Polyploidization and evolution of the polygamous breeding system from distyly

2017 Fiscal Year Final Research Report

• Project/Area Number: 26840130
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Biodiversity/Systematics
• Research Institution: Okinawa National College of Technology
• Principal Investigator: Watanabe Kenta 沖縄工業高等専門学校, 技術室, 技術専門職員 (50510111)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: Psychotria / polyploidy / heterostyly / Ryukyu Islands / breeding systems / polygamous / monoecy

Outline of Final Research Achievements

In this study, we examined the breeding system and its evolutionary pathway of Psychotria manillensis in the Ryukyu Islands. I found P. manillensis had polygamous breeding system mainly with monoecious, female, and some male and hermaphroditic individuals, and it was pollinated mostly by flies and wasps. Most species in the genus Psychotria are distylous, and distyly is thought to be an ancestral character of the genus. It is a first discovery of monoecism not only in the genus Psychotria but also in all heterostylous species group. It is difficult to explain the evolution from distyly to monoecy only by plant-pollinator interactions. P. manillensis is octoploid, and its closely related ally, P. rubra is tetraploid. If we put this ploidy levels into consideration, the evolution of monoecism in P. manillensis can be linked to polyploidization.

Free Research Field

進化生態学