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根据在 0 5、1 4、5 0、10 0 μg ml等不同浓度的含药PSA平板上能否生长 ,将玉蜀黍赤霉田间菌株对多菌灵的敏感性划分为 :敏感 (S)、中抗 (MR)和高抗 (HR)等 3个水平 ,其中S菌株在 0 5 μg ml浓度下能生长 ,但在≥ 1 4μg ml浓度下生长受到完全抑制 ;R菌株在 1 4 μg ml浓度下能快速生长 ,在 5 0 μg ml浓度下能缓慢生长 ,但在≥ 10 0μg ml浓度下不能生长 ;HR在≥ 10 0 μg ml浓度下仍能生长。没有发现在 1 4 μg ml浓度下能快速生长 ,而在 5 0 μg ml浓度下能被完全抑制的田间抗性菌株。从 2 5个敏感菌株和 31个抗性菌株中随机挑选了 2个S、3个MR和 1个HR ,并以硝酸盐营养缺陷型突变体 (nit)作为另一个遗传标记 ,按照S×S、MR×MR、MR×S、HR×S、HR×MR等共设计了 7个杂交组合 ,对各杂交后代对多菌灵的敏感性测试发现 ,在所有杂交后代中均未出现除双亲表现型以外的重组型个体 ,MR×S、HR×S及HR×MR的杂交后代出现了 1∶1的分离比例。以上结果表明玉蜀黍赤霉田间菌株对多菌灵的抗药性是由单个孟德尔基因控制的 ,该基因发生不同点突变或同一点的不同等位基因发生突变可导致不同的抗性水平 ,抗药性不受修饰基因或胞质遗传因子的影响。
According to the ability to grow on drug-containing PSA plates with different concentrations of 0, 1, 45 0, 10 0 μg ml, etc., the sensitivity of the strain of Gibberella zeae to carbendazim was classified as sensitive (S), medium (MR) and high resistance (HR). S strain could grow at the concentration of 0 5 μg ml, but its growth was completely inhibited at the concentration of ≥14 μg ml. The concentration of R strain at 14 μg ml It grew rapidly, grew slowly at a concentration of 50 μg ml but failed to grow at ≥ 100 μg ml; HR still grew at ≥10 0 μg ml. No field-resistant strains that rapidly grew at a concentration of 14 μg ml and were completely inhibited at a concentration of 50 μg ml were not found. Two S, three MRs and one HR were randomly selected from 25 sensitive strains and 31 resistant strains. Nitrate auxotrophic mutant (nit) was used as another genetic marker. According to S × S , MR × MR, MR × S, HR × S, HR × MR and so on. A total of seven hybrid combinations were designed. The sensitivity test of carbendazim to all the offspring showed that there was no significant difference Type, the hybrid progeny of MR × S, HR × S and HR × MR showed a separation ratio of 1: 1. The above results indicate that the resistance to carbendazim in field strains of Gibberella zeae is controlled by a single Mendelian gene. Mutations at different points in the gene or mutations at different alleles at the same point may lead to different levels of resistance, resistance Unaffected by modified genes or cytoplasmic genetic factors.