Reproductive biology and female frequencies of two co-occurring gynodioecious Thymus species
- PDF / 420,486 Bytes
- 9 Pages / 547.087 x 737.008 pts Page_size
- 20 Downloads / 181 Views
(0123456789().,-volV) ( 01234567 89().,-volV)
Reproductive biology and female frequencies of two cooccurring gynodioecious Thymus species Eduardo Cuevas
. M. Cristina Andre´s . Juan Arroyo
Received: 31 March 2020 / Accepted: 1 September 2020 Ó Springer Nature B.V. 2020
Abstract Gynodioecy, the co-occurrence of female and hermaphrodite plants in the same population is relatively common in the genus Thymus, where a high and variable female frequency has been reported in several species, populations and years. In most gynodioecious species, female plants produce more and/or better seeds than hermaphrodite plants, facilitating female maintenance in natural populations. Thymus 9 arundanus and T. granatensis are two sympatric gynodioecious species that inhabit the region of Andalucia, Spain. Here we studied reproductive components in two different years (1987 and 2016) as flower number, fruit-set, seed number and seed mass, and their possible relation to female frequencies in those years in natural populations of both species. In T. 9 arundanus, mean female frequency (59%) was ten times higher than that of T. granatensis (5%). Female frequency was relatively constant in T. 9 arundanus after almost 15 years (1987–2016), and in T. granatensis low female
Communicated by Siegy Krauss. E. Cuevas (&) Facultad de Biologı´a, Universidad Michoacana de San Nicola´s de Hidalgo, 58000 Morelia, Michoacan, Mexico e-mail: [email protected] M. C. Andre´s J. Arroyo Departamento de Biologı´a Vegetal y Ecologı´a, Universidad de Sevilla, Apartado 1095, 41080 Seville, Spain
frequencies were observed (0–5%) with the exception of one population (18%). However, reproductive components were variable among species, years and genders, showing no consistent female fertility advantage. High female frequencies in T. 9 arundanus are not likely to be maintained by female fertility advantage but stochastic and pleiotropic effects on sex determination may play a relevant role in sex ratio variation in the studied populations of both species. Keywords sterility
Female frequency Gynodioecy Male
Introduction Gynodioecy, the co-occurrence of female (male sterile plants) and hermaphrodite plants is a rare but widely distribute sexual system in angiosperms with more than 275 genera containing at least one gynodioecious species (Renner 2014). Female frequency may vary widely among gynodioecious species and even among populations of the same species (Dufay and Billard 2012). However, most reports of female frequency variation among populations are short term (Asikainen and Mutikainen 2003; Cuevas et al. 2006; Nilsson and ˚ gren 2006). Gynodioecy is relatively extended in the A Lamiaceae family (Rivkin et al. 2016) and it is particularly common in the genus Thymus, being T.
123
Plant Ecol
vulgaris one of the most studied species since Darwin time (1877). Two interesting and intriguing observations of T. vulgaris populations are the wide variation in female frequency (5–95%, Domme´e et al. 1978; Manicacci et al. 1998) and the very high mea
Data Loading...
