暗期中断对蕹菜和叶用莴苣光合及品质的调控效应OA

To explore the effects of dark period interruption on photosynthetic characteristics and quality regulation in vegetable crops with different photoperiodic responses,this study aimed to clarify the regulatory mechanism of night-break on growth,development,and quality formation of photoperiod-responsive vegetables,thereby providing a basis for the precise regulation of light environments in protected vegetable production.We selected water spinach(Taiwanese Bamboo Leaf Water Spinach)and leaf lettuce(Zimeng Lettuce)as research materials,respectively representing short-day crop and long-day crop.During the diurnal period,the plants were irradiated with LED Red-blue light(R:B=4:1)with intensity of 200 μmol/(m2·s)for 12 hours.3 night-break treatments were set during night period:no light interruption(CK),5 minutes of light interruption every 1 hour(11 times per night),and 5 minutes of light interruption every 2 hours(5 times per night).The effects of night-break on growth morphology,photosynthetic characteristics,nitrogen metabolism process and quali-ty indexes were investigated with those two vegetables.Results showed that night interruption significantly promoted the growth process and improved the quality of long-day crop lettuce,whereas night interruption treatment significantly inhibited the growth and reduced the quality of short-day crop water spinach,with the inhibitory effect showing an increasing trend as the number of interruptions increased.Night interruption treatment effectively enhanced the net photosynthetic rate and electron transport rate of long-day crop lettuce,promot-ed plant growth and development,and increased the contents of nitrogen-containing compounds such as soluble protein and free amino acids,thereby improving its nutritional quality,with the treatment of 5 min interruption per hour showing the optimal effect.Short-day crop water spinach exhibited growth inhibition under night interruption treatment,which was unfavorable for quality formation and im-provement.These findings provide theoretical basis and technical support for precise regulation of light environment in high-yield and high-quality cultivation of water spinach and lettuce under protected cultivation conditions.