烟草嫁接苗对黑胫病的抗性鉴定

Resistant identification of tobacco grafted seedlings to black shank

嫁接技术是植物病害绿色防控的有效措施之一,为探寻抗烟草黑胫病的高抗嫁接组合,本研究以4个高抗烟草品种为砧木,生产上4个主栽品种为接穗,开展了不同嫁接组合烟苗对黑胫病的抗性鉴定。人工接种黑胫病菌后,以‘Florida 301’作砧木时烟苗发病率和病情指数分别为0~4.76%和0~2.86;以‘革新3号’作砧木时分别为0~20.71%和0~15.72;以‘Beinhart 1000-1’作砧木时分别为1.11%~13.18%和1.11~11.47;以‘L8’作砧木时分别为20.02%~65.33%和13.58~60.89,而以接穗品种‘K326’、‘云烟87’、‘NC55’和‘红花大金元’自根苗的发病率和病情指数分别为:‘K326’,39.98%和35.46,‘云烟87’,45.81%和39.18,‘NC55’39.33%和35.93,‘红花大金元’,74.67%和65.48。统计分析结果表明,以‘Florida 301’、‘革新3号’和‘Beinhart 1000-1’品种为砧木的嫁接苗发病率与病情指数均极显著低于接穗品种自根苗(P<0.01);‘L8’品种为砧木时,只有‘云烟87’作接穗的发病率与病情指数极显著低于‘云烟87’自根苗(P<0.01)。采用平板涂布计数法,对抗、感黑胫病烟草品种根际微生物数量进行了测定,研究了抗、感病品种根际微生物群落结构,结果表明,抗、感病品种均是根际细菌>根际放线菌>根际真菌,且根际细菌、放线菌数量远多于真菌数量,抗病品种的根际微生物数量整体上多于感病品种。

The grafted technique is one of the most effective methods for plant disease control.To find the effective grafted combinations for the control of tobacco black shank,the incidence and disease index of different combinations of four disease-resistant rootstocks and four scions from commercial cultivars were determined using the self-root scion as control through artificial inoculation.The results indicated that the incidence and disease index of tobacco seedlings grafted on‘Florida 301＇rootstock were 0-4.76% and0-2.86,and on‘Gexin No.3＇rootstock were 0-20.71% and0-15.72,on‘Beinhart 1000-1＇rootstock were 1.11%-13.18% and1.11-11.47,on‘L8＇rootstock were 20.02%-65.33% and 13.58-60.89,respectively.The incidence and disease index of four self-root scions（control）were 39.98% and 35.46（‘K326＇）,45.81% and 39.18（‘Yunyan 87＇）,39.33%and 35.93（‘NC55＇）,74.67% and 65.48（‘Honghuadajinyuan＇）,respectively.The statistic results analyzed by Duncan＇s new multiple range method showed that the incidence and disease index of tobacco seedlings grafted on‘Florida 301＇,‘Gexin No.3＇and‘Beinhart 1000-1＇rootstocks were significantly lower than those of their selfroot scion control（P0.01）.When‘L8＇was used as rootstock,only‘Yunyan87＇as grafting scion showed significantly lower incidence and disease index than‘Yunyan87＇self-root plants（P0.01）.The rhizosphere microbial community structure of different resistant level tobacco varieties was investigated by plate count method.Theresults indicated that the quantity of bacteria and actinomycetes were far more than that of fungi,and the quantity of bacteria was more than that of actinomycetes.As to the total quantity of rhizosphere microorganism,those of resistant varieties are more than those of susceptible varieties.