺,叶片光合速率低,地上部光合物质累积量少,14C光合产物输出较快、向蕾铃分配比例增加;滴水下限为70%和85%处理叶片光合速率高,地上部光合物质累积量大,但85%处理14C光合产物向营养器官分配的比例过大,最终籽棉产量以70%处理最高,85%处理次之,55%处理最低。籽棉产量水分利用效率为55%〉70%〉85%;不同品种对土壤水分的响应不同,新陆早10号在55%和70%条件下籽棉产量和水分利用效率显著低于新陆早13号,85%条件下显著高于新陆早13号。【结论】土壤水分对棉花光合物质生产、分配具有明显的调节效应,花铃期滴水下限在70%～85%有利于实现棉花高产,在55%～70%范围内,棉株能通过适应性调节,有利于提高水分利用效率。依据不同品种对土壤水分响应的差异,结合滴灌棉田土壤水分可控性强的特点,制定相应的灌溉制度,对实现滴灌棉田节水高产高效具有重要意义。

英文摘要：

[Objective] In order to provide the basis used in developing the highly productive and effective water-saving agriculture in arid area, the regulation of under-mulch-drip irrigation on production and distribution of photosynthetic assimilate and cotton yield under different soil moisture contents were studied in this paper. [Method] Using water-sensitivity different cultivars Xinluzao 10 and Xinluzao 13, an irrigation experiment was conducted in field. Lower limit of soil relative moisture content in layer of 0-60 cm was controlled at 55%, 70% and 85% of the field capacity. Upper limit was set as field capacity. Leaf gas exchange and isotopic tracer techniques were used to investigate the change of photosynthesis, production and distribution of photosynthetic assimilate and yield during flowering and boll-setting stage under different soil moisture contents. [Result] When the lower limit of soil relative moisture content was 55%, leaf photosynthetic rate and photosynthesis products accumulation of aerial part decreased, the speed of export percentage ^14C-assimilates accelerated and distribution percentage ^14C-assimilates in bud and boll increased. When the lower limit was 70% and 85%, leaf photosynthetic rate and photosynthesis products accumulation of aerial part were enhanced, but the distribution percentage of ^14C-assimilates in stem and leaf significantly increased in 85% treatment. So the seed cotton yield in 70% treatment was the highest, 85% treatment was inferior to 70% treatment, 55% treatment was the lowest, however seed cotton yield water use efficiency was 55%〉 70%〉 85%. The different responses to drip irrigation among varieties were great, the seed cotton yield and water use efficiency of Xinluzao 10 were significantly lower than Xinluzao 13 in 55% and 70% treatments, but that of Xinluzao 10 were higher than Xinluzao 13 in 85% treatment. [Conclusion] These results suggest that different soil moisture contents had significant influence on production and distribution of photosynthetic assimilate