昼夜温差对设施番茄叶片光合特性和叶绿素荧光参数的影响

Effects of day and night temperature difference on photosynthetic characteristics and chlo- rophyll fluorescence parameters of greenhouse tomato.

为了揭示昼夜温差对设施番茄生长发育的影响,于2012年7—12月开展人工环境控制试验,以番茄品种"金冠五号"为试材,试验设计日均气温为18℃,昼夜温差设置0℃温差(昼温/夜温为18℃/18℃)、6℃温差(21℃/15℃)、12℃温差(24℃/12℃)共3个处理,研究不同昼夜温差对番茄苗期、开花期、幼果期和成熟期叶片的光合色素含量、光合作用特性和叶绿素荧光动力参数的影响。结果表明:番茄叶片叶绿素a(Chl-a)和叶绿素b(Chl-b)含量随昼夜温差的增加均逐渐升高,Chl-a/Chl-b的比值依次降低;12℃昼夜温差处理比0℃处理可显著增加番茄叶绿素含量;同时,同一昼夜温差处理,随着番茄生长发育的进行,番茄叶片的光合色素含量逐渐降低;在番茄不同发育阶段,番茄叶片的最大光合作用速率(P max)、CO2最大同化速率(A max)、表观量子效率(A q)及碳羧化效率(C e)均以6℃昼夜温差处理最高,0℃昼夜温差处理次之,12℃昼夜温差处理最低;番茄的最大光化学效率(F v/F m)、光化学淬灭(qP)、电子传递速率(ETR)均以6℃昼夜温差处理时最大,0℃昼夜温差时最低;研究认为,在平均温度为18℃时,6℃昼夜温差处理能够有效地促进番茄的光合作用,有利于番茄的生长。

In order to explore the effects of day and night temperature difference on tomato growth and development, a controlled experiment with tomato cv. ＇ Jinguan 5 ＇ was conducted in an arti- ficial climate chamber （TPG-1260, Australia） from July to December, 2012. The daily average temperature was designed at 18 ℃ , and the day/night temperatures were designed at 18/18 ℃ （0 ℃ difference）, 21/15 ℃ （6 ℃ difference）, and 24/12 ℃ （12 ℃ difference）, with the effects of these day and night temperature differences on the photosynthesis pigment contents, photosynthesis characteristics, and fluorescence kinetic parameters at seedling stage, flowering stage, young fruit stage, and maturity stage studied. With the increasing temperature difference, the chlorophyll （Chla and Chlb） contents increased gradually, but the Chla/Chlb ratio de- creased. The chlorophyll content at 12 ℃ difference increased significantly, as compared with that at 0 ℃ difference. At the same temperature differences, the photosynthesis pigment contents showed a decreasing trend with tomato growth. During the whole growth period of tomato, the leaf P A Aq, and Ce reached the highest at 6 ℃ difference, followed by at 0 ℃ difference,and the lowest at 12 ℃ difference. The maximum photochemical efficiency （Fv/Fm ）, photo- chemical quenching, and electron transport rate were the maximum at the 6 ℃ difference, and the lowest at the 0 ℃ difference. At the daily average temperature 18 ℃, a 6 % difference could effectively promote the leaf photosynthesis of tomato, being conducive to the tomato growth.