Studies On Photosynthetic Characteristics In Leaves And Tuberization Mechanism Of Potato Cuttings Under Blue Light

Production potato basic seed will soon become a reality with the development of protected horticulture system in greenhouse.In order to improve the production efficiency of potato basic seed tuber formation in greenhouse,the experiment uses the single-node cuttings of "Yanshu 4" which from the plant grown for 45 days,to explore the characteristics of tuber formation and photosynthetic under the different intensity of blue light treatment.The expression level of blue light receptor-related genes,chlorophyll metabolism-related genes,photosynthesis-related genes,and tuber-formation-related genes were also investigated under the different intensity blue light in potato cutting leaves.The main findings are as follows:In 250 Lx blue light,the earliest time of tuber formation,the percentage of tuber formation,average single tuber weight,average single tuber diameter,dry matter and sucrose content were the highest;the content of chlorophyll and carotenoid were the highest,and the value of chlorophyll a/b was lowest.The net photosynthetic rate(Pn)was unimodal curve under blue light and the peak at 4 d;the transpiration rate(Tr)、intercellular CO2 concentration(Gs)and stomatal conductance(Ci)were increased with the blue light intensity.The change trend of initial fluorescence(F0)was consistent with chlorophyll content,The Fv/Fm、Fv’/Fm’、Y(Ⅱ)、ETR and Y(NPQ)were unimodal curve,and the Y(NO)was increased with the blue light intensity to become bigger.The chlorophyll metabolism related genes CHLH、CHLG、CHLM were descend tendency,but the expression level of HEMA1 was rised and the highest.The expression level of CHLM decreased with the increase of blue light intensity.CAO and PPH showed downward、upward and decreased again.The expression level of NYC1 showed a unimodal curve.The expression level of photosynthesis related genes LHCb and PsbA were increased with blue light intensity,and which was consistent with the change trend of chlorophyll,and the expression level of LHCb and PsbA was the highest under the blue light intensity of 250 Lx blue light.The expression level of StSP6A、StBEL5 and St14-3-3a showed a unimodal curve,and reached the peak value at 4 d,and the expression level of StSP6A、StBEL5 and St14-3-3a were the highest under blue light intensity of 250 Lx.The expression level of St14-3-3a and StSP6A change trend was similar.The expression level of StBEL5、St14-3-3a and StFKF1 were decreased under dark condition.