Effect of phosphorus Nutrition on the growth and Development of Cymbidium

1. The effect on the growth rate of leaf buds and leaves: the phosphorus of 0.2mM had the greatest effect on the growth of leaf buds, and the growth rate of leaf buds slowed down when the concentration was higher than this concentration. In the range of 0~1.0mM phosphorus concentration, the area of one-year-old leaves increased with the increase of phosphorus concentration. The dry and fresh weight of the plant increased in direct proportion in the range of 0~1.0mM.

2. effect on morphology and incidence: when phosphorus deficiency, the plant is short, the leaf is not glossy, and the incidence is high.

3. Effect on flower bud formation and flowering: under phosphorus deficiency, flower bud formation was the latest and the number of flowers was less; in the range of 0~1.0mM, with the increase of phosphorus concentration, the earlier the flower bud formation, the more flowers.

4. Effect on photosynthesis and respiration rate: in the range of 0~1.0mM phosphorus, the photosynthetic rate increased with the increase of phosphorus concentration. For the respiration rate of leaves and pseudocorms, the trend was consistent with the law of photosynthetic rate, and phosphorus deficiency inhibited photosynthesis and respiration.

5. Effect on protein and amino acid content: under phosphorus deficiency, the protein content of pseudocorm and leaf was lower, but the amino acid content was very high; in the range of 0-1.0mM phosphorus concentration, with the increase of phosphorus level, the protein content increased and the amino acid content decreased. This may be due to the acceleration of protein degradation or the decrease of protein synthesis caused by phosphorus deficiency. Under the condition of phosphorus deficiency, the activity of acid phosphatase increases greatly, which can be used as a biochemical index of plant phosphorus deficiency.

6. effect on carbohydrate content: under phosphorus deficiency, the content of soluble carbohydrate in root and pseudocorm was higher, and decreased with the increase of phosphorus concentration, but the opposite was true for leaves. Under the condition of phosphorus deficiency, the starch content in pseudocorms and leaves was higher, and decreased with the increase of phosphorus concentration, which was obviously related to the hindrance of carbohydrate transport under phosphorus deficiency. (Ye Qingsheng, Pan Ruichi)