The germination characteristics of forty annual plants of the alpine meadow on the Qinghai-Tibet Plateau

Annual plants grow fast and can speedily revegetate areas.Germination characteristics of 40 kinds of eastern Qinghai-Tibetan plateau annual plants were studied in plant growth chamber experiments in the dark and under 12 h 5°C/12 h 25°C temperature cycling.Annual alpine meadow plants usually germinate quickly and their germination speeds are comparatively high.Cluster analysis of their germination ratios showed,there were four clusters: high germinating species(germination ratio80%),intremediate germinating species(germination ratio 55%-80%),low germinating species(germination ratio 30%-55%),lowest germination species(germination ratio lower than 30%).Seeds of high germinating species germinated more orderly and in sequence than low germinating species.Maximum germination was in 2-4 days after planting and germination showed a single-apex curve,which is more accordant to once betting.Intermediate seeds germinate discontinuously and comparatively with a multi-apex germination curve.There were 17 kinds of low germination seeds(germination ratio30%) in the experiments.These seeds germinated even more discontinuously and their germination characteristics were in accord with Bet-hedging.