Patterns of morphological and allozyme variation in sorghum landraces of northwestern Morocco

Patterns of variation in inflorescence and spikelet morphology and in alloz yme markers were studied within and among six fields of sorghum sampled fro m different areas in Northwestern Morocco. Substantial variation for both t ypes of markers is found within fields. Significant differentiation among f ields occurs for both types of traits, with 63% of morphological variation and 20% of allozyme variation expressed among fields. Discrepancies between allozyme studies based on germplasm accessions conserved ex situ and this and other studies involving in situ sampling underline the need to use appr opriate sampling schemes for assessing the patterns of genetic variation of local landraces.