Evolution of floral characters and biogeography of Heloniadeae (Melanthiaceae): an example of breeding system shifts with inflorescence change.

Heloniadeae (Melanthiaceae) presents an East Asia-North America disjunct distribution. Different molecular and morphological data nevertheless support the tribe as a monophyletic group. However, their phylogenetic relationships and biogeographic history, together with the character evolution, are not clear. Therefore, we constructed a Bayesian phylogenetic tree for Heloniadeae using cpDNA and inferred the historical biogeography and floral character evolution. The results revealed that Heloniadeae was distributed in high-latitudes of East Asia and North America, originating since 22.2 mya. The East Asia clade migrated into southwest China, and subsequently colonized the Korean Peninsula, Taiwan, the Ryukyus, and spread northward to Japan and southern Sakhalin. The evolution of the inflorescence and number of flowers were phylogenetically conserved, associated with the historical biogeography of Heloniadeae. The inflorescences transferred from raceme to sub-umbel, and the number of flowers decreased during the dispersal process, which may be accompanied by changes in the breeding system. Besides, the anthesis period was more affected by the habitat environment than phylogenetic constraints. The flowering temperature of was below 20 °C in most species, except H. kawanoi. Such a low temperature might not be conductive to pollinator activities, but it could be compensated by sustaining seed production with long-lasting flowers.

Mating consequences of contrasting hermaphroditic plant sexual systems.

For hermaphroditic angiosperms with multiple flowers, the sex roles can be exclusively combined in bisexual flowers (monocliny), strictly separated among different flowers (monoecy), or arrayed in mixtures of bisexual flowers with female flowers (gynomonoecy) or male flowers (andromonoecy). The hypothesized benefits favoring the evolution of these contrasting hermaphroditic sexual systems are typically examined individually, usually by assessing success through only one sex role. We tested predictions of most hypotheses experimentally with an andromonoecious species, Anticlea occidentalis (Melanthiaceae), based on the performance of intact plants (andromonoecy) and those with emasculated bisexual flowers (functionally monoecious) or emasculated male flowers (functionally monoclinous with sterile peripheral flowers). Andromonoecy in this species enables efficient, size-dependent resource allocation, emphasizing female function in large plants. Emasculation revealed that anthers in male flowers promote female mating quality (outcrossing rate and mate diversity), whereas anthers in bisexual flowers promote male mating quantity (pollen dispersal distance and probability of any siring success). Thus, different hermaphroditic sexual systems likely evolve to capitalize on suites of benefits, rather than just one, and provide compromises between quantitative and qualitative reproductive components. These compromises apparently maximize an individual's combined genetic contributions through female and male functions, rather than separate contributions through each sex role.

[Study on effect elements of anthers opening-closing movement and its cell morphology regulatory mechanism of Paris polyphylla var. yunnanensis].

In order to study the effect elements of anthers opening-closing movement of Paris polyphylla var. yunnanensis, and its cell morphology regulatory mechanism. Anthers daily opening in the morning and closing in the evening and its corresponding ecological elements changes were recorded. Different light, temperature, humidity experiment and artificial rainfall experiment were designed to observe the effect on anthers opening-closing movement, paraffin sections were made to observe the cell morphology change when the anthers daily opening and closing. The result showed that the movement of anthers daily opening and closing was regulated by ecological elements. The overall trend was high temperature and strong light, low humidity was favorable for anther opening, and low temperature, weak light, high humidity was favorable for anther closing. In this experiment, the effect of these ecological elements on the movement of anthers opening from strong to weak was humidity, temperature, light. The effect of these ecological elements on the movement of anthers closing from strong to weak was light, humidity, temperature. The direct contact of the raindrops causes the rapid closing of the anthers in the rain. Observing the cell morphology change when anthers opening and closing, it was a pollen sac dehydration and water-absorption process, different light, temperature and humidity conditions induce different physiological activities in the cell, which caused the cell osmotic pressure change, eventually resulting in anther opening and closing movement. But anthers closing caused by the rain was a simple physical adjustment process, the raindrops fell on the anthers directly, which caused anthers soaked water and change of the cell osmotic pressure, then resulting in anther closing.