氯胁迫对罗布麻种子萌发影响与毒害阈值研究OA

Taking Apocynum venetum as the research object,two chlorine sources,CaCl2(with Cl-concentrations of 0,20,40,60,80,100,120,140,160,180,and 200 mmol/L)and NaCl(with Cl-concentrations of 0,50,100,150,200,250,300,350,and 400 mmol/L),were set up to study their effects on the germination indices(germination rate,germination potential,germination index,and aver-age germination time)and seedling growth(stem length,root length,and fresh weight)of Apocynum venetum seeds.The results showed that under CaCl2 treatment,as the Cl-concentration increased,the germination rate,germination potential,and germination index decreased,but significantly increased at 100 mmol/L,even exceeding the control level.After exceeding 160 mmol/L,they decreased again until approaching zero.The average germination time first shortened and then lengthened,and the seedling length,root length,and fresh weight gradually decreased.Under NaCl treatment,all the indices de-creased monotonically with the increase in concentration.Through regression analysis of the Boltzmann Model,the Cl-toxicity threshold(IC50)of CaCl2 and NaCl treatments was determined to be 176.80 mmol/L and 293.48 mmol/L,respectively.This experiment provides a reference for determining the chloride ion toxicity threshold when growing Apocynum venetum in Xinjiang.