Cotyledon integrity on Anadenanthera colubrina (vell.) brenan (fabaceae - mimosoideae) germination and early establishment

Hisaias De Souza Almeida,Anne Priscila Dias Gonzaga,Henrique Nery Cipriani,Helaine De Sousa,Yule Roberta Ferreira Nunes

doi:10.1590/s0104-77602010000200015

Abstract

Despite the major ecological and economical relevance of forest species, little is known about their seedling establishment and seed germination, as well as the damage effects to seeds at these stages. This work aimed to assess the effects of partial cotyledon loss on the seed germination and early seedling establishment of Anadenanthera colubrina. Therefore, whole (control) and split seeds (with ¹/8, ¹/4, and ½ of their size cut) were evaluated. The seeds were then germinated and the early growth of seedlings was assessed. The treatments had no effect on seed germination, however, they influenced seedling survival and establishment. The highest mortality and growth reduction values were obtained with the most severe cotyledon removal. This indicates that the tegument and the partial cotyledon loss do not represent a barrier against seed germination. However, considerable damages may be detrimental to establishment and survival of A. colubrina seedlings.

Highlights

Germination and establishment are among the most critical stages of plant life cycle, in which they are prone to strong interference from the environment and their own metabolic limitations (BEWLEY, 1997; BEWLEY & BLACK, 1994; KOSZO et al, 2007)
This study aimed to evaluate the effects of partial tegument and cotyledon removal on Anadenanthera colubrina (Vellozo) Brenan seed germination and seedling establishment
No significant differences were found between the cut treatments in the germination of Anadenanthera colubrina seeds (F=1.153; p=0.341; N=400)

Summary

Introduction

Germination and establishment are among the most critical stages of plant life cycle, in which they are prone to strong interference from the environment and their own metabolic limitations (BEWLEY, 1997; BEWLEY & BLACK, 1994; KOSZO et al, 2007). In order to overcome these difficulties, species adopt many strategies to guarantee their permanence in the community. Such strategies may vary with the position which the species occupies in the forest profile (SWAINE & WHITMORE, 1988) and the environmental characteristics of the vegetation type where the species usually occurs. Species that produce thick seed tegument grant more protection to their seeds against predators that may impair or even impede the germination process (BARTIMACHI et al, 2008; CARVALHO & NAKAGAWA, 1988). In some cases, natural predators interact with microorganisms and climatic changes, acting as natural scarification agents (CARVALHO & NAKAGAWA, 1988). On the other hand, when the production of high quantities of seedlings is interesting, artificial tegument scarification techniques may be used to break seed dormancy (SCALON et al, 2007), causing tegument rupture or weakening, allowing and/or promoting germination (BEWLEY, 1997)

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