Study On Seed Development And Germination Characteristics Of Kadsura Coccinea

Kadsura coccinea(Lem.)A.C.Smith is an evergreen woody vine of the Kadsura genus in the Schisandraceae family.Its roots and stems are traditional Chinese medicinal materials in China,and its fruits are rich in nutrition.At present,the Kadsura coccinea resources are mainly wild resources.The destructive exploitation of wild resources not only leads to the loss of Kadsura coccinea germplasm resources,but also seriously destroys the ecological environment of the mining area.It is imperative to expand the artificial cultivation of Kadsura coccinea.The main reproduction mode of Kadsura coccinea population is seed reproduction,but Kadsura coccinea seeds have dormancy,long germination cycle and low germination rate.Aiming at this problem,this paper makes a systematic study on the characteristics of Kadsura coccinea seed development,dormancy and germination,so as to provide a theoretical basis for tending cultivation and seedling breeding.The main results are as follows:1.There were significant changes in fruit,small berries,seed morphology and seed nutrients during the fruit development period of Kadsura coccinea.The fruit development period of Kadsura coccinea is about 110 days.The development period is divided into three stages:green fruit stage,color conversion stage and red fruit stage.The growth curves of fruit,small berry and seed were consistent with logistic regression model,and the determination coefficient was as high as 0.9672～0.9986.The dormancy period of Kadsura coccinea zygotes was long,and the development of seed embryos was observed 84 days after anthesis.The embryo rate was 7.11%when the seeds were mature.During the development of Kadsura coccinea seeds,the starch content increased first and then decreased,the soluble sugar increased first and then decreased,the soluble protein increased gradually,and the oil content also increased gradually.Oil is the main storage material of mature Kadsura coccinea seeds.Soluble sugar and starch are actively transformed into oil during seed development;The main component of oil is linoleic acid,which accounts for 66.88%of mature seed oil.In the process of seed oil accumulation,the oil body of its storage organelle first forms a small oil body around the cell wall,then increases in volume,slowly accumulates to the center of the cell,and then forms a large oil body to fill the whole cell;The volume of oil body is positively correlated with oil content.2.Kadsura coccinea seeds belong to physical and physiological compound dormancy.The physical dormancy was mainly caused by poor permeability and mechanical binding.The seed coat of Kadsura coccinea consisted of an outer coat(1029 μm)and an inner coat(349 μm).The first layer of the outer coat was cuticle(275 μm),the second layer was palisade(754 μm),and the inner coat was membranous.The dense and hard outer coat greatly obstructs the water absorption and air permeability of seeds,and also has mechanical constraints.The germination rate of intact seeds was 62.46%,while that of peeled seeds was 86.52%.The physiological dormannia was due to the existence of germination inhibitors in the seeds.The extracts of distilled water,methanol,petroleum ether and ethyl acetate from the kernel and seed coat of Kadsura coccinea had significant inhibitory effects on the germination rate,root length and seedling height of Chinese cabbage,indicating that there were substances inhibiting germination in the seeds of Kadsura coccinea.The germination rate of Kadsura coccinea seed embryos cultured in vitro for 30 days was 21.59%,indicating that the Kadsura coccinea seed embryos were fully developed and did not need to undergo post-ripening,so there was no or very shallow morphodormancy of Kadsura coccinea seeds.3.Concentrated sulfuric acid,temperature,liquid nitrogen,hormone and stratification treatment can break the dormancy of Kadsura coccinea seeds and promote seed germination.Soaking seeds in concentrated sulfuric acid for 30 s had the best effect,and the germination rate was 83.77%;Soaking seeds in high temperature water bath at 60℃ was the best,and the germination rate was 68.53%;Soaking seeds in liquid nitrogen for 20 min had the best effect,and the germination rate was 82.47%;100 mg/L gibberellin had the best effect,and the germination rate was 89.96%.Low temperature,variable temperature and warm temperature stratification treatments can break the seed dormancy.After 60 days of low temperature stratification,the germination rate in bed for 30 days is 78.18%,which basically meets the standard of releasing dormancy.In scientific research,seeds can be soaked in concentrated sulfuric acid for 30 s to break the physical dormancy,and 100 mg/L Gibberellin Treatment and low-temperature stratification can break the physiological dormancy.In production,the seeds can be soaked at 60℃ to break the physical dormancy of black tiger seeds,and the outdoor stratification in winter can break the physiological dormancy.