李进 段婷婷 郑超 蔺中 梁燕秋 高宇 邓凯

摘  要  為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（Pn）、细胞间隙CO2浓度（Ci）、蒸腾速率（Tr）和气孔导度（Gs）均显著增加。YT236的Pn、Ci、Tr和Gs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Pn，ROC22均显著大于YT236。高磷处理下的Ci，ROC22显著大于YT236。无磷处理下的Tr和Gs，ROC22均显著大于YT236。综合分析，浓度为1 mmol/L的PO43?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。

关键词  甘蔗;生物量;磷素;光合作用

中图分类号  S566.1      文献标识码  A

Abstract  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 （Pn） intercellular CO2 concentration （Ci）， transpiration rate （Tr） and stomatal conductance （Gs） of ROC22 significantly increased with increasing P supply. Pn， Ci， Tr and Gs 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. Pn of ROC22 with 3 levels of P supply was significantly higher than that of YT236. Ci of ROC22 with 1 mmol/L P application was significantly higher than that of YT236. Tr and Gs 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.

Keywords  Saccharum officinarum L.; biomass; phosphorus; photosynthesis

DOI  10.3969/j.issn.1000-2561.2019.06.011

磷是植物三大必需元素之一，它在光合、呼吸、核酸合成、膜脂合成、物质代谢、酶活性调节以及信号传导等生理代谢过程中起着极为重要的作用[1]。甘蔗是热带亚热带的最重要糖料作物，对磷素需求量多，磷肥用量大[2-4]。然而，甘蔗生长在热带亚热带地区，其土壤绝大部分为酸性红壤，土壤脱硅富铝、富铁化严重，磷容易被土壤中的铁铝氧化物固定[5]，从而造成土壤有效磷缺乏和磷肥利用率低，使磷素缺乏成了甘蔗生产的主要限制因子之一[6]。……