The present study aimed to determine the effects of gradual drought stress on Prunus mongolica seedlings. The growth and chlorophyll fluorescence of the seedlings were investigated under drought and control conditions. The short-term (21 day) decline in soil water content from to did not significantly influence the growth of P. mongolica seedlings but increased the height, sal diameter, crown, leaf number, stem mass, leaf mass, and root mass of the seedlings. | Turkish Journal of Biology Research Article Turk J Biol (2015) 39: 532-539 © TÜBİTAK doi: Effects of gradual soil drought stress on the growth, biomass partitioning, and chlorophyll fluorescence of Prunus mongolica seedlings Youyan GUO, Hongyuan YU*, Dongsheng KONG, Fang YAN, Donghua LIU, Yajuan ZHANG Hexi University, Zhangye, . China Received: Accepted/Published Online: Printed: Abstract: The present study aimed to determine the effects of gradual drought stress on Prunus mongolica seedlings. The growth and chlorophyll fluorescence of the seedlings were investigated under drought and control conditions. The short-term (21 day) decline in soil water content from to did not significantly influence the growth of P. mongolica seedlings but increased the height, basal diameter, crown, leaf number, stem mass, leaf mass, and root mass of the seedlings. The growth of the drought group reached the maximum, but remained lower than that of the control group, within 21 days. Compared with the control group, the drought group showed , , , , , , and lower height, basal diameter, crown, leaf number, stem mass, leaf mass, and root mass, respectively. With the gradual manifestation of soil drought through the decline in soil water content from to from 21 days to 42 days, growth of the drought group became significantly lower than that of the control group (P ). The soil water content of the control group was significantly higher than that of the drought group from 7 days to 42 days (P ). By contrast, the leaf RWC of the drought group gradually decreased with increasing stress levels (Table). From 0 days to 21 days, the RWC of the drought group was unchanged. However, the RWC significantly decreased after 28 days, with a total reduction of after 42 days compared with the RCW after 0 days. The RWC of