Seed weight of Xylopia aromatica (Annonaceae): quality evaluation from X-ray and seedling emergence

Abstract

Xylopia aromatica (Lam.) Mart. (Annonaceae) is a native species of the Brazilian Savannah ("Cerrado") region, recommended for the recovery of degraded areas and also for medicinal use. Seeds of some species of the Annonaceae require a long period to germinate and many studies have focused on determining methods which can rapidly analyze seed quality. The objective of this study was to evaluate the quality of Xylopia aromatica (Lam.) Mart. seeds in accordance to their weight, through X-ray images and emergence test. Seeds were collected from dehiscent follicles with a blower and one portion was separated into weight categories: very light seeds, light seeds and heavy seeds. Another seed portion was separated in water by their density, into those that sank and those that floated. The seeds from each weight category were weighed and X-rayed. A further seed portion from the categories (separated by blower and in water) was also placed in 500 mg L -1 of a solution [gibberellin 4 (GA 4 ) + gibberellin 7 (GA 7 ) and cytocinin] to overcome dormancy and was later sown in soil taken from the "Cerrado". The internal seed morphology and seedling emergence of X. aromatica were influenced by seed weight. The elimination of badly formed and insect-infested seeds improved the physiological potential of the seed lot. The X-ray test can efficiently evaluate seed quality but does not permit a visualization of the embryos.

Avaliação da morfologia interna de sementes de Acca sellowiana O. Berg por meio de análise de imagens

“…É possível que o menor volume de tecidos de reserva possa prejudicar a germinação, como foi relatado por Socolowski et al (2011) para sementes de Xylopia aromatica. Esses autores verificaram, por meio da análise de imagens de raios X, que sementes de maior massa possuíam endosperma bem formado e que houve relação direta entre esta característica e os resultados de emergência de plântulas.…”

“…Várias pesquisas têm demonstrado que a análise de imagens de raios X possibilita a identificação de danos que afetam a qualidade de sementes de espécies florestais, como Ginkgo biloba (SALINAS et al, 2012), Tabebuia heptaphylla (AMARAL et al, 2011), Xylopia aromatica (SOCOLOWSKI et al, 2011), Tecoma stans (SOCOLOWSKI et al, 2008), Eremanthus erythropappus (FEITOSA et al, 2009), Cedrela fissilis (MASSETO et al, 2008), Platypodium elegans (SOUZA et al, 2008), Cecropia pachystachya (PUPIM et al, 2008), Eugenia pleurantha (MASSETO et al, 2007) Germoplasma da Empresa de Pesquisa Agropecuária e Extensão Rural de Santa Catarina (Epagri), os quais estavam armazenados em sacos de papel em câmara fria (15-18°C/45-50%UR). As sementes foram analisadas pelo teste de raios X e, posteriormente, foram conduzidas ao teste de germinação, doze meses após a colheita dos frutos e a extração das sementes.…”

Weight is a key factor in the physiological quality of Parapiptadenia rigida seeds

“…In general, high weight seeds exhibit higher germination capacity when compared to low weight seeds when exposed to low stress conditions (Genna & Pérez, 2016). For some forest species, it has been shown that germination and vigor of seedlings are related to seed weight (or size) (Du & Huang, 2008;Owoh et al, 2011;Socolowski et al, 2011a;Landergott et al, 2012;Kuniyal et al, 2013), but other species show no influence (Khera et al, 2004;Freire et al, 2015).…”

Radiographic analysis for the evaluation of polyembryony in Swingle citrumelo seeds

“…The X-ray test has been used in seed researches since the 1950s, when Simak and Gustafsson (1953) demonstrated its potential for evaluating the quality of seeds of Pinus sylvestris L. Thus, this technique was used in genetic improvement works, allowing the detection of abnormalities in embryos and the determination of their development stage, and also in the isolation of mutant embryos of Arabidopsis thaliana (Bino et al, 1993). The technique also allowed to correlate the internal morphology of seeds with the germination or with the morphology of seedlings from several agriculture or forest species (Machado and Cicero, 2003;Oliveira et al, 2003;Pupim et al, 2008;Pinto et al, 2009;Carvalho et al, 2010;Gagliardi and Marcos-Filho, 2011;Socolowski et al, 2011;Kobori et al, 2012;Silva, et al, 2013;Rocha et al, 2014;Arruda et al, 2016).…”