添加不同强度的远红光对黄瓜幼苗生长及光合作用的影响OACSTPCD

In order to investigate the effects of far-red light intensity on the morphology,photosynthetic traits and carbohydrates of cucumber seedlings,and to clarify the effects of different red light(R)/far-red light(FR)ratios on the photosynthesis-related indexes and parameters of cucumber,cucumbervariety'Xinjin You No.1'was taken as the study material.On the basis of fixing the red-blues light intensity and the photosynthetically active radiation,three different kinds of fixed red and blue light intensity and photosynthetically active radiation,three different kinds of far-red light were added to make the ratio of red light:far-red light of each treatment 10(L-FR),1.2(M-FR)and 0.8(L-FR),respectively,aiming to compare the effects of the different treatments on the growth and photosynthesis of cucumber seedlings.The results showed that:Increasing far-red light intensity had a significant effect on the morphological indexes of cucumber seedlings,and the fresh weight of M-FR,and H-FR groups increased significantly by 60.04％and 56.60％,respectively,compared with that of L-FR group;The plant height of H-FR and M-FR groups increased by 246.43％and 200.63％,respectively,compared with that of L-FR.With the increase of far-red light intensity,the stomatai density of the three treatment groups also increased significantly,and the relative expression of key genes of stomatal development(MUTE,EPF1)differed significantly,while their transpiration rate(E),inter-cellular CO2 concentration(Ci)and stomatai conductance(Gsw)increased;The epidermis of the leaf blade,the fenestrated tissues,spongy tissues,and the thickness of the leaf blade showed a decreasing trend.The total nitrogen content and carbon to nitrogen ratio of cucumber seedlings in all treatments showed a significant decreasing trend with the increase of far-red light intensity;the carbohydrate content of cucumber under L-FR treatment was lower than that of H-FR treatment.In conclusion,the far-red light intensity under M-FR treatment is suitable to be used as a supplemental intensity of far-red light in factory nursery production.