OVERCOMING SEED DORMANCY IN Annona macroprophyllata AND Annona purpureaUSING PLANT GROWTH REGULATORS

Abstract

Some Annonaceae seeds are known to exhibit dormancy mechanisms ranging from possible seed coat impermeability to physiological dormancy. Thus, the aim of this study was to evaluate the effects of gibberellin (GA) GA3 and GA4+7 + benzyladenine (GA4+7 + BA) application in seeds of Annona macroprophyllata Donn. Sm (papausa) and Annona purpurea Moc. & Sessé ex Dunal (chincuya). The experiment was performed by the application of GA3 and GA4+7 + BA on seeds in concentrations of 0, 200, 400, 500, 600, 800 and 1000 mg L-1. The regulators broke the dormancy of both species. However, application of the GA4+7 + BA mixture had more significant results, with greater increases in germination in A. macroprophyllata than in A. purpurea. Treatments that promoted the highest germinations were GA4+7 + BA at a concentration of 200 mg L-1 for A. macroprophyllata (77%) and 200 mg L-1 of GA4+7 + BA and 500 mg L-1 of GA3 for A. purpurea (30% and 29%, respectively). Rate index, mean time and frequency of germination were distinct for both species and both treatments. Although both GA3 and GA4+7 + BA promote germination, the GA4+7 + BA mixture was more effective than GA3 to overcoming seed dormancy of both species, A. purpurea has a harder dormancy than A. macroprophyllata

Propagation of Annonaceous plants

“…Table 2 shows treatments for overcoming dormancy of anonaceous plants, in most cases with the use of plant regulators, either alone or in mixtures. Annona macroprophyllata, A. purpurea and Xylopia aromatica seeds respond to the application of isolated plant regulators such as GA 3 , although they present higher germination rates when mixtures are used to overcome dormancy (200 to 250 mg L -1 of GA 4+7 + benziladenine), with germination rate of 77%, 30% and 63%, respectively (SOCOLOWSKI, CICERO, 2011;FERREIRA et al, 2016).…”

“…The Annonaceae family has pantropical distribution and is one of the oldest existing flower groups, with basal lineage estimated to be 112 million years old, with approximately 2100 species and 129 genera (STEVENS, 2016), significantly contributing to the diversity of forests, both for its abundance and its phenological characteristics that allow the survival of organisms that live with it (GOTTESBERGER, 2014;GONZÁLEZ-ESQUINCA et al, 2016). Four species have economic importance, Annona muricata L. (soursop), A. squamosa L. (custard apple), A. cherimola Mill.…”

Oxidative metabolism altered by plant growth regulators in atemoia seeds (Annona x atemoya Mabb.) ‘Thompson’

“…Since they are directly involved in the cell division process (MIRANSARI; SMITH, 2014), cytokinins have been commonly used in treatments combined with gibberellins to overcome dormancy in Annonaceae species (SOCOLOWSKI;CICERO, 2011;CORSATO et al, 2012;FERREIRA et al, 2016). This beneficial effect could be demonstrated when cytokinin was used in combination with the highest GA 3 concentration ( Figure 4B).…”

Optimum Sample Size in the Germination of Atemoya Seeds (Annona× atemoya Mabb.)

“…Its seeds, as well as the seeds of other Annonaceae, have been studied in several aspects, both from the technological point of view, for the production of seedlings and for the understanding of physiological processes, such as dormancy (Ferreira et al, 2016;Carvalho et al, 2018), desiccation tolerance (Corsato et al, 2013) and synthesis of specialized metabolites during germination (De La Cruz & González-Esquinca, 2012). However, for germination tests, there is no standardization in relation to the number of seeds per sampling unit and number of replicates used: Carvalho et al (2018) used 5 replicates of 25 seeds in Annona × atemoya (cv Thompson and Gefner), Menegazzo et al (2012) performed tests with 4 replicates of 20 seeds of A. squamosa.…”