| 摘要: | 樟科植物是臺灣森林中重要的組成樹種，本研究在瞭解樟樹及山胡椒開花生物學及其授粉生物學，並探討兩者與訪花昆蟲間共同演化的關係。樟樹為聚繖花序，兩性花，花期為3-4月；每朵花直徑5.52±0.58 mm，單花壽命6.45±1.41天；花粉數3170.7顆；花開放後夜間不閉合，花藥隨後開裂夜間不閉合；天然結實率1.23±2.89％；日夜皆有訪花昆蟲，共計5目102種昆蟲，以雙翅目最多，鱗翅目、鞘翅目次之。訪花昆蟲即是其潛在可能的授粉昆蟲。山胡椒為繖形花序，單性花雌雄異株，花期為2-3月；雄花花序直徑9.20±0.82 mm，小花直徑3.73±0.77 mm，單花壽命13.03±4.52天，花粉數7786.8顆；雌花花序直徑8.11±0.85 mm，小花直徑2.28±0.35 mm，單花壽命15.68±4.90天。花開放後夜間不閉合，花藥隨後開裂夜間不閉合，日夜皆有訪花昆蟲。雄株訪花昆蟲共計4目61種昆蟲，以鞘翅目最多，雙翅目、膜翅目次之；雌株共計4目14種昆蟲，雙翅目最多，鞘翅目次之。往來於雌雄花之間者有鞘翅目的菊虎、金花蟲，雙翅目的食蚜蠅、鱗翅目的夜蛾和尺蛾，其主要授粉昆蟲；天然結實率29.76±19.90％。蜜蜂不造訪樟樹花，且僅在山胡椒雄花上訪花，對山胡椒授粉並無貢獻，是盜粉者。山胡椒的授粉模式較樟樹單純、或者說是專一，但是授粉的效率高，印證單性花雌雄異株較兩性花為進化。
Lauraceae is one of the most important families of plants in Taiwan forestry. This study focuses on the floral and pollination biology of Cinamonum camphora and Litsea cueba (Lauraceae) as well as the coevolution between these plants and insects. The flora of C. camphora is as follows: inflorescence cyme, hermaphroditism, flowering season March~April, flower size 5.52±0.58mm, longevity of individual flowers 6.45±1.41 days, pollen grains 3170.7, with flower and stamens open day and night. Flower visitors arrive by day and night. In total, 5 orders 102 species of insects were observed visiting the flowers of C. camphora. The flora of L. cubeba is as follows: inflorescence umbel, dioecism, flowering season February~March, male inflorescence size 9.20±0.82mm, male flower size 3.73±0.77mm, longevity of individual flowers 13.03±4.52days, pollen grains 7786.8, with flower and stamens open day and night; female inflorescence size 8.11±0.85mm, female flower size 2.28±0.35mm, longevity of individual flowers 15.68±4.90 days. Flower visitors arrive by day and night. There were 4 orders 61 species of visitors collected from male flowers; and 4 orders 14 species of visitors from female flowers. The most important flower visitors to C. camphora are Diptera, with Lepidoptera and Coleoptera being of less importance. Honeybees don't visit the flowers of C. camphora or the female flowers of L. cubeba; they just visit the male L. cubeba, defining the honeybee as a “pollen robber” that makes no contribution to the pollination of these two plants. The natural seed-set of C. camphora is 1.23±2.89% whilst that of L. cubeba is 29.76±19.90%, substantially more than C. camphora, indicating that the pollination of L. cubeba (dioecism) is much more efficient than that of C. camphora (hermaphroditism). |
