23 - Clavispora Rodrigues de Miranda

Abstract

This chapter focuses on Clavispora genus and its constituent species. Asexual reproduction in this genus occurs by multilateral budding on a narrow base. Its cells are ovoid, ellipsoidal, or elongate, and pseudomycelium may be formed but true mycelium is not formed. Conjugation of haploid cells of opposite mating types precedes ascus formation. The ascospores are clavate, sometimes containing a small oil droplet, and one or two and rarely three or four ascospores are formed per ascus. The spore wall may have small warts visible by electron microscopy and the spores are easily liberated from the ascus. The constituent species of this genus are Clavispora lusitaniae and Clavispora opuntiae. The asci of Clavispora lusitaniae are bilobate, containing usually one or two and rarely three or four clavate ascospores. Warts in this species may or may not be visible by electron microscopy. The ascospores are liberated from the asci soon after their formation and on rare occasions, spherical ascospores are formed. Abundant sporulation occurs 2–4 days at 17–25° C after mixing cultures of compatible mating types on 1% malt extract agar. The asci of Clavispora opuntiae are bilobate, containing usually one or two (rarely three or four) clavate ascospores, similar to those formed by C.lusitaniae. Warts are visible by electron microscopy only and the ascospores are liberated from the asci soon after their formation.