Protein/Lipid ratio of pollen biases the visitation of bumblebees (Bombus ignitus Smith) to male-fertile cultivars of the Japanese pear (Pyrus pyrifolia Nakai).
Bees have been known to visit the male-fertile cultivars of self-incompatible flowering plants more frequently than the male-sterile cultivars, but the origin of this preference is poorly understood. Here, we demonstrate that this preference is driven by the higher protein/lipid ratio of male-fertil...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2024-01-01
|
| Series: | PLoS ONE |
| Online Access: | https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0297298&type=printable |
| _version_ | 1797279581929996288 |
|---|---|
| author | Shinnosuke Mori Masahiro Mitsuhata Tomoyuki Yokoi |
| author_facet | Shinnosuke Mori Masahiro Mitsuhata Tomoyuki Yokoi |
| author_sort | Shinnosuke Mori |
| collection | DOAJ |
| description | Bees have been known to visit the male-fertile cultivars of self-incompatible flowering plants more frequently than the male-sterile cultivars, but the origin of this preference is poorly understood. Here, we demonstrate that this preference is driven by the higher protein/lipid ratio of male-fertile pollen compared with male-sterile pollen by way of two caged-behavioral assays with six cultivars. In the first assay, flower-naïve bumblebees (Bombus ignitus Smith) showed a significantly higher flower-visitation rate to male-fertile cultivars (pollen germination rate > 55%; > 14 visits/10 min) of the Japanese pear (Pyrus pyrifolia Nakai) than male-sterile cultivars (pollen germination rate ≤ 20%; > 6 visits/10 min). In the second, bees still preferred the anthers of male-fertile cultivars (5-9 visits/10 min) more than those of male-sterile ones (less than 1 visit in 10 min) even in the absence of all other organs (i.e., petals, pistil, nectar), indicating that pollen is responsible for the preference. We then analyzed the macronutrient content of the pollen and its visual cues, and found that the bee preference was highly correlated with the protein/lipid ratio (0.3-1.6) but not color variables such as (a)chromatic contrast, intensity, and spectral purity. We conclude that the protein/lipid ratio influences the foraging behavior of the bumblebees likely by serving as (1) a chemotactile cue while antennating, (2) a gustatory cue after intake, and (3) an olfactory cue. In addition, the low bee visitation rate to poorly viable pollen could be due to its low protein/lipid ratio. |
| first_indexed | 2024-03-07T16:28:13Z |
| format | Article |
| id | doaj.art-0bad1dafb02e4510afe96ff0dea55f5c |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-03-07T16:28:13Z |
| publishDate | 2024-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-0bad1dafb02e4510afe96ff0dea55f5c2024-03-03T12:56:11ZengPublic Library of Science (PLoS)PLoS ONE1932-62032024-01-01192e029729810.1371/journal.pone.0297298Protein/Lipid ratio of pollen biases the visitation of bumblebees (Bombus ignitus Smith) to male-fertile cultivars of the Japanese pear (Pyrus pyrifolia Nakai).Shinnosuke MoriMasahiro MitsuhataTomoyuki YokoiBees have been known to visit the male-fertile cultivars of self-incompatible flowering plants more frequently than the male-sterile cultivars, but the origin of this preference is poorly understood. Here, we demonstrate that this preference is driven by the higher protein/lipid ratio of male-fertile pollen compared with male-sterile pollen by way of two caged-behavioral assays with six cultivars. In the first assay, flower-naïve bumblebees (Bombus ignitus Smith) showed a significantly higher flower-visitation rate to male-fertile cultivars (pollen germination rate > 55%; > 14 visits/10 min) of the Japanese pear (Pyrus pyrifolia Nakai) than male-sterile cultivars (pollen germination rate ≤ 20%; > 6 visits/10 min). In the second, bees still preferred the anthers of male-fertile cultivars (5-9 visits/10 min) more than those of male-sterile ones (less than 1 visit in 10 min) even in the absence of all other organs (i.e., petals, pistil, nectar), indicating that pollen is responsible for the preference. We then analyzed the macronutrient content of the pollen and its visual cues, and found that the bee preference was highly correlated with the protein/lipid ratio (0.3-1.6) but not color variables such as (a)chromatic contrast, intensity, and spectral purity. We conclude that the protein/lipid ratio influences the foraging behavior of the bumblebees likely by serving as (1) a chemotactile cue while antennating, (2) a gustatory cue after intake, and (3) an olfactory cue. In addition, the low bee visitation rate to poorly viable pollen could be due to its low protein/lipid ratio.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0297298&type=printable |
| spellingShingle | Shinnosuke Mori Masahiro Mitsuhata Tomoyuki Yokoi Protein/Lipid ratio of pollen biases the visitation of bumblebees (Bombus ignitus Smith) to male-fertile cultivars of the Japanese pear (Pyrus pyrifolia Nakai). PLoS ONE |
| title | Protein/Lipid ratio of pollen biases the visitation of bumblebees (Bombus ignitus Smith) to male-fertile cultivars of the Japanese pear (Pyrus pyrifolia Nakai). |
| title_full | Protein/Lipid ratio of pollen biases the visitation of bumblebees (Bombus ignitus Smith) to male-fertile cultivars of the Japanese pear (Pyrus pyrifolia Nakai). |
| title_fullStr | Protein/Lipid ratio of pollen biases the visitation of bumblebees (Bombus ignitus Smith) to male-fertile cultivars of the Japanese pear (Pyrus pyrifolia Nakai). |
| title_full_unstemmed | Protein/Lipid ratio of pollen biases the visitation of bumblebees (Bombus ignitus Smith) to male-fertile cultivars of the Japanese pear (Pyrus pyrifolia Nakai). |
| title_short | Protein/Lipid ratio of pollen biases the visitation of bumblebees (Bombus ignitus Smith) to male-fertile cultivars of the Japanese pear (Pyrus pyrifolia Nakai). |
| title_sort | protein lipid ratio of pollen biases the visitation of bumblebees bombus ignitus smith to male fertile cultivars of the japanese pear pyrus pyrifolia nakai |
| url | https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0297298&type=printable |
| work_keys_str_mv | AT shinnosukemori proteinlipidratioofpollenbiasesthevisitationofbumblebeesbombusignitussmithtomalefertilecultivarsofthejapanesepearpyruspyrifolianakai AT masahiromitsuhata proteinlipidratioofpollenbiasesthevisitationofbumblebeesbombusignitussmithtomalefertilecultivarsofthejapanesepearpyruspyrifolianakai AT tomoyukiyokoi proteinlipidratioofpollenbiasesthevisitationofbumblebeesbombusignitussmithtomalefertilecultivarsofthejapanesepearpyruspyrifolianakai |