The possibility of employing antagonistic bacteria for the control of tobacco brown spot was studied. Approximately 136 strains of bacteria were isolated from phyllospheres of tobacco and 9 of these possessed high lev...The possibility of employing antagonistic bacteria for the control of tobacco brown spot was studied. Approximately 136 strains of bacteria were isolated from phyllospheres of tobacco and 9 of these possessed high levels of antagonistic properties, They significantly reduced brown spot in detached tobacco leaves when artificially inoculated with Alternaria alternata. Culture filtrate of the most effective bacterial isolate which designated as Tpb88 was shown to be very efficient in inhibiting mycelial growth of A alternata in dual cultures. Culture filtrate of Tpb88 inhibited germination and germ tube elongation of A alternata. The results showed that the culture filtrate directly inhibited spore germination of A alternata, especially during the first hours of the paired cultivation. The rate of antagonistic activity of culture filtrate of Tpb88 depended on its concentration in the mixture. The greatest inhibition of spore germination was ob served at the highest concentration of filtrate （filtrate to fungal spores inocula mixed in proportion 1 ： 50）. These suggest that the hypothetic mechanism of Tpb88 against tobacco brown spot is to produce antagonistic substances.展开更多
采用常规分离法对不同生长季节苹果树的不同部位进行了内生细菌分离.结果表明,内生细菌的分离几率和数量不同.通过平板对峙培养和发酵液抑菌活性测定,在所分离的118个菌株中,筛选出7株对苹果斑点落叶病菌(Alternaria alternata f. sp. M...采用常规分离法对不同生长季节苹果树的不同部位进行了内生细菌分离.结果表明,内生细菌的分离几率和数量不同.通过平板对峙培养和发酵液抑菌活性测定,在所分离的118个菌株中,筛选出7株对苹果斑点落叶病菌(Alternaria alternata f. sp. Mali)具有较强拮抗作用的菌株,其中菌株B86和B91的发酵滤液在活体上对苹果斑点落叶病的防治效果显著,分别为73.72%和75.32%.两菌株培养滤液对病菌分生孢子萌发具有抑制作用,并造成芽管畸形膨大,呈泡囊状,泡囊消解破裂;两菌株产生的抑菌物质具有热稳定性.表明B86和B91菌株具有一定的生防潜力.展开更多
基金State Tobacco Monopoly Administration of China (110200201008)
文摘The possibility of employing antagonistic bacteria for the control of tobacco brown spot was studied. Approximately 136 strains of bacteria were isolated from phyllospheres of tobacco and 9 of these possessed high levels of antagonistic properties, They significantly reduced brown spot in detached tobacco leaves when artificially inoculated with Alternaria alternata. Culture filtrate of the most effective bacterial isolate which designated as Tpb88 was shown to be very efficient in inhibiting mycelial growth of A alternata in dual cultures. Culture filtrate of Tpb88 inhibited germination and germ tube elongation of A alternata. The results showed that the culture filtrate directly inhibited spore germination of A alternata, especially during the first hours of the paired cultivation. The rate of antagonistic activity of culture filtrate of Tpb88 depended on its concentration in the mixture. The greatest inhibition of spore germination was ob served at the highest concentration of filtrate （filtrate to fungal spores inocula mixed in proportion 1 ： 50）. These suggest that the hypothetic mechanism of Tpb88 against tobacco brown spot is to produce antagonistic substances.
文摘采用常规分离法对不同生长季节苹果树的不同部位进行了内生细菌分离.结果表明,内生细菌的分离几率和数量不同.通过平板对峙培养和发酵液抑菌活性测定,在所分离的118个菌株中,筛选出7株对苹果斑点落叶病菌(Alternaria alternata f. sp. Mali)具有较强拮抗作用的菌株,其中菌株B86和B91的发酵滤液在活体上对苹果斑点落叶病的防治效果显著,分别为73.72%和75.32%.两菌株培养滤液对病菌分生孢子萌发具有抑制作用,并造成芽管畸形膨大,呈泡囊状,泡囊消解破裂;两菌株产生的抑菌物质具有热稳定性.表明B86和B91菌株具有一定的生防潜力.
