短期夜间低温后番茄光合作用及叶绿体超微结构的恢复效应

Recovery effect of tomato leaves photosynthesis and chloroplast ultrastructure after a short-term low nocturnal temperature

为明确短期夜间低温后番茄光合作用在常温下的恢复效应,研究了番茄幼苗经夜间15℃(对照)、12℃、9℃和6℃处理7d后植株光合作用和叶绿体超微结构的变化.结果表明:短期夜间低温处理有利于恢复期番茄叶片的光合作用;12℃和9℃处理叶片叶绿素含量均可恢复至对照水平,6℃处理叶绿素含量则不可恢复;夜间低温处理并未严重抑制叶片气孔的形成,相反刺激了恢复期叶片气孔的形成与发育;6℃处理后叶绿体基粒片层排列较松散,片层数减少.恢复7d时,夜间处理温度越低,叶绿体中淀粉粒越小、数量越少,基粒片层排列越整齐致密.另外,短期夜间低温处理促进了番茄植株叶片在恢复期的光合产物运输.

Tomato seedlings were treated with 15 % （control）, 12 ℃, 9℃, and 6 % at night for seven days to study the changes of their leaf photosynthesis and chloroplast ultrastructure, aimed to make sure the recovery effect of the photosynthesis of tomato leaves after a short-term low nocturnal temperature. The results showed that short-term low nocturnal temperature was favorable to the photosynthesis of tomato leaves at recovery stage. The chlorophyll content could recover to the normal level as control under the treatments of 12℃ and 9 %, but not under the treatment of 6 ℃. The formation of stoma was not seriously inhibited by low nocturnal temperature. On the contrary, the stoma formation and its growth were stimulated at recovery stage. Under the treatment of 6 ℃, chloroplast grana layers arranged loosely, and their number reduced. In the seven days of recovery, the lower the treatment temperature, the smaller and the fewer the starch grains were, and the more compact and tidy the chloroplast grana became. In addition, the transportation of photosynthesis products was promoted after short-term low nocturnal temperature.