【摘要】 1979—1981年分别在温室和苗圃条件下测定了Ⅰ-69杨,Ⅰ-214杨,合作杨和群众杨等4种杨树苗木的生长和净光合速率的日进程和季节进程,以及有关的光合作用指标。分析了苗木生长速度与其光合作用特性的关系,认为以光合速率与叶面积的乘积表示单株的光合生产率能更好地反映出各杨树品种的生长潜势。更多还原

【Abstract】 The growth and photosynthetic characteristics of Populus deltoides Bartr.cv."Lux" （ex.Ⅰ-69/55） and P.×euramericana （Dode） Guinier cv.Ⅰ-214,which are clones of the tribe Algeiros;and P.×Opera Hsü and P.×popularisHsü which are hybrids of P.Simonii,were studied under the controlledcondition both in greenhouse and field during 1979—1981.Special attentionwas paid to determine their diurnal and seasonal changes of net photosynth-etic rates and other related photosynthetic index.The light compensationpoints in the two clones of Algeiros were 2×10³ Lux,the light saturationpoints were 3—4×10⁴ Lux and the dark respiration rates were 2.87—3.75mgCO₂.dm^-2.hr^-1.While those in the two hybrids of P.simonii wererespectively 3—4×10³ Lux,4—5×10⁴ Lux and 2.25—2.52mg CO₂.dm^-2.hr^-1.The diurnal changes of net photosynthetic rates of the studied fourhybrids showed bimodal curve’s patters from July to September,butmonomodal patter in October.Their highest net photosyntheic ratesappeared in July (15—19mg CO₂.dm^-2.hr^-1),the lower ones appeared inJune,August and September (10—15mgCO₂.dm^-2.hr^-1),and the lowest inOctober (3—7mgCO₂.dm^-2,hr^-1).Under the similar environmentalcondition,the net photosynthetic rates of the two hybrids of P.simonii werehigher than that of the clones of Algeiros.However,the growth rates andbiomass of the latter were rather higher than the two hybrids of P.simonii,because of their larger total leaf area.Therefore,it is feasible to determinethe growth potantial of Populus seedlings according to the magnitude ofboth net photosynthetic rate and total leaf area.更多还原