广西4个油茶品种苗期对干旱胁迫的生理响应

Physiological responses of four Camellia oleifera clones of Guangxi province in seeding stage under drought stress

以产自广西的4个油茶Camellia oleifera品种‘桂无1号’(桂1)、‘桂无4号’(桂4)、‘岑软2号’(岑2)和‘岑软3号’(岑3)的一年生嫁接苗为试材,通过PEG 6000模拟干旱胁迫,分别对其设置10%、20%和30%共3个浓度梯度,给予持续12、24、36 h以及营养液恢复12 h处理,测定幼苗各处理的生理指标,并用隶属函数分析法综合评价4个油茶品种幼苗的抗旱性。结果表明:干旱胁迫下,4个油茶品种幼苗叶片相对含水量均小于对照,其中桂1和桂4下降幅度最大;相对电导率、丙二醛、可溶性蛋白含量随着胁迫时间延长而呈上升趋势;胁迫处理36 h后,桂1和桂4的叶绿素含量显著降低,而岑2和岑3的叶绿素含量升高且始终维持在较高水平;岑2和岑3的可溶性糖含量增幅较桂1和桂4明显。复水后,岑2和岑3较多生理指标有恢复迹象。隶属函数分析表明,4个油茶品种幼苗的抗旱能力排序为岑软3号>岑软2号>桂无1号>桂无4号。

Physiological changes of the one-year-old seedlings of four Camellia oleifera clones Guiwu 1（G1）,Guiwu 4（G4）,Cenruan2（C2）,Cenruan3（C3）were observed under different PEG6000 concentrations（10%PEG,20%PEG,30%PEG）and different time（stress duration 12 hours,24 hours,36 hours and normal nutrient solution 12 hours）.Finally,a comprehensive evaluation on drought resistance of four cultivars was given according to subordinate fimction values analysis.The results showed that during drought stress period,the watercontent of the four seedlings declined,and that of G1,G4 was lower level than other two cultivars;relative electrical conductivity,content of MDA and soluble protein were increased with prolonging stress duration;chlorophyll content of G1 and G4 declined drastically,in contrast,C2 and C3 increased and maintain at a high level;the content of soluble sugar of C2 and C3 were increased much than that of G1 and G4.Most of physiological indexes of C2 and C3 generally recovered after being put in the normal nutrient solution.Subordinate function values analysis can provide a quantitative evaluation of the different physiological indexes for the seedlings under drought,which indicated that the order of drought resistance of the four seedlings was Cenruan 3 〉 Cenruan 2 〉 Guiwu 1 〉 Guiwu 4.