Dormancy And Germination Characteristics Of Cercis Canadensis ’Forest Pansy’ Seeds

Cercis canadensis Forest Pansy belongs to Leguminosae,which is a new variety of Cercis canadensis.The tender shoots are bright red,and the leaves are bright purplish red in spring,summer and autumn,especially in summer.It is a kind of excellent color leaf tree species loved by people.Because of dual dormancy characteristics of its seeds,the scale and quality of its production have been seriously restricted.In this study,the seeds of Cercis canadensis Forest Pansy were selected as the research objects.On the one hand,the dormancy characteristics of new mature seeds were determined through the verification of dormancy and morphological dissection.In addition,by studying the effects of different treatments on the germination of newly mature seeds and the physiological and ecological changes of seeds during stratification.To explain the ecological characteristics of seed dormancy and germination.The main results are shown as follows:1、The newly mature seeds have cuticle,clear line and dense palisade cell layer,which leads to poor water permeability.The water absorption rate of intact seeds was significantly lower than that of treated seeds.Therefore,seed coat is an important cause of seed dormancy.By analyzing the effect of seed extract on the germination rate of Chinese cabbage seeds.It can be indicated that there are germination inhibiting substances in seeds,which is one of the reasons that seeds cannot germinate normally.2、Hot water treatment and appropriate acid etching treatment can break the dormancy of seeds to a certain extent.However,the seed germination could not be promoted by removing the firmness of the seed without any hormone treatment;However,after the seed firmness was released,the seed dormancy could be broken to a certain extent by several different hormone treatments,among which GA3 was the best.It can also be treated with low temperature lamination,enabling seeds reaching a maximum germination rate of 67%at 15/25℃,immersed for 24 h,with 300 mg/L after 10 min of acid erosion and combined with low temperature lamination for three months.3、In the process of stratification,the contents of various substances in seeds changed significantly.However,GA3 did not have much influence on the overall change trend,but accelerated the change process.There was a peak value of soluble sugar in the process of stratification,after which the seeds began to be active.The content of starch decreased in general,and the content of protein decreased in the early stage of stratification,and then began to increase.The content of protein began to decrease significantly during the active period of seeds.POD as an important protective enzyme,increased rapidly in the early stage of laminar accumulation and then again in the early activity of dormancy.The overall trend of α-amylase content change shows an upward trend,promoting seed elongation growth.β-amylase is mainly involved in hydrolysis activities and has complex changes.CAT is an important enzyme that prevents seed deterioration,rising early in layer accumulation and then stabilizing at a relatively high content.4、The overall trend of the ABA content of the two different treated seeds during the layer accumulation process always helps to break the seed dormancy.Overall IAA content rose in both treatments,with two peaks during lamination.The GA3 content in the control group continued to rise 70 days before the layer accumulation,and then slowly decreased to the end of the layer product.The endogenous GA3 content of the seed treated by GA3 decreased first,and then began to rise substantially by 30 days ago,after which the content remained basically at a higher level.The overall CTK content of the two treated seeds was upward,together with GA3,antagonizing ABA and reducing the inhibitory effect of ABA on seeds.