Species, Distribution And Dynamics Of INA Bacteria On Apricot And Screening Of Bactericides For Frost Control In Beijing District

In this paper, the species, distribution and dynamics of INA bacteria on apricot were reported as well as the screening of bactericides for frost control in Beijing DistrictThese results were illustrated as follows:First, the species of INA bacteria on apricot in Beijing were identified.Twenty-second strains of INA bacteria were isolated from apricot.Based on bacteriological methods, they were identified as three species belonging to two genera: 10 srains of Pseudomonas syringae.pv.syringae, 9 strains of Pantoea agglomerans, 3 strains of Pantoea ananas pv.uredovora and they made 45.5%, 40.9%, 13.6% of total amount, respectively.As a kind of INA bacteria, Pantoea agglomerans was first discovered on apricot.Second, their distribution and dynamics of INA bacteria was demonstrated primarily.By investigation, INA bacteria could be isolated from 89.2% of apricot, showing INA bacteria were widespread in apricotThe distribution of INA bacteria varied in apricot cultivar, geographic position and ecological conditions. They were easily isolated from floral organs, and had a maximum populations 106CFU/g.f.w.In Haidian Zone, the INA bacteria population on 'apricot Yubada" was checked periodically. The results revealed three peaks of population dynamics during flowering stage, fruiting stage and early stage of overwintering, respectively, and their population were 3.0×10~2, 2.5×10~3, 2.5×10~3 CFU/g.f.w, respectively. On the contrary, INA bacteria could not isolated easily during hot summer and cold winter. It was the first report that populations of INA bacteria varied in seasons.Third, it was verified that INA bacteria could induce and aggravate frost injury on apricot blooms.The frost index of petal after application of INA bacteria was 49.3, 23.0% higher than that of petal treated with distilled water in programmable frost chamber at -4℃ ; Similar example happened in field the frost index of petal after application of INA bacteria was higher 65.5% than that of untrement at -5℃ .These findings illustrated INA bacteria could induce and aggravate frost injury of apricot blossoms.Fourth, some bactericides were screened for frost control.1) According to the laboratorial test of 10 bactericides, different bactericide...