修枝和乙烯对降香黄檀光合系统特性影响

Effects of Pruning and Ethylene on Photosynthetic System Characteristics in Dalbergia odorifera

为探讨不同修枝强度和乙烯浓度对降香黄檀光合色素、光合特性、叶绿素荧光参数的影响,以6～8 cm降香黄檀幼树为试验材料,通过测定叶片光合色素含量、1 800μmol·m-2·s-1光强下光合指标及叶绿素荧光参数分析不同修枝强度及乙烯浓度下降香黄檀的光合色素含量、光合特性。结果表明:轻度修枝(D)和重度修枝(H)叶绿素a、叶绿素b、叶绿素(a+b)、类胡萝卜素含量均高于CK。树干注射乙烯利溶液E0.1%、E0.5%、E2.5%处理叶片叶绿素a、叶绿素b、叶绿素(a+b)、类胡萝卜素含量均高于CK。降香黄檀轻度修枝(D) Pn、Tr、Ci及Cond与CK均有明显差异。重度修枝(H)与CK除Tr外均差异不明显,但都大于CK。乙烯各处理净光合速率(Pn)气孔导度(Cond)胞间二氧化碳浓度(Ci)随乙烯浓度的增加在E0.1%达到最大值后逐渐降低,蒸腾速率(Tr)最大值为E0.5%处理后降低,但都大于CK。Fo、Fm随修枝强度的增加升高,轻度修枝(D)、重度修枝(H)和CK的Fv有明显差异,Fv/Fm、Y(Ⅱ)各处理差异不明显。乙烯处理后降香黄檀叶片Fo、Fm、Fv随着乙烯浓度的增加表现出先升高后降低的趋势,E2.5%的Fv/Fm显著低于其他各处理,Y(Ⅱ)的大小在各处理间没有明显差异。因此,适度修枝和注射乙烯利溶液可以促进降香黄檀叶片叶绿素的合成与积累及提高植株的光合能力。本研究旨在为降香黄檀人工培育提供一定的理论基础。

In order to investigate the effects of different pruning intensities and ethylene concentration on photosynthetic pigments, photosynthetic characteristics and chlorophyll fluorescence parameters of Dalbergia odorifera, 6.8 cm Dalbergia odorifera young trees were selected as the materials. The photosynthetic pigments content and photosynthetic characteristics of Dalbergia odorifera with different pruning intensities and ethylene concentrations were analyzed by measuring photosynthetic pigments content in leaves, photosynthetic indexes under 1 800 p,molem 2,sH light intensity and chlorophyll fluorescence parameters. The results showed that the contents of Chia, Chib, Chi (a+ b) and Car were higher in light pruning (D) and heavy pruning (H) than in CK. The contents of Chia, Chib, Chi (a+ b) and Car in leaves treated with ethephon solution E0.1%, E0.5% and E2.5% were higher than those of CK. The Pn, Tr, Ci, and Cond were significantly different from those of CK with light pruning (D) treatment. There was no significant difference in heavy pruning (H) and CK except Tr, but both were greater than CK. The Pn, Cond, Ci gradually decreased with increasing ethylene concentration after reaching a maximum at E0.1%, and Tr was the highest at E0.5%, then decreased, but both were greater than CK. Fo and Fm increased with the increase of pruning intensity, and the Fv of light pruning (D), heavy pruning (H) and CK were quite different. In addition, Fv/Fm and Y(II)of each treatment were not significantly different. After ethylene treatments, Fo, Fm, Fv of Dalbergia odorifera showed a trend of increasing first and then decreasing with the increase of ethylene concentration. E2.5% of Fv/Fm was significantly lower than other treatments, and Y( U) had no significant difference between treatments. Therefore, moderate pruning and injection of ethylene solution could promote the synthesis and accumulation of chlorophyll and improve the photosynthetic capacity of Dalbergia odorifera. This study aimed to provide a theoretical basis for artificial cultivation of Dalbergia odorifera.