遮阴对凤仙花生长和开花的影响1）

以凤仙花为试验材料，研究了一层遮阴（遮光度为45％，简称S45）、二层遮阴（遮光度为70％，简称S70）、CK（全光照）对凤仙花生长和开花的影响。结果表明：与CK相比，S45和S70的凤仙花株高分别增加了48．02％、34．16％，叶片数分别减少了8．28％、68．98％；两个遮阴处理组叶片叶绿素总质量分数分别比CK增加了1．31、1．39 mg· g－1，均达到极显著水平（ p＜0．01），净光合速率分别减少了0．93、4．52μmol· m－2· s－1，也达到了极显著水平（ p＜0．01）；S45和S70的开花持续时间分别比CK减少了18、19 d，植株成活率分别降低了17．63％、33．75％，同时，CK、S45和S70在盛花期当日的平均开花量分别为2．78、4．20、3．50朵·株－1，至观测结束，CK、S45和S70的平均结实量分别为89．13、112．29、54．00个。因此，适度的遮阴有利于增加凤仙花植株的单株开花量，提高凤仙花的观赏价值，而过度的遮阴则会对凤仙花的生长甚至繁育产生不良影响。

Effects of Shading on Growth and Flowering of Impatiens balsamina L.

We studied the effects of one layer shading treatment (shading degree is 45%, S45 for short), two layers shading treatment (the shading degree is 70%, S70 for short), CK (full exposure) on the growth and flowering of Impatiens bal-samina L..The height of S45 and S70 increased by 48.02%and 34.16%, and the number of leaves decreased 8.28%and 68.98%, respectively, compared with CK.The contents of chlorophyll increased at a highly significant level ( p<0.01) and raised 1.31 and 1.39 mg· g-1 , when I.balsamina L.was under different shading treatments.The net photosynthetic rate of S45 and S70 also decreased at a highly significant level ( p<0.01) and dropped by 0.93 and 4.52μmol· m-2 · s-1 , re-spectively.The flowering duration of S45 and S70 shortened by 18 and 19 d, and the surviving rate reduced by 17.63%and 33.75%than those of control.At the same time, the mean single flowering amount of CK, S45 and S70 on full-bloom stage were 2.78, 4.20, and 3.50 per plum.The mean seeds of CK, S45 and S70 were 89.13, 112.29 and 54.00 per plum at the end of observation.Therefore, moderate shading is beneficial for gaining the single flowering amount of I.balsamina L.and improves its ornamental value.However, excessive shading will affect the growth and breeding of I.balsamina L..