设施菊花品种“金背大红”叶片光合特性对高温胁迫的响应

Response of Photosynthetic Characteristics of Leaves of Protected Chrysanthemum Variety‘Jinbeidahong’to High Temperature Stress

以多头菊品种"金背大红"幼苗为试材,在大型人工气候室中设置日最低气温/最高气温分别为25℃/35℃、30℃/40℃,处理3、6、9、12 d,昼夜分别恒温处理12 h,并于处理后在20℃/30℃下恢复5、10、15 d,以20℃/30℃为对照处理(CK),测定不同处理下菊花幼苗叶片的光合参数及光合色素含量,以期揭示高温胁迫及恢复对设施菊花叶片光合特性、光合色素含量的影响。结果表明:在日最高温度35℃以上,随着温度升高和胁迫时间增加,菊花叶片光饱和点(LSP)、表观量子效率(AQE)、净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、气孔限制值(Ls)、水分利用率(WUE)、叶绿素含量、类胡萝卜素含量均有所降低,日最高气温为40℃时各参数分别比CK降低了56.42%、41.22%、78.54%、90.33%、54.55%、31.29%、54.09%、42.44%、40.26%,恢复后,各项指标有不同程度增加,但趋于稳定后仍无法恢复到CK水平,恢复15 d时,各参数分别比CK低47.04%、35.88%、50.56%、76.52%、33.84%、19.45%、32.75%、23.90%、23.07%。研究表明,高温胁迫严重抑制了菊花幼苗的生长,对菊花幼苗光系统的结构和功能造成了不可逆的伤害。

In order to reveal the effects of high temperature stress and recovery on photosynthetic characteristics and photosynthetic pigment content of greenhouse chrysanthemum leaves,taking the seedlings of‘Jinbeidahong’as the experimental material,the experiments of high temperature and durations were carried out in a large artificial climate chamber with the daily minimum temperature/maximum temperature as 25℃/35℃,30℃/40℃,and durations as 3,6,9,12 days respectively,then recoverd at 20℃/30℃which been taken as control check(CK)for 5,10,15 days.The photosynthetic parameters and photosynthetic pigment content of greenhouse chrysanthemum leaves with different treatments were determined in seedlings stages.The results showed that when the daily maximum temperature was above 35℃,all the indexes for the light saturation point(LSP),apparent quantum efficiency(AQE),net photosynthetic rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),stomata limitation(Ls),water use efficiency(WUE),chlorophyll content and carotenoid content of greenhouse chrysanthemum leaves decreased with the increase of temperature and duration.When the daily maximum temperature reached 40℃,all the values were 56.42%,41.22%,78.54%,90.33%,54.55%,31.29%,54.09%,42.44%and 40.26%lower than that of the CK,respectively.After recovery,each index increased to some extent,but it could not recover to CK level after stabilizing.After 15 days recovery,the parameters were 47.04%,35.88%,50.56%,76.52%,33.84%,19.45%,32.75%,23.90%and 23.07%lower than CK.This study revealed high temperature stress seriously inhibited the growth of chrysanthemum seedlings and caused irreversible damage to the structure and function of the light system of chrysanthemum seedlings.