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Member of Board of Trustees of the Maine Biological and Medical Sciences Symposium

Research Interests:

Research in my laboratory focuses on genetic structure of plant populations. Our major project is an investigation of the causes and consequences of self-compatibility in a Central American shrub that shows variation in mating system. This project has several components.

Biochemical: We are obtaining DNA sequences from the S-locus, which encodes the gene responsible for recognition and rejection of self-pollen. Examination of these sequences shows that individuals capable of self-fertilization have mutations in otherwise invariant sections of the sequence. Biochemical work will indicate whether these mutations affect functioning of the enzyme responsible for self-pollen rejection.

Phylogenetic: We will build a phylogenetic tree showing relationships among alleles at the S-locus. Mathematical analysis of this tree will yield insight into how many times mutations have led to self-compatibility, and how long it has been since these mutations have occurred. This is of special interest in populations having both types of individuals (those who can and cannot self-fertilize), because theory predicts that mutations causing selfing should either be fixed or be lost rapidly.

Ecological: We would like to know under what conditions a self-fertilizing mutant is successful and under what conditions it is not. We have studied inbreeding depression in the greenhouse. A long-term goal of the project is to study pollination limitation and inbreeding depression in the field.

Stone, J. L., and E. G. Jenkins*. Pollinator Abundance and Pollen Limitation of a Solanaceous Shrub at Premontane and Lower Montane Sites. Accepted by Biotropica, March 30, 2007.

Stone, J. L., and B. A. Drummond*. 2006. Rare estuary monkeyflower in Merrymeeting Bay is genetically distinct. Northeastern Naturalist 13(2): 179-190.

Stone, J. L., M. A. Sasuclark*, and C. P. Blomberg*. 2006. Variation in stylar RNase production and the self-incompatibility response within and among populations of the tropical shrub Witheringia solanacea (Solanaceae). American Journal of Botany 93(4): 592-598.

Stone, J. L., and S. E. Pierce*. 2005. Rapid recent radiation of S-RNase lineages in Witheringia solanacea (Solanaceae). Heredity 94: 547-555.

* = student co-author

Stone, J. L. 2004. Sheltered load associated with S-alleles in Solanum carolinense. Heredity 92: 335-342.

Stone, J. L., and A. F. Motten. 2002. Anther-stigma separation is associated with inbreeding depression in Datura stramonium, a predominantly self-fertilizing annual. Evolution 56: 2187-2195.

Stone, J. L. 2002. Molecular mechanisms underlying the breakdown of gametophytic self-incompatibility, Quarterly Review of Biology 77: 17-32.

Motten, A. F. and J. L. Stone. 2000 Heritability of stigma position and the effect of stigma-anther separation on outcrossing in a predominantly self-fertilizing weed, Datura stramonium (Solanaceae). American Journal of Botany 87: 339-347.

Stone, J. L. 2000. Does anthocyanin affect outcrossing rates in Datura stramonium (Solananceae)? American Journal of Botany 87: 348-354.

Stone, J. L. 1996. Components of pollinator effectiveness in Psychotria suerrensis, a tropical distylous shrub. Oecologia 107: 504-512.

Stone, J. L. 1996. Pollen donation in a tropical distylous shrub (Psychotria suerrensis; Rubiaceae). American Journal of Botany 82: 1390-1398.

Stone, J. L., and J. D. Thomson. 1994. The evolution of heterostyly: pollen transfer in artificial flowers. Evolution 48: 1595-1606.