不同石砾含量栽培基质对降香黄檀生理指标的影响

Effects of Cultivation Medium with Different Gravel Contents on Physiological Indexes of Dalbergia odorifera Seedlings

试验以粉碎的石灰石与壤土配制成不同石砾含量的栽培基质,通过测定不同石砾含量栽培基质对降香黄檀(Dalbergia odorifera)幼苗叶片光合作用及叶绿素荧光参数的影响,评价降香黄檀幼苗对不同石砾含量栽培基质的适应性,探讨降香黄檀在石漠化治理中的应用前景。结果表明,对照组(0%石砾含量土壤)和各处理组叶片净光合速率、气孔导度、叶片胞间CO2浓度、叶片蒸腾速率日变化均呈单峰型,趋势一致,无明显差异;在25%、50%石砾含量栽培基质下,相比较于对照组,降香黄檀幼苗叶片全天净光合速率较高,表明适当的石砾栽培基质胁迫可以提升降香黄檀幼苗叶片的光合能力;叶片实际光化学效率、电子传递速率明显呈现出随着土壤石砾含量的升高而降低的趋势,但对最大光化学效率和非光化学淬灭系数影响不大。降香黄檀幼苗对不同石砾含量栽培基质具有较强的适应能力,在100%石砾含量栽培基质处理时,仍可以适应胁迫环境。降香黄檀叶片的气孔随着石砾含量的增加,有增大和变长的趋势。

By measuring the effects of cultivation medium with different gravel contents on leaf photosynthesis and chlorophyll fluorescence parameters of Dalbergia odorifera seedlings,the D. odorifera＇s adaptability to different cultivation medium was evaluated,and the application prospect of D. odorifera under desertification control was discussed. The results showed that the diurnal variation of the net photosynthetic rate,stomatal conductance,intercellular CO2 concentration and transpiration rate all showed a single peak and no significant difference between the control group（the soil without gravel） and each treated groups.The net photosynthetic rate of D. odorifera seedlings were obviously higher than control group when the content of gravel were25%,50%; which indicated that cultivation medium with appropriate gravel stress could enhance leaf photosynthetic capacity of D. odorifera seedlings. It appeared clearly that actual photochemical efficiency blade and the electron transfer rate decreased with the increasing of gravel in soil;but there was little effect on the maximum photochemical efficiency and non-photochemical quenching coefficient. There was strong adaptive ability for D. odorifera seedlings to kinds of soils with different gravel contents. Even to the growing media with 100% gravel, it still could adapt to environmental stress. Under the increasing of gravel in soil, effects on the pore structure of D. odorifera leaves become bigger and longer trend.