Plant Genome III Conference

EVIDENCE FOR CONSERVED QTL IN MAIZE AND SORGHUM.

Patterns of genetic linkage between maize and sorghum have been documented primarily on the basis of RFLP loci detected by common sets of maize DNA probes in several comparative mapping studies. These studies have revealed a high degree of sequence homology, evidence for extensive conservation of locus order, and a few examples of large scale rearrangements (Pereira et al. 1994. Genome 37:236-243). Subsequent QTL mapping studies in sorghum have identified regions with major effects on a suite of traits such as plant height, leaf blade and panicle dimensions, flowering, and tiller development. Four unlinked QTL for plant height have been identified in a sorghum population, CK60 x PI229828. On the basis of linkage relationships among the QTL, their gene action and effect, and associations with other traits, some of these QTL may correspond to qualitative loci (dw) characterized in sorghum. Three of the plant height QTL have been placed to regions of the sorghum genome which, on the basis of common sets of maize RFLP probes and genetic effects on plant height and other traits, appear to be orthologous with three regions of the maize genome.