Phylogenetic relationships of industrial chicory varieties revealed by RAPDs and AFLPs

Abstract

Seventeen industrial chicory varieties were subjected to molecular marker analysis revealing genetic vari- ation within varieties and genetic relationships between varieties. Banding profiles from 66 RAPD loci (random amplified polymorphic DNA) and 171 AFLP loci (amplified fragment length polymorphism) were produced with total genomic chicory DNA of leaf bulks from four to eight plants per variety. The DICE similarity index was calculated and transformed to genetic distances for construction of phylogenetic trees. We found that there was no clear and strict grouping of the varieties. Genetic distances were nearly the same between all varieties. Marker analysis of individual plants of the variety Fredonia revealed a considerable degree of intravarietal variation typical for open pollinated vari- eties. The following conclusions were drawn: 1) among the root chicory varieties distant phylogenetic groups do not exist or formerly existing groups were eroded by successive intercrosses; 2) potentially existing phylogenetic or het- erotic group structures are concealed by the high within population genetic variability; 3) the selection/breeding inten- sities were low during the last decades; and (4) the high degree of genetic variability can be used for selecting superior genotypes from already existing varieties by mass selection. root chicory / Cichorium intybus / phylogeny / molecular markers / RAPDs / AFLPs Rsum -Relations phylogntiques entre varits de chicore industrielles tablies partir de locus RAPD et AFLP. Dix-sept varits de chicore industrielle ont t analyses et les marqueurs molculaires ont permis de rv- ler la variabilit gntique intravaritale et les relations gntiques entre ces varits. Les profils de bandes correspondants 66 locus RAPD (random amplified polymorphic DNA) et 171 locus AFLP (amplified fragment length polymorphism) ont t obtenus partir d'ADN gnomique total de mlanges de feuilles de quatre huit individus par vari- t. L'indice de similarit DICE a t calcul et transform en distances gntiques pour construire des arbres phylogntiques. Aucun regroupement clair et bien individualis n'a t observ entre les varits. Les distances gntiques entre varits taient toutes du mme ordre de grandeur. L'analyse de plantes individuelles de la varit Fredonia a rvl une importante variabilit intravaritale typique de varits en fcondation libre. Cette analyse a permis de tirer les conclusions suivantes : i) parmi les varits de chicore racine il n'existe pas de groupes phylogntiquement dis- tants ou bien les groupes anciennement distants n'existent plus du fait des intercroisements successifs, ii) d'ventuelles structures de groupes phylogntiques ou htrotiques sont masques par la forte variabilit gntique intrapopulation,