Department of Environmental, Population, and Organismic Biology, University of Colorado, Campus Box #334, Boulder, Colorado 80309 USA.
Am J Bot. 2003 May;90(5):707-15. doi: 10.3732/ajb.90.5.707.
Quantitative analyses of sexual expression show extensive interspecific variation in the strength of andromonoecy (proportions of hermaphroditic and staminate flowers) among Solanum species in the monophyletic section Lasiocarpa. The roles of phenotypic plasticity and inter- and intra-inflorescence architecture in the diversification of andromonoecy within this small clade were analyzed. Four species that represent a range of expression of andromonoecy were examined. Staminate flowers produced within inflorescences ranged from 3% (S. candidum) to 7% (S. ferox) in weakly andromonoecious species and from 39% (S. pseudolulo) to 60% (S. quitoense) in more strongly andromonoecious species. Manipulation of fruit set on clonal replicates of multiple genotypes demonstrated variation among species for phenotypic plasticity. The strongly andromonoecious species, S. pseudolulo and S. quitoense, were not plastic and produced a large proportion of staminate flowers regardless of fruiting treatment, whereas S. candidum and S. ferox were phenotypically plastic and produced significantly more staminate flowers in the presence of developing fruit. Staminate flower production of all four species varied both within and among inflorescences. A greater proportion of staminate flowers were produced in distal (later produced) inflorescences. Within inflorescences, hermaphroditic flowers occurred in basal positions, whereas staminate flowers, when produced, occurred more distally. This pattern of staminate flower production is qualitatively the same in all species investigated; however, quantitative variation in the transition from hermaphroditic to staminate flower production within and among inflorescences is associated with variation in the strength of andromonoecy. At least three factors have contributed to the diversification of andromonoecy in section Lasiocarpa including the presence or absence of phenotypic plasticity in response to fruit set, quantitative variation in intra- and inter-inflorescence architectural effects, and total flower production.
定量分析表明，在单系的 LasioCarpa 组中，茄属植物的雌雄同体（两性花和雄花的比例）的强度存在广泛的种间变异。分析了表型可塑性以及花序内和花序间结构在这个小分支内雌雄同体多样化中的作用。研究了代表雌雄同体表达范围的四个物种。在弱雌雄同体物种中，花序内产生的雄花比例从 3%（S. candidum）到 7%（S. ferox），而在较强的雌雄同体物种中，比例从 39%（S. pseudolulo）到 60%（S. quitoense）。对多个基因型的克隆重复进行果实设置操纵表明，物种之间存在表型可塑性的差异。强雌雄同体物种 S. pseudolulo 和 S. quitoense 没有可塑性，无论果实处理如何，都会产生大量的雄花，而 S. candidum 和 S. ferox 具有表型可塑性，在有发育果实的情况下会产生更多的雄花。四个物种的雄花产生都存在于花序内和花序间的差异。在远端（后期产生）花序中产生了更大比例的雄花。在花序内，两性花位于基部位置，而雄花在产生时位于更远处。在所有研究的物种中，这种雄花产生的模式都是相同的；然而，花序内和花序间从两性花到雄花的产生的数量变化与雌雄同体的强度变化有关。至少有三个因素导致了 LasioCarpa 组中雌雄同体的多样化，包括对果实设置的表型可塑性的存在与否、花序内和花序间结构效应的定量变化以及总花产量。
