Abstract

                                The occurrence of thin, wiry plants is one of the many seedling abnormalities in Sorghum. Sieglinger (1929) found such plants in a single head-row population of F.5 generation from a cross between two varieties of Kafir. He termed these plants as tenuous' and described them as slender grass-like plants which produced practically no secondary or coronal roots and made all their development from single seminal roots. He also considered that a single factor explanation seemed plausible to account for their occurrence and that in the recessive condition the factor prevents the development of the coronal roots and the thickening of the stems to such an extent that the plants do not fruit. This is the only previous record of tenuous plants in cereals, as far as the author is aware. An experience similar to that of Sieglinger's (loc. cit.) was obtained at the Millet Breeding Station, Coimbatore, in the monsoon crop-season of 1953, with a variety of Sorghum locally known as Thalaivirichan cholam and taxonomically described by Snowden (1936) as Sorghum Roxburghii var. hians, Stapf. The present study was undertaken to gather more details and confirmatory data on the occurrence and behaviour of such tenuous plants in Sorghum.

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