Study On Community Characteristics、Seed Characteristics And Cutting Propagation Technology Of Endangered Plant Acer Miaotaiense

Acer miaotaiense belongs to acer of Aceraceae,is a rare and endangered tree species in China,and is a national second-class protected plant.Its population is rare and natural regeneration is difficult,so conservation measures are urgently needed.In this paper,the community characteristics,seed characteristics and cutting propagation techniques of Acer miaotaiense were studied,aiming to analyze the status and endangerment causes of Acer miaotaiense,and to provide theoretical basis for its in situ and ex situ conservation.The main results are as follows:1.Based on the investigation of Acer miaotaiense community in Baima Valley,Foping County,Shaanxi Province,a total of 59 families,103 genera and 112 species of vascular plants were found in the community.In the vertical structure,the community was divided into tree layer,shrub layer and herb layer.In the tree layer,Acer miaotaiense was the dominant tree species in the tree layer,and there were many aged individuals in the forest,while there were no young seedlings under the forest,and the population as a whole was declining.Margalef index,Simpson index and Shannon-Wiener index were herb layer >shrub layer > tree layer,Pielou index was tree layer > herb layer > shrub layer.2.The seed of Acer miaotaiense is composed of three parts: outer seed coat,inner seed coat and embryo.The biological characteristics of seeds from different provenances showed significant differences(P < 0.05).The 1000-seed weight of tianshui seeds from Gansu province was the highest(88.88 g),the empty seed rate was the lowest(20.00%),the plumpness was higher(36.67%),the seed viability was stronger(93.33%),and the seed quality was the best.The lignified seed coat of Acer miaotaiense has water permeability,but the rate is slow.There were inhibition substances in the outer seed coat,inner seed coat and embryo,and the inhibition effect was in the order of inner seed coat > outer seed coat >embryo,respectively.The germination rate of in vitro embryos was significantly increased after 150 days of seed stratification.These results indicated that mechanical hindrance,inhibitory substances contained in seed coat and embryo dormancy were the main factors causing seed dormancy,and stratification could break seed dormancy to some extent.Biochemical characteristics of seeds in different provenances during low temperature stratification were measured.The results showed that the soluble sugar content of Acer miaotaiense seeds decreased first and then slowly increased,the starch content decreased first and then increased and then slowly decreased,and the soluble protein content decreased first and then increased and then slowly decreased.3.The cuttage propagation experiment of Acer miaotaiense showed that when the cuttage thickness was 11-14 mm,the cuttage depth was 9cm,and the light intensity was 70%,the survival rate,average seedling height and average seedling diameter of Acer miaotaiense were relatively high,respectively 54.46%,36.5 cm and 6.56 mm.The range analysis table showed that light intensity played a leading role in the survival rate of cuttings,and the cuttings diameter played a leading role in the average height and diameter of cuttings.Light intensity and cuttings thickness had significant effects on cuttings propagation effect of Acer miaotaiense,while cuttings depth had little effect on cuttings propagation effect.