南、北方冬小麦品种光合速率对环境条件的反应

研究陕鲁和四川两地区5个小麦地方品种的光合速率对光强、温度和水分变化的反应。结果看出,北方陕鲁地区的小麦比南方四川的小麦光合的光饱和点高,适宜温度范围广。所有品种在水分亏缺下,光合速率都下降。当供水恢复时,北方小麦放出的 CO2比南方小麦多。这是由于北方小麦气孔关闭得早,CO2在体内积累得多。说明了北方小麦对干

Different Responses of Photosynthetic Rate of Wheat Varieties from South and North China to Environmental Conditions

Using five local wheat varieties from southern and northern wheat regions,the investigation on response of photosynthetic rate to various light intensity,temperatureand water supply were carried out.The results showed that light saturatio pointsof photosynthcsis of northern wheat was highter,their optimum temperature rangewaswider than that of the southem wheat.Under drought condition,photosythfic rate inall varieties was deercased,once the water supply was recovcred,the CO_2 release wasresumed instantly.But the amount of CO_2 released by the northern wheat was morethan that by the southern.This is because stomatal closure was carlier and amount ofCO_2 accumulated was larger in northern wheat than that in southern wheat,indicating that the northern wheat adapted to drought condition better than the southern did.The difference in responses of varieties from both regions to environment factors inthe early and middle stages was more obvious than that in the latter period.This issimilar to our previous observation on leaf structure,and it may be related to therhythmic of the climates of their habitat.