Occurrence and structure of extrafloral nectariesin Pterodon pubescens Benth. and Pterodon polygalaeflorus Benth.

Pesquisa Agropecuária Brasileira

Élder Antônio Sousa E Paiva²  Helena Castanheira De Morais¹  Rosy Mary Dos Santos Isaias²  Dulce Maria Sucena Da Rocha¹  Paulo Eugênio Oliveira¹ 

[1] ,Universidade Federal de Minas Gerais Dep.de Botânica Belo Horizonte MG

关键词: nectaries;    plant anatomy;    plant secretions;    nectar;    plant protection;    herbivores;    plant animal relations;    nectários;    anatomia vegetal;    secreção vegetal;    néctar;    proteção das plantas;    herbívoros;    relação planta-animal;   

DOI  :  10.1590/S0100-204X2001000200002

来源: SciELO

【 摘 要 】

Extrafloral nectaries (EFNs) are structurally variable and widely spread among the angiosperms. The occurrence of EFNs in leaves of Pterodon polygalaeflorus Benth. and Pterodon pubescens Benth. (Fabaceae: Papilionoideae) were detected in adult specimens, at the time of production of new buds and flowers. The goals of the present study are to register the occurrence of the EFNs in P. pubescens and P. polygalaeflorus, and provide comparative data on the anatomical structures. The EFNs occur in the rachis and are located under the insertion of each petiolule. Each nectary consists of a small elevation whose apical portion is deeply invaginated, resulting in a depression (secretory pole), a common characteristic of both species. Unicellular, nonglandular trichomes occur along the rachis, being less numerous in P. polygalaeflorus while in P. pubescens they cover the EFNs. The secretory tissue consists of parenchyma cells with dense cytoplasm compactly arranged. The nectar reaches the surface of the EFNs by rupturing the thin cuticle which covers the secretory pole, since both species lack stomata or any other interruption at the epidermis. The basic difference between the two species, in relation to the EFNs, is the density of the pubescence, which is always greater in P. pubescens. Structural and dimensional modifications may be observed, even between basal and apical nectaries in the same rachis, so it does not constitute a taxonomical tool.

【 授权许可】

CC BY   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License