Isolation And Identification Of Ice Nucleation Bacteria And Screening Of Antagonistic Bacteria

Cryogenic chilling caused by frosts has a significant impact on crops and plants.The study of domestic and foreign scholars shows that the existence of ice nucleation bacteria is an important factor to induce and aggravate plant frost disaster.In this paper,the species and distribution of ice nucleation bacteria in Guizhou Province were studied,and the soil was collected and isolated from soil to control the antagonistic bacteria,field frost test is the base of Guizhou University experimental field.The main results are as follows:1,Identification and identification of ice nuclei bacteriaFourteen kinds of plant frost specimens were collected from 5 cities in Guiyang City,Zunyi City,Liupanshui City,Tongren City,Tongren City and Xingyi City,Guizhou Province when December 2014,December 2015 and December 2016.1275 strains were isolated by plate dilution separation method and identified by Vali small droplet freezing method,And 11 strains of ice nuclei were obtained.They were numbered as BA,BB,BC,BD,BE,BF,BG,ZA,ZB,ZC and Z-QCH.The results showed that the strains ZA,ZC and BD were Pantoea ananatis,and the host plants were Dianthus superbus,Camellia sinensis and Chrysanthemum coronarium.The sites were Zunyi Fenghuangshan and Liupanshui,BE and ZB were Pantoea agglomerans.host plants are citrus reticulata and Iris tectorum,which are collected by Guiyang Small Car river Park and Zunyi City Botanical Garden.The strains BB was Pseudomonas fluorescens,host plants were cabbage,collecting place was Guiyang City Gaopo.The strains BC and BF were Pseudomonas syringae.host plants were Trifolium repens and Brassica pekinensis,collected in Guiyang City Qianling Park and Guiyang Gaopo.The strains BA,BG,Z-QCH were Pseudomonas viridiflava,and the host plants are Fatsia japonica,Petunia hybrida and Musa basjoo,respectively.The collection sites were Liupanshui Danxiashan,Guiyang jingyunshan and Tongren fanjingshan.2.Identification and Screening of Antagonistic Bacteria Against Ice Nucleation BacteriaThree rooted soils of frosted plants were collected from five sites in Guiyang City and Zunyi City,Guizhou Province.Six strains of antagonistic bacteria were obtained by plate dilution method and double plate plate drilling method.They are numbered XF,XD,XH,XM,XL,F1.Morphological identification,physiological and biochemical reactions and 16 s r DNA sequence analysis Six strains of Streptomyces phaeochromogenes were identified by morphological identification,Streptomyces phaeochromogenes were identified.Strain XF,XD,XH and XM were Bacillus amyloliquefaciens and strain XL was Bacillus methylotrophicus.In this paper,we first understand the species and distribution characteristics of ice nuclei bacteria in some plants in Guizhou,and lay a certain foundation for the prevention of plant frost in Guizhou.