Linkages between restriction fragment length, isozyme, and morphological markers in lentil

Abstract

A genetic linkage map of lentil comprising 333 centimorgans (cM) was constructed from 20 restriction fragment length, 8 isozyme, and 6 morphological markers segregating in a single interspecific cross (Lens culinaris × L. orientalis). Because the genotypes at marker loci were determined for about 66 F₂ plants, linkages are only reported for estimates of recombination less than 30 cM. Probes for identification of restriction fragment length polymorphisms (RFLPs) were isolated from a cDNA and EcoRI and PstI partial genomic libraries of lentil. The cDNA library gave the highest frequency of relatively low-copy-number probes. The cDNAs were about twice as efficient, relative to random genomic fragments, in RFLP detection per probe. Nine markers showed significant deviations from the expected F₂ ratios and tended to show a predominance of alleles from the cultigen. Assuming a genome size of 10 Morgans, 50% of the lentil genome could be linked within 10 cM of the 34 markers and the map is of sufficient size to attempt mapping of quantitative trait loci.