白灰毛豆对土壤pH的生态适应性研究

Ecological Adaptability of Tephrosia candida to pH

外来种入侵机制之一就是其对环境的广泛适应性.通过研究白灰毛豆种子在不同pH缓冲液的萌发以及一年生植株在不同pH土壤生长的生理指标变化,确定其生态幅,为扩展区域预测和生态风险评估提供依据.试验以不同pH值(pH=6,7,8)的磷酸缓冲液和蒸馏水浇灌,研究白灰毛豆种子萌发情况.以其一年生植株为试材,以实验室调配的pH分别为3.5(L),7.49(M1),7.9(M2)三种土壤做栽培基质,并以pH为5.25的红壤作对照,测定移栽后植株生长中形态和叶绿素、Pro、MDA含量和POD活性变化,研究其对pH的生态适应性.结果表明:种子在不同基质中均都能萌发,萌发率分别为4.85%,3.64%,6.06%,约为对照的1/2-3/5.L较M1、M2对一年生植株生长表现出了更强的胁迫效应,但90天后,各处理植株均恢复了正常的生长,且L植株生长好于M1、M2.各处理植株Pro、MDA含量和POD活性均表现先升后降的趋势,表明其对环境的逐步适应.在酸性至碱性土壤上种子萌发和生长特性以及表现出的生理上适应性,使其扩展适应范围较大.

One of the invasive mechanisms of alien species is its wide adaptability to the environment.To provide the basis for extending regional prediction and ecological risk assessment,the ecological amplitude of Tephrosia candida's seeds was determined by studying the their germination at different pH buffer,and the morphological and physiological indexes of annual plants grown in the soil of different pH.Experiment was conducted on the germination of the seeds watered with different pH (pH = 6,7,8) phosphate buffer and distilled water.With the annual plants of Tephrosia candida as test materials,using three kinds of soil cultivation matrix—pH 3.5 (L),7.49 (M1),7.9 (M2),and with red soil (pH 5.25) as control group,the change of shape,chlorophyll,Pro,MDA content and POD activity were measured after transplanting.The results showed that the seed germinated in different substrates,with the germination rate 4.85 %,3.64 % and 6.06 %,respectively—about1/2-3/5 of that of CK.Compared to those in alkali environment,annual plants in acid environment show stronger stress effect.However,90 days later,all plants return to normal state,and the acid ones grow better than the alkali ones.Proline,MDA content and POD activity in annual plants under different treatments all show decline,which indicates Tephrosia candida's seeds are adapting to the environment gradually.The seed germination in acidic and alkaline soil,and its physiological adaptability and growth characteristics expand the adaptation scope of tephrosia candida.