Genetic architecture of grain hardness — A durable resistance mechanism for grain moulds in sorghum [Sorghum bicolor (L.) Moench]

The main constraint to the value of sorghum grain during rainy season is its deteri9ration due to grain moulds caused by a complex of fungi. The traits like glume colour, glume cover and grain hardness were found to be associated with resistance to grain moulds in white grained sorghum. A study was conducted to understand the nature and magnitude of gene effects for grain hardness in a cross involving a soft grained sorghum line, 278 and a hard and grain mould resistant line, 858586 by generation mean analysis in two seasons. Sorghum grain hardness was recorded by measuring the grinding time required to obtain a fixed volume of flour from the grains. The F₂ frequency distribution showed continuous variation indicating polygenic nature of inheritance of grain hardness. The generation mean analysis showed that the additive gene effects and additive x additive gene interactions were more important. The frequency of desirable genes can be increased by direct selection.