Nopal: A Strategic Resource for Arid Regions: Optimizing Germination: From Polyembryony to Morphogenetic Polymorphism in Opuntia ficus-indica (L.)

The Nopal cactus (Opuntia ficus-indica (L.) Mill.) is a xerophytic species of major importance to arid regions. Its propagation by seed remains limited by low seed germination rates, due to the hardness of the seed coats. This study aims to optimize conditions for sexual germination, both in vivo and in vitro, while investigating the embryonic and post-germination development of seedlings. The results show that chemical scarification with fuming sulfuric acid for 30 minutes is the most effective treatment, yielding a germination rate of 68%. The study also reveals a polyembryony rate of 16%, indicating a seed's ability to produce multiple embryos. It confirms the existence of marked morphogenetic polymorphism in plants grown from seed, with variations in the number and symmetry of cotyledons as well as other growth abnormalities. These results shed new light on the reproductive biology of O. ficus-indica and open up new avenues for the selection, conservation, and improvement of this species of agronomic and ecological interest.