A NEW FACTOR DETERMINING THE TINT OF RED AND YELLOW GRAIN COLOURS IN SORGHUM

Abstract

In a previous publication (Rangaswami Ayyangar, et al, 1933) the inter- relationships between red, yellow and white grain colours in sorghum have been pursued. Yellow (factor Y) is the basic colour. With R, red grains are produced. A factor W determines the manifestation of colour in wholeness. on the pericarp. Without W, R gives a white grain with a red base. Simi- larly Y gives a white grain with an yellow base, the red and yellow bases being within the protection of the covering glume. Dry anther colours run parallel to grain colours and help in the separation of the white grains into their respective allelomorphs to coloured grains. A factor-I-determines the intensity of colour manifestation and is unmistakably noticeable in good red grains. W being present, R, without the-I-factor, gives a pink grain. It was noted that the yellow grains with and without the-I-factor are difficult of separation. The lightness of the colour and the quick reaction to weather conditions coupled with a brown wash found in most of the yellow varieties added to this difficulty. Even so, with the help of the R factor the yellow allelomorphs could be separated. It was thus clear that there were two shades of yellow colour, the typical yellow with the-I- factor and the light yellow without this intensification factor.