Variation Of Floral Longevity And Influenting Factors In Flowering Plants At The Alpine Meadow Of Qinghai-Tibetan Plateau

Floral longevity,usually refers to the length of time that a flower remains open and functional.There's a significantly difference in the flower life among the different species and it is one of the hereditary flowers characteristics,however,to some extent,it still has some plasticity,which can reflect the adaptability of plants to the environment.Flower life has become an important flower characteristic of plant propagation under unfavorable pollination conditions and has attracted more and more attention.It is not only affected by biological factors such as flowering time,pollination,flower size,pollen and ovule number,plant sex distribution,flower maintenance consumption and plant breeding system.It is also affected by abiotic factors such as temperature,altitude and precipitation.In this work,the flowering plants of the alpine meadow plant community in the eastern margin of the Qinghai Tibet Plateau were studied the following:(1)the variation in floral longevity of flowering plants in grazing areas(or ungrazing areas)at the different altitude habitats;(2)the variation of floral longevity of flowering plant between grazing areas and grazing prohibition areas at the same altitude;(3)the variation of floral longevity of flowering plants at different pollination treatments(pollinator exclusion,supplemental pollination and open pollination);(4)the plasticity of floral longevity to respond the pollination treatments in grazing and ungrazing areas at the same altitude(or that in low altitude and high altitude areas at the same grazing conditions).The experimental results show that:1.Species,altitude,pollination and grazing status have a extremely significant impact on flower longevity.2.Under grazing conditions,the potential flower life of plants(bagging treatment)distributed at high altitude(3600m)and actual flower life(natural pollination treatment)were significantly higher than those of low altitude(2900m),while the shortest flower life(supplemental pollination treatment)had no significant difference.Under the grazing condition,the potential flower life and the actual flower life of the plants distributed at different altitudes were not significantly changed,while the shortest flower life of the high-altitude(3600m)plants was significantly longer than the low altitude(2900m).3.At low altitudes(2900m),the potential flower longevity and actual longevityof plants in the forbidden grazing area were significantly longer than those in the grazing area,while the shortest flower life did not change significantly.However,at high altitudes(3600m),there was no significant difference in the potential flower life,the actual flower life and the shortest life span of flowering plants in the forbidden grazing area and the grazing area.4.No matter the variation in altitude or the difference of grazing measures,bagging significantly extended the flower life of flowering plants,while artificial supplemental pollination significantly shortened the flower life of flowering plants,that is,the potential flower life of flowering plants > actual flower life > the shortest flower life.5.Under grazing conditions,the life span of high altitude(3600m)plants is more plastic,which is mainly related to the pollination intensity,that is,the variation of pollinators' frequency of visiting flowers affects the plasticity of the flower life.