The assessment and breeding of Acroceras macrum Stapf.

Abstract

Acroceras macrum Stapf is a palatable and nutritious tropical species which was popular as a pasture grass in South Africa approximately twenty five years ago. Its susceptibility to diseases and an apparent lack of seed setting ability were two serious detractions of an otherwise desirable species. A breeding programme was initiated at Cedara in 1970 and has, to some extent, overcome these deficiencies. Cytological and field investigations have revealed that tetraploid (2n = 36), pentaplaid (2n = 45) and hexaploid (2n = 54) chromosome races occur and that the species is self sterile, but in certain combinations of strains of similar chromosome number and flowering date, highly cross fertile. Seed of A. macrum has a dormancy characteristic, germination improving after nine month storage. Several high yielding, disease resistant and otherwise desirable parental strains were selected for hybridization as single crosses and seed derived from these crosses has recently been planted in field experiments.

Keywords: acroceras macrum; botany; breeding; breeding programme; cedara; chromosome number; diseases; dormancy; flowering; germination; grasses; hybridization; pasture grasses; races; seed; south africa; storage