摘要:
针对华北地区常绿树种油松耐严寒酷暑的特性，测定生长季针叶叶绿素荧光随短时温度胁迫的变化规律，以探讨油松光合机构对异常温度波动的响应特性。结果显示：在30 和35 ℃常见高温下，随温度升高，初始荧光(F0)、非光化学淬灭系数(qN)逐渐上升，最大光化学效率(Fv/Fm)、最大量子产额(Yield)、电子传递速率(ETR)逐渐下降，变化的幅度较平稳，表明夏季常见高温可影响油松针叶PSⅡ的活性，但造成的损伤不大；而40 ℃以上的高温胁迫，F0、qN上升与Yield、ETR下降的幅度明显增大，Fv/Fm降低到0.8以下，表明针叶的光合机构受损严重。在零上低温(0~15 ℃范围)胁迫下，随温度降低各参数变化不明显，表明生长季油松PSⅡ对零上低温的扰动较稳定；零下低温胁迫时，Fv/Fm、ETR、Yield、qN急剧下降，F0显著上升，且这种损伤是不可恢复的，表明油松PSⅡ在生长季对零下低温是敏感的。
Abstract:
Pinus tabulaeformis Carr. is a species of evergreen plants with the characteristics of heat and cold resistance in north China. The changing patterns of its needles chlorophyll fluorescence parameters after various temperatures were investigated in order to find out how the needles photosynthetic institution respond to unusual temperatures. The data showed that when needles were subjected to 30 and 35 ℃, the minimal fluorescence (F0) and the nonphotochemical quenching coefficient (qN) increased by degrees, while the maximal quantum yield of PSⅡ(Fv/Fm), the maximum quanta yield (Yield), and the electron transport rate (ETR) decreased gradually as the temperature went up. Whereas, all the data varied within a small range, indicating that common high temperature in summer had effects on the PSⅡ reaction centre activity, but cause slight damage. However, when dealt with over 40 ℃ high temperatures, F0, qN ascended and Yield, ETR descended sharply, meanwhile, Fv/Fm reduced to the value below 08. This suggested that the PSⅡ reaction centre might have suffered severe damage. When subjected to low temperatures above zero (ranged from 0 to 15 ℃), parameters didnt have notable changes. That is to say, PSⅡ reaction centres activity of the needles in growing seasons can be stable to the above freezing temperatures influence. Under subzero temperatures, Fv/Fm, ETR and qN decreased considerably while F0 increased visibly, and didnt have significant recovery in the next 12 hours, which implied that subzero temperatures have done irreversible harm to the photosynthetic institution of P. tabulaeformiss needles.
百度学术
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