Genetic Structure and Agronomic Value of Italian Lucerne Landraces: A Synopsis

Abstract

Because of their long history of cultivation and good characterization of collecting sites, lucerne landraces from northern Italy are particularly useful for studies of genetic structure, evolutionary adaptation to specific growing conditions and comparison with modern germplasm, which can drive the efficient management and exploitation of landrace germplasm. This work aims to summarize the information from such studies. Each study included ten to 13 farm landraces belonging to the seven former commercial ecotypes of northern Italy, and four to seven well-adapted varieties. Each landrace was represented by over 250 single plants grown in dense stand under field conditions or in four artificial environments created by the combination of almost nil or high summer drought with sandy-loam or silty-clay soil. On average, landrace germplasm was at least as performing as variety material for forage yield and persistence over two or three years. Landraces exhibited specific adaptation towards drought-stress levels similar to those of their environment of origin. No mean difference between landrace and variety germplasm emerged for forage quality (as estimated by the leaf:stem ratio) or seed yield. The estimated genetic variance within population was always much larger than that among populations. These results support the exploitation of landrace germplasm through breeding procedures able to exploit its remarkable within-population diversity and its adaptation to specific environments.