不同温度对烟草生长发育及光合作用的影响

摘要

Tobacco (Nicotiana tabacum L.)plants were cultivated in phytotron set at relatively low temper-ature (daily average 16.5 ℃),normal temperature (daily average 23.5 ℃)and relatively high temperature (daily average 30.5 ℃),and the effects of different temperature on growth,development and photosyn-thesis of tobacco plants were investigated.The results showed that:(1 )Compared with the plants under normal temperature,the plants grown under the relatively higher and lower temperatures decreased the plant height,leaf length,width and showed an inhibiting effects on tobacco plants to some extent.(2) Plants under relative higher and lower temperature reduced the net photosynthetic rate (Pn ),intercellular CO2 concentration (Ci ),stomatal conductance (Gs ),transpiration rate (Tr ),maximum quantum yield of PSⅡ photochemistry (Fv/Fm ),quantum efficient of PSⅡ (ΦPSⅡ ),photochemical quenching (qp ),Rubisco activity,but increased the minimal fluorescence of dark-adapted state (F0 )of tobacco leaves.Tobacco plants grown under long-term relative higher and lower temperatures both inhibited the growth by partly damaging or inactiving the photosynthetic apparatus,and reduced the photosynthesis efficiency of tobacco plants to some extent.Long-term daily average temperature at 23.5 ℃ could be the optimal temperature for growth and photosynthesis of tobacco plants.%该试验通过人工气候室模拟相对低温(日均温16.5℃)、常温(日均温23.5℃)和相对高温(日均温30.5℃)3种日动态温度,研究了不同温度对烟草生长发育及光合作用的影响.结果表明:(1)与常温下生长的烟草相比,相对低温和高温处理均降低了烟株的株高、叶长和叶宽,在一定程度上抑制了烟草的生长.(2)相对低温和高温处理比常温处理下有较低的烟叶净光合速率(Pn)、胞间CO2浓度(Ci)、气孔导度(Gs)、蒸腾速率(Tr)、PSⅡ最大光化学量子效率(Fv/Fm)、PSⅡ实际光化学量子效率(ΦPSⅡ)、光化学猝灭系数(qp)、Rubisco羧化酶活性和相对较高的初始荧光强度(F0).长期较高或较低的温度均会对烟草的生长发育产生抑制,这可能因其在一定程度上抑制了烟叶的光合机构活性并对反应中心造成了损伤,从而降低了烟草的光合作用,抑制了烟株的生长,长期日均温23.5℃有利于烟草的生长和光合作用.