Cross-virility in two tropical tree species: proof inbreeding despair in this communities and you will hereditary divergence certainly one of communities †

Cross-virility in two warm tree species: proof inbreeding anxiety within communities and genetic divergence certainly communities †

Mcdougal thanks S. Gunatilleke and Letter. Gunatilleke at the Institution off Botany, University away from Peradeniya having pointers and you may logistic assistance; the newest Forest Company regarding Sri Lanka for permission so you’re able to run it really works inside the Sinharaja Industry Society Web site; the Botany Agency, College from Peradeniya for usage of its establishment; S. Harischandran, H. Gamage, and you can M. Gunadasa for advice about hand-pollinations; and S. Harischandran and you may A good. Anura to own tending greenhouse seedlings. P. Ashton, K. Bawa, N. Gunatilleke, J. Hamrick, L. Kaufman, and J. Mitton considering beneficial conversations; P. Ashton, S. Dayanandan, and you site de rencontre pour filles de voyage may C. Schneider commented toward prior to drafts; and you will B. Wieninger helped to your rates. It performs is supported simply of the funds from the brand new Conservation, Dining, & Wellness Basis, Inc.

Abstract

Understanding the spatial patterns out-of cross-virility within the absolute plant communities output trick understanding of biparental inbreeding depression, isolation of the length, and you will, at some point, speciation. About three people each one of a couple exotic forest varieties (Syzygium rubicundum and you may Shorea cordifolia) was indeed for every crossed having four conspecific pollen donors between worry about to trees happening from inside the separate tree supplies (twelve and you may 35 km length to have S. rubicundum and you will Sh. cordifolia, respectively). Cross-virility was estimated once the fruits put, seed products germination, and you may seedling survivorship and you may top in the 1 yr. Manner of really cross-virility strategies improved continuously having outcrossing distance, peaking on step one–2 km for S. rubicundum and you can 1–ten km for Sh. cordifolia, then declining in the between-forest crosses. not, seed germination and you can seedling height having Sh. cordifolia ideal hybrid energy in-between-tree crosses. The latest suggest physical fitness price of nearby-neighbor mating in accordance with crossing with an increase of faraway neighbors is forty five% to possess S. rubicundum and you can 0% having Sh. cordifolia. The latest mean physical fitness cost of between-forest crosses is 52% and 70% into the several varieties. Crossing consequences on fitness reduced involving the levels regarding good fresh fruit place and you may step one-yr-old seedlings. Results mean a powerful possibility inbreeding despair within forest forest communities and you can partial reproductive isolation among woods for the Sri Lanka’s wet zone.

Estimating get across-fertility on several spatial scales within this a plant species‘ variety allows insight into the significance of hereditary incompatibility and you will inbreeding and you can outbreeding depression below absolute conditions. At shorter spatial bills, the fresh new minimal seed dispersal trait of many plant life should produce relatedness certainly one of near-residents into the pure populations. In which nearby vegetation is relevant, mating anywhere between locals (we.age., biparental inbreeding; Uyenoyama, 1986) could lead to smaller reproductive exercise due to inbreeding depression or genetic incompatibility between friends. When you are activities out-of good-size hereditary relatedness was indeed found for a number of herbaceous types (e.g., Epperson and Clegg, 1986; Waser, 1987; Schoen and Latta, 1989), to have woody kinds, particularly angiosperms, data towards inside-inhabitants hereditary construction try minimal. Certain research has shown spatial clustering from adult genotypes (otherwise alleles) when you look at the animal-pollinated forest woods (Acer saccharum-Perry and you can Knowles, 1991; Swartzia simplex-Hamrick, Murawski, and you will Nason, 1993; Quercus rubra-Sork, Huang, and you can Wiener, 1993; Quercus laevis-Berg and Hamrick, 1995; Cordia alliodora-Boshier, Chase, and you can Bawa, 1995), while others failed to support new assumption away from genetic relatedness among nearby people (Psychotria nervosa-Dewey and you can Heywood, 1988; Alseis blackiana and Platypodium elegans-Hamrick, Murawski, and Nason, 1993). Aside from designs off relatedness, mating can often be restricted to local communities in herbaceous types (Levin and you can Kerster, 1974; Endler, 1979; Waser and you may Rate, 1983) along with woody species, especially if flowering grownups is actually clustered (Linhart, 1973; Stacy et al., 1996). The potential for biparental inbreeding despair in pure communities has been presented for many herbaceous and coniferous forest types (Coles and Fowler, 1976; Playground and you can Fowler, 1982; Levin, 1984; Schemske and you can Pautler, 1984; McCall, Mitchell-Olds, and Waller, 1991; Heywood, 1993; Waser and you will Price, 1994; Trame, Coddington, and you can Paige, 1995; Byers, 1998). Little or no is known, not, of biparental inbreeding despair during the pure communities regarding woody angiosperms.