{"title":"雌雄异株鼠李花(鼠李科)的开花及苍蝇和蜜蜂向雌花的花粉传递","authors":"W. Wiesenborn","doi":"10.3398/064.082.0106","DOIUrl":null,"url":null,"abstract":"Abstract. Rhamnus ilicifolia (Rhamnaceae) is a large shrub found in a range of habitats from southern Oregon south to Baja California and east into Arizona. During spring, the plant produces clusters of unisexual flowers, each with a 5–6-mm-diameter, open perianth of green or yellowish-green sepals. I investigated the pollination of R. ilicifolia in western Arizona during 27 April to 21 May 2020 by examining the distribution and phenology of male and female flowers on shrubs, collecting insects from female flowers, and determining the proportions of conspecific pollen on insects to estimate floral constancy. Shrubs were dioecious, and individual male and female plants flowered for 11–15 d, with male flowers preceding female flowers by 2 d. Pollen grains from male flowers viewed in brightfield microscopy are tricolporate in structure and suboblate in shape, with a polar-axis length of 15 µm and equatorial diameter of 18 µm. Insects on female flowers comprised flies (Diptera) in 6 families and less abundant bees (Hymenoptera: Apoidea) in 3 families. The most abundant insects were the flies Allophorocera sp. (Tachinidae) and Phormia regina (Calliphoridae) and the bees Lasioglossum spp. (Halictidae) and Andrena cerasifolii (Andrenidae). Bees appeared more specific to R. ilicifolia flowers by transporting a higher mean proportion of conspecific pollen (0.57) compared with flies (0.36). The large bee A. cerasifolii carried the highest mean proportion of conspecific pollen (0.93). Proportions of conspecific pollen on the saprophytic P. regina were moderately high (0.48) and higher than on most other flies. Dioecious R. ilicifolia shrubs appear to be pollinated by a diversity of flies and bees that are generally not specific to the plant's flowers. Similar pollination of European Rhamnus by generalist insects suggests that plants in the genus and their pollinators have evolved independently.","PeriodicalId":49364,"journal":{"name":"Western North American Naturalist","volume":"63 1","pages":"67 - 76"},"PeriodicalIF":0.5000,"publicationDate":"2022-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":"{\"title\":\"Flowering by Dioecious Rhamnus ilicifolia (Rhamnaceae) and Pollen Transport to Female Flowers by Flies and Bees\",\"authors\":\"W. Wiesenborn\",\"doi\":\"10.3398/064.082.0106\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Abstract. Rhamnus ilicifolia (Rhamnaceae) is a large shrub found in a range of habitats from southern Oregon south to Baja California and east into Arizona. During spring, the plant produces clusters of unisexual flowers, each with a 5–6-mm-diameter, open perianth of green or yellowish-green sepals. I investigated the pollination of R. ilicifolia in western Arizona during 27 April to 21 May 2020 by examining the distribution and phenology of male and female flowers on shrubs, collecting insects from female flowers, and determining the proportions of conspecific pollen on insects to estimate floral constancy. Shrubs were dioecious, and individual male and female plants flowered for 11–15 d, with male flowers preceding female flowers by 2 d. Pollen grains from male flowers viewed in brightfield microscopy are tricolporate in structure and suboblate in shape, with a polar-axis length of 15 µm and equatorial diameter of 18 µm. Insects on female flowers comprised flies (Diptera) in 6 families and less abundant bees (Hymenoptera: Apoidea) in 3 families. The most abundant insects were the flies Allophorocera sp. (Tachinidae) and Phormia regina (Calliphoridae) and the bees Lasioglossum spp. (Halictidae) and Andrena cerasifolii (Andrenidae). Bees appeared more specific to R. ilicifolia flowers by transporting a higher mean proportion of conspecific pollen (0.57) compared with flies (0.36). The large bee A. cerasifolii carried the highest mean proportion of conspecific pollen (0.93). Proportions of conspecific pollen on the saprophytic P. regina were moderately high (0.48) and higher than on most other flies. Dioecious R. ilicifolia shrubs appear to be pollinated by a diversity of flies and bees that are generally not specific to the plant's flowers. Similar pollination of European Rhamnus by generalist insects suggests that plants in the genus and their pollinators have evolved independently.\",\"PeriodicalId\":49364,\"journal\":{\"name\":\"Western North American Naturalist\",\"volume\":\"63 1\",\"pages\":\"67 - 76\"},\"PeriodicalIF\":0.5000,\"publicationDate\":\"2022-02-10\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"1\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Western North American Naturalist\",\"FirstCategoryId\":\"93\",\"ListUrlMain\":\"https://doi.org/10.3398/064.082.0106\",\"RegionNum\":4,\"RegionCategory\":\"环境科学与生态学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"BIODIVERSITY CONSERVATION\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Western North American Naturalist","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.3398/064.082.0106","RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"BIODIVERSITY CONSERVATION","Score":null,"Total":0}
Flowering by Dioecious Rhamnus ilicifolia (Rhamnaceae) and Pollen Transport to Female Flowers by Flies and Bees
Abstract. Rhamnus ilicifolia (Rhamnaceae) is a large shrub found in a range of habitats from southern Oregon south to Baja California and east into Arizona. During spring, the plant produces clusters of unisexual flowers, each with a 5–6-mm-diameter, open perianth of green or yellowish-green sepals. I investigated the pollination of R. ilicifolia in western Arizona during 27 April to 21 May 2020 by examining the distribution and phenology of male and female flowers on shrubs, collecting insects from female flowers, and determining the proportions of conspecific pollen on insects to estimate floral constancy. Shrubs were dioecious, and individual male and female plants flowered for 11–15 d, with male flowers preceding female flowers by 2 d. Pollen grains from male flowers viewed in brightfield microscopy are tricolporate in structure and suboblate in shape, with a polar-axis length of 15 µm and equatorial diameter of 18 µm. Insects on female flowers comprised flies (Diptera) in 6 families and less abundant bees (Hymenoptera: Apoidea) in 3 families. The most abundant insects were the flies Allophorocera sp. (Tachinidae) and Phormia regina (Calliphoridae) and the bees Lasioglossum spp. (Halictidae) and Andrena cerasifolii (Andrenidae). Bees appeared more specific to R. ilicifolia flowers by transporting a higher mean proportion of conspecific pollen (0.57) compared with flies (0.36). The large bee A. cerasifolii carried the highest mean proportion of conspecific pollen (0.93). Proportions of conspecific pollen on the saprophytic P. regina were moderately high (0.48) and higher than on most other flies. Dioecious R. ilicifolia shrubs appear to be pollinated by a diversity of flies and bees that are generally not specific to the plant's flowers. Similar pollination of European Rhamnus by generalist insects suggests that plants in the genus and their pollinators have evolved independently.
期刊介绍:
The Western North American Naturalist places neither restriction nor preference on manuscripts within the disciplines of the biological sciences. Each issue treats diverse taxa from the perspectives of various disciplines (e.g., ecology, population dynamics, behavior, systematics, anatomy, and physiology).