Comparison of Four Methods of Multiple Trait Selection for Five Traits in Alfalfa¹

Abstract

Tandem, modified independent culling levels, estimated index, and base index methods of multiple trait selection were compared for improvement of alfalfa, Medicago sativa L., for resistance to Pseudopeziza medicaginis (Lib.) Sacc., Leptosphaerulina briosiana (Poll.) Graham & Luttrell, Ascochyta imperfecta Peck, and Uromyces striatus Schroet. vat. medicaginis (Pass.) Arth., and for increasing recovery after cutting in greenhouse and growth chamber facilities. Base index and estimated index methods were most effective, modified independent culling levels was intermediate, and tandem was least effective. Resistance to P. medicaginis and U. striatus , and recovery after cutting responded well to selection; there was little response for resistance to L. briosiana and A. imperfecta .