Semlitsch Raymond D, Reyer Heinz-Ulrich
Institute of Zoology, University of Zurich, CH-8057, Zurich, SWITZERLAND.
Evolution. 1992 Jun;46(3):665-676. doi: 10.1111/j.1558-5646.1992.tb02074.x.
The performance of three genotypes (LL, LR, RR) of tadpoles resulting from the hybrid mating system of Rana lessonae (phenotype L, genotype LL) and Rana esculenta (phenotype E, genotype LR) was determined in artificial ponds. The effects of interspecific competition and pond drying on growth, development, and survival of tadpoles were used to measure the performance of genotypes and the relative fitness of offspring. Among the three genotypes, tadpoles from the homogametic mating RR had the lowest survival, growth, and development under all environmental conditions. Body size of the LL and LR genotype tadpoles at metamorphosis was reduced by competition and pond drying. Days to metamorphosis were also higher for the LL and LR genotype tadpoles in competition ponds. The proportion of individuals metamorphosing of each genotype was differentially lowered by competition and pond drying. The LL genotype produced more metamorphs than the LR genotype in the constant water level ponds, but the LR genotype produced more in drying ponds. In competition ponds, the LR genotype produced more metamorphs than the LL genotype, but the LL genotype produced more metamorphs in ponds without competition. The RR genotype produced no metamorphs in any of the experimental environments. Increased performance of LR offspring from the heterogametic mating, in harsh conditions, and reduced performance of RR offspring from the homogametic mating, even under favorable conditions, relative to the parental genotype (LL) suggests that the population dynamics of this hybridogenetic system is strongly dependent on mate choice in mixed populations and the subsequent pond environment females select for oviposition and larval development.
在人工池塘中测定了由湖蛙（表型L，基因型LL）和食用蛙（表型E，基因型LR）杂交交配系统产生的三种基因型（LL、LR、RR）蝌蚪的表现。利用种间竞争和池塘干涸对蝌蚪生长、发育和存活的影响来衡量基因型的表现和后代的相对适合度。在这三种基因型中，同配交配RR产生的蝌蚪在所有环境条件下的存活、生长和发育水平最低。竞争和池塘干涸使LL和LR基因型蝌蚪变态时的体型减小。竞争池塘中LL和LR基因型蝌蚪的变态天数也更多。竞争和池塘干涸使每种基因型变态个体的比例有不同程度的降低。在水位恒定的池塘中，LL基因型产生的变态个体比LR基因型多，但在干涸池塘中LR基因型产生的变态个体更多。在竞争池塘中，LR基因型产生的变态个体比LL基因型多，但在无竞争的池塘中LL基因型产生的变态个体更多。RR基因型在任何实验环境中都没有产生变态个体。相对于亲本基因型（LL），异配交配产生的LR后代在恶劣条件下表现增强，而同配交配产生的RR后代即使在有利条件下表现也降低，这表明这种杂交起源系统的种群动态强烈依赖于混合种群中的配偶选择以及雌性随后为产卵和幼体发育所选择的池塘环境。
