Breeding for disease resistance, forage, and seed production in Lotononis bainesii Baker

Abstract

In 1999, INIA Uruguay initiated a plant breeding program on Lotononis bainesii Baker, a subtropical forage legume from Southern Africa. Seeds from nine different geographical origins were grown and subsequently hand‐crossed. Ninety crosses were generated and their variability was used to improve disease resistance, and forage and seed yield. Fusarium oxysporum, a fungal pathogen responsible for crown and stolon rot, is common in Uruguayan soils and the only public cultivar available is reported to be susceptible to this pathogen. In winter 2001, a seedling screening method was used that allowed seeds to grow in Petri plates in the presence of the fungus. The resistant plants of each of the 90 crosses were transplanted into trays in a naturally lit glasshouse and subsequently divided into three sets with equal representation. Two of them were transplanted as spaced plant nurseries into each of two sites with distinct soil types in the basaltic region of Uruguay. The third set was transplanted into 10‐litre pots to select for seed production. The best 17 crosses were selected based on their performance in forage and seed yield evaluations. In this paper we present the breeding methodology used in developing the cultivar ‘INIA Glencoe’ with improved disease resistance and improved forage and seed production. Preliminary tests conducted in 2003 to compare the new cultivar ('INIA Glencoe') with the public one ('Miles') demonstrated that ‘INIA Glencoe’ has superior disease resistance as well as enhanced forage and seed yield.