【摘要】 桔青霉(Penicillium citrinum)CICC 4011菌株经60Coγ射线辐照处理以及多菌株连续多轮原生质体融合后,变异株产核酸酶P1能力与形态性状出现了较大差异。研究表明黄绿色或灰绿色菌落产酶水平较高,绿色或艾绿色菌株产酶水平较低。选择不同产色特征的变异株(J1Y6、F-13、F-R-33)与CICC 4011进行比较,表明4株桔青霉生长速度没有明显差异。融合子F-R-33菌落呈深艾绿色,产水溶性红色素,核酸酶P1低产(23.1U/ml);诱变菌株J1Y6菌落呈黄绿色,产水溶性黄绿色素,核酸酶活较高(167.3U/ml);融合子F-13菌落呈灰绿色,不产水溶性色素,核酸酶活较高(578.6U/ml)。电镜观察发现J1Y6、F-13分生孢子梗上帚状分枝减少,菌丝生长粗壮,产孢能力不及4011及F-R-33。核酸酶P1和色素虽然都是次级代谢产物,但核酸酶P1的合成明显与生长相关,而色素的合成则表现出非相关性。诱变株RAPDDNA多态性检测率为70%。UPGMA聚类分析,菌株F-R-33与出发菌株4011聚为一类(相似系数0.9),核酸酶P1高产菌株J1Y6和F-13聚为一类,高产与低产突变株的DNA多态性表现出明显差异(相似系数0.8)。更多还原

【Abstract】 Diversification of colony characteristics of mutants derived from Penicillium citrinum CICC 4011 treated with ⁶⁰Co γ-irradiation and protoplast fusion were analyzed.There were distinct differences among mutants with different nuclease P1 activity,especially in pigment productivity.Color of colony was changed from the original green to white,grey-green,or yellow-green etc., while the nuclease P1 activity would be fluctuated with the color change.The hypothesis was suggested that there would be a relationship between pigments and nuclease P1 production.Mutants with grey-green colony would give out high nuclease P1 outputs in a high probability such as mutant J1Y6（nuclease P1 activity,167.3U/ml） and fusant F-13（nuclease P1 activity,568.7U/ml）,while others with deep-green colony observed low nuclease outputs.Four variation strains didn’t show any significant difference in growth rate.Broom branches of conidiophore stem in J1Y6 and F-13 were obviously reduced,conidiophores productivity reduced,but hyphae growth haled.These suggested that nuclease P1 production was associated with growth phase,but pigment synthesis course wasn’t.RAPD from 6 randomly selected primers was used to analyze the polymorphic rich of the four strains,the results showed that there were 70 percent polymorphism detection rate among those.UPGMA cluster analysis and genetic map constructed by NTSYS-PC software,which showed that J1Y6 and F-14 were clustered as one group at similar coefficient 0.9,where there was an appear distance from the group of 4011and F-R-33 strains（similar coefficient 0.8）.更多还原