早实核桃与晚实核桃光合特性比较研究.

[Objective] A comparative study was carried out on the photosynthetic characteristics of the early fruiting walnut ‘Nonghe 1’ and the late fruiting walnut ‘Jinlong 2’ .[Method] Taking ‘Nonghe 1’ and ‘Jinlong2’ as test materials, the leaf photosynthetic parameters were determined by Li-6400 photosynthetic instrument, and the relationship between net photosynthetic rate and main environmental factors was analyzed. [Result]The diurnal variation of net photosynthetic; rate for ‘Jinlong 2’ showed a ‘double peak’ curve, and the photosynthetic ‘siesta’ phenomenon was caused by non-stomatal limiting factors. ‘Nonghe 1’ was a single peak curve. Transpiration rate, intercellular CO2 concentration and stomatal conductance of ‘Jinlong 2’ were significantly increased by 27.46 % ,17.78 % and 22.73 % compared with that of ‘Nonghe 1’ (P <0. 05) . Compared with ‘Jinlong 2’ , the net photosynthetic; rate, water utilization rate and stomatal limit values of ‘Non-ghe 1’ were significantly increased by 20. 00 % ,45.40 % and 42. 40 % (P <0. 05 ). Path analysis showed that photosynthetic effective radiation was the main decision-making factor in affecting the diurnal change of net photosynthetic; rate of ‘Nonghe 1’ and ‘Jinlong 2’ . Air relative humidity and air CO2 concentration were the main limiting factors of ‘Jinlong 2’ and ‘Nonghe 1 ’ respectively. [Conclusion] Early walnut ‘Nonghe 1’ had stronger photosynthetic; capacity than late walnut ‘Jinlong 2’. Photosynthetic; effective radiation is the main environ-mental factor in affecting the net photosynthetic rate of early and late fruiting walnut. In the production, appropriate plant spacing and reasonable pruning can be adopted to promote ventilation and light transmission. [ABSTRACT FROM AUTHOR]