CERNE ISSN: 0104-7760 [email protected] Universidade Federal de Lavras Brasil de Souza Almeida, Hisaias; Dias Gonzaga, Anne Priscila; de Sousa, Helaine; Ferreira Nunes, Yule Roberta; Nery Cipriani, Henrique Cotyledon integrity on Anadenanthera colubrina (Vell.) Brenan (Fabaceae - Mimosoideae) germination and early establishment CERNE, vol. 16, núm. 2, abril-junio, 2010, pp. 227-234 Universidade Federal de Lavras Lavras, Brasil Available in: http://www.redalyc.org/articulo.oa?id=74421665014 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Cotyledon integrityCOTYLEDON on Anadenanthera INTEGRITY colubrina ON... Anadenanthera colubrina (VELL.) BRENAN 227 (FABACEAE - MIMOSOIDEAE) GERMINATION AND EARLY ESTABLISHMENT Hisaias de Souza Almeida1, Anne Priscila Dias Gonzaga2, Helaine de Sousa3, Yule Roberta Ferreira Nunes4, Henrique Nery Cipriani5 (received: September 16, 2009; accepted: March 31, 2010) 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 1 1 (with /8, /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. Key words: Seedlings, seeds, Red-Angico. INTEGRIDADE DOS COTILEDONES NA GERMINAÇAO E NO DESENVOLVIMENTO INICIAL DE Anadenanthera colubrina (VELL.) BRENAN (FABACEAE - MIMOSOIDEAE) RESUMO: Apesar da grande importância ecológica e econômica das espécies florestais, pouco se sabe sobre a germinação e o estabelecimento de suas plântulas, bem como os efeitos dos danos à semente para estas etapas. Neste sentido, conduziu-se este trabalho, com o objetivo de avaliar os efeitos da perda parcial dos cotilédones de Anadenanthera colubrina, na germinação das sementes e no desenvolvimento inicial de suas plântulas. Para isso, foram avaliadas sementes inteiras e sementes seccionadas nas proporções: controle; ¹/8 da semente; ¹/4 da semente e ½ da semente. Posteriormente, as sementes foram colocadas para germinar e avaliado o estabelecimento das plântulas formadas. Os tratamentos não influenciaram na germinação, todavia influenciaram no estabelecimento e sobrevivência das plântulas. Os valores de crescimento e mortalidade foram maiores para os tratamentos com cortes mais severos. Isso indica que a perda de parte dos cotilédones não constitui uma barreira à germinação das sementes, no entanto, danos consideráveis podem prejudicar o estabelecimento e a sobrevivência das plântulas de A. colubrina. Palavras-chave: Plântulas, sementes, Angico-Vermelho. 1 INTRODUCTION forest profile (SWAINE & WHITMORE, 1988) and the environmental characteristics of the vegetation type where Germination and establishment are among the most the species usually occurs. critical stages of plant life cycle, in which they are prone to Furthermore, species that produce thick seed strong interference from the environment and their own tegument grant more protection to their seeds against metabolic limitations (BEWLEY, 1997; BEWLEY & BLACK, predators that may impair or even impede the germination 1994; KOSZO et al., 2007). In order to overcome these process (BARTIMACHI et al., 2008; CARVALHO & difficulties, species adopt many strategies to guarantee NAKAGAWA, 1988). However, the action of predators their permanence in the community. Such strategies may may, through tegument disruption, facilitate gas exchange vary with the position which the species occupies in the and imbibitions, promoting germination (CÁCERES & 1Biologist, PhD Candidate in Forest Engineering – Laboratório de Dendrologia e Ecologia de Florestas Tropicais – Deptartamento de Ciências Florestais – Universidade Federal de Lavras – Cx. P. 3037 – 37200-000 – Lavras, MG, Brazil – [email protected] 2Biologist, PhD Candidate in Forest Science – Laboratório de Dendrologia – Departamento de Engenharia Florestal – Universidade de Brasília – Cx. P. 04357 – 70919-970 – Brasília, DF, Brazil – [email protected] 3Forest Engineer – Laboratório de Dendrologia e Ecologia de Florestas Tropicais – Deptartamento de Ciências Florestais – Universidade Federal de Lavras – Cx. P. 3037 – 37200-000 – Lavras, MG, Brazil – [email protected] 4Biologist, Dr. Professor – Laboratório de Ecologia e Propagação Vegetal – Departamento de Biologia Geral – Universidade Estadual de Montes Claros – Cx. P. 126 – 39401-089 – Montes Claros, MG, Brazil – [email protected] 5Forest Engineer, Masters student of the Soil and Plant Nutrition Program of Universidade Federal de Viçosa/UFV – Av. Peter Henry Holfs s/n – Campus Universitário – Viçosa, MG – 36570-000 – [email protected] Cerne, Lavras, v. 16, n. 2, p. 227-234, abr./jun. 2010 228 ALMEIDA, H. de S. et al. MONTEIRO-FILHO, 2007; CARVALHO & NAKAGAWA, germination and seedling establishment. Therefore, the 1988) and establishment. Therefore, in some cases, natural following hypotheses were tested: i) little cotyledons and predators interact with microorganisms and climatic tegument area loss positively influence germination, not changes, acting as natural scarification agents interfering with seedling establishment, conversely to (CARVALHO & NAKAGAWA, 1988). On the other hand, significant cotyledon loss; and ii) mortality increases along when the production of high quantities of seedlings is with cotyledon area loss. interesting, artificial tegument scarification techniques may be used to break seed dormancy (SCALON et al., 2007), 2 MATERIAL AND METHODS causing tegument rupture or weakening, allowing and/or For this study, in November 2004, dark brown or promoting germination (BEWLEY, 1997). near-dehiscence closed fruits of ten donor trees located at Although tegument scarification may have positive the State University of Montes Claros – UNIMONTES effects, breaking seed dormancy, for instance, negative (16º43’16,49"S and 43º52’38,59"O) campus and at Guimarães effects on population density due to natural Rosa Municipal Park (16º44’05.40"S and 43º52’59.28"O) (BARTIMACHI et al., 2008) and artificial (FONSECA & were collected. The fruits were stored in plastic bags and PEREZ, 2003) scarification have also been reported. In this then screened at the Ecology and Plant Propagation Lab regard, deep or superficial damages in the seed can act in of UNIMONTES. During screening, 400 seeds with entire different ways, promoting or hindering germination and, morphology, identified by color and absence of surface subsequently, the seedling establishment. Nevertheless, deformations, pathogens, predation damages and abortion, the effects of seed rupture by natural (e.g. predators) or were selected. artificial (e.g. mechanical scarification methods) agents on The seeds were then submitted to cut treatments, the germination and establishment of native species are consisting in reduction of seed length in the following still largely unknown. proportions: (1) , approximately 12.5% of the seed, (2) ¼, Anadenanthera colubrina (Vellozo) Brenan approximately 25% of the seed, (3) ½, approximately 50% belongs tto tthee FFaabbaacceeaaee –– MMiimmoossooiiddeeaaee ffaammiliyly (THE of the seed and (4) control treatment, consisting of whole ANGIOSPERM PHYLOGENE GROUP - APG, 2003). It is an seeds. The cuts were made on the side opposite to the autochoric tree species, whose individuals may reach more hilum. The purpose was to partially remove cotyledons than 20 m high and 80 cm DBH (diameter at breast height and tegument, avoiding direct damage to embryo axis or 1.3 m above ground). structures (VIDAL & VIDAL, 1992). Anadenanthera colubrina is light-demanding and Subsequently, the seeds were distributed in 40 often occupies the canopy of seasonal forests. It produces plastic germination boxes with 10 seeds each, being 10 long coriaceus fruits, with size ranging from 20 to 30 cm boxes per treatment. At first, the seeds were moistened (MARTIUS et al., 1876), containing about 10 to 15 rounded with 20 ml of distilled water, being rehydrated when brown thin-coated seeds. necessary during the assessment periods. In order to keep According to Prado (2000) and Prado & Gibs (1993) humidity within the boxes, the seeds were placed on a the species has wide distribution in South America and, filter paper, which was on a thin layer of foam (0.5 cm). among other 32 species, allows inferring about the Both materials were sterilized. distribution of deciduous forests on the continent and the The germination boxes were marked according to “dry diagonal” formation, which links the Brazilian Caatinga the treatments and placed in a germination chamber with to the south-western Bolivia. four fluorescent lamps, 12-hour photoperiod and The species is