不同土壤相对湿度对果实膨大期野生欧李生长发育及光合特性的影响OA

In order to explore the effects of different relative soil moisture at fruit enlargement stage on the growth and photosynthetic characteristics of Cerasus humilis,the wild Cerasus humilis acces-sion collected were used as materials.The experimental materials at fruit enlargement stage were treated with potted water control,and the growth and development related indexes,photosynthetic pa-rameters,chlorophyll fluorescence parameters and osmoregulatory substances content of Cerasus hu-milis were measured during fruit maturity.The results showed that with the decrease of relative soil moisture,the growth and development related indexes such as plant height,branch length and single fruit weight increased first and then decreased.The net photosynthetic rate(Pn),stomatal conduc-tance(Gs)and transpiration rate(Tr)of Cerasus humilis leaves showed a downward trend,the intercel-lular CO2 concentration(Ci),chlorophyll content,maximum photochemical efficiency(Fv/Fm),ac-tual light energy conversion efficiency(ΦPS Ⅱ),photochemical quenching coefficient(qP),and con-tents of soluble sugar and soluble protein increased first and then decreased with the increase of drought stress,the non photochemical quenching coefficient(qN)decreased first and then increased,and the growth and photosynthetic characteristics of Cerasus humilis were significantly affected.The relative soil moisture was lower than 50%,and the growth and photosynthetic characteristics of Cera-sus humilis were inhibited.The relative soil moisture was 50%-60%,promoting the growth,develop-ment and photosynthetic characteristics of Cerasus humilis.At this time,the growth and photosyn-thetic characteristics of Cerasus humilis were the best.This conclusion provides a theoretical basis for scientific irrigation and popularization of Cerasus humilis.