| Abstrakt: |
[Objective]Photosynthetic characteristic comparison of 'Hongyang' kiwifruit grafted with four different rootstocks was conducted to provide references for selecting suitable rootstock for 'Hongyang' kiwifruit. [Method] The light response curve and diurnal variation of photosynthetic physiological parameters of two-year-old 'Hongyang' kiwifruit grafted with four different rootstocks (Actinidia latifolia, A. guilinensis, A. longicarpa and A. chinensis) were measured by using Li-6400 portable photosynthesis system. The non-rectangular hyperbolic model was adopted to fit the light response curve. [Result] The results of light response curve measurement indicated that the photosynthetic characteristics of 'Hongyang' kiwifruit grafted with four rootstocks showed obvious variations. The variations of maximum net photosynthetic rate (Pmax), apparent photosynthetic quantum yield (AQY), light saturation point (LSP) and light compensation point (LCP) were 17.6853-24.8340 μmol/m2 ·s, 0.0465-0.0538 μmol/m2 ·s, 433.60-494.79 μmol/m2 · s and 33.19-61.79 (μmol/m2 ·s, respectively. The Pmax, AQY and LSP in 'Hongyang' kiwifruit grated with rootstock of Actinidia longicarpa were all the highest. The results of diurnal variation of photosynthesis measurement showed that the diurnal variation of net photosynthetic rate (Pn) in 'Hongyang' kiwifruit was a double-peak model. and the first photosynthetic peaked at about 9:30 a.m. The midday depression of photosynthesis appeared at 13:00-14: 00, and it was because of the stomatal closure caused by high temperature and the decrease of air humidity. The Pn, water use efficiency (WIE), light use efficiency (LLE) and carboxylation efficiency (CE) in 'Hongyang' kiwifruit grafted with rootstock of A. longicarpa were all the highest compared with those grafted with other three root-stocks. [Conclusion] Based on the performances of photosynthetic characteristics, A. longicarpa may be the best for 'Hongyang' kiwifruit among the four rootstocks tested. [ABSTRACT FROM AUTHOR] |
