朝天椒苗期对水涝胁迫的生长及生理响应

以耐涝性不同的朝天椒品系‘ZHC1’‘ZHC2’和‘ZHS2’为试材,采用模拟短期水涝胁迫方法,研究了水涝胁迫对朝天椒苗期生长及生理指标的影响,以期探讨辣椒的耐涝机制。结果表明:在淹水24h(W24h),供试辣椒茎粗比对照显著增加;‘ZHC2’(耐涝)植株的鲜、干质量大于对照。在恢复24h(R24h)时,‘ZHC2’和‘ZHS2’(中等耐涝)株高分别比对照显著增加。水涝胁迫促进‘ZHC2’和‘ZHS2’根系浅层分布及不定根形成。‘ZHC2’叶绿素受水涝胁迫的伤害较小,淹水时类胡萝卜素含量升高。水涝胁迫下3个辣椒品系的可溶性糖、脯氨酸含量上升。每个时期‘ZHC2’叶片和根系中丙二醛(MDA)含量最低,‘ZHC1’则最高。总之,茎增粗,根系浅层分布及不定根形成,叶绿素受伤害较小,类胡萝卜素、可溶性糖及脯氨酸含量上升可能有助于提高‘ZHC2’的耐涝性及淹水后的生长恢复。不定根形成、类胡萝卜素及丙二醛含量是朝天椒耐涝性鉴定的重要指标。

Growth and Physiological Responses of Capsicum frutescens Seedlings to Waterlogging Stress

Capsicum frutescens strains‘ZHC1’‘ZHC2’and‘ZHS2’with different waterlogging tolerance were used as test materials.The effects of waterlogging stress on seedling growth and physiological indexes of pepper were studied by simulating short-term waterlogging stress,in order to explore the waterlogging tolerance mechanism of pepper.The results showed that the stem diameter of these peppers increased significantly at the 24hours after the waterlogging treatment(W24h);the fresh weight and dry weight of waterlogging-tolerant‘ZHC2’plants were higher than those of the control.The plant height of‘ZHC2’and‘ZHS2’(medium waterlogging tolerance)was significantly higher than that of the control at the 24hours after the recovery(R24h).Waterlogging stress promoted the shallow root distribution and adventitious root formation in‘ZHC2’and‘ZHS2’.The chlorophyll of‘ZHC2’was less damaged by waterlogging stress,and the carotenoid content increased under the waterlogging stress.The contents of soluble sugar and proline in three pepper lines increased under the waterlogging stress.The MDA contents of the leaves and roots in‘ZHC2’were the lowest,while those in‘ZHC1’were the highest.In conclusion,thick stem,root shallow distribution,adventitious root formation,less damage to chlorophyll,and the content increase of carotenoid,soluble sugar and proline might contribute to waterlogging tolerance and growth recovery of‘ZHC2’.Adventitious root formation and contents of carotenoid and malondialdehyde were important indexes for waterlogging-tolerant identification of Capsicum frutescens.