非硝酸鹽還原細(xì)菌K18 降低TSNA 機(jī)理的初步研究
Mechanism of Non-nitrate Reduction Endophytic Bacteria K18 on TSNA Reduction
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摘要: 對21 株煙草內(nèi)生細(xì)菌還原硝酸鹽和亞硝酸鹽的能力進(jìn)行檢測,，驗(yàn)證了非硝酸鹽還原細(xì)菌K18 的內(nèi)生性，并鑒定為嗜麥芽寡養(yǎng)單胞菌(Stenotrophomonas sp.),。結(jié)果表明,，用K18 菌株對煙草進(jìn)行移栽前浸根、團(tuán)棵期噴施,、旺長期噴施及采前噴施處理,，可有效降低煙葉中TSNA 含量，降低程度與煙草品種有關(guān),。溫室中TSNA 的降低作用與煙葉的細(xì)菌數(shù)量相關(guān),，K18 處理的云煙87，團(tuán)棵期和旺長期煙葉細(xì)菌數(shù)量增高,，TSNA 分別降低23.7%和9.1%,；云煙87 和TN86 經(jīng)K18 處理后，NN 降低百分率最高,，而且對TN86 各組分的降低百分率高于云煙87,。對于大田栽培的云煙87，旺長期噴霧和浸根處理可顯著降低煙葉中TSNA 含量,，與清水對照比較,，分別使TSNA 含量降低了50.1%和39.6%。對于大田栽培的TN86,，旺長期噴霧,、調(diào)制期噴霧和浸根處理使煙葉中TSNA 含量分別降低52.6%, 51.1%和44.7%,。Abstract: From all tobacco endophytic bacteria, 21 strains were tested for their ability to reduce NO3- to NO2-, the endophytic characteristic of strain K18 which didn’t have the ability on nitrate reduction was confirmed and was tested for the ability on TSNA reduction in greenhouse and in field. Tobacco were treated with K18 on different growing stage, such as root dipping during transplanting, spraying on tobacco leaves during branching and luxuriant growing stage, spraying a week before harvest, and chemical contents of TSNA in the leaves were examined. Results showed that the amount of TSNA in the leaves was different responding to different treatment of bacteria K18 on different tobacco variety. The total amount of TSNA was reduced at all treatments with K18 in greenhouse and in field, but the reduction efficacy was related to the tobacco variety. TSNA reduction was suspected to relate to the total bacterial number in tobacco leaves, The total bacterial number in tobacco leaves treated with K18 during the branching stage and luxuriant growing stage was higher than that control, and the TSNA reduction rate reached 23.7% and 9.1% respectively. NNN, a major content of TSNA was reduced effectively at the treatments by K18 either in YunYan87 or in TN86. And it was higher in TN86 than that in YunYan87 In terms of YunYan87 planted in field, the reduction rate could reach 50.1% and 39.6% respectively at the treatment of spraying luxuriant growing stage and root dipping stage compared to the treatment without K18.And as to TN86 grew in field, the reduction rate reached 52.6%, 51.1% and 44.7% respectively at the treatment of spraying luxuriant growing stage, the treatment of spraying at curing and the treatment of root dipping compared to control.
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