Evidence for an extreme bottleneck in a rare Mexican pinyon: genetic diversity, disequilibrium, and the mating system in Pinus maxamartinezii

Abstract

Maxipinon (Pinus maximartinezii Rzedowski), which is confined to a single population of approximately 2000 to 2500 mature trees, covers about 400 ha in southern Zacatecas, Mexico. Genetic diversity measured by expected heterozygosity was 0.122, which is moderate for pines. However, percentage polymorphic loci was low, 30.3%. The fixation index (F) of 0.081 indicated only slight heterozygote deficiency. Mating system analysis indicated a significant but low level of selfing; the multilocus outcrossing rate, t_m, was 0.816. The mean of single locus estimates, t_s, was smaller (0.761), perhaps suggesting mating among relatives, although the difference between t_m and t_s was not statistically significant.

Citation

Ledig, F. Thomas; Conkle, M. Thompson; Bermejo-Velázquez, Basilio; Eguiluz-Piedra, Teobaldo; Hodgskiss, Paul D.; Johnson, David R.; Dvorak, William S. 1999. Evidence for an extreme bottleneck in a rare Mexican pinyon: genetic diversity, disequilibrium, and the mating system in Pinus maxamartinezii. Evolution 53(1):91-99