Effects of fertilization on seedling growth and photosynthetic characteristics of Gleditsia sinensis
In order to find out the optimal nitrogen application rate suitable for the rapid growth of two-year-old Gleditsia sinensis grafted seedlings,the two-year-old G.sinensis graf-ted seedlings with the same growth were used as experimental materials,the effects of differ-ent nitrogen application rates on the growth,photosynthetic characteristics and chlorophyll fluorescence parameters of two-year-old G.sinensis seedlings with the same growth rate were studied.The results showed that:(1)Nitrogen fertilizer significantly increased the net growth of plant height,ground diameter,thorn length and thorn stem of G.sinensis seed-lings,and reached the maximum value under N3(pure nitrogen 90 g/plant).After the ex-periment,compared with CK,the growth of plant height and ground diameter increased by 59.71％and 50.10％,respectively.(2)N3 treatment could greatly promote the synthesis of chlorophyll in the leaves of G.sinensis,increase the net photosynthetic rate and stomatal conductance of the leaves,and then improve the photosynthetic capacity of G.sinensis seed-lings.(3)With the increase of fertilizer application,the maximum fluorescence(Fm)and the maximum photochemical efficiency(Fv/Fm)of PS Ⅱ in G.sinensis leaves increased first and then decreased with the increase of nitrogen application,while the initial fluorescence(Fo)had the opposite trend,and both reached the extreme value under N3 treatment.(4)In terms of the activity of PS Ⅱ reaction center,reasonable application of nitrogen fertilizer could increase the light energy absorbed by the unit reaction center(ABS/RC),captured light energy(TRo/RC)and energy used to transfer electrons(ETo/RC)and reduce the energy used for heat dissipation(DIo/RC).According to the comprehensive parameters,the opti-mal nitrogen application rate for the growth of two-year-old G.sinensis grafted seedlings was 60-90 g/plant.
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NSTL
万方数据
维普
