Cross-fertility in two warm tree types: evidence of inbreeding anxiety within populations and you may hereditary divergence among populations †
The author thanks a lot S. Gunatilleke and you will N. Gunatilleke from the Service out-of Botany, College regarding Peradeniya to have advice and you can logistic support; the fresh Tree Company of Sri Lanka getting permission so you can carry out that it work when you look at the Sinharaja Globe Traditions Website; new Botany Agencies, College or university of Peradeniya for usage of the business; S. Harischandran, H. Gamage, and you will Meters. Gunadasa to own advice about give-pollinations; and you can S. Harischandran and you can A. Anura to possess tending greenhouse seedlings. P. Ashton, K. Bawa, N. Gunatilleke, J. Hamrick, L. Kaufman, and you may J. Mitton considering helpful discussions; P. Ashton, S. Dayanandan, and C. Schneider commented towards earlier drafts; and B. Wieninger assisted into numbers. It work are supported partly by the money from the fresh Conservation, Eating, & Health Base, Inc.
Abstract
Understanding the spatial habits regarding cross-virility from inside the pure plant populations output secret insight into biparental inbreeding anxiety, separation by range, and, eventually, speciation. About three people every one of several tropical tree species (Syzygium rubicundum and you will Shorea cordifolia) had been for every crossed with five conspecific pollen donors ranging from self so you’re able to woods occurring into the independent tree supplies (twelve and you may thirty five kilometres length to possess S. rubicundum and you can Sh. cordifolia, respectively). Cross-fertility try estimated given that fresh fruit set, seed products germination, and seedling survivorship and peak within step 1 yr. Means of most get across-virility steps increased continuously with outcrossing range, peaking from the step 1–dos kilometres to possess S. rubicundum and you will step one–10 km having Sh. cordifolia, following declining on between-forest crosses. However, seed products germination and seedling level to have Sh. cordifolia recommended crossbreed vitality among-forest crosses. The new indicate fitness cost of nearby-neighbors mating according to crossing with increased distant locals try forty five% to possess S. rubicundum and you will 0% to own Sh. cordifolia. The fresh indicate fitness price of between-tree crosses was 52% and you can 70% on several species. Crossing outcomes towards the physical fitness diminished between your levels out of fresh fruit put and you will step one-yr-old seedlings. Overall performance mean a robust possibility inbreeding despair within tree tree communities and you will partial reproductive separation one of forests in the Sri Lanka’s moist region.
Quoting get across-fertility during the numerous spatial scales inside a plant species’ variety allows insight into the importance of hereditary incompatibility and you can inbreeding and you can outbreeding anxiety under absolute conditions. During the shorter spatial balances, this new minimal seed dispersal trait of several flowers is produce relatedness among close-locals from inside the pure communities https://datingranking.net/it/incontri-giapponesi/. Where neighboring herbs is actually related, mating between natives (we.age., biparental inbreeding; Uyenoyama, 1986) could lead to quicker reproductive fitness on account of inbreeding anxiety otherwise genetic incompatibility anywhere between friends. While you are patterns out-of good-scale genetic relatedness were found for a number of herbaceous types (e.g., Epperson and you can Clegg, 1986; Waser, 1987; Schoen and you can Latta, 1989), getting woody species, particularly angiosperms, investigation toward within-people hereditary build was limited. Certain studies have shown spatial clustering off mature genotypes (or alleles) inside animal-pollinated forest trees (Acer saccharum-Perry and you can Knowles, 1991; Swartzia simplex-Hamrick, Murawski, and Nason, 1993; Quercus rubra-Sork, Huang, and Wiener, 1993; Quercus laevis-Berg and Hamrick, 1995; Cordia alliodora-Boshier, Pursue, and you can Bawa, 1995), while others failed to support the latest presumption out of genetic relatedness certainly one of surrounding grownups (Psychotria nervosa-Dewey and you will Heywood, 1988; Alseis blackiana and you will Platypodium elegans-Hamrick, Murawski, and you may Nason, 1993). Despite habits from relatedness, mating might be restricted to local neighborhoods when you look at the herbaceous varieties (Levin and you may Kerster, 1974; Endler, 1979; Waser and you will Speed, 1983) along with woody kinds, particularly when flowering adults try clustered (Linhart, 1973; Stacy mais aussi al., 1996). The potential for biparental inbreeding depression in the pure communities might have been demonstrated for a lot of herbaceous and you may coniferous forest kinds (Coles and you may Fowler, 1976; Playground and you can Fowler, 1982; Levin, 1984; Schemske and you can Pautler, 1984; McCall, Mitchell-Olds, and you will Waller, 1991; Heywood, 1993; Waser and you may Speed, 1994; Trame, Coddington, and you can Paige, 1995; Byers, 1998). Hardly any known, however, from biparental inbreeding anxiety when you look at the natural communities regarding woody angiosperms.