Asexual genetic variability in Agave fourcroydes II: selection among individuals in a clonally propagated population

Abstract

Henequen is a perennial monocot that produces flowers only once towards the end of its long life cycle and then dies. Its high levels of ploidy (5x) render it sterile. It produces seeds with very low viability in the laboratory. Therefore, in plantations it is multiplied only through vegetative propagation using rhizomes. In previous work using AFLP, it was shown that despite its asexual reproduction henequen can be genetically variable. This variability is accompanied by differences in morphological characteristics. This fact indicates the possibility of selection among individuals in a clonally propagated population and its use for an improvement program via micropropagation through somatic embryogenesis. In this work, the study of morphological characters in selected individuals of henequen shows that differences exist in a clonally propagated population. Analysis with AFLP indicated that differences also exist at the genomic level. After micropropagation through somatic embryogenesis of three elite lines and 3 years under field conditions, we demonstrated using morphological analysis that plants originating from the same mother plant formed a group in Principal Component Analysis (PCA). AFLP and cluster analysis using Unweighted Pair-Group Method Arithmetic-Average (UPGMA) showed that each mother plant and its somatic embryogenesis derived daughter plants clustered, indicating the conservation of molecular marker patterns in the micropropagated daughter plants.