低温弱光胁迫对设施黄瓜叶片面积与干物质量的影响

Effects of low temperature and weak light stress on leaf area and dry matter of cucumber in greenhouse

为研究黄瓜不同叶龄叶片的叶面积、干物质量在低温弱光胁迫下的变化规律,以黄瓜品种碧玉3号为试材,在温室无土栽培管理模式下,分别设置4个低温弱光水平,采用正交试验设计进行实验,测定不同叶龄叶片的叶面积、植株干物质量变化。结果表明:低温胁迫对叶龄小于15 d的叶片形态发育影响较大,与对照相比,叶片面积下降幅度较大;对叶龄为15~25 d的叶片影响相对较小;在中度低温(10~15℃)与弱光(光量子通量密度PPFD为100~200μmol·m^(-2)·s^(-1))胁迫下,处于伸展期(叶龄5~15 d)的叶片叶面积增长量明显减少,叶干物质量有所增加;而重度低温(5~10℃)与弱光(PPFD为0~100μmol·m^(-2)·s^(-1))条件下叶龄小于15 d的叶片形态发育基本停滞,与对照相比,叶片干物质量下降幅度较大;轻度低温弱光(15~20℃,PPFD为200~400μmol·m^(-2)·s^(-1))胁迫对黄瓜叶片的正常发育不构成显著威胁,尤其是对发育初期叶片面积增长与干物质量积累影响较小。研究结果表明,为保证叶片从发育初期至扩展期的正常生长,应避免中度以上低温弱光胁迫(5~15℃,PPFD为0~200μmol·m^(-2)·s^(-1))。

To study the change rules of leaf area and dry matter weight of cucumber with different leaf ages under low temperature and weak light stress,cucumber variety Biyu 3 was used as the test material,four treatment levels of low temperature and weak light were set,changes of leaf area,dry matter weight with different leaf ages were measured.The results showed that low temperature stress had a great effect on morphological development of leaves less than 15 days old,compared with the control,the decrease of leaf area was relatively large,but the effect on leaves aged 15-25 days was small;Under moderate low temperature(10-15℃)and weak light(photosynthetic photon flux density,PPFD 100-200μmol·m^(-2)·s^(-1)),growth of leaf area decreased significantly and dry matter weight of leaves increased in the extension stage(5-15 d);The morphological development of leaves less than 15 days was basically stagnated under severe low temperature(5-10℃)and weak light(0-100μmol·m^(-2)·s^(-1)),compared with the control,the decrease of leaf dry matter weight was relatively large;Mild low temperature and weak light stress(15-20℃,PPFD 200-400μmol·m^(-2)·s^(-1))did not significantly threaten the normal development of cucumber leaves,especially had little effect on the growth of leaf area and dry matter accumulation at the early stage of development.The results showed that in order to ensure the normal growth of leaves from the early stage of development to the expansion stage,moderate or above low temperature and weak light stress(5-15℃,PPFD 0-200μmol·m^(-2)·s^(-1))should be avoided.