‘欧乐可可’秋海棠对干旱胁迫的生理响应

Physiological Response of Begonia ‘Orococo’ to Drought Stress

[目的]探究‘欧乐可可’秋海棠的抗旱能力。[方法]采用盆栽控水法,以‘欧乐可可’秋海棠(Begonia‘Orococo’)为试材,开展人工模拟干旱胁迫(连续干旱0、7、17、21、28、35 d)下‘欧乐可可’秋海棠的抗旱性研究。[结果]干旱胁迫期间,‘欧乐可可’秋海棠叶片自然含水量对照组与干旱28、35 d试验组存在显著差异(P<0.05),相对含水量呈下降—上升—下降的趋势,土壤含水量减少。随着干旱天数的增加,叶片的叶绿素含量、叶绿素a含量、叶绿素b含量均呈上升—下降—上升—下降的趋势;可溶性糖含量呈上升—下降—上升的趋势,在第21天出现峰值(0.151%),第28天下降至0.089%,第35天上升到0.139%;丙二醛含量呈上升积累趋势;叶片相对电导率变化呈“N”形波动,存在显著差异(P<0.05)。随着干旱天数的增加,‘欧乐可可’秋海棠植株有一定程度的生长,植株长高、叶片数增加,到后期植株生长缓慢,叶片颜色变浅,叶片卷缩;且干旱下的‘欧乐可可’秋海棠植株根系更加发达。[结论]通过在干旱胁迫条件下对‘欧乐可可’秋海棠叶片5个生理指标的测定及隶属函数法综合评定,对比其他植物的抗旱性,表明‘欧乐可可’秋海棠具有较强的抗旱性,应用前景较好。

[Objective]To explore the drought resistance ability of Begonia‘Orococo’.[Method]Begonia‘Orococo’was used as the experimental material to study the drought resistance under artificial drought stress(continuous drought 0,7,17,21,28,35 d)by using potted water control method.[Result]The results showed that during drought stress,there was a significant difference in the natural water content of Begonia‘Orococo’leaves between the control group and the experimental group for 28 days and 35 days of drought(P<0.05).The relative water content first decreased,then increased and decreased in the end.The soil moisture content showed a decreasing trend.With the increase of drought days,the contents of chlorophyll,chlorophyll a and chlorophyll b in leaves increased first,then decreased,then increased again and finally decreased;the content of soluble sugar first increased,peaked at 0.151%on the 21st day,then decreased to 0.089%on the 28th day,and finally increased to 0.139%on the 35th day.The content of malondialdehyde increased;the relative conductivity of leaves fluctuated in the shape of N,with a significant difference(P<0.05);with the increase of drought days,the plants of Begonia‘Orococo’grew to a certain extent,the plant height and the number of leaves increased,and in the later stage,the plants grew slowly,the leaves became lighter,and the leaves shrank;the roots of Begonia‘Orococo’plants were more developed under drought.[Conclusion]Under the condition of drought stress,the determination of five physiological indexes of the leaves of Begonia‘Orococo’and the comprehensive evaluation of the drought resistance of Begonia‘Orococo’compared with other plants by using the membership function method show that Begonia‘Orococo’has strong drought resistance and a good application prospect.