Comparison Of Developmental Period And Fruit Quality And Analysis Of Chilling Requirement Of Different Sweet Cherry Cultivars In Tongchuan Area Of Shaanxi Province

Sweet cherry(Prunus avium L.),as a fruit tree popular in the market,has a unique fruit flavor and bright colors.It has been widely cultivated and bred in Europe and America in recent years.The industry has developed rapidly.After being introduced to China,it is also popular among consumers favorites.At present,domestic investigations and breeding of sweet cherry cultivars on phenology and fruit quality are mostly limited to traditional cultivars,and are seldom combined with local phenological conditions,which cannot well reflect the growth characteristics of sweet cherry planted in different regions.The BBCH scale(Biologische Bundesanstalt,Bundessortenamt Chemische Industrie)is a method commonly used internationally to describe the specific growth state of plants.It is widely used in the statistics and description of the phenology of various fruit trees such as persimmon,kiwi,sweet cherry,and apple.In addition,when introducing sweet cherries in China,due to the blind pursuit of increasing production,ignoring the selection of cultivars and the local adaptability of different cultivars,the fruit quality is reduced,and the cultivars sold in the market is single.The investigation is also mainly based on traditional cultivars,and there is a lack of research and investigation on the introduction of new cultivars.This paper investigates the key phenological periods of sweet cherry cultivars planted in Tongchuan,Shaanxi,measures the fruit quality of different sweet cherries,and analyzes the chilling requirement and influencing factors of different sweet cherry cultivars,provide reference for planting and promotion.The specific research results are as follows:1.Six representative sweet cherry early-maturing cultivars ‘Qinying 1’ and ‘Hongdeng’,mid-maturing cultivars ‘Summit’ and ‘Rainier’ and late-maturing cultivars ‘Kordia’ and ‘Jimei’were summarized.According to the standard of BBCH scale,this experiment systematically coded and described the main phenological stages of sweet cherries and divided the main growth stages of sweet cherries into vegetative phenology period and reproductive phenology period.The vegetative growth phenology period can be divided into leaf development stage(stage 1)and shoot development stage(stage 3),and the reproductive growth phenology stage can be divided into flower bud development stage(stage 5),flowering stage(stage 6),fruit development stage(stage 7)and fruit ripening stage(stage 8),and a schematic diagram of its main developmental stages was drawn based on this standard.In the stage of flower development(stage 5 and stage 6),the flower bud development and flowering time of ‘Summit’and ‘Rainier’ were earlier.In addition,‘Hongdeng’ and ‘Jimei’ have a longer blooming period,which is conducive to cross breeding.In the fruit development stage(stages 7 and stage 8),the fruit development time of the early-maturing cultivars is shorter,followed by the middlematuring cultivars,and the fruit development time of the late-maturing cultivars is the longest.Among them,the fruit of ‘Qinying 1’ ripens is the latest,which is conducive to the reasonable planning of horticultural measures and fruit market time in Tongchuan area and similar climate areas.2.Some of the main plantings and newly introduced ones in Tongchuan,Shaanxi Province.The extrinsic and intrinsic quality analysis of the fruit of two sweet cherry cultivars revealed that the sweet cherry cultivar ‘Jimei’ with excellent comprehensive fruit quality and the relatively excellent sweet cherry cultivars ‘Carina’ and ‘Kordia’,‘Summit’ and the yellow sweet cherry cultivar ‘Rainier’ had better fruit quality and rich contents.In addition,the sweet cherry cultivars ‘Qinying 1’ and ‘Valeriy’ have short and thick fruit stalks,‘Regina’,‘Skeena’,‘Snelders’ and ‘Sweetheart’ have high fruit hardness.These cultivars meet the characteristics of cultivars required by the sweet cherry market,and both have good development prospects and crossbreeding value.3.Based on the quantitative analysis of the 0-7.2°C model,through the combination of natural low temperature accumulation in the field and artificial low temperature treatment at4°C,the scions of sweet cherry cultivars ‘Qinying 3’ and ‘Qinying 1’,‘Brooks’,‘Russia 8’,‘Kordia’,‘Regina’,‘Jimei’,‘Tieton’ and the sweet cherry disease-resistant rootstock ‘Mahaleb CDR-1’,the chilling requirement of each cultivar were roughly calculated to be between 600CH-1200 CH,and ‘Brooks’ has least amount of chilling requirement,which is 600 CH,and‘Qinying 3’ and ‘Kordia’ have the highest amount of chilling requirement,which is 1200 CH.The rootstock ‘Mahaleb CDR-1’ has 1400 CH chilling requirement.In addition,by measuring the content of phytohormones in shoots,it was preliminarily concluded that the changes in the level of abscisic acid(ABA)could reflect and define the process of plant dormancy to a certain extent.