紫外线诱导小麦条锈菌毒性突变及突变体的RAPD分析

以夏孢子相对致死率90%左右作为紫外线处理最适时间,发现8min为小麦条锈菌条中29号单孢菌系(CY29-3)最适处理时间,其夏孢子相对致死率达88.97%。CY29-3的夏孢子经紫外线处理、扩繁、筛选品种筛选及4代的稳定选择后,获得了两个毒性变异的突变菌株。毒性突变产生的Jubi菌株对尤皮Ⅱ号的毒性增强,反应型由野生菌系的0型变为4型;非毒性突变产生的Funo菌株在阿夫上的反应型由野生菌系的4型变为2型。研究结果表明两突变菌株在鉴别寄主上的反应型和毒性范围也明显不同于野生菌系,说明紫外线诱导的小麦条锈菌变异是不定向和复杂的。对野生菌系和两个突变菌株进行RAPD分析后发现,两突变菌株与野生菌系之间的DNA多态性存在显著差异,多态率分别为10.58%和11.57%,说明紫外线可使小麦条锈菌基因组DNA发生较大的变化且突变位点比较复杂。     

ENZYMES IN ONTOGENESIS (ORTHOPTERA) : XIV. THE ACTION OF PROTEINS ON CERTAIN ACTIVATORS OF PROTYROSINASE

1. Proteins, when added to activators (sodium oleate. Aerosol) of protyrosinase, greatly decrease the degree of activation. 2. Certain proteins adsorbed on activator micelles are markedly affected by temperature and are rendered more sensitive by ultraviolet light. 3. Ideas are expressed as to the possible nature of activating and inhibiting phenomena especially as they relate to the enzyme tyrosinase.     

NUTRITIONAL CONTROL OF CELL PIGMENTATION IN CHLORELLA PROTOTHECOIDES WITH SPECIAL REFERENCE TO THE DEGENERATION OF CHLOROPLAST INDUCED BY GLUCOSE

1. Measuring the chlorophyll contents and growth of the algalcells grown in media containing different amounts of glucose(G) and urea fas a nitrogen source, N), it was found that theratio N/G determines pigmentation of the cells (colourless,yellow, yellowish green and green) under the experimental conditionsused, and thus a sort of colour map of the differently pigmentedcells was obtained. 2. The bleached cells produced at lower N/G ratios and the greencells obtained at higher ratios could he cultured successivelyunder heterotrophic and photoautotrophic conditions, respectively,and both forms were interconvertible on transferring each celltype into a new medium having appropriate N/G ratio. 3. Studies on these bleaching and greening processes under differentexperimental conditions revealed that the greening requiresessentially the supply of N-sources—no strict specificitywas observed with different N-sources tested—as well aslight, but can take place independently of growth, while thebleaching is caused most strongly by glucose (and fructose)among the carbon sources examined and proceeds essentially independentof light. 4. The bleaching effect of glucose at its higher concentrationsis primarily due to its degradation effect on chloroplast structuresincluding lamellae. This effect of glucose is markedly diminishedat its decreasing concentrations and is also counteracted bythe supply of N-source (urea) of higher concentrations. ¹ This work was partly reported at the Symposium on Cell Differentiationsponsored by the Society of Agricultural Chemistry, Japan, inApril, 1963 and at the Symposium on Nitrogen and Plant by theJapanese Society of Plant Physiologists in October, 1963.     

鲢、鳙肌肉生化成分的分析

同一季节收集的不同体长组的鲢、鳙肌肉的生化成分,随着鱼体的增长水分含量逐渐下降,而脂肪含量则逐渐增加,蛋白质、无氮浸出物及灰分变幅不大,且与体长变化无明显的从属关系;同一体长组的鳙肌肉水分高于鲢,而脂肪含量则低于鲢,蛋白质、灰分、无氮浸出物含量差异不大。同年收集的1+及2+龄鲢、鳙的肌肉生化成分随着季节的延续,水分含量逐步下降,蛋白质及脂肪含量逐步上升,无氮浸出物及灰分含量变化不大;1+龄鱼水分含量比2+龄鱼高,蛋白质及脂肪含量则比2+龄鱼低,其余成分含量差别不显著。