高海拔冻土层地区不同土壤温度对花叶海棠光合特性的影响

摘要

With the purpose of promoting the growth of Malus transitoria in high-altitude tundra, the self-ad-justing heat tape used to heat soil is employed to execute soil warming test. 4 warming gradients, namely, 2. 0℃(S1), 3. 0℃ (S2), 4. 0℃ (S3), 5. 0℃ (S4) and 1 CK are presented in the test to measure Pn, Tr, Gs as well as Ci of M. transitoria under different temperature gradients. The result is achieved that among the 4 group of experi-mental objects, the leaves of S4 enjoy the highest Pn, Tr and Ci with a respective growth rate at 13. 88%, 58. 55%and 18. 42%, S3 boasts the highest Gs with a growth rate at 8. 68%. Besides, the soil temperature is significantly correlated to Pn, Gs as well as Ci of M. transitoria leaves and is correlated to Tr of the plant. Compared with CK, S4 and S3 can prominently improve Pn and Tr while S4, S3 and S2 can obviously raise Gs and Ci. After a comprehensive analysis of all indicators, the result is achieved that a raise of 4. 0-5. 0℃ of soil temperature is mostly suitable for M. transitoria to grow.%为促进花叶海棠在高海拔冻土层地区的生长，通过使用自控温电热带土壤增温措施对土壤进行增温试验，分别设置2.0( S1)、3.0( S2)、4.0( S3)、5.0( S4)℃4种增温梯度和1个CK对照组，测量不同梯度下花叶海棠的净光合速率、蒸腾速率、气孔导度及胞间CO2浓度。结果表明：在4种处理中， S4的花叶海棠叶片净光合速率、蒸腾速率、胞间CO2浓度最大，与对照相比，其增长率分别为13.88％、58.55％、18.42％； S3的花叶海棠叶片气孔导度最大，增长率为8.68％。土壤温度与花叶海棠叶片的净光合速率、气孔导度、胞间CO2浓度呈极显著相关，与蒸腾速率呈显著相关。与对照组相比S4与S3能明显提高净光合速率、蒸腾速率，与对照组相比S4、S3、 S2能明显地提高气孔导度、胞间CO2浓度。综合各项指标分析，在试验范围内土壤温度增加4.0~5.0℃最适宜花叶海棠的生长。