Sodium hypochlorite for removal of the sarcotesta from newly extracted and stored papaya seeds

Abstract

-The objective of this study was to evaluate the effect of sodium hypochlorite on removal of the sarcotesta and the germination process of newly harvested papaya seeds before and after storage for 44 days. Nine treatments were evaluated using a completely randomized design with six treatments in a split plot arrangement and three additional treatments (control), each treatment with eight replications. The plots consisted of methods for breaking dormancy: M1 -sieve method + drying to 7%, M2 -sieve method + drying to 7% + NaOCl, and M3 -NaOCl + drying to 7%. The split plots consisted of different storage periods (0 and 44 days). The three additional treatments consisted of A -NaOCl at 6% for 12 hours, B -sieve method, and C -intact seeds in running water for 24 hours. Germination and the first count of germination were evaluated. Results showed that sodium hypochlorite is effective in removal of the sarcotesta, but there is a negative effect on germination. Storage for 44 days also had a negative effect on germination. Removal of the sarcotesta by the sieve method followed by drying to 7% moisture content was effective in promoting germination of papaya seeds.Index terms: Carica papaya L., active chlorine, germination.Hipoclorito de sódio na remoção da sarcotesta de sementes de mamão recém-extraídas e armazenadas RESUMO -Objetivou-se avaliar o efeito do hipoclorito de sódio na retirada da sarcotesta e no processo germinativo de sementes de mamão recém-extraídas, previamente armazenadas, antes e após armazenamento por 44 dias. Foram avaliados nove tratamentos segundo delineamento inteiramente casualizado, sendo seis tratamentos no esquema de parcelas subdivididas e três tratamentos adicionais (controles). As parcelas foram constituídas pelos métodos para quebra de dormência: M1 -Método da Peneira + Secagem a 7%; M2 -Método da Peneira + Secagem a 7% + NaOCl; e M3 -NaOCl + Secagem a 7%. As subparcelas pelo tempo de armazenamento (zero e 44 dias). Os três tratamentos adicionais consistiram em: A -NaOCl a 6% por 12 horas; B -Método da Peneira e C -Sementes intactas em 24 horas em água corrente. Avaliou-se o teste de germinação e a primeira contagem do teste de germinação. O uso do hipoclorito de sódio é eficiente para retirar a sarcotesta, porém afeta negativamente a germinação. O armazenamento por 44 dias é prejudicial à germinação. A remoção da sarcotesta pelo método da peneira, seguida da secagem até 7% de teor de água foi eficiente para propiciar a germinação das sementes de mamão.Termos para indexação: Carica papaya L., cloro ativo, germinação.

Germination and growth improvement of papaya utilizing oxygen (O2) plasma treatment

“…However, papaya generally suffers from several quality issues, such as different sizes and low germination rate at the initial stage [1,5]. The low and irregular germination percentage of papaya seeds can be attributed to the seed encapsulated within sarcotesta (aril, or outer seed coat forms the outer integument), preventing the seed germination [3,5,6]. In other cases, the dormancy was still reported after removing sarcotesta because of the presence of phenolic compounds and phytohormones inside sarcotesta, which acts as an inhibitor in germination [3,5,6].…”

“…The low and irregular germination percentage of papaya seeds can be attributed to the seed encapsulated within sarcotesta (aril, or outer seed coat forms the outer integument), preventing the seed germination [3,5,6]. In other cases, the dormancy was still reported after removing sarcotesta because of the presence of phenolic compounds and phytohormones inside sarcotesta, which acts as an inhibitor in germination [3,5,6]. Besides, other factors affect the germination rates of papaya, namely, moisture content, temperature, light, and storage time of seeds [5].…”

“…Hence, ongoing research has been carried out to break the latency and improve the germination of papaya seeds. Some of the common methods used scarification such as, nitric acid, hydrochloric acid, concentrated sulfuric acid, sodium hypochlorite (NaOCl) [6], and gibberellic acid (GA) to break this latency [1,3]. Scarification is a process that scratches, breaks, softens the outer layer of the seeds to make them permeable to gases and water to stimulate germination.…”

Pengaturan Lingkungan Inkubasi Suhu dalam Upaya Meningkatkan Daya Tumbuh Benih Carica

“…Sarcotesta yang tetap dipertahankan selama proses pengeringan benih menimbulkan induksi dormansi (Zainudin and Adini, 2019). Aplikasi NaOCl pada benih Carica mampu mengatasi sarcotesta namun berdampak negatif terhadap daya kecambah benih dibandingkan dengan dilakukan pengeringan sampai kadar air benih 7% dengan hasil masing-masing 88% dan 35% (Jesus et al, 2016). Perlakuan pematahan dormansi yang efektif perlu dikembangkan untuk mengatasi kendala dalam perkecambahan yang mempunyai viabilitas rendah.…”

Physiological maturation and postharvest resting of papaya fruits and seeds in agroecological transition

“…The location of the seed inside the fruit may influence its internal morphology, thereby affecting the physical and physiological quality. According to Jesus et al (2016), at this stage, the removal of the sarcotesta may simultaneously promote the removal of compounds that could be used at the later stages by seeds for structuring the cell walls and/or the germ-promoting substances in sarcotesta, endosperm and embryo during the germination. We found that the resting in the laboratory environment at room temperature induced the maximum seed germinability (Tables 1 and 2), which would presumably be associated with a change between the promoters and inhibitors of germination caused by presence of seeds inside the fruit during the ripening phase.…”