| 【Objective】The study was carried out to explore the effects of exogenous Ca on the growth, physiology and nutrient absorption of betel nut.【Method】Different Ca concentration（0 mg/kg, 50 mg/kg, 100 mg/kg, 200 mg/kg, 300 mg/kg, 400 mg/kg, 500 mg/kg）treatments were used to study the morphological changes, physiological response and nutrient absorption status of betel nut by the method of pot experiment.【Result】The morphology, physiology and nutrient absorption of betel nut all responded positively when the exogenous Ca concentration was less than or equal to 300 mg/kg, with the increase of Ca treatment concentration, the soluble sugar and proline contents of betel nut leaves increased, the antioxidant enzyme system SOD, POD, and CAT activities increased, the osmotic regulation and active oxygen scavenging ability of betel nut were enhanced, and the reduction of membrane lipid peroxidation products malondialdehyde（MDA）improved the accumulation of Ca and transfer coefficient, increased the absorption of N, P and K nutrients, and promoted the plant height, root length, root number and dry matter of betel nut. When the Ca concentration was more than or equal to 400 mg/kg, with the increase of Ca concentration, the content of soluble sugar and proline in betel nut leaves decreased, the activity of antioxidant enzyme system POD and CAT decreased, the osmotic regulation and active oxygen scavenging ability of betel nut cells decreased, MDA increased, and the accumulation of N, P, K and Ca began to decrease, and the growth of betel nut decreased with the increase of Ca concentration.【Conclusion】The suitable Ca treatment concentration of betel nut is 200-300 mg/kg. At this point, osmotic aregulation, antioxidant enzyme system, N, P, K and Ca nutrient absorption, and aboveground
Ca migration capacity are at a high level to promote the growth of betel nut. |
