中文摘要：

【目的】揭示小麦叶片逆向衰老规律,探讨其理论意义和实践价值。【方法】从2005年起进行了小麦叶片逆向衰老顺序和正常衰老顺序的比较试验,对冠层温度和一些重要生物学参数进行测定。【结果】自然界存在小麦叶片逆向衰老现象,具此现象的小麦其部分茎生叶片的衰老顺序和大多数小麦的正常衰老顺序不同,即最晚衰老的叶片不是旗叶而是倒2叶;和这种叶片逆向衰老状态相对应,在结实后期出现顶层叶黄、邻层叶绿的叶色结构,和一般小麦的顶层叶绿、邻层叶黄完全相反;叶片的叶绿素含量、可溶性蛋白质含量、蒸腾速率、净光合速率也在生育期向前推进中出现旗叶被倒2叶反超的异常状况,另外,这类小麦结实期的冠层温度总是显示出以冷结尾（冷尾态）或全程偏冷（冷型态）的特征;由于生理过程的特殊性,导致这类小麦倒置茎上的粒重明显高于正置茎,并由此带动其籽粒亦比一般小麦为重,这和＂接力式＂灌浆机制密切相关,不同于一般小麦的旗叶作为向籽粒输送养分的主源其作用贯穿于结实全过程的灌浆模式。【结论】这项研究为小麦结实和衰老理论的探讨、小麦产量的进一步提升以及冷型、冷尾小麦的培育提供了一种新的思路和途径。

英文摘要：

【Objective】 Revealing the laws of inverted senescing sequence of wheat leaves and researching into its significances in theory and practice.【Method】 The study arranged comparative experiments of wheat materials presenting inverted and conventional leaf senescing sequences with the measurements of canapy temperature and some important biological parameters since 2005.【Result】 There was a type of wheat that presents an inverted leaf senescing sequence differing from the conventional leaf senescing sequence of the majority of wheats in nature,i.e.,a part of the leaves at the latest age were the penultimate leaves rather than the flag leaves.Together with this inverted leaf senescing sequence,it presented a leaf color distribution with yellow upper part and green lower part during the late fruiting stage,which is completely opposite to the conventional leaf color distribution of wheat that had green upper part and yellow lower part.As its development moved forward,its leaf chlorophyll contents,soluble protein contents,transpiration rates and net photosynthetic rates presented an unconventional pattern that they became higher in the penultimate leaves than in the flag leaves,and it always had ＂cold＂ canopies for a period of time before its ripening （cold tail state） or in whole fruiting stage （cold type state）.The above mentioned special physiological processes caused that the kernel weights of the stems presenting the inverted leaf senescing sequence were obviously higher than those of the stems presenting a conventional leaf senescing sequence in the wheat with an inverted leaf senescing sequence,thereby causing this type of wheat to increase its kernel weight compared with wheat with a conventional leaf senescing sequence,and this was closely related to the ＂relay＂ kernel filling mechanism differing from the kernel filling model of the conventional wheat whose flag leaves worked as the main nutrient sources for kernel filling in its whole fruiting process.【Conclusion】 The study has p