Effects Of Spraying Exogenous Brassinolide On The Growth And Quality Of Flowering Chinese Cabbage

Brassinolide has been recognized as the sixth largest hormone in plants and is widely used in various crop fields.Current studies on the effects of brassinolide treatment on the growth and quality of Chinese cabbage plants are rare,To investigate the effect of brassinolide treatment on the growth and quality of cabbage,To provide a theoretical basis for the rational application of brassinolide in production to improve the yield and quality of cabbage.The test was carried out under the conditions of facility cultivation and production,and the“Youqing No.33”dish was used as the material.The water was sprayed on the leaf of the cabbage as the control treatment(CK).The other treatments applied different concentrations of epibrassinolide to the leaves of the cabbage(EBR was 0.05mg/L,0.10mg/L,0.15mg/L,0.20mg/L),the laws of growth,photosynthesis,nutritional quality and nutrient absorption of Chinese cabbage were studied.The main findings are as follows:1.The effect of different concentrations of brassinolide on the growth and developme nt of cabbage.Compared with the control(CK),low concentration of brassinolide Compared with the control(CK),low concentration of brassinolide(0.05～0.15mg/L)significantly promoted the growth of cabbage.High concentrations of brassinolide(0.20mg/L)inhibited the growth of cabbage.2.Effects of Different Concentrations of Brassinolide on Photosynthetic Parameters of Flowering Chinese Cabbage.Compared with the control(CK),low concentration of brassinolide(0.05～0.15mg/L)ignificantly promoted the increase of net photosynthetic rate(Pn)and transpiration rate(Tr),high concentrations of brassinolide(0.20 mg/L)are inhibited.Each treatment had no effect on the intercellular carbon dioxide concentration(Ci)of the cabbage heart.3.Effects of different concentrations of brassinolide on chlorophyll fluorescence parameters of Brassica campestris L.Low concentration of brassinolide(0.05～0.15mg/L)compared with control(CK)Significantly promoted the increase of the actual photochemical efficiency Y(II),photochemical quenching coefficient(Qp)and effective photochemical efficiency(Fv’/Fm’),high concentrations of brassinolide(0.20 mg/L)are inhibited.4.Effects of different concentrations of brassinolide on the quality of cabbage and the absorption of mineral nutrients.(1)Effects of different concentrations of brassinolide on the quality of Chinese cabbage.Under the treatment of 0.10mg/L EBR,the antioxidant capacity,soluble sugar and Vc content of Chinese cabbage were the highest;Under the treatment of EBR of 0.05mg/L,the soluble protein content of Chinese cabbage was the highest and the nitrate content was the lowest,and the treatment was 0.10mg/L;Under the condition of EBR of 0.20mg/L,the quality indicators were the lowest.(2)Effects of Different Concentrations of Brassinolide on Mineral Nutrient Absorption of Cabbage.After EBR treatment,the content of mineral nutrients in the upper part of the c abbage was increased except potassium,and it increased first and then decreased with the in crease of EBR concentration.When the EBR is 0.05mg/L,the content of phosphorus,magn esium and sulfur is the highest;when the EBR is 0.10mg/L,the content of nitrogen,calciu m,iron and zinc is the largest,nitrogen,phosphorus,magnesium,sulfur and potassium.The accumulation of calcium,iron and zinc elements reached a maximum.In summary,when the concentration of exogenous EBR is 0.10,the biomass,photosyn thetic efficiency,nutrient quality and mineral nutrient absorption and accumulation of Chin ese cabbage are the highest.Therefore,under the conditions of facility substrate cultivation,the EBR concentration of the leaves of the cabbage leaves was 0.10 mg/L.