Identification of sex-linked markers in the sexually cryptic coco de mer: are males and females produced in equal proportions?

Details

Serval ID
serval:BIB_3CB929B4014C
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Identification of sex-linked markers in the sexually cryptic coco de mer: are males and females produced in equal proportions?
Journal
AoB PLANTS
Author(s)
Morgan E.J., Kaiser-Bunbury C.N., Edwards P.J., Scharmann M., Widmer A., Fleischer-Dogley F., Kettle C.J.
ISSN
2041-2851 (Print)
Publication state
Published
Issued date
02/2020
Peer-reviewed
Oui
Volume
12
Number
1
Pages
plz079
Language
english
Notes
Publication types: Journal Article
Publication Status: epublish
Abstract
Lodoicea maldivica (coco de mer) is a long-lived dioecious palm in which male and female plants are visually indistinguishable when immature, only becoming sexually dimorphic as adults, which in natural forest can take as much as 50 years. Most adult populations in the Seychelles exhibit biased sex ratios, but it is unknown whether this is due to different proportions of male and female plants being produced or to differential mortality. In this study, we developed sex-linked markers in Lodoicea using ddRAD sequencing, enabling us to reliably determine the gender of immature individuals. We screened 589 immature individuals to explore sex ratios across life stages in Lodoicea. The two sex-specific markers resulted in the amplification of male-specific bands (Lm123977 at 405 bp and Lm435135 at 130 bp). Our study of four sub-populations of Lodoicea on the islands of Praslin and Curieuse revealed that the two sexes were produced in approximately equal numbers, with no significant deviation from a 1:1 ratio before the adult stage. We conclude that sex in Lodoicea is genetically determined, suggesting that Lodoicea has a chromosomal sex determination system in which males are the heterogametic sex (XY) and females are homogametic (XX). We discuss the potential causes for observed biased sex ratios in adult populations, and the implications of our results for the life history, ecology and conservation management of Lodoicea.
Keywords
Borasseae, Lodoicea maldivica, Seychelles Islands, conservation management, ddRAD sequencing, dioecy, palm, reproductive ecology, sex ratios, sex-linked markers
Pubmed
Open Access
Yes
Create date
29/01/2020 17:36
Last modification date
25/02/2020 7:26
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