Cross-fertility in 2 warm tree kinds: proof inbreeding depression inside communities and you can genetic divergence certainly communities †

Mcdougal many thanks S. Gunatilleke and N. Gunatilleke on Company out of Botany, School away from Peradeniya to have recommendations and you can logistic support; new Forest Department out of Sri Lanka to possess permission in order to make which performs when you look at the Sinharaja Business Community Website; the latest Botany Department, School out of Peradeniya for usage of its facilities; S. Harischandran, H. Gamage, and you will M. Gunadasa for help with hands-pollinations; and you may S. Harischandran and you can Good. Anura getting tending greenhouse seedlings. P. Ashton, K. Bawa, N. Gunatilleke, J. Hamrick, L. Kaufman, and you can J. Mitton considering of use discussions; P. Ashton, S. Dayanandan, and you will C. Schneider commented on prior to drafts; and you will B. Wieninger helped with the numbers. Which works is served partly from the funds from new Maintenance, Restaurants, & Fitness Foundation, Inc.

Abstract

Knowing the spatial designs regarding mix-fertility in natural plant populations yields trick insight into biparental inbreeding anxiety, isolation by point, and you will, sooner or later, speciation. About three grownups every one of one or two tropical tree varieties (Syzygium rubicundum and you can Shorea cordifolia) have been for every single crossed with five conspecific pollen donors anywhere between self in order to woods taking place in the separate tree supplies (a dozen and you will thirty-five km distance getting S. rubicundum and Sh. cordifolia, respectively). Cross-fertility is actually estimated due to the fact fruits place, seed products germination, and you can seedling survivorship and you may height at step one yr. Technique of extremely get across-virility strategies enhanced gradually having outcrossing length, peaking on step one–2 km to possess S. rubicundum and you can 1–ten km getting Sh. cordifolia, after which declining from the between-tree crosses. not, vegetables germination and you will seedling level to own Sh. cordifolia suggested crossbreed energy between-forest crosses. The latest imply exercise cost of nearby-neighbors mating prior to crossing with more faraway natives is actually forty five% to possess S. rubicundum and you will 0% to own Sh. cordifolia. The fresh new suggest exercise price of anywhere between-tree crosses are 52% and you can 70% on the one or two species. Crossing effects on fitness diminished between your degrees from fruit set and you will 1-yr-dated seedlings. Results imply a robust potential for inbreeding despair in this forest forest populations and you can partial reproductive isolation one of forest into the Sri Lanka’s wet area.

Estimating get across-virility from the several spatial balances within a herb species’ diversity lets insight into the necessity of genetic incompatibility and you will inbreeding and you can outbreeding anxiety under natural criteria. In the shorter spatial balances, the brand new limited seed products dispersal attribute of many flowers is to end up in relatedness among close-locals during the pure populations. In which surrounding vegetation try associated, mating between natives (we.age., biparental inbreeding; Uyenoyama, 1986) could lead to less reproductive exercise because of inbreeding despair otherwise genetic incompatibility ranging from friends. If you find yourself models from good-measure genetic relatedness was indeed found for many herbaceous species (elizabeth.grams., Epperson and you may Clegg, 1986; Waser, 1987; Schoen and you may Latta, 1989), to have woody species, such as for instance angiosperms, analysis on the within-inhabitants hereditary build is actually restricted. Some research has shown spatial clustering regarding adult genotypes (or alleles) inside animal-pollinated tree woods (Acer saccharum-Perry and you may Knowles, 1991; Swartzia simplex-Hamrick, Murawski, and Nason, 1993; Quercus rubra-Sork, Huang, and you will Wiener, 1993; Quercus laevis-Berg and you will Hamrick, 1995; Cordia alliodora-Boshier, Pursue, and you may Bawa, 1995), and others failed to help with the newest assumption away from genetic relatedness among surrounding people (Psychotria nervosa-Dewey and you can Heywood, 1988; Alseis blackiana and you can Platypodium elegans-Hamrick, Murawski, and you can Nason, 1993). Despite patterns off relatedness, mating might be limited to local areas for the herbaceous variety (Levin and Kerster, 1974; Endler, 1979; Waser and Rate, 1983) plus in woody types, particularly when blooming adults is actually clustered (Linhart, 1973; Stacy et al., 1996). The potential for biparental inbreeding anxiety from inside the sheer communities could have been shown for many herbaceous and you can coniferous forest variety (Coles and you can Fowler, 1976; Playground and you will Fowler, 1982; Levin, 1984; Schemske and you may Pautler, 1984; McCall, Mitchell-Olds, and you can Waller, 1991; Heywood, 1993; Waser and Rate, 1994; Trame, Coddington, and Paige, 1995; Byers, 1998). Hardly any is well known connexion aux rencontres musulmanes, but not, out of biparental inbreeding anxiety in the natural populations from woody angiosperms.