Genetic Resources and Crop Evolution 50: 723–735, 2003. 723  2003 Kluwer Academic Publishers. Printed in the Netherlands. RAPD and AFLP assessment of genetic variation in a landrace of pepper ( Capsicum annuum L.), grown in North-West Italy * Sergio Lanteri , Alberto Acquadro, Luciana Quagliotti and Ezio Portis ` DI. VA.P .R. A. settore Genetica Agraria, Universita degli Studi di Torino, via L. Da Vinci 44, Grugliasco * ( Turin) I-10095, Italy; Author for correspondence (e-mail: sergio.lanteri@unito.it; fax: 1 39 011 6708826) Received 7 December 2001; accepted in revised form 26 April 2002 Key words: AFLP, Capsicum annuum, Genetic variability, In situ germplasm conservation, Landrace, RAPD Abstract In several regions of Italy as well as other parts of southern Europe, the heterogeneity of the land, the climate and the soil favour the survival in cultivation of a large number of landraces specifically adapted to local conditions. Knowledge on the level and distribution of their genetic variation can help to develop appropriate strategies, in order to suistainably manage in situ these germplasm resources at risk of genetic erosion. C. annuum is an herbaceous diploid species and is considered to be self-pollinating, although different rates of out-crossing have been recorded. We used random amplified polymorphic DNA (RAPD) and amplified fragment length poly- morphism (AFLP) markers to assess genetic diversity within and between five populations of a landrace of Capsicum annuum L., grown in a limited area in north-west Italy and locally known as ‘Cuneo’ pepper. Partitioning the genetic variation with Shannon’s diversity index revealed that 41.6% occurred between and 58.4% within populations. Analogous results were obtained when the analysis was based only on RAPD or AFLP markers. However, AFLP was more reliable, since a lower range of variation was observed among primer combinations in detecting the two components of genetic variation. Notwithstanding the rather high level of within genetic variation detected, the five populations were clearly differentiated and differed in the frequency of alleles exclusive and / or present at very low frequencies. Our results show the need for accurate estimation of allele frequencies, in order to identify populations to which priority should be given for dynamic conservation of landraces. Introduction common gene pool. The adaptation zone of an ecotype is the region where it has evolved under local In the last decades a drastic change in the genetic climatic, pedological and biotic conditions and, for material used for vegetable crops has occurred all crops, under anthropic pressure (Pupilli et al. 2000). over the world. Traditional landraces, locally selected Thanks to European and national institutions pro- over many years, have given way to commercial moting sustainable use of agricultural resources, the varieties and hybrids which can give higher and more farmers’ awareness and willingness both to grow and uniform yields and often carry resistance to diseases. preserve this germplasm ‘on farm’ and to prize com- However, in several regions of Italy, as well as in mercially their production have increased (1997). other parts of southern Europe, the heterogeneity of This new rationale, not only based on self-consump- the land, the unique and variable climatic conditions tion, but also on commercialization of the products, and the different types of soil favour the survival in carries the risk of genetic erosion, mainly as a conse- cultivation of a large number of specifically adapted quence of the techniques of seed production applied, landraces rich in genetic variation. A landrace is which may not take into account the preservation of defined as a population growing in a specific geo- genetic variability. Analysis of the extent and dis- graphical environment, whose individuals share a tribution of genetic diversity within a landrace is