不同土壤水分下黑果枸杞生理特点分析

对盆栽的2a生黑果枸杞采用土壤人工控水方式进行干旱生理试验,通过叶片光合参数的变化规律,研究黑果枸杞对土壤干旱的相对适应性。结果表明:土壤含水量在5%时,对黑果枸杞叶片生理作用形成胁迫;在不同土壤水分条件下,黑果枸杞净光合速率、蒸腾速率的日变化均呈双峰曲线,水分利用效率的日变化因土壤含水量的不同表现出不同的线型;净光合速率、蒸腾速率和水分利用率与土壤含水量的相关系数r分别为0.949、0.917和0.904,土壤含水量与净光合速率随土壤水分变化的趋势为二次三项式,蒸腾速率和水分利用率随土壤水分变化的趋势为三次四项式;最适于光合作用、蒸腾作用和叶片水分利用的土壤含水量分别为17.2%、18.0%和17.6%;土壤水合补偿点为3.81%,从而证明黑果枸杞为较耐旱树种。

Physio Characteristics of Lycium ruthenicum under Different Soil Water Conditions

Seedlings of 2-year-old Lycium ruthenicum were planted in pots,in which the soil water levels were manually controlled in order to observe their physiological characteristics under different water levels.The results showed that physiological functions of the leaf were stressed under the soil moisture content of 5%.Under different soil water conditions,the daily variation patterns of net photosynthetic rate and transpiration rate exhibited bimodal curves,while that of water use efficiency presented different variation curves.The relative coefficients r between soil water soil content and net photosynthetic rate,evaporation rate and water use efficiency were 0.949,0.917 and 0.904,respectively.The trends of soil water content and photosynthetic rate exhibited second degree trinomial expression along with the variations of soil water,while those of transpiration rate and water use efficiency varied in the pattern of tertiary degree quadrinomial expression.The most suitable soil water contents for photosynthesis,transpiration and water use were 17.2 %,18.0% and 17.6%,respectively.The soil aggregate compensation point was 3.81%,indicating L.ruthenicum as a drought tolerant species.