@article{ChmielewskiGoetzHomannetal.2017,
  author    = {Chmielewski, Frank M. and G{\"o}tz, Klaus-Peter and Homann, Thomas and Rawel, Harshadrai Manilal},
  title     = {Identification of Endodormancy Release for Cherries (Prunus Avium L.) by Abscisic Acid and Sugars},
  series = {Journal of Horticulture},
  volume    = {4},
  journal   = {Journal of Horticulture},
  number    = {3},
  issn      = {2376-0354},
  doi       = {10.4172/2376-0354.1000210},
  pages     = {9},
  year      = {2017},
  abstract  = {In order to develop reliable and physiologically sound models for the plant development in spring, the date of endodormancy release is always a crucial and mostly unknown model parameter. Until present, classical approaches - such as climate chamber experiments - are used to derive this unknown parameter. In these experiments, progressive plant development or significant changes in bud's fresh weight or water content are measurable markers for dormancy release. This study presents an alternative approach, which is based on four well-known metabolites. For 5 seasons (2011/12-2015/16), the content of abscisic acid (ABA) and sugars such as fructose, sucrose and glucose in sweet cherry flower buds (cultivar 'Summit') were weekly analysed between beginning of October and April. These data allow comparing the annual course of these metabolites with the date of endodormancy release, derived from a classical climate chamber experiment, published in a previous study. Results showed that ABA and sucrose are two important metabolites which can help to identify the date of endodormancy release of sweet cherries. On average, ABA content reached a plateau of 5.65 μg g-1 DW-1 during endodormancy, which was maintained for 3-6 weeks. The significant reduction of the ABA content after this period to 4.41 μg g-1 DW-1 on average during ecodormancy was nearly in agreement with the date of endodormancy release of 'Summit' on 28 November (332 DOY). The annual cycle of sucrose, which has a cryoprotective effect during winter, is well comprehensible and showed a close relationship to the annual course of minimum air temperature after leaf fall(r=-0.90). The nearly constant level of sucrose during ecodormancy (21.0 mg g-1 DW-1, 5 yr. mean) did not only allow deriving the date of endodormancy release but can also be helpful to define the beginning of ontogenetic development.},
  language  = {en}
}
@article{ChmielewskiBaldermannGoetzetal.2018,
  author    = {Chmielewski, Frank M. and Baldermann, Susanne and G{\"o}tz, Klaus Peter and Homann, Thomas and G{\"o}deke, Kristin and Schumacher, Fabian and Huschek, Gerd and Rawel, Harshadrai Manilal},
  title     = {Abscisic acid related metabolites in sweet cherry buds (Prunus avium L.)},
  series = {Journal of Horticulture},
  volume    = {5},
  journal   = {Journal of Horticulture},
  number    = {1},
  issn      = {2376-0354},
  doi       = {10.4172/2376-0354.1000221},
  pages     = {221},
  year      = {2018},
  abstract  = {As our climate changes, plant mechanisms involved for dormancy release become increasingly important for commercial orchards. It is generally believed that abscisic acid (ABA) is a key hormone that responds to various environmental stresses which affects bud dormancy. For this reason, a multi-year study was initiated to obtain data on plant metabolites during winter rest and ontogenetic development in sweet cherry buds (Prunus avium L.). In this paper, we report on metabolites involved in ABA synthesis and catabolism and its effect on bud dormancy in the years 2014/15-2016/17. In previous work, the timings of the different phases of para-, endo-, ecodormancy and ontogenetic development for cherry flower buds of the cultivar 'Summit' were determined, based on classical climate chamber experiments and changes in the bud's water content. Based on these time phases, we focused now on the different aspects of the ABA-metabolism. The results show that there is a continual synthesis of ABA about 5 weeks before leaf fall, and a degradation of ABA during ecodormancy and bud development until the phenological stage 'open cluster'. This is confirmed by relating the ABA content to that of the total precursor carotenoids, neoxanthin and violaxanthin. The tentative monitoring of individual intermediate metabolites revealed that dihydroxyphaseic acid is the most abundant catabolite of ABA and ABA glucosyl ester is in terms of mass intensity, the most abundant ABA metabolite observed in this study. The results suggest that the direct route for ABA biosynthesis from farnesyl pyrophosphate may also be relevant in cherry flower buds.},
  language  = {de}
}
@article{GoetzChmielewskiHomannetal.2014,
  author    = {Goetz, Klaus-Peter and Chmielewski, Frank M. and Homann, Thomas and Huschek, Gerd and Matzneller, Philipp and Rawel, Harshadrai Manilal},
  title     = {Seasonal changes of physiological parameters in sweet cherry (Prunus avium L.) buds},
  series = {Scientia horticulturae : an international journal sponsored by the International Society for Horticultural Science},
  volume    = {172},
  journal   = {Scientia horticulturae : an international journal sponsored by the International Society for Horticultural Science},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0304-4238},
  doi       = {10.1016/j.scienta.2014.04.012},
  pages     = {183 -- 190},
  year      = {2014},
  abstract  = {The transition from dormant stage to the beginning of growth was first obvious by markedly changes of the water content. The phase from green tip to tight cluster, with a length of only 4 days, was the period of the most physiological activity in single buds, because of the highest daily accumulation rates of fresh/dry weight, C, N. We assume a concentration dependant regulation of the member of the aspartate family (asparagine, aspartic acid, isoleucine) during dormancy, growth and development in sweet cherry buds. The ABA content showed 2011/12 a clear bimodal pattern which was at lower level similar in 2012/13, but not so strong incisive. In both years, the first peak was probably related to the end of endodormancy. However the ABA-isomer content showed in both seasons a unimodal pattern. The maximum of the ratio of ABA-isomer/ABA indicated the beginning of ontogenetic development which starts 3 and 2 weeks later, respectively. Our results suggest that ABA and the ABA-isomer in the sweet cherry buds regulate differentiated metabolic processes in the dormant stage and during bud growth and development. After replication in the season 2013/14 the estimated dates of release of endodormancy, beginning of ecodormancy and start of ontogenetic development will be used to validate and improve phenological models for the beginning of cherry blossom. (C) 2014 Elsevier B.V. All rights reserved.},
  language  = {en}
}