Genetic diversity of guava (Psidium guajava L.) from Central Mexico revealed by morphological and RAPD markers

Guava fruit produced in Calvillo, Aguascalientes(Mexico) is considered to be of the best quality in this country. Nevertheless,growers from this place empirically know that there is anoticeable variation among individual trees within the same orchard,and variation among individuals from different orchards. In orderto have a clear evidence of this, morphology analysis of guava wasperformed taking data from seventy nine individuals out of thirtysix orchards, while RAPD was performed on a subset of twentysix individuals. Similarity was found for morphology data rangingfrom 87-100%, while similarity from RAPD data ranged from 30-100%. Combined data of RAPD and morphology showed similaritygreater than 80%. Clades from combined data sorted genotypes intoclearly defined groups according to fruit shapes and banding pattern.These markers could be used as helper tools for breeding programsfor guava genotypes of Mexico. Furthermore, these may help on theclaims from growers when checking origin authenticity if packedguava from somewhere else is labeled as guava from Calvillo.