Analysis Of The Above-ground Morphology And Rhizosphere Microbial Diversity Of Solidago Canadensis L. And Its Related Species And Prediction Of Suitable Areas

As one of the five global environmental problems in the 21st century,alien plant invasion has caused serious negative effects on biodiversity,socio-economic development and human health.Solidago canadensis L.has become a malignant alien invasive plant in the world,which has caused great harm to the ecological environment and agricultural production,and caused serious losses to the global economy.This paper mainly focuses on the prediction of the potential suitable area of S.canadensis in China,expounds the differences of morphological structure and rhizosphere microorganisms between S.canadensis and Solidago decurrens.L,so as to realize the early warning of invasion dynamics of S.canadensis,and provide theoretical basis for the management and control of S.canadensis,at the same time,we can analyze the theoretical basis of successful invasion and extensive propagation of S.canadensis.(1)Difference analysis of morphological structure between S.canadensis and S.decurrensThe stems,petioles and leaves of S.canadensis and S.decurrens planted in laboratory incubator were sectioned by paraffin method,and observed and measured by camera biomicroscope and scanning electron microscope.The results showed that:1.The T values of plant height,leaf length,leaf area and petiole length of S.canadensis and S.decurrens were 7.341,10.111,4.145 and-10.904 respectively,and the absolute values were greater than t0.05(2.306);2.The stem of S.canadensis has thick cortex,circular vascular bundles and large pith,which can help it to improve its survival and invasion ability;3.The number of vascular bundles in the petiole of S.canadensis was less than that of S. decurrens,but there were 10 layers of xylem cells in the petiole of S.canadensis,while there were only 5 layers of xylem cells in the petiole of S.decurrens,.The T value of petiole cortex of these two plants was-2.308,and the petiole cortex of S.decurrens,was significantly larger than that of S.canadensis;4.There are three vascular bundles in the midrib of S.canadensis,while there is only one vascular bundle in the midrib of S. decurrens.The T values of midrib width,xylem width and phloem width are 12.746,-7.589 and-4.750 respectively,and the absolute values are greater than t0.05(2.306);5.There was no significant difference in leaf thickness,palisade tissue and spongy tissue between the two plants,but the palisade tissue thickness of S.canadensis was larger,while the spongy tissue thickness of S.decurrens was larger;6.The number of stomata in the upper epidermis of S.canadensis was less than that in the upper epidermis of S.decurrens,while the number of stomata in the lower epidermis was more than that in the upper epidermis of S.decurrens.The number of stomata in the upper epidermis of S.decurrens is more than that in the lower epidermis.The results showed that S.canadensis and S.decurrens had some differences in morphological structure,which provided some morphological characteristics for distinguishing the two plants and further explained the reason why S.canadensis could be widely propagated and invaded.(2)Analysis of microbial diversity in roots of S.canadensis and S.decurrensIn order to explore the difference of Rhizosphere Microorganism between invasive plant S.canadensis and native species S.decurrens,and provide theoretical basis for successful invasion of S.canadensis.The rhizosphere soil samples of S.canadensis and S.decurrens were collected and analyzed by high-throughput sequencing.The results showed that S.canadensis changed the bacterial community structure and increased the diversity of soil bacteria to a certain extent;To a certain extent,it also reduced the diversity of fungal community,but the differences were not significant(P>0.05).The relative abundance of Proteus in S.canadensis was 4.1%more than that in S.decurrens,3.2%more than that in acidobacteria,1.9%more than that in Bacteroides,0.8%more than that in lvwan,1%more than that in Bacteroides and 0.3%more than that in Bacillus.The relative abundance of Trichoderma in S.canadensis is 4%higher than that in S.decurrens.The results showed that the diversity of bacteria in S.canadensis was higher than that in S.decurrens,and the diversity of fungi was lower than that in S.decurrens.It may be that the number of beneficial microorganisms in the rhizosphere soil increased,while the number of potential pathogenic bacteria and other harmful microorganisms decreased,which improved the disease resistance of S.canadensis.(3)Prediction of suitable growing area of S.canadensis in ChinaIn order to prevent the further spread of invasive species,it is of great practical and theoretical significance to use the Maxent niche model based on GIS to predict and analyze their potential suitable areas.In this paper,the geographic distribution information of S.canadensis in China was obtained through field investigation and relevant data from China Digital Herbarium.The suitable area of S.canadensis in China was predicted by combining Maxent niche model and bioclimatic factors.The results show that at present,the highly suitable areas of S.canadensis are mainly concentrated in Jiangsu Province,Shanghai City,Anhui Province,Zhejiang Province,Jiangxi Province,Northern Guangxi Zhuang Autonomous Region,Southeast Henan Province,Eastern Hubei Province,Hunan Province and coastal coastline.As time goes on,the suitable area increases by 128186.46km~2,6.02%in 2050 and 105192.73km~2in 2070,4.94%?The results provide a basis for predicting and early controlling the invasion of S.canadensis.