水分胁迫对云南松苗生长及生物量的影响

Growth and Biomass of Pinus yunnanensis Seedlings Under Water Control

以2年生云南松盆栽苗为试验材料,采用称重控制土壤含水量的方法,设置正常水分(T1)、轻度干旱(T2)、中度干旱(T3)和重度干旱(T4)4个处理,研究水分控制对云南松苗生长、水势、生物量及其相关性的影响。结果表明:1随着干旱程度加剧,云南松幼苗株高、地径生长量逐渐增加,土壤和叶片水势呈现下降趋势,根、叶、茎生物量增量占总生物量增量的百分比逐渐增加,根冠比逐渐增大。2苗高与地径、土壤水势与叶水势都呈现正相关关系,生长指标与水势指标大体呈现负相关关系。在4种水分处理下云南松苗木的生长指标与生物量指标之间呈正相关关系,且相关性均达显著相关水平。研究表明随着干旱的加剧,云南松苗木的生物量增量分配到根系的生物量增加,而分配到茎、叶器官上的生物量减小,以此来提高自身的抗旱能力。

To study the growth,biomass and water potential under different water control,two year old Pinus yunnanensis seedlings were potted under four different water content levels： normal water content（ T1）,mild drought（ T2）,moderate drought（ T3） and severe drought（ T4）,which were controlled by weighing the soil. Results showed that：（ 1） with water control became more serious,the heights,diameters of the seedlings increased significantly,the soil and leaf water potential were decreased; the stem and leaf biomass percentage of the total were increased slowly,the root biomass and root shoot ratio were increased.（ 2） The height was positively correlated with diameter,and soil water potential was positively correlated with leaf water potential,too. Growth indexes are negatively correlated with water potential indexes for the most part. The correlation of gradient T1 is the weakest while gradient T4 is the strongest. The growth and biomass index under four water treatment was positively correlated,and the correlation relationship were significant. We can concluded that the biomass of Pinus seedling increment allocated to roots increased,while the biomass allocated to stem,leaf organs decreased,so as to improve the drought resistance ability.