No abstract

The drought stress resistance is a characteristic of the desert rose and its estimable beauty flowers, which gave it great relevance in the ornamental market. However, the desert rose production and germination is hampered by possible sterility of their male and female flowers and frequent problems in pollination, so the tissue culture is a promising alternative to the propagation of these plants. This study aimed to evaluate the effect of gibberellic acid on four commercial varieties of desert rose (Adenium obesum) cultivated in vitro. The seeds of the varieties 'Orange Pallet', 'Carnation violet', 'Diamond ring' and 'Vermiliont' were sterilized and inoculated on Water + Agar (T0), medium MS (T1), ½ MS (T2), MS + 0.25 mg L -1 GA 3 (T3), MS + 0.5 mg L -1 GA 3 (T4), ½ MS + 0.25 mg L -1 GA 3 (T5), ½ MS 0.5 mg L -1 GA 3 (T6). The seeds germination of A. obesum was initiated on the fourth day of cultivation and on the tenth day was possible to observe the expansion of the cotyledons and leaf expansion with subsequent development of early secondary root. The 'Orange pallet' variety germinated 100% of seeds on water + agar and MS ½ + 0.5 mg L -1 of GA 3 . For 'Diamond Ring' and 'Carnation violet' the highest rate of germination occurred in treatments MS ½; 0.25 mg L -1 GA 3; MS + 0.5 mg L -1 GA 3 MS ½ + 0.5 mg L -1 GA 3 averaging 80% and 70%, respectively. For 'Vermiliont' the best response was in MS and MS ½ + 0.5 mg L -1 GA 3 ranging between 70-90% germinated embryos. It was registered different malformations in all treatments like absence of roots and apexes during seedling development. The concentrations of GA 3 did not affect significantly the seed germination.

Sour passion fruit (Passi ora edulis Sims) has economic and social relevance and is an alternative crop mainly for family farming agriculture. The aim of this work was to evaluate the in uence of polyethylene glycol (PEG) on the maturation of somatic embryos associated with differential accumulation of proteins and changes in the endogenous polyamine (PA) content during somatic embryogenesis of P. edulis 'UENF Rio Dourado'. Maturation of somatic embryos was performed using embryogenic callus in MS culture medium with PEG 6% or without PEG (control). PEG 6% promoted the maturation of a signi cantly higher number of somatic embryos at globular and cotyledonary stages when compared to the control treatment. The higher somatic embryo formation induced by PEG 6% was associated with an increase in endogenous contents of free spermine, a PA with an important role in the maturation process of somatic embryogenesis cultures. PEG also promoted a signi cantly higher content of putrescine and total free PAs at the end of maturation, which was relevant for the increase in the number of somatic embryos.Comparative proteomic analyses of PEG 6%/control revealed that PEG 6% treatment induced the upaccumulation of proteins related to the ATP metabolic, glycolytic, generation of precursor metabolite energy, and the response to light stimulus processes. The down-accumulated proteins were related mainly to the cellular metabolic process. The use of PEG induced the maturation and development of somatic embryos of P. edulis Sims 'UENF Rio Dourado' by the differential accumulation of proteins and modulation of endogenous contents of PAs.

Sour passion fruit (Passiflora edulis Sims) has economic and social relevance and is an alternative crop mainly for family farming agriculture. The aim of this work was to evaluate the influence of polyethylene glycol (PEG) on the maturation of somatic embryos associated with differential accumulation of proteins and changes in the endogenous polyamine (PA) content during somatic embryogenesis of P. edulis ‘UENF Rio Dourado’. Maturation of somatic embryos was performed using embryogenic callus in MS culture medium with PEG 6% or without PEG (control). PEG 6% promoted the maturation of a significantly higher number of somatic embryos at globular and cotyledonary stages when compared to the control treatment. The higher somatic embryo formation induced by PEG 6% was associated with an increase in endogenous contents of free spermine, a PA with an important role in the maturation process of somatic embryogenesis cultures. PEG also promoted a significantly higher content of putrescine and total free PAs at the end of maturation, which was relevant for the increase in the number of somatic embryos. Comparative proteomic analyses of PEG 6%/control revealed that PEG 6% treatment induced the up-accumulation of proteins related to the ATP metabolic, glycolytic, generation of precursor metabolite energy, and the response to light stimulus processes. The down-accumulated proteins were related mainly to the cellular metabolic process. The use of PEG induced the maturation and development of somatic embryos of P. edulis Sims ‘UENF Rio Dourado’ by the differential accumulation of proteins and modulation of endogenous contents of PAs.