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PRINCÍPIOS ATIVOS INIBIDORES DA GERMINAÇÃO IN VITRO DE PÓLEN DE MACIEIRA COMO POTENCIAIS RALEANTES DE FLORAÇÃO
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The objective of this work was to evaluate the feasibility of using ammonium thiosulfate as a chemical blossom thinner in 'Maxi Gala' apple (Malus domestica) trees and its effects on fruit quality. The experiment was carried out in an experimental orchard in the Southern Brazil, in a randomized complete block design, with five replicates. Ammonium thiosulfate was sprayed on the apple trees at the full bloom stage, at 0, 1.5, 2.5, and 3.5%. Evaluations were performed for the effects on crop load, fruit set, yield efficiency, and fruit quality parameters such as weight, shape, total soluble solids, seed number, flesh firmness, color, and russeting occurrence. Ammonium thiosulfate at 2.5% is effective to reduce crop load and to improve fruit quality. The thinning effect of ammonium thiosulfate is not dependent on the weather conditions during the crop season. The rate of 3.5% of ammonium thiosulfate causes overthinning and does not result in the improvement of fruit quality.
Abscission of apple (Malus xdomestica Borkh.) fruitlets is associated with increased ethylene evolution, although the role of ethylene is not clear. Fruit let ethylene evolution and expression of ethylene-related MdACO1, MdACS5A, and MdACS5B genes were followed in the abscission zone (AZ) and fruit cortex (FC) of king and lateral fruitlets of 'Golden Delicious'/M.9 after spraying with 15 mg-L- 1 naphthalene acetic acid (NAA), 150 mg-L- 1 6-benzyladenine (BA), 500 mg-L- 1 ethephon, and after 3 days 96% shading, all applied at a mean 10 mm fruit let diameter. Lateral fruitlets (LF) were more susceptible to abscission after treatment with chemical thinners or shading compared with king fruitlets (KF) in which only ethephon-treated KF abscised later. On KF, only ethephon increased fruit let ethylene evolution, MdACO1 expression in FC and AZ 8 days after treatment (DAT), and abscission of KF 10 DAT, but the other treatments did not. Although ethephon increased MdACO1 expression in FC of KF 8 DAT, the expression of MdACS5A and MdACS5B remained unchanged. On LF, all treatments at 8 DAT increased ethylene evolution and MdACO1 expression in FC and enhanced abscission 10 to 22 DAT. Expression of MdACS5A and MdACS5B in FC of LF 8 DAT was expressed at a lower level compared with MdACO1. In the AZ of both KF and LF, only ethephon increased expression of MdACO1, MdACS5A, and MdACS5B.
Background: In commercial almond [Prunus dulcis (Mill.) D.A. Webb] orchards in Chile, the percentage of fruit set is low and commonly reaches 5–30%. As almond trees bloom during a cool period and also suffer from self-incompatibility, any factor that can improve pollination, pollen germination and pollen tube growth or extend the effective pollination period, such as the application of plant bioregulators (PBRs), should be beneficial for fruit production.
Results: Three plant bioregulators (PBRs): brassinolide (BL), gibberellic acid (GA3) and kinetin (KN) were evaluated for pollen germination and pollen tube growth in vitro, as well as for fruit set in almond cultivars Non Pareil and Carmel, in central Chile, during the 2013 and 2014 seasons. For pollen germination in vitro, the BL concentration of 10 mg L-1 had the highest value in Non Pareil (97.7%), after 4 h germination in 2014 growing season (the control was 90.9%). KN at a concentration of 50 μL L-1 induced the longest pollen tube growth of 1243.4 μm in Carmel after 8 h germination in 2013 (the control was 917.7 μm). In Non Pareil, the highest percentage of fruit set (31.0%) was achieved in 2014 by spraying during bloom at pink bud stage with KN at 50 μL L-1 (the control was 16.7%).
Conclusions: A significant favorable effect of the tested PBRs was observed in pollen germination and pollen tube growth in vitro, as well as on fruit set in Non Pareil and Carmel almonds.
Sisvar is a statistical analysis system with a large usage by the scientific community to produce statistical analyses and to produce scientific results and conclusions. The large use of the statistical procedures of Sisvar by the scientific community is due to it being accurate, precise, simple and robust. With many options of analysis, Sisvar has a not so largely used analysis that is the multiple comparison procedures using bootstrap approaches. This paper aims to review this subject and to show some advantages of using Sisvar to perform such analysis to compare treatments means. Tests like Dunnett, Tukey, Student-Newman-Keuls and Scott-Knott are performed alternatively by bootstrap methods and show greater power and better controls of experimentwise type I error rates under non-normal, asymmetric, platykurtic or leptokurtic distributions.
In this review we address the question of how the tip growing pollen tube achieves its rapid rate of elongation while maintaining an intact cell wall. Although turgor is essential for growth to occur, the local expansion rate is controlled by local changes in the viscosity of the apical wall. We focus on several different structures and underlying processes that are thought to be major participants including exocytosis, the organization and activity of the actin cytoskeleton, calcium and proton physiology, and cellular energetics. We think that the actin cytoskeleton, in particular the apical cortical actin fringe, directs the flow of vesicles to the apical domain, where they fuse with the plasma membrane and contribute their contents to the expanding cell wall. While pH gradients, as generated by a proton-ATPase located on the plasma membrane along the side of the clear zone, may regulate rapid actin turnover and new polymerization in the fringe, the tip-focused calcium gradient biases secretion towards the polar axis. The recent data showing that exocytosis of new wall material precedes and predicts the process of cell elongation provides support for the idea that the intussusception of newly secreted pectin contributes to decreases in apical wall viscosity and to cell expansion. Other prime factors will be the localization and activity of the enzyme pectin methyl-esterase, and the chelation of calcium by pectic acids. Finally we acknowledge a role for reactive oxygen species in the control of wall viscosity.
The objective of this study was to investigate the mechanism of action of the treatments: Ammonium thiosulfate (ATS), benzyladenine (BA), GA4+7+BA, foliar fertilizer, lime sulphur (LS), LS + mineral oil, mineral oil, NAA, urea, and vegetal oil in the interaction of these treatments with: 1) pollen grain germination, 2) stigma/style pollen tube (PT) development, and 3) the effectiveness of the treatments in field conditions on decreasing crop load and enhancing fruit quality of ‘Fuji More’ apple trees. In experiment 1 it was evaluated the effect of the treatments in inhibiting the in vitro pollen germination of ‘Maxi Gala’ apples. In Experiment 2 it was evaluated in vivo ‘Maxi Gala’ pollen germination in ‘Fuji’ pistils to assess the effect of the treatments applied 24 h before and after the pollination, in three portions of the styles. In experiment 3 it was evaluated the effect of the treatments sprayed at 90% full bloom in a commercial ‘Fuji More’ apple orchard on the variables: fruit set, crop load, yield efficiency, mean fruit weight, cluster size, fruit height and diameter, total soluble solids, flesh firmne, mean seed number, skin russet and red color. ATS reduced in vitro pollen germination and caused the greatest damage to the stigmas/styles, while in the field, it was effective to reduce crop load. Treatments containing LS were the most effective to reduce in vitro pollen germination, but the in vivo essay, mode of action seemed to be related to arresting pollen tube growth, and in the field these treatments caused severe russeting. Mineral and vegetal oil do not have direct effect on pollen germination, but arrest pollen tube growth, and in field conditions mineral oil and ATS reduced crop load. All growth regulators (BA, GA4+7 + BA, and NAA decreased greatly crop load and increased fruit weight and quality.
Fruit thinning is an activity that is normally done over a relatively wide time period from bloom until fruit grow to above 18 mm in diameter. Manual, chemical and mechanical methods are used, alone or in combination, but the method chosen depends upon species, climatic conditions and the historic reliability of the proposed method. Pome-fruit are most frequently thinned using chemical methods whereas stone-fruit are routinely thinned manually. The chemicals most frequently chosen to thin pome-fruit, and apple in particular, at bloom are 2-chlorophosphonic acid (ethephon), ammonium thiosulfate (ATS), oil and lime sulfur while the auxins naphthaleneacetic acid (NAA) and naphthaleneacetamide (NAAm), the cytokinin 6- benzyladenine (6-BA) and, in some locations, the insecticide carbaryl are applied at the fruitlet stage. Stone-fruit and in particular peach are most frequently thinned at bloom using bloom thinners (caustic compounds, dormancy breaking agents, oils) and fruitlet thinners are infrequently used. In this category, ethephon has been tested but it is not been shown to be very reliable and there are undesirable side effects that do not allow this formulation be used as a routine practice. Recently mechanical thinning has emerged as potential viable option for thinning both pome and stone fruit using the Darwin and Baum machines. The precision and predictability of thinners and thinner responses have been significantly improved using newly developed modeling systems that monitor fruit growth or estimate the carbon balance within a tree. In addition, new molecules have emerged and are under evaluation that shows real promise as new chemical thinners. These include the photosynthesis inhibitor metamitron (Brevis) and two naturally occurring compounds, abscisic acid (ABA) and 1-aminocyclopropane-1- carboxylic acid (ACC).
Efeito da adição de uréia e sulfato de amônio sobre o pH e nitrificação em um solo ácido. Anais da Escola Superior de Agricultura Luiz de Queiroz
- F A F Mello
- E L De Possídio
- J R Pereira
- De
- J P Araújo
- L Abramof
MELLO, F. A. F.; DE POSSÍDIO, E. L.; PEREIRA, J. R.; DE ARAÚJO, J. P.;
ABRAMOF, L. et al. Efeito da adição de uréia e sulfato de amônio sobre o pH e
nitrificação em um solo ácido. Anais da Escola Superior de Agricultura Luiz de
Queiroz, v.37, n.1, p.1-10, 1980. Disponível em: < http://dx.doi.org/10.1590/S0071-12761980000100001.>. doi: 10.1590/S0071-12761980000100001
Germinação in vitro e armazenamento do pólen de Eugenia involucrata DC (Myrtaceae)
- R C Franzon
- M C B Raseira
FRANZON, R.C.; RASEIRA, M.C.B. Germinação in vitro e armazenamento do pólen
de Eugenia involucrata DC (Myrtaceae). Revista Brasileira de Fruticultura, v.28,
n.1, p.18-20, 2006. Disponível em: <http://www.scielo.br/scielo.php?pid=S0100-29452006000100008&script=sci_arttext&tlng=es>.
doi:
10.1590/S0100-
Mitochondrial dysfunction mediated by cytoplasmic acidification results in pollen tube growth cessation in Pyrus pyrifolia
- S Tao
TAO, S. et al. Mitochondrial dysfunction
mediated by cytoplasmic acidification results in pollen tube growth cessation in Pyrus
pyrifolia. Physiologia Plantrum, v.153, n.4, p.603-615, 2014. Disponível em:
<https://onlinelibrary.wiley.com/doi/full/10.1111/ppl.12260>. doi: 10.1111/ppl.12260
Corn oil emulsion for early bloom thinning of trees of 'Delicious' apple
- Z Ju
- A Guo
JU, Z.; GUO, A. Corn oil emulsion for early bloom thinning of trees
of 'Delicious' apple, 'Feng Huang' peach, and 'Bing' cherry. The Journal of
Horticultural Science and Biotechnology, v.76, n.3, p. 327-331, 2001. Disponível
em:
<http://dx.doi.org/10.1080/14620316.2001.11511371>.
doi:
10.1080/14620316.2001.11511371
An in vitro Study on the Postinfection Activities of Hydrated Lime and Lime Sulphur against Apple Scab (Venturia inaequalis)
- J Montag
- L Schreiber
- J Schönherr
MONTAG, J.; SCHREIBER, L.; SCHÖNHERR, J. An in vitro Study on the
Postinfection Activities of Hydrated Lime and Lime Sulphur against Apple Scab
(Venturia inaequalis). Journal of Phytopathology, v.153, p.485-491, 2005.
Disponível
em:
<
https://doi.org/10.1111/j.1439-0434.2005.01007.x>.
doi:
10.1111/j.1439-0434.2005.01007.x
Precision apple flower thinning using organically approved chemicals
- G M Peck
- L D Combs
- C Delong
- K S Yoder
PECK, G.M.; COMBS, L.D.; DELONG, C.; YODER, K.S. Precision apple flower
thinning using organically approved chemicals. Acta Horticulturae, v.1137, p. 47-52,
2016. Disponível em: < https://doi.org/10.17660/ActaHortic.2016.1137.7>. doi:
10.17660/ActaHortic.2016.1137.7