A LINKAGE MAP WITH RFLP AND ISOZYME MARKERS FOR ALMOND

Inheritance and linkage studies were conducted with seven isozyme gene s and 120 RFLPs in the F-1 progeny of a cross between almond cultivars 'Ferragnes' and 'Tuono'. RFLPs were detected using 57 genomic and 43 cDNA almond clones. Eight of the cDNA probes corresponded to known gen es (extensin, prunin (2), alpha-tubulin, endopolygalacturonase, oleosi n, actin depolymerizing factor and phosphoglyceromutase). Single-copy clones were found more frequently in the cDNA (65%) than in the genomi c libraries (26%). Two maps were elaborated, one with the 93 loci hete rozygous in 'Ferragnes' and another with the 69 loci heterozygous in ' Tuono'. Thirty-five loci were heterozygous in both parents and were us ed as bridges between both maps. Most of the segregations (91%) were o f the 1:1 or 1 : 1 : 1 : 1 types, and data were analyzed as if they de rived from two backcross populations. Eight linkage groups covering 39 3 cM in 'Ferragnes' and 394 in 'Tuono' were found for each map. None o f the loci examined in either map was found to be unlinked. Distorted segregation ratios were mainly concentrated in two linkage groups of t he 'Ferragnes' map.