Effects Of Environmental Factors On The Reproduction And Distribution Of Wild Broussonetia Papyrifera

This primary research of this paper mainly focus on the effects of environmental factors such as hormones on the reproduction and distribution of wild mulberry trees(Broussonetia papyrifera).The basic experiments were carried out on the seed germination of wild Broussonetia papyrifera by temperature and light experiments.Then the seed leaching experiments were carried out with different kinds and concentrations of hormones.The effects of germination rate,germination energy and germination index on seed germination were evaluated.Using the sterile seedlings and the isolated leaves as explants,different concentrations of auxin and cytokinin were added to carry out a two-factor randomized block experiment to explore the different types and concentrations of hormones on the callus producing,adventitious bud proliferating and rooting.The research on the reproduction of Broussonetia papyrifera has established a foundation for its planting and promotion,but the reasonable suitable planting area is the premise of tree planting promotion.The Maxent model combined with Arcgis technology was used to predict the potential suitable distribution area of Broussonetia papyrifera in China,and the appropriate planting areas were constructed reasonably,in order to provide reference for Broussonetia papyrifera planting and promotion.The results of this study are as follows:(a)Temperature is the key environmental factor affecting the seed germination of Broussonetia papyrifera,which seed is a light neutral seed,and the light has little effect on its seed germination,but the light affects the growth of the seedling.(b)Different hormones had different effects on seed germination.The cytokinin 6-BA and gibberellin GA3 promoted seed germination,while auxin NAA inhibited.The germination rate of gibberellin 1600 mg/L soaking treatment is 72.4%,which is the best soaking concentration.Using the preferred method,sterilized with 70%ethanol and 0.1%HgCl2 for 6 min,1600 mg/L GA3 soaked for 24 h,30 ℃temperature,16 h/d light culture conditions,can effectively establish the technical system of germination and promote germination.(c)During the establishment of the cultivating tissue culture and rapid propagation system,different types of hormones play a leading role in different culture stages.NAA is dominant in callus explants.The 6-BA plays a major role in the diameter and proliferation of explants of stems.The main hormone that induces rooting is NAA.The concentration ratio of hormone combination can effectively establish a tree-planting tissue culture system.(d)Using Maxent model combined with ArcGis technology to simulate and predict the potential suitable distribution area of Broussonetia papyrifera in China.The data accuracy is 0.935,the prediction result is extremely accurate,and good prediction results are obtained.The suitable area of’Broussonetia papyrifera is 307,104 million km2,the proportion of suitable areas is 31.99%,and the area of high-adapted areas and extremely high-adapted areas is 1,787,250 km2,accounting for 18.62%.The Yangtze River Basin,Sichuan Basin,Yunnan-Guizhou Plateau and parts of the Yellow River Basin are potential high-yielding areas for Broussonetia papyrifera.Rainfall and temperature are meteorological elements that affect the potential distribution of Broussonetia papyrifera.The research results can provide sufficient and stable seedling source for the development of Broussonetia papyrifera planting industry,provide scientific basis for germplasm conservation and breeding,and can also promote the improvement of forestry industry system and provide reference for Broussonetia papyrifera planting.