Biology:Dioicy (botany)
Dioicy is a sexual system where archegonia and antheridia are produced on separate gametophytes.[1] It is one of the two main sexual systems in bryophytes. One biologist [who?] stated there is a good reason for the distinction between dioecy and dioicy. Others have stated that the term dioecy is meaningless for bryophytes.[2]:62 Nonetheless dioecy and dioicy are comparable in many respects.[3]
Sexual dimorphism is commonly found in dioicous species.[2]:71
Occurrence
68% of liverwort species,[1] 57% to 60%[4] of moss species, and 40% of hornwort species are dioicous.[1] In all cases sex determination is always genetic.[5]
Evolution of dioicy
The ancestral sexual system in bryophytes is unknown but it has been suggested monoicy and dioicy evolved several times.[6] Hornworts have gone through twice as many transitions from dioicy to monoicy than monoicy to dioicy.[1] In order for dioicy to evolve from hermaphroditism it needs two mutations, a male sterility mutation and a female sterility mutation.[6]
References
- ↑ 1.0 1.1 1.2 1.3 Villarreal, Juan Carlos; Renner, Susanne S. (2013-11-02). "Correlates of monoicy and dioicy in hornworts, the apparent sister group to vascular plants" (in en). BMC Evolutionary Biology 13 (1): 239. doi:10.1186/1471-2148-13-239. ISSN 1471-2148. PMID 24180692. PMC 4228369. https://doi.org/10.1186/1471-2148-13-239.
- ↑ 2.0 2.1 (in en) Reproductive Biology of Plants. CRC Press. 2016-04-19. ISBN 978-1-4822-0133-8. https://books.google.com/books?id=qXvSBQAAQBAJ&newbks=0&printsec=frontcover&pg=PA62&dq=Sexual+systems+in+bryophytes&hl=en.
- ↑ Bisang, Irene; Ehrlén, Johan; Hedenäs, Lars (2006). "Reproductive effort and costs of reproduction do not explain female-biased sex ratios in the moss Pseudocalliergon trifarium (Amblystegiaceae)" (in en). American Journal of Botany 93 (9): 1313–1319. doi:10.3732/ajb.93.9.1313. ISSN 1537-2197. https://bsapubs.onlinelibrary.wiley.com/doi/abs/10.3732/ajb.93.9.1313.
- ↑ Rensing, Stefan (2016-03-23) (in en). Advances in Botanical Research. 78. Academic Press. pp. 109. ISBN 978-0-12-801324-3. https://books.google.com/books?id=LlfBBwAAQBAJ&pg=PA109&dq=Dioicy&hl=en&newbks=1&newbks_redir=0&source=gb_mobile_search&sa=X&ved=2ahUKEwioocv_xMXyAhWWZM0KHXhnBZUQ6AF6BAgIEAM.
- ↑ Renner, Susanne S. (2014). "The relative and absolute frequencies of angiosperm sexual systems: Dioecy, monoecy, gynodioecy, and an updated online database" (in en). American Journal of Botany 101 (10): 1588–1596. doi:10.3732/ajb.1400196. ISSN 1537-2197. https://bsapubs.onlinelibrary.wiley.com/doi/abs/10.3732/ajb.1400196.
- ↑ 6.0 6.1 McDaniel, Stuart F.; Perroud, Pierre-François (2012). "Invited perspective: bryophytes as models for understanding the evolution of sexual systems". The Bryologist 115 (1): 1–11. ISSN 0007-2745. https://www.jstor.org/stable/41486736.
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