Dormancy in native fruit seeds of the Brazilian South Region

Abstract

The aim of the present study was to investigate whether seeds from six native fruit species ofthe South Brazilian regionhad any type of dormancy, as well as, to verify if they havephotoblastism. The work was carried out at the Plant Physiology Laboratoryofthe Federal Technological University of Paraná –Câmpus Dois Vizinhos, Paraná State, Brazil. The influence of photoperiod factors and techniques for overcoming dormancy were tested on the germination of Eugenia uniflora L.(Surinan cherry), Plinia peruviana(native jabuticaba), Plinia cauliflora(hybrid jabuticaba), Eugenia involucrataDC. (Rio Grande cherry), Myrcianthes pungens(guabiju) and Campomanesia guazumifolia(sete capoteiro). The seeds were exposed in a condition of total darkness or photoperiod of 24 hours, being the levels of one of factors tested. The techniques for breaking dormancy tested werethe immersion in gibberellic acid solution (200 mg L-1); stratification at 5°C for 30 days; immersion in water at room temperature for 24 hours; immersion in hot water (80°C) for five minutes; immersion in sulfuric acid solution (96%) for five minutes; and manual physical scarification with 120 grit sandpaper. The seeds were also tested without using any technique, making up the controlstreatments with or without light. The experimental design was completely randomized, in a 2 x 7 factorial scheme (luminosity x treatment for breaking dormancy), with four replications of 100 seeds. After 60 days, germination (%), percentage of accumulated germination, germination speed index and average germination time were analyzed. The seeds of most of the studied native species do not present dormancy or the effect of photoblastism, except for “sete capoteiro”seedswho are supposed to have morphophysiological dormancy, with negative photoblastism. The use of hot water or sulfuric acid in the seeds of native fruit trees is not recommended.

Effects of seed size and toucan regurgitation on the germination of the tropical tree Eugenia uniflora

“…Our results are similar to other studies on Eugenia species (Amador and Barbedo, 2015). Eugenia uniflora seeds have no dormancy period and are sensitive to desiccation (Stricker and Stiling, 2013;Pavithra et al, 2020;Pirola et al, 2021). Typically, seeds sensitive to desiccation, which are more common in tropical systems, are larger, have a greater moisture content, and have faster germination rates (Bazzaz and Pickett, 1980;Vázquez-Yanez and Orozco-Segovia 1993;Daws et al, 2005).…”

Dormancy overcoming in seeds of Myrciaria glomerata O. Berg.

“…Stimulate ® has been used in several crops with satisfactory results regarding shoot growth, as observed for Hymenaea courbaril L. (SMIDERLI et al, 2022). Hormonal treatment in seeds positively contributed to germination and seedling formation of Myrtaceae species (HOSSEINI et al, 2020;PIROLA et al, 2021), which is similar to what was observed for M. glomerata. For seeds of Physalis angulata L., an increase in the first germination count, germination speed index, and seedling formation was observed when seeds were pre-imbibed in Stimulate ® solution 1.50% (SANTIAGO et al, 2019).…”

“…Similarly, Pirola et al (2021) reported that it is not recommended to use water at 80 ºC and sulfuric acid to overcome the dormancy of seeds of Eugenia uniflora L., Plinia peruviana (Poir.) Govaerts, Plinia cauliflora (Mart.)…”

Campomanesia guazumifolia (Cambess.) O. Berg: Ethnobotany, cultivation and potentialities

“…The seeds of C. guazumifolia present negative photoblastism with morphophysiological dormancy, and using hot water or sulfuric acid in the seeds is not recommended (Pirola et al, 2021). The seeds are recalcitrant, do not support desiccation with short post-harvest longevity, and it is recommended that the seeds be washed with running water, keeping them in a humid place with planting after a short storage time (MIRANDA et al, 2020;MOSER et al, 2022).…”