<b>Use of phytoregulators in overcoming macaw palm seed dormancy</b> - doi: 10.4025/actasciagron.v35i4.16385

Abstract

ABSTRACT. The macaw palm is a tropical palm with significant potential for biofuel production; however, seed dormancy is a major factor limiting its agro-industrial use. The present study evaluated the effects of phytoregulators in overcoming macaw palm seed dormancy. We evaluated the effects of immersion in solutions of gibberellic acid (GA 3 ) (0, 2000 and 5000 mg L ) , indole-3-butyric acid (IBA) and benzylaminopurine (BAP) and the effects of repeated applications (one, two or five) of combinations of these phytoregulators. The seeds were sown in vermiculite and incubated in a humid growth chamber at 95 ± 5% relative humidity and 30°C for 18 weeks in all experiments. GA 3 application and removal of the opercular tegument had positive effects on germination, but no significant differences were observed in immersion times for this phytoregulator. The application of IBA and BAP did not influence germination. The application of GA 3 on five separate occasions gave the best results, with 41% germination at the end of the experiment.Keywords: Acrocomia aculeata, germination, GA 3 , IBA, BAP, Arecaceae. ), ácido indol-3-butírico (AIB) e benzilaminopurina (BAP) e o efeito da quantidade de aplicações (uma, duas ou cinco) das combinações dos fitorreguladores. Em ambos os experimentos, as sementes foram plantadas em vermiculita e a germinação foi conduzida em câmara úmida com 95 ± 5 % de UR, a 30°C, durante 18 semanas. Observou-se efeito positivo da aplicação de GA 3 e da retirada do tegumento opercular, não havendo diferenças significativas entre os tempos de imersão. A imersão em AIB e BAP, não influenciou a germinação. A aplicação de GA 3 por cinco vezes separadas proporcionou os maiores percentuais de germinação, atingindo 41% ao final do experimento. Uso de fitorreguladores na superação da dormência em sementes de macaúba

Tissue‐specific hormonal profiling during dormancy release in macaw palm seeds

“…However, it was possible obtain important information concerning the roles of the different seed structures and the different hormone classes in the germinative processes through comparative studies of the tissue‐specific hormonal profile of dormant seeds and those treated to overcome dormancy by the removal of the operculum or by the application of GA 3 . It is noteworthy that while operculum removal rapidly induces germination, GA 3 application induces germination in a longer term (Ribeiro et al , Oliveira et al ), which allowed for evaluating the involvement of hormones in specific tissues in two temporally distinct physiological processes. While operculum removal rapidly induced growth of the embryo during the study period, GA 3 application did not lead to growth, but stimulated the seed to germinate later.…”

“…Dormancy thus favors seed bank formation and seedling development only during subsequent rainy periods (Ribeiro et al , ). Germination control based on the reduced capacity for embryo growth (with the embryo being unable to overcome growth restriction imposed by adjacent tissues) is classified as non‐profound physiological dormancy (Baskin and Baskin ), which can be overcome in some palm species by the removal of the operculum (Hussey , Carpenter et al , Neves et al , Oliveira et al ) or by the application of GA 3 (Nagao et al , Ribeiro et al , Oliveira et al ).…”

Enzyme activity and reserve mobilization during Macaw palm ( Acrocomia aculeata ) seed germination

“…In addition to storage lipids, macaw palm seeds (endosperm and embryo) contain other storage compounds such as protein (Moura et al 2010); the endosperm has cells with thickened noncellulosic and non-lignified walls (Moura et al 2010) composed of non-soluble carbohydrates characteristic of mannan -although how macaw palm seeds use these embryo and endosperm storage compounds and how they are mobilized during germination is still unclear. Macaw palms only multiply through seeds (Ellis et al 1985), but their dormancy (Ribeiro et al 2011;Oliveira et al 2013b) will hinder the establishment of future commercial plantations. Thus, a better understanding of seed physiology and initial seedling development will be important to assure successful germination rates, and while the hormonal dynamics involved in overcoming dormancy and allowing the early germination of macaw palm seeds have recently been determined (Bicalho et al 2015;Ribeiro et al 2015), the physiology of reserve mobilization during germination and post-germination events is still poorly understood.…”

THE ROLE OF NAA, GA3, ACTIVATED CHARCOAL, AND SUCROSE ON ZYGOTIC EMBRYOS CULTURE OF HYBRID OG OPEN POLLINATED CLONE (Elaeis guineensis JACQ. X Elaeis oleifera)

“…Dari segi persentase perkecambahan, perlakuan A6 menghasilkan persentase perkecambahan tertinggi dibandingkan dengan perlakuan lainnya (Gambar 4), namun kecepatan berkecambah yang paling lambat (Tabel 1, Gambar 3). Persentase perkecambahan yang tinggi disebabkan oleh penambahan zat pengatur tumbuh pada media yang berupa giberelin dan auksin NAA, pemberian ZPT secara tunggal maupun kombinasi berperan positif terhadap perkecambahan (Oliveira et al, 2013). Penggunaan GA maupun NAA telah diteliti untuk kultur embrio 3 kelapa sawit Dura (Suranthran et al, 2011), dan GA 3 juga digunakan untuk perkecambahan tanaman palmae lainnya diantaranya macaw palm (Acrocomia aculeate Jacq.)…”