Teste de sanidade em sementes de Luetzelburgia auriculata.
Native species are, generally, sexually propagated (through seeds), and that is why the sanitary quality of forest seeds assume major importance on its viability and initial growth. The presence of pathogens in seeds, inside or on its surface, may reduce its germination due to losses caused by deterioration, abnormalities, damping-off, and plantlet lesions, what may result in death or the transference of diseases to trees.
Pathogens associated with native species’ seeds need special attention due to the fact that some of these microorganisms may reduce quality and seedling production. About 90% of diseases occurring in nurseries are caused by pathogens associated with seeds. Out of this 90%, fungi are the most important causal agent, which are disseminated by seeds, and keep it viable for long periods (RESENDE et al., 2008).
The main disease-related problems occur during the germination and seedling growth in nurseries. Important fungi genres presents in seeds from native species are: Alternaria, Aspergillus, Cladosporium, Curvularia, Fusarium, Penicillium e Rhizopus.
Seed sanitary evaluation and the identification of microorganisms are crucial steps to control it. The instructions to run seed quality tests are presented in the Regras para Análise de Sementes (RAS), especially for commercial crops. However, the Agriculture Ministry (Ministério da Agricultura, Pecuária e Abastecimento – MAPA), published an issue, the Instruções para Análise de Sementes de Espécies Florestais (BRASIL, 2013), complementing the RAS with instructions for 319 native and exotic species. For microorganisms identification an illustrated fungi key is used.
This way, to reduce or eliminate damage causing microorganisms a seed treatment is required. Chemical treatment is one of the most efficient methods, seeking to reduce future diseases, however, there is no fungicide registered for treatment in native species. Superficial disinfestation with alcohol (70%) and sodium hypochlorite (2.5%, for one minute) is efficient in reducing microorganisms in native species from the Caatinga.
Here are some images of fungi colonizing seeds of native species assessed by our team in the Projeto Caatinga:
PUBLICATIONS
Avaliação sanitária das sementes de Piptadenia stipulacea (Benth.) e Amburana cearensis (Allemão) A. C. Smith
- Authors: Maria Ianca Dias Oliveira, Afonso Luiz Almeida Freires, Luan Vítor Nascimento, Maria Bruna Medeiros Araújo, Márcia Michelle de Queiroz Ambrósio
- Event: III Simpósio Nacional de Estudos para Produção Vegetal no Semiárido (III SINPROVS, 2018)
- Language: Portuguese
- Access: Download here
Sanidade de sementes de Crataeva tapia e Ziziphus joazeiro
- Authors: Maria Ianca Dias Oliveira, Maria Bruna Medeiros Araújo, Luan Vítor Nascimento, Erick Daniel Gomes da Silva, Márcia Michelle de Queiroz Ambrósio
- Event: III Simpósio de Ciências e Tecnologia Agroalimentar (III SIMTAGRO, 2017)
- Language: Portuguese
- Access: Download here
Sanidade de sementes de plantas nativas
- Authors: Mária Bruna Medeiros Araújo, Maria Ianca Dias Oliveira, Mayara Varela N. da Silva, Natália Isabel L. Quirino, Márcia Michelle de Queiroz Ambrósio
- Event: III Simpósio de Ciências e Tecnologia Agroalimentar (III SIMTAGRO, 2017)
- Language: Portuguese
- Access: Download here
Sanidade de sementes de Crataeva tapia e Ziziphus joazeiro (Seed health of Crataeva tapia and Ziziphus joazeiro)
- Authors: Maria Ianca Dias Oliveira, Maria Bruna Medeiros Araújo, Luan Vítor Nascimento, Erick Daniel Gomes da Silva, Márcia Michelle de Queiroz Ambrósio
- Journal: Revista Verde de Agroecologia e Desenvolvimento Sustentável
- Language: Portuguese (abstract in English)
- Access: Revista Verde (v. 12, n. 5, 2017)
Sanitary quality in seeds from Caatinga biome and control methods for fungi
- Authors: Luan Vítor Nascimento, Geovane de Almeida Nogueira, Tatianne Raianne Costa Alves, Maria Bruna Medeiros Araújo, Jeferson Luiz Dallabona Dombroski, Frederico Santos Machado, Márcia Michelle de Queiroz Ambrósio
- Journal: Emirates Journal of Food and Agriculture
- Access: EJFA (v. 31, n. 12, 2019)
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REFERENCES
- BRASIL – MINISTÉRIO DA AGRICULTURA PECUÁRIA E ABASTECIMENTO. Instruções para análise de sementes de espécies florestais. Brasília: MAPA, 2013. p. 97.
- RESENDE, M. L. V.; PÁDUA, M. A.; TOYOTA, M. Manejo de doenças associadas a viveiros florestais. In: DAVIDE, A. C; SILVA, E. A. A. (Eds). Produção de sementes e mudas de espécies florestais. Lavras: UFLA, 2008. v. 1, p. 80-89.