不同供磷水平下2个甘蔗品种的光合作用及生长特征

为研究磷素调控不同品种甘蔗生长的光合作用机制,从而选择磷高效品种和科学施肥,本文以研究区常见甘蔗品种台糖22（ROC22）和粤糖236（YT236）为材料,设置3个供磷水平和2个品种,研究磷素对2个甘蔗品种光合作用及生长的影响。结果表明：（1）随着供磷水平提高,2个甘蔗品种的株高和生物量显著增加;移栽60 d后ROC22的株高显著大于YT236的。高磷处理下的生物量ROC22显著大于YT236,鲜重和干重分别是YT236的1.6和1.4倍。（2）随供磷量的提高,ROC22的叶绿素总量（Chl）、净光合速率（P_n）、细胞间隙CO₂浓度（C_i）、蒸腾速率（T_r）和气孔导度（G_s）均显著增加。YT236的P_n、C_i、T_r和G_s在低磷和高磷处理下均显著大于无磷处理,YT236的Chl在高磷处理下显著大于低磷和无磷处理;低磷和高磷条件下的Chl,ROC22比YT236分别提高了16%和14%。在3个供磷水平下的P_n,ROC22均显著大于YT236。高磷处理下的C_i,ROC22显著大于YT236。无磷处理下的T_r和G_s,ROC22均显著大于YT236。综合分析,浓度为1 mmol/L的PO₄ ^3-高磷处理对2个甘蔗品种的光合作用及生长较为适宜。ROC22甘蔗在3个供磷量下光合作用和生长均优于YT236,建议在研究区或低磷地区种植ROC22。

The Photosynthesis and Growth Characteristics of Two Sugarcane Cultivars in Different Phosphorus Rate Condition

The aim was to select phosphorus (P) efficient sugarcane variety and to apply P fertilizer scientifically after investigating the photosynthesis mechanism regulated by phosphorus. Using sugarcane varieties ROC22 and YT236, three levels of P supply were set in the study. The plant height and biomass of ROC22 and YT236 significantly increased with increasing P supply. The plant height of ROC22 was significantly higher than that of YT236 after the plants were cultivated in the nutrient solution for 60 days. The biomass of ROC22 with P application of 1 mmol/L was significantly higher than that of YT236, and the fresh weight and dry weight of ROC22 increased 1.6 fold and 1.4 fold compared to YT236. The total chlorophyll (Chl), net photosynthetic rate (P_n) intercellular CO₂ concentration (C_i), transpiration rate (T_r) and stomatal conductance (G_s) of ROC22 significantly increased with increasing P supply. P_n, C_i, T_r and G_s of YT236 with P application of 0.1 and 1 mmol/L were significantly higher than that without P application. Chl of YT236 with P application of 1 mmol/L was significantly higher than that without P application and with 0.1 mmol/L P application. Chl of ROC22 with P application of 0.1 and 1 mmol/L increased by 16% and 14% compared to YT236, respectively. P_n of ROC22 with 3 levels of P supply was significantly higher than that of YT236. C_i of ROC22 with 1 mmol/L P application was significantly higher than that of YT236. T_r and G_s of ROC22 without P application were significantly higher than that of YT236. Considering the photosynthesis and growth of sugarcane, the optimum level of P supply for ROC22 and YT236 was 1 mmol/L. The photosynthesis and growth of ROC22 in the study area was obviously better than that of YT236, so ROC22 was suggested to be planted in the study area and the phosphorus deficiency soil.