水分胁迫对番茄生长及光合系统结构性能的影响

Effects of water stress on growth and photosynthetic system characters of Lycopersicon esculentum L.

以普通番茄和樱桃番茄为试材,分别在正常供水和水分胁迫条件下,研究不同生态型番茄生长指标及光合系统结构的变化。水分胁迫显著抑制了番茄的生长,叶片水势及叶片相对含水量显著下降,普通番茄和樱桃番茄单株总干重分别下降了59.36%和51.17%,二者的根冠比分别上升了37.93%和29.17%。水分胁迫后,叶片净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、胞间CO2浓度(Ci)、PSⅡ光化学量子效率(ΦPSⅡ)、光化学猝灭系数(qP)及光合电子传递速率(ETR)均下降,非光化学猝灭系数(NPQ)和水分利用效率(WUE)提高。水分胁迫后叶片气孔密度、气孔大小均有所下降,大部分气孔关闭且深陷。叶绿体变大变圆,基粒片层排列紊乱,淀粉粒减少或消失。

The experiment was conducted under two water levels： no stress（75%-80% of field capacity）,stress（30%-40% of field capacity）.The changes of growth and photosynthetic system characters of tomato were investigated.The results showed that,under the water stress condition,the growth of the plants was inhibited,leaf water potential and leaf relative water content decreased.The total plant dry weight declined significantly and the reduction was 59.36% for Meifen-2 and 51.17% for Hongsheng,respectively.The root/shoot ratio increased 37.93% for Meifen-2 and 29.17% for Hongsheng.The net photosynthesis rate（Pn）,stomata conductance（Gs）,transpiration rate（Tr）,intercellular CO2 concentration（Ci）,the actual photosynthesis efficiency of PSⅡ in the light（ΦPSⅡ）,the electron transport rate（ETR） and photochemical quenching（qP） decreased whereas the non-photochemical quenching（NPQ） and water use efficiency（WUE） increased.The stomata became smaller and the density decreased,most of them closed.The chloroplasts became round in shape,the lamellae arranged disorderly and the number of starch grain decreased or disappeared.