达乌里胡枝子种子发芽吸水规律及吸水模型研究

试验选用5个地区的野生达乌里胡枝子(Lespedeza daurica (Laxm.) Schindl.)及其对应的栽培种种子进行32 h的浸种处理,分别在2、4、6、8、10、12、14、16、18、22、26、32 h测定种子的吸水量来研究其发芽过程中的吸水规律,并运用动力学隔室理论建立吸水模型,为生产中需水量供应和理解种子吸水机制提供理论依据.结果表明:无论是野生种还是栽培种,在萌发过程中吸水量同千粒重呈正相关;从种子的吸水变化趋势来看种子发芽时的吸水过程可以分为吸胀阶段(物理吸水阶段)和萌发阶段(胚的生长阶段);运用动力学隔室理论对其变量建立模型,确定达乌里胡枝子种子物理吸水阶段模型为单室模型:W=-e^-5.7t×10-3,胚生长阶段模型亦为单室模型:W=1.4728+e-e^-t×10-3,对模型值与观察值进行拟合度检验,物理吸水过程的拟合度R²=0.7256(P<0.01),胚芽生长过程的拟合度R²=0.9350(P<0.01).

Study on Seed Germination and Model of Water Imbibition of Lespedeza daurica (Laxm.) Schindl.

Lespedeza daurica(Laxm.) Schindl.is a perennial herbaceous shrub with excellent properties of drought resistance and its seedling growth status is dependent upon the water imbibition amount of the seeds.Wild seeds from 5 regions and the corresponding cultivated seeds were treated by 32h water soakage and the water imbibition amount was measured at 2 h,4 h,6 h,8 h,10 h,12 h,14 h,16 h,18 h,22 h,26 h,and 32 h,respectively.The water imbibition principle during the germinating course was studied and a new model on seed water imbibition was established with the kinetics compartmental theory.The results show that there was a positive correlation between water imbibition amount and 1000-seed weight during the germinating course,regardless of wild or cultivated seeds.The procedure of water imbibition during germinating course was divided into the swelling phase(physical water imbibition phase) and the sprouting phase(embryo development phase).The model of water imbibition was composed of two single-roomed models: W=-e^-5.7t?10-3(Physical Imbibing Model) and W=-e^-5.7t?10-3(Embryo Development Model).The superposition degree for the swelling phase was R²=0.7256(P<0.01) and for the embryo development phase R²=0.9350(P<0.01) according to the superposition analyze of the measured and predicted values.