EVALUATING THE CORRELATION OF PLOIDY LEVEL, LEAF SIZE, STOMATA CHARACTERISTICS AND TUBER WEIGHT IN Dioscorea spp. POPULATIONS FROM JALISCO, MÉXICO

Abstract

Background. “Camote de cerro” (Dioscorea spp.) is a plant of great importance in West rural areas of Mexico as food source and alternative medicine. Dioscorea is an important crop around the world for its carbohydrate contribution to diets. Yams are polyploid plants, and species with modifications at ploidy level also present changes in leaf size and stomata characteristics. These variations can favor resistance to adverse conditions. Objective. In the present study, evaluation and correlation of ploidy levels, leaf size, stomata characteristics and tuber weight were carried out for Dioscorea remotiflora Kunth and Dioscorea sparsiflora Hemsley in accessions obtained from 11 localities in México. Methodology. Chromosome counting was carried out in root meristems. Measuring and counting stomata were carried out. Productivity rate (PR) was calculated dividing harvested tuber weight over seed tuber weight, for each experimental unit. Leaves width and length were measured. Results. Show that variation is higher among different localities than among specimens from the same locality. Significant differences were observed for, ploidy levels (P), stomata dimensions and number of chloroplasts in stomata. Differences in chloroplast numbers present in occlusive cells were also significant for different species. Implications. Ploidy level showed a relation with chloroplasts numbers in stomata and stomata width. Leaf size presented a relation with stomata dimensions, and leaf width showed a relation with tuber weight. Conclusions. These observations allowed us to determine that there are variation among populations; stomata width and chloroplast number in a population can help to determine ploidy levels, and leaf width is a response variable that allows to predict tuber weight.

Keywords

• yam
• dioscoreaceae
• polyploids
• geophyte
• population variation.