从形态、生理角度研究了杭州园林中应用最广泛的杜鹃‘紫萼’(Rhododendron mucronatum cv Plenum)的光适应性和最适光强生境。结果表明:随着叶片遮荫程度的增加,杜鹃的叶面积和叶绿素含量增加;光补偿点、光饱和点及暗呼吸强度下降,说明杜鹃对弱光生境有一定的适应性。另一方面,随着相对光强的增加,叶片厚度,比叶重以及栅栏组织、海绵组织厚度及其比值,可溶性蛋白质及净光合速率增加,表现出对阳生生境更好的适应性。在生境65％全光照时,植株在形态,解剖及生理上均处于最佳状态。因此,65％全光照的生境是毛鹃‘紫萼’的最佳光生境。

The light acclimation and optimum light habitat of azalea were studied under natural condition in Hangzhou Botanical Garden. The results showed that average leaf area, chlorophyll content per unit leaf area, the value of chlb/ chla and nitrogen content increased, and light saturation point, light compensation point and respiration tend to decrease with shading. It showed that a certain ability of acclimation to low light intensity habitats. Shade-grown leaf, palisade tissue and spongy tissue were thinner than sun-grown ones, and dry weight per fresh weight or per unit leaf area was the hightest in sun-grown leaves and the lowest in leaves grown in heavy shade. Protein content, and Pn increased with increasing %full daylight. It is more adapted to higher light intensity habitats than to lower's. The experiment also indicated that morphological, physiological state is optimum when azalea is grown in 65% full daylight habitats.