Germination Physiology Of Seed And Winter Bud Of Brasenia Schreberi And The Response Of Leaves On Temperature Stress

Brasenia schreberi is a world-famous rare aquatic vegetable,which has high edible and medicinal value and has a long history of cultivation.However,long-term asexual reproduction resulted in a serious decline in the growth,quality and yield of B.schreberi,and the frequent occurrence of diseases and insect pests.The rejuvenation of B.schreberi has become one of the urgent problems to be solved in production.Previous studies have shown that the rejuvenation of B.schreberi can be achieved through seeds and winter buds,so the reasons for dormancy of seeds and winter buds of B.schreberi can be found out,and the best way to relieve dormancy is the basic premise of rejuvenation.In addition,it is important to find out the tolerance of functional leaves to temperature stress for the rejuvenation and production of B.schreberi.In this experiment,the reason of dormancy of B.schreberi seeds was analyzed by cold and wet stratification,exogenous gibberellin,low temperature water storage and moderate dehydration,and the dormancy release method of winter buds of B.schreberi was explored by controlling light and temperature.The responses of ecotype leaves to temperature(low temperature and high temperature)stress were compared with antioxidant enzyme activity analysis.The results demonstrate that:1.Fresh and mature seed of B.schreberi has shallow physiological dormancy.Cold and wet stratification can promote the dormancy release and germination of the seed,and light can promote the germination of the seed of B.schreberi.2.Seed of Brasenia schreberi is normal seed,and moderate dehydration is beneficial to the release of dormancy and rapid germination of B.schreberi seed.The germination rate of seeds with water content of 9.7 ± 0.1% was 84.0 ± 2.8% after 135 days of cold and wet stratification,which was the best scheme for dormancy release and germination of B.schreberi seed.3.Moderate water bath heating treatment can effectively relieve dormancy of winter buds of B.schreberi,and 35°C water bath treatment for 6 h is the best treatment scheme.4.Large leaves which did not produce ecotypes of winter buds and leaves producing ecotypes of winter buds had strong tolerance to temperature stress or couldbe used for rejuvenation of B.schreberi.