日光温室土壤定时加温对黄瓜幼苗光合特性的影响

Effects of timed soil warming on photosynthetic characteristics of cucumber seedlings in greenhouse

采用定时土壤加温处理,研究日光温室内土壤温度变化对黄瓜幼苗光合特性的影响。结果表明,与对照相比,日光温室在6:00—8:00时进行土壤加温,显著提高了土壤温度,尤其是在7:00—12:00,较高的土壤温度不仅降低了黄瓜幼苗叶片气孔限制值,增加气孔导度和细胞间CO2浓度,而且还显著提高黄瓜叶片ФPSII、Pn、AQY和CE,如在12:00,加温处理黄瓜幼苗叶片Pn和ФPSII分别比对照处理高62.3%、19.67%;而土壤温度变化对黄瓜幼苗叶片Fv/Fm影响不大;日光温室土壤加温显著促进黄瓜幼苗的生长,表现在黄瓜幼苗株高、茎粗、鲜重均明显增加,地上部鲜重比对照高113.8%。总之,日光温室内土壤定时加温通过提高土壤温度,增强了黄瓜幼苗叶片对CO2和光能利用能力,提高了黄瓜幼苗光合作用,进而促进黄瓜幼苗的生长。该结果可为低温季节设施黄瓜高产栽培提供理论依据。

Effects of soil temperature variation on photosynthesis of cucumber seedlings were studied in greenhouse by using timed soil warming with heating lines. The results showed that, compared with the control, soil warming at 6：00-8：00 significantly increased soil temperature. Especially at 7：00-12：00, higher soil temperature not only reduced the stomatal limit of cucum- ber leaves, increased the stomatal conductance and intercellular CO2 concentration, but also sig- nificantly increased ~bpsn, Pn, AQY and CE of cucumber leaves. When soil was warmed at 12：00, P. and ~bpsn of cucumber leaves were 62.3% and 19.67% higher than those of the con- trol, respectively, while soil temperature had little effect on F,,/Fm of cucumber leaves. Soil war- rning in solar greenhouse significantly promoted the growth of cucumber seedlings hy increasing the plant height, stem diameter, and fresh weight; the shoot fresh weight was 113.8% higher than that of the control. In short, soil warming improved the utilization capability of CO2 and light energy by cucumber seedling leaves, improved photosynthesis of cucumber seedlings and promo- ted the growth of cucumber seedlings through increasing soil temperature. The results can serve as a theoretical basis for cucumber cultivation in cold seasons.