Studies On The Adaptability Difference To Short-time Elevated Temperature Of Different Area Malus Baccata Borkh

The experiment had been carried out in college of horticulture science and engineering, Shandong Agriculture University from 2006-2008 with Malus baccata Borkh seedlings which collected in Zhejiang, Shandong, Beijing, Shenyang. It mainly studied the change rule of the seedling nutrition, the difference of heat resistence of different area seedling and the change of photosynthesis during the rise of temperature.The main results were as follows:1.During the rise of temperature, the nutrition of the four area seedlings first went up then declined. It reached its top at 25/20℃, then following the rise of temperature, the nutrition declined. In the man-made temperature grads, the higher the temperature,the lower the nutrition. The nutrition of the four area seedlings is different at the normal temperature 20/15℃and 25/20℃, but the difference is not obvious.when the temperature reached 30/25℃,35/30℃and 40/35℃,the difference is obvious: Shenyang>Beijing>Shandong>Zhejiang.In the natural temperature grads,the nutrition is opposite to the temperature. It showed that the nutrition of the seedling is in negative correlation with temperature.2. When the temperature exceeded 25/20℃, the SOD,CAT activity of the four area seedlings went up and the content of Pro and soluble sugar increased according to the rise of temperature.This is the adapting ability of the seedlings.But the SOD,CAT activity, the Pro and soluble sugar content is not the same at 30/25℃,35/30℃and 40/35℃, and the different is obvious: Zhejiang >Shenyang> Shandong> Beijing. The rule is not consistent to the nutrition.3. When the temperature exceeded 25/20℃,the GS,Tr,Pn, Fv/Fm,φPSⅡ, qP declined. The Ci declined at 30/25℃,35/30℃,then went up quickly at 40/35℃.It meant that the photosynthesis was from Stomatal and nonstomatal Limit. The differences of photoparameter and fluorescenceparameter of the four area seedlings were obvious at 30/25℃,35/30℃and 40/35℃. Thereinto the Gs, Tr, Pn, Fv/Fm,φPSⅡ, qP: Zhejiang >Shenyang> Shandong> Beijing, and the qP,NPQ: Beijing >Shandong >Shenyang >Zhejiang. It showed that the photosynthesis and the resistence of the photo organ to the high temperature is different, exhibiting the same rule as the heat resistence.