原生质体电融合酵母多倍体生理特性的研究

对原生质体电融合技术获得的11株酵母多倍体融合株，进行了一系列生理特性的分析比较．结果发现，在电融合过程中，融合株的细胞体积及DNA含量并不随着核倍性呈线性递增．而是有其特殊的变化规律。当糖化酵母sta1、sta2和sta3在细胞核中各自纯合时，明显表现出表达的剂量效应。其中sta1、sta2纯合的融合株．在YEPS培养中，GA分泌可被淀粉大量诱导，表现出一定的二次生长特性。从分析结果推测，在亲株5301-14D及HU-TY—1A中可能有对GA分泌不利的因素。

Physiological Characteristics Studies of Yeast Polyploids Obtained from Protoplast Electrofusion

Eleven yeast polyploids obtained by protoplast electrofusion technique were identified and analyzed physiologically and biochemically.The results indicated that the cell volumes and DNA contents of the fusants did not increase linearly with the nuclear ploidies.They had their own special rules in changing.When sta1,sta2 and sta3 genes were respectively homozygous in S.diastaticus fusants,the expression of these genes showed distinct dosage effects.The fusants being homozygous in sta1 or sta2 displayed secondary growing in the culture of YEPS.Their GA secretion could be induced obviously by starch.The results also suggested that there might be some negative regulating factors in the parental strains 5301 14D and HU TY 1A respectively to control the GA secretion.