1. Translocation of heavy metals from soils into floral organs and rewards of Cucurbita pepo: Implications for plant reproductive fitness
- Author
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Jimin Zhao, Jixun Guo, Yan-Wen Zhang, and Erna Xun
- Subjects
0106 biological sciences ,Plant Nectar ,Health, Toxicology and Mutagenesis ,Stamen ,Flowers ,010501 environmental sciences ,medicine.disease_cause ,01 natural sciences ,Plant reproduction ,Cucurbita pepo ,Cucurbita ,Pollinator ,Pollen ,Metals, Heavy ,Botany ,medicine ,Nectar ,Animals ,Soil Pollutants ,Hyperaccumulator ,Pollination ,0105 earth and related environmental sciences ,biology ,Reproduction ,fungi ,Public Health, Environmental and Occupational Health ,food and beverages ,General Medicine ,Bees ,biology.organism_classification ,Pollution ,Seeds ,010606 plant biology & botany ,Squash - Abstract
Metals and metalloids in soil could be transferred into reproductive organs and floral rewards of hyperaccumulator plants and influence their reproductive success, yet little is known whether non-hyperaccumulator plants can translocate heavy metals from soil into their floral organs and rewards (i.e., nectar and pollen) and, if so, whether plant reproduction will be affected. In our studies, summer squash (Cucurbita pepo L. cv. Golden Apple) was exposed to heavy-metal treatments during bud stage to investigate the translocation of soil-supplemented zinc, copper, nickel and lead into its floral organs (pistil, anther and nectary) and rewards (nectar and pollen) as well as floral metal accumulation effects on its reproduction. The results showed that metals taken up by squash did translocate into its floral organs and rewards, although metal accumulation varied depending on different metal types and concentrations as well as floral organ/reward types. Mean foraging time of honey bees to each male and female flower of squash grown in metal-supplemented soils was shorter relative to that of plants grown in control soils, although the visitation rate of honeybees to both male and female flowers was not affected by metal treatments. Pollen viability, pollen removal and deposition as well as mean mass per seed produced by metal-treated squash that received pollen from plants grown in control soils decreased with elevated soil-supplemented metal concentrations. The fact that squash could translocate soil-supplemented heavy metals into floral organs and rewards indicated possible reproductive consequences caused either directly (i.e., decreasing pollen viability or seed mass) or indirectly (i.e., affecting pollinators' visitation behavior to flowers) to plant fitness.
- Published
- 2017