Study on the Diurnal Variations of Photosynthetic Characteristics of Four Elytrigia Desv.
Using an LI-6400 portable photosynthesis analyzer, we measured the net rate of photosynthesis, the photosynthesis availability radiation, the transpiration rate, and some other related eeo-physiological factors of four Elytrigia varieties. The net photosynthetic rates and transpiration rates of all four Elytrigia showed two peaks on the curves of diurnal changes; and all witnessed obvious phenomena in midday depression of the two afore-mentioned rates. What leading to the phenomena exhibited in E. intermedia and E. repens was the decrease of photosynthetic capacity of the leaves, while that causing the midday depression of E. elongata and E. trichophora was the reduction of leaf stomatal conductance. Midday depression of transpiration was due to the high radiation, high leave temperature, low relative humidity, water scarcity in leaves, and the partial closure of stomata. E. elongata which boasts high light and low water use efficiency would enhance yield when it grows in areas with rich water resources, while E. repens is a preferable choice for water deficient areas. Appropriate thick planting of E. trichophora and E. intermedia could multiply yield.
Elytrigia Desv.Net rate of photosynthesisWater use efficiencyLight use efficiencyStomatal conductance
NETL
NSTL
万方数据
维普
