Cross-virility in two tropical forest variety: evidence of inbreeding despair within this populations and you may genetic divergence among populations †

Cross-fertility in two warm tree varieties: evidence of inbreeding depression inside populations and you may genetic divergence certainly one of communities †

The author thanks a lot S. Gunatilleke and you will N. Gunatilleke at Department of Botany, College or university off Peradeniya getting information and logistic support; the fresh new Tree Institution off Sri Lanka for consent in order to perform this really works inside Sinharaja Business Tradition Site; brand new Botany Department, College or university off Peradeniya for usage of their establishment; S. Harischandran, H. Gamage, and you will Meters. Gunadasa getting advice about give-pollinations; and S. Harischandran and you can A beneficial. Anura to own tending greenhouse seedlings. P. Ashton, K. Bawa, N. Gunatilleke, J. Hamrick, L. Kaufman, and you can J. Mitton offered helpful discussions; P. Ashton, S. Dayanandan, and you can C. Schneider commented into before drafts; and B. Wieninger aided towards numbers. Which works try served simply by funds from the newest Preservation, Food, & Health Foundation, Inc.

Abstract

Knowing the spatial activities out-of get across-virility in natural bush communities efficiency secret insight into biparental inbreeding depression, separation from the point, and you will, ultimately, speciation. Three grownups every one of a few warm tree kinds (Syzygium rubicundum and you will Shorea cordifolia) was for every crossed having four conspecific pollen donors anywhere between notice so you’re able to trees occurring into the separate tree reserves (12 and you may thirty-five kilometres distance for S. rubicundum and you can Sh. cordifolia, respectively). Cross-virility is actually estimated given that fresh fruit place, vegetables germination, and you can seedling survivorship and you may height at 1 yr. Manner of very cross-virility strategies improved continuously that have outcrossing range, peaking in the 1–2 Dating für religiöse Erwachsene km to own S. rubicundum and you can step one–10 kilometres to have Sh. cordifolia, after which declining at ranging from-forest crosses. Although not, seeds germination and seedling top getting Sh. cordifolia suggested hybrid vitality in between-tree crosses. The mean physical fitness cost of nearest-neighbor mating relative to crossing with more faraway locals are forty five% to possess S. rubicundum and 0% to possess Sh. cordifolia. This new mean fitness price of between-forest crosses are 52% and you can 70% towards a few types.

Crossing consequences on the fitness reduced within level away from good fresh fruit set and you can 1-yr-dated seedlings. Results indicate a robust potential for inbreeding anxiety contained in this tree tree communities and partial reproductive isolation certainly one of woods during the Sri Lanka’s moist zone.

Quoting cross-virility at numerous spatial scales in this a herb species’ range lets understanding of the necessity of hereditary incompatibility and you can inbreeding and you will outbreeding anxiety not as much as absolute standards. During the quicker spatial balances, the newest restricted seed dispersal characteristic of several plants is end up in relatedness certainly close-residents in absolute populations. In which surrounding flowers is relevant, mating anywhere between locals (we.elizabeth., biparental inbreeding; Uyenoyama, 1986) could lead to smaller reproductive physical fitness because of inbreeding despair otherwise hereditary incompatibility ranging from mates. When you find yourself patterns regarding okay-scale hereditary relatedness were shown for a lot of herbaceous kinds (e.g., Epperson and you can Clegg, 1986; Waser, 1987; Schoen and Latta, 1989), to own woody varieties, such as for example angiosperms, data toward within-society genetic build is actually limited. Certain studies have found spatial clustering from mature genotypes (or alleles) inside the animal-pollinated tree trees (Acer saccharum-Perry and you may Knowles, 1991; Swartzia simplex-Hamrick, Murawski, and you can Nason, 1993; Quercus rubra-Sork, Huang, and you will Wiener, 1993; Quercus laevis-Berg and you will Hamrick, 1995; Cordia alliodora-Boshier, Pursue, and Bawa, 1995), although some have failed to support new expectation out of genetic relatedness one of nearby grownups (Psychotria nervosa-Dewey and Heywood, 1988; Alseis blackiana and Platypodium elegans-Hamrick, Murawski, and you will Nason, 1993). No matter designs from relatedness, mating can often be limited by local neighborhoods during the herbaceous species (Levin and you may Kerster, 1974; Endler, 1979; Waser and you will Speed, 1983) plus in woody variety, particularly when blooming adults try clustered (Linhart, 1973; Stacy mais aussi al., 1996). The chance of biparental inbreeding despair inside the pure populations might have been displayed for a lot of herbaceous and you will coniferous forest kinds (Coles and Fowler, 1976; Park and you will Fowler, 1982; Levin, 1984; Schemske and you can Pautler, 1984; McCall, Mitchell-Olds, and Waller, 1991; Heywood, 1993; Waser and you may Rates, 1994; Trame, Coddington, and Paige, 1995; Byers, 1998). Little or no is famous, however, of biparental inbreeding despair in pure communities out-of woody angiosperms.