柔嫩艾美耳球虫早熟株选育及相关生物学特性

为了研究柔嫩艾美耳球虫(Eimeria tenella)早熟株与母株之间基本生物学特性的差异,运用Jeffers创立的艾美耳属球虫早熟株选育方法对E.tenella进行了连续26代的早熟选育,并通过对早熟株与母株的孢子化卵囊大小、繁殖能力以及致病性等指标进行测定,分析E.tenella早熟株与母株之间基本生物学特性的差异.经过早熟选育后,其潜在期由母株的141 h缩短至118 h;早熟株的孢子化卵囊大小比母株的明显减小(P<0.05);繁殖能力与母株的相当(P>0.05);在致病性方面,4个剂量组的早熟株平均增重与对照组相比差异不显著(P>0.05),而母株组与对照组相比平均增重显著下降(P<0.05或P<0.01);4个剂量的早熟株组死亡率均为0,而母株组分别为0,25%,25%及31.3%;感染剂量越大,早熟株与母株间病变记分差异越显著.经选育的E.tenella早熟株具有潜在期缩短,致病性较母株弱以及繁殖力与母株相当等特点.

Selection and Characteristics of a Precocious Strain of E.tenella

To find differences of characteristics between precocious and parent strains of E.tenella,26 passages were selected by serial through chickens using the method as described by Jeffers.The differences between the two strains were analysised according to the sizes of sporulated oocysts,reproduction and pathogenicity.The prepatent period of precocious strain was 118 h compared with 141 h of parent strain.The size of sporulated oocysts of precocious strain was remarkably smaller than that of the parent strain(P<0.05),and reproductive potential was correspondent with that of parent strain(P>0.05).In the pathogenicity assay,average weight gains of 4 different doses of the precocious strain were not significant difference compared with the control group(P>0.05),whereas average weight gains of the parent strain were decreased markedly than control group(P<0.05 or P<0.01).The mortality of 4 different doses of the precocious strain was zero,whereas that of the parent strain was 0,25%,25%,31.3% respectively,More dose infected,there were more differences in lesion score between the precocious and parent strain.These results showed that the precocious strain of E.tenella possessed shorter prepatent period and less pathogenicity than parent strain and its reproductive potential was corresponding with parent strain.