Note on the Dating of Terraces in the Lake Melville District, Labrador.
Note on the Dating of Terraces in the Lake Melville District, Labrador.
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关于拉布拉多梅尔维尔湖区梯田年代测定的说明。
DOI：
10.1126/science.121.3134.112-a
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发表时间：
1955
期刊：
影响因子：
56.9
通讯作者：
W. Blake
中科院分区：
文献类型：
--
作者：
W. Blake
基本上与以前用于烟草N. tabacum的培养相同的技术被用于粘粒N. glutinosa,(1)。详情将在以后的通讯中公布。硝酸钙和硫酸镁被相应的钠盐代替，硫酸镁被氯化物代替，铁盐被省略，分别引起钙、镁、硫和铁的缺乏。进行5个缺镁试验和4个缺镁试验，每个试验32 ~ 80株。实验是从1952年到1954年在一年中的不同季节进行的。在一个特定的实验中，所有的植物都是在明显的、特征性的缺乏症状(2)出现后接种的。钙和镁缺乏对随后形成的局部病变的大小没有明显影响。然而，铁和硫缺乏症始终比对照叶片产生更大的病变，视觉估计是两到三倍。塞缪尔（Samuel）(3)观察到，温度显著影响谷氨酰胺对烟草花叶病毒感染的反应。温度升高至350C，局部病变大小增大；高于此温度未见坏死，发生全身性感染。McKinney和Clayton(4)注意到烟叶属植物在高温下产生花叶症状，在75华氏度时携带坏死因子，这与Samuel的发现一致。在N. glutinosa上，番茄丛矮病毒在幼叶上比在老叶上产生更大的局部损伤(5)。显然，根据我们的发现，矿物质营养也可以影响病变的大小。此外，如果病变大小的增加通常代表全身性感染的趋势，那么矿物质营养可能会以一种迄今为止尚未认识到的方式影响植物病毒的传播。
Essentially the same techniques as were employed previously for the culture of N. tabacum were used for N. glutinosa,(1). Details will be published in a later communication. Calcium nitrate and magnesium sulfate were replaced by the corresponding sodium salts, magnesium sulfate was replaced by the chloride, and the iron salt was omitted to induce deficiencies of calcium, magnesium, sulfur, and iron, respectively. Five magnesium-defieiency experiments and four each of the other deficiency experiments were performed, with 32 to 80 plants per experiment. The experiments were carried out from 1952-54 atdifferent seasons of the year. All plants in a particular experiment were inoculated after pronounced, characteristic deficiency symptoms (2) had developed. Calcium and magnesium deficiencies had no apparent influence on the size of subsequently formed local lesions. Both iron and sulfur deficiencies, however, consistently produced larger lesions than those that developed on control leaves, by a factor of two to three estimated visually. Samuel (3) observed that the response of N. glutinosa to infection by tobacco mosaic virus was markedly influenced by temperature. Local lesion size in-creased by increasing the temperature to 350C; above this temperature no necrosis was observed, and systemic infection occurred. McKinney and Clayton (4) noted the production of mosaic symptoms at high temperatures in Nicotiana spp. carrying the factor for necrosis at 75 F, which agrees with Samuel's findings. On N. glutinosa, tomato bushy stunt virus produces largert local lesions on young leaves than on old leaves (5). Apparently, on thebasis of our findings, mineral nutrition can also influence lesion size. In addition, if increased lesion size in general represents a tendency toward systemic infection, mineral nutrition may affect the spread of plant viruses in a heretofore un-recognized manner.