Escuela de Biología, Universidad de Costa Rica, Ciudad Universitaria "Rodrigo Facio," San Pedro de Montes de Oca, San José, Costa Rica.
Am J Bot. 2001 Sep;88(9):1600-6.
We studied the breeding systems of four populations of Enterolobium cyclocarpum (guanacaste, earpod tree) in Costa Rica. Multilocus estimates of the outcrossing rate indicate that E. cyclocarpum is a predominant outcrossing species (t(m) ranged between 0.881 and 0.901) and biparental inbreeding is low (range between 0.058 and 0.079). Overall, our analyses showed significant differences in the gene frequencies between pollen and ovules and significant differences in pollen gene frequencies between the four populations. We also found significant differences in the pollen gene frequencies calculated for single trees in the same population. Outcrossing rates and pollen gene frequencies varied in two consecutive years in two populations of E. cyclocarpum. The correlated mating model revealed that there are differences in the correlation of paternity between populations and years. These findings indicate that there is variation in the average number of trees that father the seed crop of each tree and/or that some fathers are overrepresented in the seed crop of each tree. The implication of these findings for the development of strategies for conservation and management of this species are discussed.
我们研究了哥斯达黎加四个 Enterolobium cyclocarpum（瓜纳卡斯特树，耳豆树）种群的繁殖系统。多基因座估计的异交率表明，E. cyclocarpum 是一个主要的异交物种（t(m) 在 0.881 到 0.901 之间），并且双亲的近交率较低（范围在 0.058 到 0.079 之间）。总体而言，我们的分析表明花粉和胚珠之间的基因频率存在显著差异，以及四个种群之间的花粉基因频率存在显著差异。我们还发现同一种群中单个树木的花粉基因频率存在显著差异。在两个 E. cyclocarpum 种群中，两年内的异交率和花粉基因频率都有所变化。相关交配模型表明，不同种群和年份之间的父本相关性存在差异。这些发现表明，每个树木的种子作物的父树数量存在差异，或者每个树木的种子作物中存在一些代表性过高的父树。这些发现对制定该物种保护和管理策略的意义进行了讨论。
