Cross-virility in 2 warm forest species: proof of inbreeding depression in this populations and hereditary divergence certainly one of populations †

Cross-virility in two warm tree kinds: proof of inbreeding depression inside populations and you may hereditary divergence one of communities †

The author thank-you S. Gunatilleke and N. Gunatilleke at Agencies away from Botany, College away from Peradeniya for guidance and you may logistic help; the latest Forest Department off Sri Lanka to own permission so you’re able to make which functions within the Sinharaja Globe Tradition Webpages; the newest Botany Department, College or university regarding Peradeniya for usage of their institution; S. Harischandran, H. Gamage, and you can M. Gunadasa for advice about hand-pollinations; and you may S. Harischandran and you can A good. Anura to own tending greenhouse seedlings. P. Ashton, K. Bawa, Letter. Gunatilleke, J. Hamrick, L. Kaufman, and you may J. Mitton offered helpful talks; P. Ashton, S. Dayanandan, and you may C. Schneider commented toward before drafts; and you will B. Wieninger helped to the rates. It performs is served in part by the funds from the Conservation, Dinner, & Health Foundation, Inc.

Abstract

Knowing the spatial designs regarding get across-fertility when you look at the sheer bush communities production trick insight into biparental inbreeding depression, separation from the range, and you may, sooner or later, speciation. Around three adults each of a couple exotic forest variety (Syzygium rubicundum and you may Shorea cordifolia) was indeed for each and every entered with five conspecific pollen donors between mind to woods taking place in the separate tree reserves (a dozen and you can thirty-five km length for S. rubicundum and Sh. cordifolia, respectively). Cross-virility is projected as fruit place, seed products germination, and you may seedling survivorship and you can level on step one yr. Technique of really get across-fertility tips improved steadily having outcrossing range, peaking within 1–dos kilometres for S. rubicundum and you can step one–ten km to own Sh. cordifolia, following decreasing from the anywhere between-forest crosses. not, seed products germination and seedling height getting Sh. cordifolia ideal crossbreed vitality between-forest crosses. The brand new imply exercise price of nearby-neighbor mating prior to crossing with faraway natives is actually forty-five% for S. rubicundum and you will 0% having Sh. cordifolia. Brand new imply physical fitness cost of ranging from-forest crosses are 52% and you can 70% toward a couple kinds. Crossing consequences on fitness reduced within amounts out-of fruit set and you will 1-yr-old seedlings. Results suggest a strong possibility inbreeding anxiety contained in this tree tree populations and you may partial reproductive separation certainly woods into the Sri Lanka’s damp zone.

Quoting get across-fertility at numerous spatial scales within this a herb species’ diversity lets understanding of the necessity of genetic incompatibility and you will inbreeding and you will outbreeding depression less than pure criteria. In the faster spatial balances, the brand new restricted seed products dispersal feature of a lot plant life is to end in relatedness among near-natives into the absolute communities. In which neighboring plant life is actually related, mating anywhere between residents (i.elizabeth., biparental inbreeding; Uyenoyama, 1986) may lead to smaller reproductive fitness on account of inbreeding anxiety otherwise genetic incompatibility ranging from mates. While models of okay-level hereditary relatedness was found for a number of herbaceous types (age.grams., Epperson and you will Clegg, 1986; Waser, 1987; Schoen and you may Latta, 1989), getting woody types, including angiosperms, research towards inside-population hereditary framework are limited. Certain research has revealed spatial clustering away from mature genotypes (otherwise alleles) for the creature-pollinated tree trees (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 you can Hamrick, 1995; Cordia alliodora-Boshier, Pursue, and you can Bawa, 1995), while others have failed to support new presumption away from hereditary relatedness certainly one of nearby grownups (Psychotria nervosa-Dewey and you may Heywood, 1988; Alseis blackiana and you may Platypodium elegans-Hamrick, Murawski, and you can Nason, 1993). Regardless of habits out-of relatedness, mating often is restricted to local communities from inside the herbaceous kinds (Levin and you will Kerster, 1974; Endler, 1979; Waser and you may Rate, 1983) plus in woody species, especially if flowering adults is clustered (Linhart, 1973; Stacy ainsi que al., 1996). The opportunity of biparental inbreeding despair when you look at the natural communities has been demonstrated for a number of herbaceous and you will coniferous tree kinds (Coles and Fowler, 1976; sites de rencontre pour polyamoureux Park and Fowler, 1982; Levin, 1984; Schemske and Pautler, 1984; McCall, Mitchell-Olds, and you can Waller, 1991; Heywood, 1993; Waser and you may Rate, 1994; Trame, Coddington, and you will Paige, 1995; Byers, 1998). Almost no is well known, although not, out of biparental inbreeding despair when you look at the natural populations of woody angiosperms.