III.—Cytological Studies in the Genus Solanum. I. Wild and Native Cultivated “Diploid” Potatoes

Abstract

Previous studies on the cytology of the wild and less highly developed “diploid” forms of potatoes have been mainly concerned with the number of chromosomes. Rybin (1933) in his cytological investigation on the South American cultivated and wild potatoes has recorded 12 as the haploid number of chromosomes in seven species including S. Rybinii. Ratera (1938) reported the same number of haploid chromosomes in S. Parodii and six other species indigenous to Argentine.The present study is concerned primarily with the secondary pairing of chromosomes at meiosis in six “diploid” species with a view to determining the basic number in potatoes and to ascertaining the exact “status” of these species.