干旱及复水对野生苦瓜幼苗生长和生理特性的影响

为了研究干旱及复水处理对野生苦瓜幼苗生长和生理特性的影响,探讨野生苦瓜的抗旱机制,为其栽培育种提供理论依据。以野生苦瓜‘JH01’为试验材料,对干旱胁迫4、8、12、16 d和复水处理2、5 d野生苦瓜幼苗部分生理指标的变化进行研究。结果显示,随着干旱胁迫时间的延长,植株长势变弱,叶片萎蔫程度加重,叶片相对电导率、丙二醛含量、超氧阴离子含量、过氧化氢含量和脯氨酸含量逐渐上升,叶绿素含量呈先升高后降低的变化趋势;复水后,各指标得到了不同程度的恢复,复水5 d时叶绿素含量、相对电导率、过氧化氢含量均恢复到接近对照水平;此外,脯氨酸的可塑性指数达0.98,明显大于其他生理指标,叶绿素含量的可塑性指数最小为0.29。综上表明,野生苦瓜幼苗具有一定的耐旱能力,复水对干旱胁迫具有缓解作用。

Effects of drought stress and rewatering on the growth and physiological properties of wild bitter gourd seedlings

The research aimed at the effects of drought stress and rewatering on the growth and physiological properties of wild bitter gourd seedlings, discussing the drought resistance mechanism of wild bitter gourd and providing the theoretical basis for its cultivation and breeding. Wild bitter gourd‘JH01’was selected as experimental material in order to study the growth and physiological response of seedlings subjected to 4,8,12,16 days drought stress and subsequent 2 d,5 d rewatering treatments. The results showed that with the extension of drought stress time, the plant grew weaker and the degree of leaf wilting increased, and the relative conductivity, the contents of malondialdehyde, superoxide radicals,hydrogen peroxide and proline increased, while the level of chlorophyll increased firstly and then decreased. After rewatering treatments,most parameters recovered in certain degree. The content of chlorophyll, relative conductivity and hydrogen peroxide all recovered approximately to the control level at 5 d after rewatering. In addition, the plasticity index of proline was 0.98, which was significantly higher than other physiological indexes, and the plasticity index of chlorophyll content was 0.29 at the minimum. It was concluded that the wild bitter gourd seeding had certain drought tolerance and rewatering could release the drought stress.