Effects Of Different Temperature,Light Quality And Light Time On The Growth And Quality Of Ice Plant

Ice plant(Mesembryanthemum crystallinum L.),also known as Ice Leaf Sunflower,is an annual herbaceous plant belonging to the genus Aceraceae,which is native to Africa.It is characterized by a large number of large vesicular cells growing on the leaves and stems,which are filled with liquid and reflect light under the sun,just like ice crystals.It is a facultative CAM(sedum acid metabolism pathway)plant,which has high nutritional value,but due to the short introduction time,the cultivation technology and the cultivation environment are immature,making it impossible to standardize industrial production.In order to meet the agricultural demand for strong vegetable seedlings and achieve the goal of modern agriculture with high efficiency and energy saving,traditional model nursery is rapidly developing in the direction of factory nursery.Adjusting the light environment is an important measure to achieve industrial seedling raising,which plays an important role in the high-quality production of plants and has an important impact on plant growth and metabolism.In this paper,Ice plant was used as the experimental material,the ice plant seeds were treated with different temperatures,and the germination characteristics of the ice plant seeds were analyzed in order to find out the most suitable temperature for the ice plant seeds to germinate.Then use white LED light source as the control in the plant factory,set different red and blue light quality LED light sources,select the best red and blue light quality ratio for the growth of ice plant,and based on this red and blue light quality Set the light time in different time periods,study the effects of different red and blue light quality ratios and different light time on the growth and quality of ice plant,and select the most suitable red and blue light quality ratio and light time.The main findings are as follows:(1)The germination rate,germination potential,germination index,average fresh weight and vitality index of ice plant seeds are highest at 25?,and the temperature is most conducive to the germination of ice plant seeds.(2)The research results of different red and blue light quality ratios on the growth and nutritional quality of ice plant show that the content of photosynthetic pigments in ice plant under the red-blue composite light quality treatment is significantly higher than that of monochrome light treatment As the ratio of red light increases,various indicators of ice plant also increase to varying degrees.When the ratio of red and blue light is 3:1,the morphological index parameters and SPAD values of ice plant are larger,the photosynthetic pigment content is highest,and the transpiration rate It has the highest conductance with stomata and the highest soluble protein content;the soluble protein content,soluble sugar content and vitamin C content under red and blue composite light are higher than those of red and bluemonochromatic light treatment and control.The nitrate content of red-blue composite light(2:1,3:1,4:1)was lower than that of red and blue monochromatic light treatment and control.It shows that the proper ratio of red and blue light can improve the photosynthetic characteristics,biomass,and quality of ice plant.In addition,under the 3:1 ratio of red and blue light,the growth of ice plant is more robust,the growth is large,and the nutrition The quality is better,and the red-blue light ratio can be used as a reference basis for the suitable ratio of red-blue light for plant factory ice plant cultivation.(3)The effect of different light time on the growth and nutritional quality of ice plant showed that under the 3:1 ratio of red and blue light,the net photosynthetic rate of ice plant leaves increased with the increase of light time.The net photosynthetic rate reached the maximum,but when the light time reached 16 h,the net photosynthetic rate began to decrease,and the Fv/Fm and ?? values were the lowest under the 16 h light;under the 14 h light,the ice plant had the best growth morphology and photosynthetic pigments The highest content and high antioxidant enzyme activity;12h light treatment is beneficial to the accumulation of soluble sugar and vitamin C in ice plant;with the extension of light time to 16 h,the content of nitrate in ice plant leaves also reached the highest.It shows that the ratio of the quality of ice plant in red and blue light is 3:1,and the light time of 14 h is more conducive to the growth of ice plant and improve their nutritional quality.