温度对西洋参幼苗早期生长和发育的影响

Impacts of Temperature on Growth and Development of American Ginseng in Its Early Seedling Stage

以西洋参为试材,在6~18℃设5个温阶(T)培养,研究温度对西洋参萌芽籽出苗率、展叶期株高和发育历期(N),数据纳入方差分析。结果表明:6~12℃利于萌芽籽出苗却显著抑制幼苗高度,而15~18℃引起出苗率显著下降却促进幼苗正常生长;幼苗自萌芽至展叶期的发育起点温度(C)为3.7℃,有效积温(K)为272.1℃·d。变量N与T呈反比,新建倒数模型为N=K/(T-C)=(272.1±22.9)/[T-(3.7±0.8)]。这2个参数反映幼苗完成早期发育所需热量条件,利于阐明温度效应并优化这一药用植物的催芽和栽培技术。

American ginseng（Panax quinquefolium）was taken as a test material,and five gradients of temperature（T）ranging from 6℃ to 18℃ were set up to rear its seedlings to determine impacts of temperature on growth and development of the medicinal plant.Agronomic characters such as emergence rate of germinating seeds,height of seedlings on the date of leaf expansion,and developmental duration（N）of seedlings from seed germination to leaf expansion were observed and measured,and data were subject to an ANOVA.The results indicated that T ranging from 6 ℃ to 12 ℃ was favorable to emergence of the seeds but significantly inhibited height of the seedlings,whereas that ranging from 15 ℃ to 18 ℃ caused emergence rate to decrease to some extent but promoted seedlings to grew into a normal height.The threshold temperature（C）was calculated 3.7℃ in its early seedling stage,and the thermal constant（K）was 272.1℃·d.Variable N was inversely proportional to T,and a new reciprocal model between them was established then,N=K/（TC）=（272.1±22.9）/[T-（3.7±0.8）].The 2 parameters reflect thermal quantities needed by the plant for development in the stage,which contributed to explain temperature effects,and optimize both techniques of accelerating seed germination and cultivation for the medicinal plant.