SEED QUALITY AND SEEDLINGS SURVIVAL OF Echinocactus platyacanthus FROM THREE REGIONS OF MEXICO

Abstract

Echinocactus platyacanthus is an endemic specie of Mexico used to cook a cactus candy called acitron, it is also used as fodder and ornamental. The Official Mexican Standard NOM-059-SEMARNAT-2010 considers it under special protection; thus, it is necessary to promote its conservation. In this regard, the propagation by seed into a greenhouse or nursery of threatened specimens could prevent the collection of wild individuals. The objective of this research was to evaluate the seed quality, survival and development of E. platyacanthus seedlings from three regions of central Mexico (Tehuacán-Cuicatlán Valley, Queretaro Semi-desert and Potosi Highland) in two substrates into a greenhouse. For each collection site the fruit weigh and the number of seeds per fruit were determined, the physical quality of the seeds was evaluated through the weight of 100 seeds, and the physiological quality through germination test. The development of seedlings was evaluated after transplantation in two substrates (soil of origin and commercial substrate peat moss). The change in diameter, height and survival were measured for 120 days. The highest seed number on average (522 ± EE 35) was that of the fruits from a site of the Queretaro Semi-desert and the Potosi Highland; however, the site with the least number of seed per fruit obtained the seeds with the highest weight. In most of the study sites germination was successful with values of 74 to 100% in 30 days, but seeds from the Queretaro Semi-desert only had 22 %. This poor germination was probably due to seed deterioration or dormancy. Seedlings grew better in the soil of origin, as they reached the largest dimensions and presented high survival at the final stage of the experiment compared to that obtained in the commercial substrate. Results indicate that the populations of E. platyacanthus with the highest seed quality are found in the Tehuacán-Cuicatlán Valley and in the Potosi Highland.