Effect of different phosphorus supply levels on photosynthetic performance and phosphorus absorption and utilization of millet

WANG Lei; ZHANG Hao; SONG Wei; ZHAO Xin; WU Zi-long

doi:10.13557/j.cnki.issn1002-2813.2023.23.015

Abstract：The experiment was to explore the relationship between phosphorus supply and growth,photosynthesis and phosphorus uptake and utilization of millet.Jizajinmiao 1 and Jigu 39 millet varieties were used as test materials.Three phosphorus supply levels(0,75 and 150 mg/kg)were set through greenhouse pot experiment.The results showed that under the same phosphorus supply level,the plant height,leaf area index,shoot dry weight,plant biomass,chlorophyll content,net photosynthetic rate and transpiration rate of Jigu 39 were significantly higher than that of Jizajinmiao 1(P＜0.05),and the root length and root shoot ratio were significantly lower than that of Jizajinmiao 1(P＜0.05).Under different phosphorus supply levels,plant height,shoot dry weight,whole plant biomass,chlorophyll content,chlorophyll and net photosynthetic rate of millet varieties increased significantly with the increase of phosphorus supply concentration(P＜0.05).The comparison of fitting parameters of light intensity-photosynthetic response curve showed that under the same phosphorus supply level,the apparent quantum efficiency of Jigu 39 was higher than the Jizajinmiao 1,and the two cultivars increased significantly with the increase of phosphorus concentration.At the same phosphorus supply level,the phosphorus uptake of Jigu 39 was significantly higher than that of Jizajinmiao 1(P＜0.05).With the increase of the phosphorus supply concentration,the phosphorus absorption of the two cultivars increased significantly(P＜0.05).The experiment indicates that adding phosphorus nutrition during the jointing and heading stages can effectively improve the growth indicators and photosynthetic characteristics of millet,increase its phosphorus absorption,and promote the accumulation of dry matter quality.