RFLP mapping of manganese efficiency in barley

Ln many cropping regions of the world, yield is limited by the availability of micronutrients, and micronutrient-efficient cultivars provide a yield a dvantage. Traditional methods of testing cultivars for micronutrient effici ency are time-consuming and laborious. Molecular markers linked to loci con trolling micronutrient efficiency will allow more rapid and efficient selec tion and introgression of these traits than is currently possible. Using a pot-based bioassay and bulked segregant analysis of an F-2 population, we h ave identified several RFLPs (grouped distally on chromosome 4HS) linked to a locus for manganese efficiency in barley, This manganese efficiency locu s has been designated Mel1. Pot bioassay analysis of intercrosses suggests that three useful sources of manganese efficiency are likely to be allelic at the Mel1 locus. Field evaluation of marker selected F-4 progeny supports the major role of Mel1 in the genetic control of manganese efficiency. Ado ption of marker assisted selection for this trait in the Southern Australia n barley breeding program has occurred. This has been facilitated by the de monstration that the Mel1 allele of Amagi Nijo can be distinguished from 95 other locally useful varieties and breeder's lines on the basis of RFLPs i dentified by just two molecular markers.