scholarly journals Modelling transport of inhibiting and activating signals and their combined effects on floral induction: application to apple tree

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fares Belhassine ◽  
Damien Fumey ◽  
Jérôme Chopard ◽  
Christophe Pradal ◽  
Sébastien Martinez ◽  
...  
2019 ◽  
Vol 10 ◽  
Author(s):  
Fares Belhassine ◽  
Sébastien Martinez ◽  
Sylvie Bluy ◽  
Damien Fumey ◽  
Jean-Jacques Kelner ◽  
...  

Author(s):  
José Luiz Petri ◽  
André Amarildo Sezerino ◽  
Cristhian Leonardo Fenili

Aims: Research on alternate bearing in apple trees is usually focused on chemical                thinning techniques, but in recent decades synthetic bioregulators have proven to be             effective in promoting or inhibiting floral induction in apple trees. However, the results can be variable since some cultivars are prone to alternation, as Fuji and its clones. The objective of the present study was to observe the effect of naphthalene acetic acid (NAA), Ethephon,                   and their combinations in the formation of flowering buds avoiding flowering alternation, in Cv, Fuji Suprema. Place and Duration of Study: The experiments were carried out in southern Brazil, municipality of Caçador / SC, during the cycles from 2014 to 2019, in the cultivar Fuji Suprema / Marubakaido / M9, with 12 years old. Methodology: Several variables were evaluated such as flowering return, fruit set, yield, number of fruits per plant, average fresh fruit mass, and biennial bearing index (BBI). Results: The results were variable and showed that NAA and Ethephon had little effect on reducing flowering alternation when applied during the vegetative phase of the Fuji Suprema apple tree. After years of high productivity, there was a decrease in the yield, even in the treatments of NAA and Ethephon. Ethephon or its combination with NAA has a thinning effect, but without influence on the return of flowering.


2000 ◽  
Vol 70 (3) ◽  
pp. 92-101 ◽  
Author(s):  
Burim Ametaj ◽  
Brian Nonnecke ◽  
Ronald Horst ◽  
Donald Beitz

Individual and combined effects of several isomers of retinoic acid (RA) and 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) on interferon-gamma (IFN-gamma) secretion by blood mononuclear leukocytes (MNL) from nulliparous and postparturient Holstein cattle were evaluated in vitro. In the first experiment, effects on incubation period (24 to 72 hours) and time of supplementation (0 to 32 hours) with all-trans, 9-cis, 13-cis-, and 9,13-dicis-RAs (0 to 100 nM) on IFN-gamma secretion by pokeweed mitogen (PWM)-stimulated (0 and 10 mug/ml) MNL from nulliparous cattle were evaluated. In the second experiment, MNL from postparturient cows (bled at 0, 2, 4, and 16 days postpartum) were stimulated with PWM (0 and 10 mug/ml) in the presence of RA isomers (9-cis- or 9,13-dicis-RA; 0 to 100 nM), 1,25-(OH)2D3 (0 to 100 nM), or with combinations of these metabolites. The results show that individual isomers of RA had no effect on IFN-gamma secretion by PWM-stimulated MNL from nulliparous or postparturient cows. Furthermore 1,25-dihydroxyvitamin D3 inhibited IFN-gamma secretion by MNL from nulliparous and postparturient dairy cows; however, the degree of inhibition was greater when 9-cis- and 9,13-dicis-RA were also present in the cultures. Finally mononuclear leukocytes from postparturient dairy cows produced substantially less IFN-gamma than did MNL from nulliparous cattle. It is concluded that retinoic acids individually did not affect the capacity of leukocytes from dairy cattle to secrete IFN-gamma. This result is in marked contrast to studies in monogastric species indicating that RAs inhibit IFN-gamma secretion by peripheral blood T cells. Inhibition of IFN-gamma secretion by 1,25-(OH)2D3 was potentiated by 9-cis- and 9,13-di-cis-retinoics acids, suggesting that an excess of dietary vitamins A and D may compromise further the naturally immunosuppressed postparturient dairy cow. Additional research is necessary to determine if the combined effects of these metabolites on IFN-gamma secretion represent an increased susceptibility of the dairy cow to infectious diseases during the periparturient period. Lower secretion of IFN-gamma by MNL from postpartutient dairy cows, relative to nulliparous cattle, suggests that recently-calved cows are naturally immunosuppressed.


2018 ◽  
Vol 44 (2) ◽  
pp. 277-285 ◽  
Author(s):  
Carine Signoret ◽  
Ingrid Johnsrude ◽  
Elisabet Classon ◽  
Mary Rudner
Keyword(s):  

1879 ◽  
Vol 7 (167supp) ◽  
pp. 2651-2651
Keyword(s):  

2015 ◽  
Vol 53 (12) ◽  
Author(s):  
M Krawczyk ◽  
M Rau ◽  
J Schattenberg ◽  
H Bantel ◽  
A Pathil ◽  
...  
Keyword(s):  

2019 ◽  
Author(s):  
Z Bari ◽  
I Maleki ◽  
M Hadizadeh ◽  
H Fakheri ◽  
SM Valizadeh ◽  
...  

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