不同光环境下3种藤本植物幼苗的光合特性

Photosynthetic characteristics of three species of liana seedlings in different light environments

用100%(ck),68%～75%(S1),40%～49%(S2)和10%～21%(S3)等4种人为控光处理常春藤Hedera nepalen-sis var.sinensis,常春油麻藤Mucuna sempervirens和葛藤Pueraria lobata1年生苗木,研究其光合特性。结果表明:常春油麻藤的光饱和点和光补偿点均较高,为喜光植物;葛藤的光饱和点和光补偿点较低,反应了葛藤耐荫性的同时,它对光能有效辐射的利用范围较窄;常春藤光饱和点较高、光补偿点较低,即常春藤具有一定的耐荫性且对光能有效辐射的利用范围较宽。10%～21%控光处理叶绿素质量分数最高,葛藤、常春油麻藤、常春藤的叶绿素质量分数分别高达2.888,2.242和2.955mg·g-1,叶绿素a/b值差异显著。不同光环境下根冠比均表现为10%～21%控光处理最低,随着光照强度的增加,根冠比随之增加。

One-year-old liana seedlings of Hedera nepalensis var.sinensis,Mucuna sempervirens,and Pueraria lobata were grown in full light （control） and three less than full light conditions：68%-75% of full light （S1）,40%-49% （S2）,and 10%-21% （S3） with photosynthetic characteristics of light saturation point,light compensation point,total chlorophyll,chlorophyll a/b,and root-shoot ratio being studied.Results showed that the light saturation and light compensation points of M.sempervirens were highest,whereas P.lobata were both lowest.The light saturation point of H.nepalensis var.sinensis was high,and its light compensation point was low.In 10%-21% of full light （S3）,the total chlorophyll of P.lobata （2.888 mg·g-1）,M.sempervirens （2.242 mg·g-1）,and H.nepalensis var.sinensis （2.955 mg·g-1） were highest.The chlorophyll a/b ratio in different light environments also showed strong differences.Additionally,the root-shoot ratio of the three liana seedlings in different light environments increased with increasing light.From these results,M.sempervirens was shade intolerant,P.lobata was shade tolerant for a narrow range of light,and H.nepalensis var.sinensis was somewhat shade tolerant for a wide range of light.