Effects of drought stress on the growth and biomass of Pinus massoniana seedlings in different provenances.

The effects of periodic drought stress on the growth and biomass of Pinus massoniana seedlings in different provenances including Lechang,Guangdong Province,Yuan'an,Hubei Province,Rucheng,Hunan Province,Jiangshan,Zhejiang Province and Huoshan,Anhui Province were studied.The results were as follows:(1) The morphological injuries of seedlings from all 5 provenances were aggravated along with the decrease of soil water potential.There were no significant differences in appearance among different provenances under the same level of drought stress.(2) The seedling height growth of all 5 provenances was inhibited under drought stress.Seedlings from Jiangshan,Zhejiang Province had the amount of height growth with minimal impact among all 5 provenances.Its height increment was 1.86 cm,and height increment rate was 15.79% under severe drought stress.And the seedlings from Lechang,Guangdong Province had the amount of height growth with maximum impact among all 5 provenances.Its height increment was only 0.35 cm,and height increment rate was only 2.33% under severe drought stress.(3) The response of seedling biomass in different