The Relationship of Leaf Water Potential and Soil Water Content of Five Kinds of Seedings in South China

Five species in South China area,two fast-growing species( Eucalyptus urophylla × Eucalyptus grandis and bamboo-willow) and three Karst area species( Rhaphiolepis indica,Evodia glabrifolia,and Zenia insignis) were tested by pot experiment to study the relationships of soil water content and leaf water potential under drought stress,and to estimate water holding capacity and drought resistance of five kinds of seedings from the perspective of water potential changes. The results showed that: 1soil water content and leaf water potential were used to fit curve,exponentiation was best for Rhaphiolepis indica( R2= 0. 98,P 0. 01),logarithmic was best for Eucalyptus urophylla × Eucalyptus grandis,bamboo-willow,Evodia glabrifolia,and Zenia insignis( R2 0. 92,P 0. 01). 2Rhaphiolepis indica and bamboo willow maintained a high leaf water potential,indicating a strong ability to maintain moisture and to delay dehydration; leaf water of Eucalyptus urophylla × Eucalyptus grandis,Evodia glabrifolia and Zenia insignis Sharply declined in moderate and sever drought,its ability to maintain moisture was weak. 3Three species in Karst area( Rhaphiolepis indica,Evodia glabrifolia,and Zenia insignis),leaf water potential of Rhaphiolepis indica decreased rapidly,in same soil water content,leaf water of Rhaphiolepis indica was significant higher than Zenia insignis and Evodia glabrifolia,drought resistance of Rhaphiolepis indica was higher than Zenia insignis and Evodia glabrifolia,for fast-growing species( Eucalyptus urophylla × Eucalyptus grandis and bamboo-willow),leaf water potential of bamboo-willow decreased rapidly than Eucalyptus urophylla × Eucalyptus grandis,and indicating higher drought resistance.