WHEN the Spaniards settled in Peru during the sixteenth and subsequent centuries they introduced many domesticated plants and animals, which initially were adapted to south European conditions, and which have now become adapted to the high altitudes of the Andes. The Andean region may thus be regarded as an important secondary centre of diversity of such crops as wheat, barley, peas, alfalfa, broad beans, etc. These exist as "land races," showing much heterogeneity in respect of both morphological and physiological characters. Part of the heterogeneity is due to the fact that little or no selection has ever been practised with these crops ; part is perhaps due to four hundred years of isolation in a new environment, providing an opportunity not only for new systems of gene frequencies to become established, but also for new mutations and combinations of mutations of ecological value to be tested. In the case of Pisum sativum L., part of the heterogeneity is certainly due to a change in the breeding system, whereby a previously self-pollinated plant becomes fairly frequently cross-pollinated in an environment with new insect visitors. In 1943 the writer collected a sample of locally grown peas in Huancabamba, a small town in the Andes of northern Peru, which until quite recently was so isolated that a journey of several days by mule was required to reach it from the coastal town of Piura. Huancabamba is situated at an altitude of 6391 feet above sea-level (Lat. S. 50 15', Long. W. 790 30') in the middle of a typically temperate climate agriculture. The principal crops of the region are maize, barley, potatoes, alfalfa, peas, and beans (Faba vulgaris L.). The Huancabamba peas sown in the genetics garden in Lima were for the most part attacked violently by the mildew, Erysiphe polygoni D.C., which, except in the middle of the cold season, is a limiting factor in the cultivation of this crop on the coast. About io per cent, of the plants, however, were completely immune to mildew, and at no time showed the slightest trace of infection. This paper gives an account of the mode of inheritance of immunity, and of the linkage relationship of the gene for immunity to flower colour, in crosses with the susceptible variety First of All.

中文翻译：

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秘鲁豌豆的霉菌免疫力遗传


当西班牙人在十六世纪及随后的几个世纪定居秘鲁时，他们引入了许多驯化的植物和动物，这些植物和动物最初适应了南欧的条件，现在已经适应了安第斯山脉的高海拔。因此，安第斯地区可以被视为小麦、大麦、豌豆、苜蓿、蚕豆等作物多样性的重要次要中心。这些作物以“陆地品种”的形式存在，在形态和生理特征方面表现出很大的异质性。异质性的部分原因在于这些作物很少或根本没有进行过选择。部分原因可能是由于在新环境中隔离了四百年，这不仅为建立新的基因频率系统提供了机会，而且还为测试具有生态价值的新突变和突变组合提供了机会。就豌豆而言，异质性的部分原因肯定是由于育种系统的变化，即以前自花授粉的植物在有新昆虫访客的环境中变得相当频繁地异花授粉。 1943 年，作者在秘鲁北部安第斯山脉的一个小镇万卡班巴 (Huancabamba) 采集了当地种植的豌豆样本，直到最近，该小镇还是与世隔绝，需要骑骡子从沿海小镇皮乌拉 (Piura) 长途跋涉几天才能到达。 。万卡班巴海拔 6391 英尺（南纬 50 米 15'，西经 790 米 30'），处于典型的温带农业气候之中。该地区的主要农作物是玉米、大麦、马铃薯、苜蓿、豌豆和菜豆 (Faba vulgaris L.)。 利马遗传花园中播种的万卡班巴豌豆大部分都受到霉菌白粉病的严重侵袭，除了冷季中期之外，这种霉菌是沿海种植这种作物的一个限制因素。然而，大约10%的植物对霉菌完全免疫，并且在任何时候都没有表现出最轻微的感染痕迹。本文首先阐述了与感病品种杂交的免疫遗传方式，以及花色免疫基因的连锁关系。