DORMANT RUPTURE AND HORMONES LEVELS IN JATROPHA CURCAS L. AND JATROPHA MACROCARPA GRISEB SEED

• DOI: 10.37572/EdArt_21122150714

• Palavras-chave: Dormancy, Phytohormones, Seeds, Jatropha

• Keywords: Dormancy, Phytohormones, Seeds, Jatropha

• Abstract:

  J. curcas L. and J. macrocarpa Griseb. are perennial shrub with the greatest importance mainly from its biofuel potential. Several authors consider that seed tegument is one of the factors that induce dormancy. The aim of the work was to study the role of tegument and abscisic acid (ABA) y jasmonic acid (JA) in dormancy and germination in these species. J. macrocarpa present dormancy since it does not germinate by traditional methods. Consequently, seeds of J. macrocarpa were subjected to different treatments to break seed dormancy: T1) Control; T2) Scarification with sandpaper; T3) Total elimination of the tegument; T4) Immersion in boiling water; T5) Alternating hot and cold water; T6) Immersion in concentrated H2SO4 for 15 min; T7) Immersion in concentrated  H2SO4 for 30 min; T8) Stratification in wet and cold paper; T9) Stratification in moist sand and cold. After each treatment the seeds were placed in Petri dishes containing distilled water at 30°C temperature. Germination percentages (GP) were determined during 30 days. We used 20 seeds by treatment, with three replications each one. ABA and JA were extracted and purified from both Jatropha species tegument. These hormones were identified and quantified from tissue using reverse-phase high-performance liquid chromatography (HPLC)-mass spectrometry (MS). The total removal of tegument showed a 50% increase in germination percentage, with the other treatments achieved between 0-10%. JAs were the most abundant compound detected in tegument. ABA level was higher in J. curcas (628%) than in J. macrocarpa, for this reason we assume that the tegument ABA level is not directly linked to germination and/or dormancy of these Jatropha species. In contrast, level of JAs was higher in J. macrocarpa (101%) than in J. curcas. In effects JA could have a roll in inhibition of germination of J. macrocarpa seeds.

• Número de páginas: 20