花椒干腐病的寄主抗病性与病原菌致病性分化

Resistance of Prickly Ash to Stem Rot and Pathogenicity Differentiation of Fusarium sumbucinum

对陕西省凤县、耀县、富平和韩城的花椒干腐病病情调查表明,同一地方的不同花椒品种之间的发病程度存在明显差异,豆椒、大红袍病情较重,而米椒发病较轻。在PDA培养基上,凤县菌系(Ffx)和耀县菌系(Fyx)菌落呈绒毛状、紫红色,生长速度明显快于富平菌系(Ffp)和韩城菌系(Fhc),并以三隔膜镰刀型分生孢子多见。Ffp菌落独特,呈短绒毛至绢毛状,薄或稀疏,桔黄色,其分生孢子较其它菌系产生时间早、形态大,以4～5隔膜孢子多见。Fhc的菌落特征虽然与Ffx、Fyx菌系基本相似,但在相同条件下不易产孢或产生孢子较小。用各菌系菌丝体对大红袍花椒茎干刺伤接种,结果表明,接种Ffp后的病斑扩展时间早、速度快,Ffp的致病性明显强于Ffx和Fyx菌系,后两者对大红袍的致病性相近。试验证明,花椒干腐病菌存在着培养性状和致病性分化。

Situations of the resistance of prickly ash plants to stem rot and pathogenicity differentiation of the pathogenic fungus Fusarium sumbucinurn were investigated in the areas of Fengxian, Yaoxian, Fuping and Hancheng within Shaanxi Province. The results showed that the different varieties of prickly ash in same place behaved distinctly different resistances to the fungus, ＂Doujiao＂ and ＂Dahongpao＂ were seriously infected, but ＂Mijiao＂ had lower incidence. On the PDA medium, the colonies of F. sumbucinum strains Ffx （from Fengxian） and Fyx （from Yaoxian） showed villiform, purple and faster growing rate than the strains Ffp （from Fuping） and Fhc （from Hancheng）, with 3-septate conidia mostly. The colony of Ffp showed unique, short villous to silk hairy, thin or sparse, orange, producing early spores with 4- 5 septa, larger than other strains. Although the colony characteristics of the strain Fhc were similar to Ffx and Fyx, it was difficult to produce spores or conidia significantly smaller under the same conditions. After inoculating the mycelia of these strains on the stem of the Dahongpao, strain Ffp exhibited earlier and more rapid lesion expansion, demonstrating higher pathogenicity than strains Ffx and Fyx. The tests also proved that there were colony characteristic and pathogenic type differentiation of stem rot fungus F. sumbucinum.