Study On Photosynthesis Of Loqaut Trees (Eriobotrya Japonica Lindl.) During Winter And Spring

In this study, Loqaut Trees (Eriobotryajaponica Lindl) were used experiment material. The changes of photosynthetic rate and effects of fruit on photosynthesis were studied in this study. The effect of low temperature treatment on loqaut leaves is the emphases in this study. The mostly purpose of this study is explore the mechanism of the effect of low temperature treatment on loqaut leaves. The results are as follows:1. The changes of photosynthetic rate in a day in Loqaut Tree leaves are one-apex in winter. In other seasons the change is two apexs. The max photosynthetic rate appear at 11 a.m. The second photosynthetic rate appear at 2 p.m. The change of photosynthetic rate in a year in Loqaut Trees leaves is two-apex. The max photosynthetic rate appear in may. The second photosynthetic rate appear July.2. Fruits and flowers can promote the photosynthetic rate in Loqaut Trees leaves. After wiping off fruits the photosynthetic rate depresses by reason of stomatal in beginning. Some time later the other factors make for the results.3. irradiance of Loqaut Trees leaves is 400umol. m-2. s-1 in winter. On the other hand, the light compensation point is 25 mol. m-2. s-1. This results indicate Loqaut Trees adapt shade place.4. Chilling led to decline in stomatal conductance, net photosynthetic rate and intercellular CO2 concentration. But Intercellular CO2 concentration increases after chilling at 0 for 3 days. The results indicate the main reason of photosynthetic rate depresses by chilling at 10 , 5 is stomatal. The other factors make for the photosynthetic rate depresses by chilling at 0 .5. Chilling at 10 , 5 led to decline in apparent quantum yield of photosynthesis and carboxylation efficiency. Although decline for Chilling at 10 , 5 for 3 days stomatal conductance, net photosynthetic rate and Intercellular CO2 concentration can increase to normal after 15 for 3 days .Chilling at 0 for 3 days it can not increase to normal.6. Fv/Fo and Fv/Fm will decline by chilling at 5 , 0 whereas it maintain normal by chilling 10 . This imply that the ability of absorb and translate light-energy decline bychilling at 5 , 0 . This ability does not decline by chilling at 10 .7. Chilling at 10 for 3 days led to decline FO, whereas chilling at 5 led to increase FO slimly. Chilling at 0 for 3 days will led to increase FO distinctly. This suggest photosynthetic machine is not destroyed by chilling at 10 for 3 days, whereas is destroyed by chilling at 5 ,specially at 0 .8. Chilling at 10 and 5 for 3 days led to decline PS slimly, whereas PS decline distinctly by chilling at 0 . Declining by chilling at 10 and 5 , PS can resume after placed at normal temperature .But it can not occur by chilling at 0 for 3 days .This prove the conclusion of "7"paragraph.