Inheritance and Utilization of Five Dwarfs in Pearl Millet (Pennisetum typhoides) Breeding1

Abstract

Height measurements were made on over 39,000 parent, F1, F2, and backcross plants of hybrids involving five dwarf and four normal inbreds of pearl millet, grown in replicated randomized blocks. F1 hybrids between four of the dwarfs were as tall as normal × dwarf hybrids, proving that these dwarfs carried different recessive genes for dwarfness. One dwarf × dwarf hybrid was little taller than its taller dwarf parent, suggesting that both carried similar dwarf genes. Most dwarf × normal F1 hybrids were significantly taller (up to 37%) than their normal parents. Inheritance of dwarfness in D1 and D2 appeared to be conditioned largely by one or two recessive genes. Near‐normal F2 distribution curves and minimum‐gene‐number estimates indicated that dwarfness in D3, D4, and D5 was controlled by more than two recessive genes. When transferred to a near‐isogenic background, dwarfness in D1 and D2 was controlled by single but different recessive genes, named d1 and d2, respectivel.Gahi‐2 seed, produced by harvesting all seed from a field planted to a mixture of equal numbers of seeds of D1, D2, D3, and D4, contains about 75% of tall hybrids and yields nearly as much as Gahi‐1. Cytoplasmic malesterile dwarfs can be used as females to facilitate singlecross seed production. They will give tall hybrids if tall or different dwarf males are used. By using males carrying the same dwarf genes, short, extra‐leafy, high‐quality forage hybrids can be produced.