Inheritance of Plant Height in Cotton. I. A Cross Between Lubbock Dwarf and Texas Marker‐1

Abstract

In Upland cotton (Gossypium hirsutum L.), plant height is determined primarily by the number and length of the main stem internodes, but it can be significantly modified by variation in the node on the main stem where fruiting branches are first initiated. F1, F2, and backcross populations from a cross between the inbred lines of Lubbock Dwarf and Texas Marker‐1 provided estimates about the inheritance of plant height, number of main stem nodes, length of main stem and fruiting branch internodes, and node of the first fruiting branch. Phenotypic correlations were computed from the F2 population for all character combinations.The parental lines differed in plant height, main stem and fruiting branch internode lengths, and the node of the first fruiting branch. The parental lines were not different in the number of main stem nodes; only environmental variation occurred for this character. Each of the other characters were quantitatively inherited with additive genetic effects, without any indication of significant dominance genetic effects. Plant height was shown to be associated with the number of main stem nodes (r = 0.57), main stem internode length (r = 0.88), and node of the first fruiting branch (r = 0.38). A significant association was also found between the number of main stem nodes and node of the first fruiting branch (r = 0.34). The lack of significant association between the main stem internode length and the fruiting branch internode lengths suggested that these characters can be manipulated by traditional breeding techniques independently of each other.