| Limonium chrysocomum were classified to plumbaginaceae, which most plants in plumbaginaceae had the phenomenon of heterostyly, had complex geneic relationship between types and species, that were a special category of experimental materials for sex expression and breeding system. It mainly distributed in desert environment which were dry heat, strong wind and temperature fluctuation. Taking wild L.chrysocomum as materials, using flowering phenology obversitions, bagging treaments, pollination investigations and germination experiments to describ its reproductive biology, and addressed such problems as monotypic or dimorphic species ? Whether a self-incompatibility system ? What was the affinity law of stigma and pollen ? Some of main conclusions showed that :1. L.chrysocomum usually turn green in late March, form bug in April, start flowering in early May, bloom prosperously in mid May, come the end of flowering at early June, have seed in mid June, and then the whole plants become dry. The bloomed flowers of L.chrysocomum can last different time at different levels.2. The single flower of L.chrysocomum is tubular, having yellow calyx with white densely villous and 5pistils and stamens wrapped in orange collora. They are asynchronous at inflorescences and plants levels:the one near rachis opens early in the same spikelet, and in the same spray some spikelets have opening flowers while others stay in the flower bug differentiation,that can extend flowering time to increase the rate of pollination. Pistils and stamens in single flower are even maturing at out-corolla stage, at the same time show a peak for stigma receptivity, however the fastigium of pollen viability appears at blade stage, never overlap.3. The breeding system of L.chrysocomum are facultative xenogamy, self-compatible, sometimes need pollinators and apomixes slightly.Try xenogamy as major as possible,and hold autogamy at the same time.That is available for the habitat and guarantees to have offsprings even in case no pollinators,which can lead the species to extinct.4. By anatomical observation found that: L.chrysocomum is distyly, containing stigmas with polygonal cells and A type pollen(C plants)or stigmas with papillose cells and B type pollen(P plants), and the pollen size in two morphs are also dimorphic, only existing the phenomenon of approach herkogamy and no exact complementary herkogamy,which are in differ from others.5. By fluorescent staining shows that the speed of pollen germination and tube growth are:heterotype >homotype, and the process of fertility can not be completed for B type pollen adhered to papillate stigmas. Moreover artificial pollination experiments also confirm that the seed rate of heterotype treatments are significantly higher than homotype treatments, however among homotype treatments the seed production of P plants are exiguous. Actually the researchs indicate that: the cob stigmas are compatibility for A/B type pollen, while the papillate stigmas are compatibility for A type pollen, but incompatibility for B type pollen.The one break the inhibition of self-incompatibility in types,which is the main reasons for imbalance of two morphs.6. Temperature is the main factor effecting on pollination in populations. Entomophily is the main medium for pollen transmission, the main pollinator are the insects in apidae and rhopalocera. Because of the different flower structures and patterns, bees prefer to the C plants, which leads to the unequal mating opportunities in two morphs.7. In nature, seed were the main mode of reproduction for L.chrysocomum, having low seed set and fierce competition between flowers and gains. Seed morphology of two kinds have no significantly difference, and emerging after-ripenin, but the germination of C plants are higher than the P plants. Seed appendages, such as persistent calyx and corollas, have inhibitory effects on its germination. Seeds need wind to fly longer, and the calyx lobes diameter is positive correlation with the propagation distance. |
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