Trioecy in Coccoloba cereifera Schwacke (Polygonaceae), a narrow endemic and threatened tropical species

Brazilian Archives of Biology and Technology

Celice Alexandre Silva²  Marco Antonio Oliva¹  Milene Faria Vieira¹  Geraldo Wilson Fernandes¹ 

[1] ,Universidade do Estado do Mato Grosso Departamento de Ciências Biológicas Tangará da Serra MT ,Brasil

关键词: agamospermy;    breeding systems;    Coccoloba cereifera;    sex determination;    sexual morphs;    trioecy;   

DOI  :  10.1590/S1516-89132008000500017

来源: SciELO

【 摘 要 】

Trioecy, the co-occurrence of the males, females, and hermaphrodite morphs in natural populations, is a rare and poorly studied breeding system. It is expressed in Coccoloba cereifera, an endemic, and endangered species from the rupestrian fields of Serra do Cipó, southeastern Brazil. Male individuals produce staminate flowers but no fruits. Female individuals produce pistillate flowers and set fruits. Both staminate and pistillate flowers present non-functional organs of the opposite sex that simulate perfect flowers. Hermaphrodite individuals produce two different perfect flowers, each one belonging to distinct individuals, and set fruits. Perfect flowers differ in the amount of pollen produced, in pollen viability, and in some morphological traits. Two Hymenoptera species visited the flowers sporadically. The low natural fructification indicated a limited pollination, while the fruit set recorded in bagged pistillate flowers indicated agamospermy. Female individuals represent more than 40% of the population studied and must be the result of agamospermic seeds.

【 授权许可】

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