中文摘要：

选用北疆棉区主栽品种新陆早33号和新陆早45号,设置常规滴灌量（CI）、轻度水分亏缺滴灌量（SDI）、中度水分亏缺滴灌量（MDI）3种处理,在田间条件下研究了不同滴灌量对棉花叶片和非叶绿色器官叶绿素（Chl）含量、净光合速率（Pn）、气孔导度（gs）和光合物质累积的影响,明确了水分亏缺下棉株非叶绿色器官光合作用对产量的贡献。结果表明,各滴灌量条件下棉花非叶绿色器官单位面积的Pn、Chl含量下降幅度较叶片小,且随棉花生育进程的变化较小。在棉铃生长发育后期,随滴灌量减少,棉花非叶绿色器官光合物质生产能力对产量起着更为重要的作用。中度水分亏缺条件下,棉铃（铃壳和苞叶）和茎秆光合作用对铃重的相对贡献率分别增加至16.8%-34.9%和7.6%-17.5%。因此,采用膜下滴灌植棉技术时适当控制滴水量,在保证叶片具有较高光合速率的同时,发挥棉花非叶绿色器官的光合抗逆能力,对挖掘滴灌棉花节水增产潜力具有重要意义。

英文摘要：

Leaf is one of the main photosynthetic organs, while other green parts of plant also retain or develop chlorophyll and have photosynthesis. To better understand the whole plant photosynthesis production potential and contribution to cotton yield, we selected Xinluzao 33 and Xinluzao 45 （two common cultivars in Northern Xinjiang） with three irrigation treatments （CI, conventional irrigation; SDI, slight deficit irrigation; MDI, moderate deficit irrigation） to measure the chlorophyll content （Chl）, net photosynthetic rate （Pn）, stomatal conductance （gs） and photosynthate accumulation in leaf and non-leaf green organs during different growth stages and the contribution of non-leaf green organs to yield. The results showed that the Pn and Chl in non-leaf organs were relatively insensitive to soil moisture stress, decreasing by only a small amount between 25 and 45 days after anthesis. With reduction of water supply, the dry matter production in non-leaf green organs played more important roles in cotton yield forma- tion. Cotton boll weight in the moderate deficit irrigation treatment decreased by 16.8% to 34.9% when the bolls （capsule walls plus bracts） were shaded and by 7.6% to 17.5% when the stalks were shaded. Hence, limiting-irrigation treatment is important to maintain high leaf photosynthetic rates. It is also important to develop the potential photosynthetic capacity of non-leaf green organs. This is especially important when leaf photosynthesis capacity declines due to leaf aging or water stress.