Flowering in strawberry is known to be significantly affected by temperature and photoperiod (Kumakura and Siilsiildo, 1995), and the floral initiation of strawberry is regulated by a complex set of environmental and physiological cues (Awang and Atherton, 1995; Opstad et al., 2011; Sønsteby et al., 2013). Furthermore, the appearance and development of inflorescences are significantly influenced by genotype as well as several environmental factors such as temperature, light intensity, and light quality/photoperiod (Nestby and Sønsteby, 2017; Zahedi and Sarikhani, 2017). Researchers have attempted to explain how various lighting environments affect plant physiological responses such as leaf initiation, time to flowering, flowering rate, and fruit quality. Cervantes et al. (2019) evaluated several strawberry genotypes under multiple light exposure treatments and evaluated how genotype and light exposure interactions affected fruit quality. Choi et al. (2016) showed correlations between multiple photosynthesis-related parameters and lighting environment by measuring fruit productivity. Tsuruyama and Shibuya (2018) reported that different photoperiods in controlled environment chambers altered the growth and flowering responses in seed-propagated strawberry seedlings; moreover, flower bud initiation after transplanting was likely accelerated by increasing the photoperiod length. Takeda et al. (2010) evaluated the effect of using photoselective shade nets over strawberry plug plants and concluded that because of the removal of the light signal that initiates flowering, the initiation of flower buds was delayed. Overall, research has shown that increasing both light and photoperiod increases productivity and fruit quality. However, most studies focus on individual strawberry plants of different genotypes and their response to different lighting conditions or different light effects on growth and yield (Cervantes et al., 2019; Choi et al., 2014; Mochizuki et al., 2019; Nestby and Sønsteby, 2017; Young and Ho, 2013). Understandably, the number of buds determines the harvest to a large degree. Therefore, evaluating the variability of flowering characteristics of a whole population will likely produce results that are more applicable in a commercial production setting as compared with genotypic response evaluations.
In Japan, strawberry plants are transplanted once the differentiation of primary inflorescence has occurred into commercial off-season production greenhouses in mid-September, and the fruit is harvested from late November to June (Kumakura and Siilsiildo, 1995; Yoshida et al., 1997, 2012). Owing to environmental conditions and seasonal changes that occur after transplanting, the time to flowering of the second inflorescence increases, which is directly related to the increase in time required for fruit formation. Uniform flower development is also directly related to how uniformly fruits mature, which is important for the logistics and planning in commercial production. Furthermore, to improve harvesting techniques and increase fruit shelf life, Miyashita et al. (2019) suggested that investigating and promoting flowering uniformity would promote uniformity of maturation and allow cluster harvesting in blueberries.
To analyze the effects of different lighting conditions, we applied shading treatments and light-emitting diode (LED) exposure treatments. The aims of this study were 1) to investigate the variability of uniform flower development in different light environments and 2) to evaluate the photosynthetic performance of strawberry and how it is related to maintaining uniformity with a population.
AwangY.B.AthertonJ.G.1995Growth and fruiting responses of strawberry plants grown on rockwool to shading and salinityScientia Hort.622531
CervantesL.ArizaM.T.Gomez-MoraJ.A.MirandaL.MedinaJ.J.SoriaC.Martinez-FerriaE.2019Light exposure affects fruit quality in different strawberry cultivars under field conditionsScientia Hort.252291297
ChoiH.G.ByoungY.M.KangN.J.2016Correlation between strawberry (Fragaria ananassa Duch.) productivity and photosynthesis-related parameters under various growth conditionsFron. Plant Sci.1607113
ChoiH.G.MoonB.Y.KangN.J.KwonJ.K.BekhzodK.ParkK.S.LeeS.Y.2014Yield loss and quality degradation of strawberry fruits cultivated under the deficient insolation conditions by shadingHort. Envi. Biol.55263270
CorbesierL.LejeuneP.BernierG.1998The role of carbohydrates in the induction of flowering in Arabidopsis thaliana: Comparison between the wild type and a starchless mutantPlanta06131137
DavidencoV.ArguelloJ.A.MonicaP.VegaC.R.C.2017Day length modulates precocity and productivity through its effect on developmental rate in Origanum vulgare sspScientia Hort.218164170
KumakuraH.SiilsiildoY.1995Effects of temperature and light conditions on flower initiation and fruit development in strawberryJpn. Agr. Res. Q.29241250
MiyashitaC.YukaK.IsaoO.2019Utility of parthenocarpic interspecific hybrids between Vaccinium corymbosum and Vaccinium virgatum for breeding blueberry cultivars suitable for cluster harvestingJ. Jpn. Soc. Hort. Sci.882670675
MochizukiY.SekiguchiS.HoriuchiN.AungT.OgiwaraI.2019Photosynthetic characteristics of individual strawberry (Fragaria ×ananassa Duch.) leaves under short-distance lighting with blue, green, and red LED LightsJ. Amer. Soc. Hort. Sci.54452458
NestbyR.SønstebyA.2017Effect of plant type and delayed planting on growth and yield parameter of two short day strawberry cultivars in open fieldJ. Berry Res.7179194
OpstadN.SønstebyA.MyrherimU.HeideO.M.2011Seasonal timing of floral initiation in strawberry: Effects of cultivar and geographic locationScientia Hort.129127134
ShahanR.ZaworaC.WightH.SittmannJ.WangW.P.MountS.M.LiuZ.C.2018Consensus co-expression network provide insights into wild strawberry flower and fruit developmentPlant Physiol.178202216
SønstebyA.OpstadN.HeideO.M.2013Environmental manipulation for establishing high yield potential of strawberry forcing plantsScientia Hort.1576573
TakedaF.GlennD.M.CallahanA.SlovinJ.StutteG.W.2010Delaying flowering in short-day strawberry transplants with photo selective netsInter. Fruit. Sci.10134142
ThomasW.J.ChabotJ.F.BrainF.C.1982Effects of light and nutrients on leaf size, CO2 exchange, and anatomy in wild strawberry (Fragaria virginiana)Plant Physiol.7010441048
TsuruyamaJ.ShibuyaT.2018Growth and flowering responses of seed-propagated strawberry seedlings to different photoperiods in controlled environment chambersHortTechnology28453458
YoshidaY.OzakiE.MurakamiK.GotoT.2012Flower induction in June-bearing strawberry by intermittent low temperature storageJ. Jpn. Soc. Hort. Sci.814670675
YoshidaY.MorimotoY.YokoyamaK.1997Soil organic substances positively affect carbon dioxide environment in greenhouse and yield in strawberryJ. Jpn. Soc. Hort. Sci.65791799
ZahediS.M.SarikhaniH.2017The effect of end of day far-red light on regulating flowering of short-day strawberry in a long-day situationJ. Rus. Plant Physiol.641670675