Longitudinal analysis of stem growth in half-sib families of sotol ( Dasylirion Zucc.) from northeastern Mexico

Abstract

Sotol plants belong to the Dasylirion genus, a group of perennial angiosperms distributed from the southern United States to southern Mexico. They have been used historically for food and crafts, and they are the source of a distilled beverage called sotol. Since nearly all production relies on wild populations, identifying genotypes with strong growth potential is a priority. Early growth variation was evaluated in 30 half-sib families of sotol collected from southeastern Coahuila, along with a control population. A total of 522 plants were grown under greenhouse conditions using a one-way random design. Through 21 months, stem diameter was measured to assess early growth potential. Growth trends were modelled through longitudinal analysis with 3,460 data points. Heritabilities among genotypes were estimated based on the variance of predicted values from a mixed model. The most promising families were selected through best linear unbiased prediction (BLUP). The longitudinal analysis revealed significant genetic variation in stem diameter growth rate among genotypes over the 21-month period, and the trajectories were approximately linear. Heritability for stem diameter growth rate was estimated at 0.725 when the 30 families and the control genotype were included in the model. Without considering the control genotype, heritability was estimated at 0.707. BLUP allowed ranking of the 30 families for selection. The results show the existence of genetic variation in Dasylirion for early growth rate and open the possibility of selecting promising genotypes to be grown under cultivation conditions, with good behaviour in the greenhouse stage.