Study On The Biological Traits And Seed Dormancy Characteristic Of Heracleum Moellendorffii Hance

Heracleum moellendorffii Hance is a perennial herbaceous plant belonging to Saposhnikovia divaricata(Trucz.)Schischk.,which is one of the common hill potherb species in Heilongjiang province.It presents high edible value and medicinal health effect.Under the circumstance of the increasing demand and inadequate supply of wildfif resources,a large amount of wild resources is excavated,resulting in a sharp drop in recoverable resources.Therefore,with the necessity and urgency of reality,the full use of idle forest resources to plant large-scale artificial cultivation of Heracleum moellendorffii Hance,to improve the utilization of forest,develop the forest economy and achieve the adjustment and transformation of forestry economic structure are necessary for sustainable development.In the past,the input of human and material resources less,the lack of appropriate theoretical research,technical achievements,and practical technology were the key factors,which restricting development of Heracleum moellendorffii Hance.As the Heracleum moellendorffii Hance grow in the mountains and under the forest or other damp environment,most of the plants are root breeding,the amount of natural reproduction is low,and dormancy characteristic presents in the seeds,germination rate is low,germination is more difficult,leading to seed germination rate low and the emergence of irregular,cause the limitation of the Heracleum moellendorffii Hance production development.Moreover,it is necessary for grasping the growth-development law of Heracleum moellendorffii Hance to improve the level of cultivation techniques and obtain a higher yield and economic benefits.Therefore,it is of great theoretical and practical significance for the development of forest economy and the improvement of forest farmer’s income by studying the growth-development law of Heracleum moellendorffii Hance and the characteristics of seed dormancy.In this study,by observing the phenological phase,measuring the main morphological indexes,and the main storage contents of seeds of plants and seeds from the leaf expansion stage to the seed development stage.The dynamic changes of different stratification treatment on the anatomical structure,permeability,endogenous inhibitory substances and embryo morphology of the seeds were systematically studied,which provide theoretical basis and technical support for the development of the old celery industry.The main results are as follows:(1)The results indicated that the growth and development process of Heracleum moellendorffii Hance plants could be divided into seven stages: the sprouting stage,the leaf expansion stage,the budding stage,the bolting stage,the flowering stage,the seed development stage and the seed harvesting stage.(2)Furthermore,based on the growth and development curve of plant height and maximum leaf area,the process of plant morphology after leaf expansion could be divided into three stages:the plant height rapid growth stage,the plant height slow growth stage,and the plant height stagnant growth stage.These results suggested that it was an appropriate time for the stems and leaves of Heracleum moellendorffii Hance to be picked as food on 10~20 d after leaf expansion stage.(3)In addition,based on the morphological changes of seeds,the process of Heracleum moellendorffii Hance seeds could be divided into three periods: the rapid swelling stage,the slow growth stage,and the harvest stage.It was an importation period for dry matter to be rapidly accumulated in seeds on 5~20 d after seed development.And the Heracleum moellendorffii Hance seeds could be harvested after 35 d of the seed development.During the growth and development of seeds,the color of seed coat experienced four stages which were dark green,emerald green,withered yellow and brown successively.(4)The seed dormancy of Heracleum moellendorffii Hance is a comprehensive dormancy caused by factors such as incomplete development of embryo and endogenous inhibitory substances.But seed coat barrier is not a key factor for causing seed dormancy.(5)In this study,low temperature stratification is more favorable than the alternating temperature stratification for the development of the embryo and the transformation of the storage material.