Effect Of Water And Fertilizer On The Photosynthetic Characteristics Of Raspberry And Blackberry

Being of pretty high nutritive and health value as well as eco-economic value, Rubus idaeus L. and Rubusspp have become one of the fastest new-developed fruits in the world in recent years. However, full exploitation of the unique resources is only just in the initial stages in China, particularly, little has been done with their fundamental research into photosynthesis. We carried out research in the light of this matter, comparatively studied on the photosynthetic characteristics of Rubus idaeus L. and Rubusspp in a relatively systematical way and preliminarily researched on the physiological response of photosynthetic characteristics in Rubus idaeus L. to different water and fertilizer conditions for the first time, which will provide theoretical basis for establishing cultivation and management patterns to gain high quality and yield.With a portable photosynthesis analysis system (TPS-1) as a measuring device, a field experiment on the photosynthetic characteristics in Rubus idaeus L. and Rubusspp in pot culture was conducted.The diurnal characteristics of photosynthetic rate,the correlation between the net photosynthetic rate and some physio-ecological factors,the effect of different NP fertilizer and soil moisture levels on the photosynthetic rate of Tulemeen and Boysen leaves were compared. Besides,the discrepancy of the net photosynthetic rate of Tulemeen and Boysen leaves under different photosynthetic available radiation and NP fertilizer levels was analyzed. The main results were as follows:1,The carves of diurnal variation and seasonal changes on the photosynthetic rate of Tulemeen and Boysen leaves typically showed two peaks,appeared obvious phenomenon of"midday depression", which was mainly affected by such environmental factors as high temperature and low humidity, besides,stomatal limitation was the main cause of"midday depression"in the photosynthetic rate. The results were in accord with that of deflection correlation analysis: a negative correlation appeared significantly between the net photosynthetic rate and leaf temperature, while a significant positive correlation between the net photosynthetic rate and stomatal condunctance in Tulemeen; at the same time, the net photosynthetic rate of Boysen was positively significantly correlated with stomatal conductance,while a significant negative correlation between the net photosynthetic rate and vapor pressure.