高温胁迫对黑穗醋栗幼苗光合特性的影响

以黑穗醋栗品种94-4-13和黑丰1年生扦插苗为试材,测定不同时间、不同温度(25、35、42℃)处理下叶片光合作用和荧光参数的变化,探讨高温胁迫对黑穗醋栗幼苗叶片光合机构的影响,以期为黑穗醋栗的优质生产和丰产栽培技术提供理论依据.结果表明,25℃对黑穗醋栗生长没有明显影响,35、42℃高温对黑穗醋栗生长均造成一定伤害,35℃能通过自身的调节适应高温胁迫,而42℃对黑穗醋栗产生严重影响,导致光合作用和蒸腾作用不可逆下降.黑丰在42℃处理下1~5 d内,Pn下降原因是非气孔因素占主导地位,5 d后则是气孔因素占主导地位,而94-4-13则正好相反.黑穗醋栗叶片的Fv/Fm对高温胁迫反映并不敏感.高温胁迫明显降低黑穗醋栗叶片的光合电子传递量子效率ETR和光化学淬灭系数qP,而提高非光化学淬灭系数NPQ.高温胁迫对黑穗醋栗光合机构的伤害程度与伤害部位均存在明显的剂量效应.

Effect of heat stress on photosynthesis and chlorophyll fluorescence parameters in black currents seedlings

In order to provide theoretical basis for black current high quality production and productive cultivation management,the study took black currents Heifeng and 94-4-13 1-year-old cutting seedlings as test materials,measured the changes of the photosynthesis and fluorescence parameters under different temperature and processing time,and discussed the impacts of high temperature stress to leaf photosynthesis.The results showed that temperature of 25 ℃ had no significant effect on the growth of black currents,high temperature of 35,42 ℃ all cause certain damage,under the temperature of 35 ℃,black currents could adapt to the high temperature stress through adjustment,but 42 ℃ had a serious effect,leading to the photosynthesis and transpiration decline irreversibly.Within time of 1-5 d and temperature of 42 ℃,the decline of the black currents Pn might be dominantly caused by non-stomatal factors,5 d later might be dominantly caused by the stomatal factors.And the 94-4-13 was just the reverse.The Fv/Fm of black current leaf might not sensitive to high temperature stress.High temperature stress effectively reduced the photosynthetic electronic transfer efficiency ETR and light quantum chemical quenches coefficient qP of black current leaf,and improved the non-photochemical quenches coefficient NPQ.High temperature stress had obvious dose effect on the damage degree and damage parts of black current photosynthetic institutions.