根茎禾草乳熟期净光合速率日变化的比较研究  

Comparative study on daily change of photosynthesis rate of the rhizomatous grasses in milky ripe stage

作　　者：何文兴[1] 易津[2] 李洪梅 

机构地区：[1]四川大学生命科学学院,成都610065 [2]内蒙古农业大学农学院,呼和浩特010018 [3]内蒙古通辽市科尔沁区畜牧工作站,通辽028000

出　　处：《应用生态学报》2004年第2期205-209,共5页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金资助项目 (C3 9760 0 12 )

摘　　要：对 6种具有不同根茎长度的禾草乳熟期净光合速率日变化进行了比较研究 .结果表明 ,除了中间偃麦草 (Elytrigiaintermedia)为“单峰”曲线外 ,另外 5种禾草的净光合速率日变化曲线均呈“双峰型” ,且其总体趋势是根茎越发达、根冠比越大 ,其净光合速率越迟到达第 1峰、“午降”经历时间也越短 ,而大气相对湿度偏低 (<5 5 % )和叶片温度偏高 (>36℃ )是导致“午降”的重要因素 .羊草 (Leymuschinense)、茹莎娜牧冰草 (Pascopyrumsmithii)、赖草 (Leymussecalinus)、大赖草 (Leymusracemosus)、蒙古冰草 (Agropyronmongolicum)、中间偃麦草 (Elytrigiaintermedia)的净光合速率第 1峰值分别出现在 10 :12、10 :0 0、9:5 1、9:39、9:0 6、8:13;“午降”经历时间分别是 4 71、4 74、4 6 4、4 6 7和 5 5 1min ;“午降”期间的叶片温度均值分别是 37.8、37.5、36 .9、37.0和 36 .3℃ .羊草和蒙古冰草、赖草和大赖草分别具有相似的净光合速率日变化曲线 ,在P =0 .0 1时 ,r值分别是 0 .88和 0 .96 .Comparative study on daily change of photosynthesis rate of the rhizomatous grasses in their milky ripe stage was carried out, and the results showed that photosynthetic rate of five grasses appeared to be two-apex curve, except Elytrigia intermedia appeared to be one-apex curve. The general trend was that the higher the root/shoot ratio was, the later the first apex of the photosynthetic rate reached, and the shorter the noon break period was. Moreover, low relative humidity and high leaf temperature were the important factors for noon break. Leymus chinense, Pascopyrum smithii Rydb. cn. Rosana, Leymus secalinus, Leymus racemosus, Agropyron mongolicum and Elytrigia intermedia reached the first apex at 10:12, 10:00, 9:51, 9:39, 9:06 and 8:13, the noon break period was 471, 474, 464, 467 and 551 min, and the average leaf temperature during noon break was 37.8, 37.5, 36.9, 37.0 and 36.3 ℃, respectively. Leymus chinense and Agropyron mongolicum, Leymus secalinus and Leymus racemosus had similar daily change in photosynthetic rate, respectively, and their r values were 0.88 and 0.96 respectively when R=0.01.

关 键 词：根茎禾草 乳熟期 净光合速率 叶片温度 

分 类 号：S54[农业科学—作物学]