Observation Of Vessel In Grape Stem And Study On Physiologically Substances In Bleeding

Grape has an obvious bleeding period in spring.The study of bleeding fluid can help us understand the mechanism of bleeding,the change and transfer of energy and the physiological metabolism of aboveground growth and development.Previous studies on grape bleeding fluid were mostly limited to basic physiological substances and medicinal values,and the exploration of unknown substances and physiological metabolic activities of bleeding fluid have not been in-depth.In this study,In this study,the branches and bleeding sap of Summer Black,Zuijinxiang,Midknight Beauty,Shine Muscat,Golden Finger grape are taken as samples,and the amino acids,protein,mineral elements,hormones,sugar components and acid components were detected by stereoscopy,non-target metabolism detection,the observation and dissociation statistics of branch sections of different branch ages,the possible physiological substances and metabolic pathways of bleeding fluid were measured,and the differences of physiological substances of bleeding fluid of different varieties and branch ages were studied and analyzed.The conclusions are as follows:（1）Through the observation and statistics of stem sections of grapes with different branch ages,it was found that with the increase of branch age,the stem pith gradually decreased and the proportion of xylem increased.The diameter,xylem rate and tube hole density rate of three-year-old branches were higher than those of one and two-year-old branches,and the xylem rate and tube diameter of zuijinxiang were larger than those of Shine Muscat;By dissecting the vessels of different branch ages of grapes,it was found that there were three common types of vessel molecules,and some transitional vessels;According to whether there is a tail or not,it includes vessel molecules with tails at both ends,with tails at one end and without tails at the other end,and vessel molecules without tails at both ends;There are four types of vessel element perforation plates.A small part of the vessels are double perforation plates at one end,and the perforation plates are also on the side wall.Most vessel elements have beaks,and the beaks are especially long in annual branches;From the angle of the inclination of the end arms at both ends of the catheter,the proportion of the inclination of the catheter element above 45° is the highest.In general,the average length of vessel elements of annual branches is greater than that of biennial and triennial branches,but the width is just the opposite;The catheter length is concentrated in 601-750μm.The diameter is mostly distributed in 0-100μm.To study the relationship between branch age,variety,cross section and duct,so as to lay a foundation for the study of grape bleeding fluid transportation and growth potential.（2）A total of 158 substances were identified in the bleeding fluid of Midknight Beauty,including 36 primary metabolites,69 secondary metabolites and 43 exogenous substances.In particular,3 alkaloids,8 growth substances and 4 Phenylpropanes were detected.These physiologically substances were located in 34 pathways,and 75 metabolites failed to find the corresponding metabolic pathways.Taking the tricarboxylic acid cycle as the skeleton,the metabolic pathways involved include glycolysis/gluconeogenesis,ascorbic acid and bitter almond metabolism,pentose and glucuronide tautomerism,fructose and mannose metabolism,pyrimidine metabolism,alanine metabolism,flavonoid biosynthesis,phenylalanine metabolism,niacin and nicotinamide metabolism and multiple amino acid metabolism.21 kinds of mineral elements were detected,including 6 kinds of massive elements;8 kinds of trace element iron;There are 7 other elements.The determination of the concent of the bleeding fluid will form a systematic structure of the formation and function of the bleeding fluid.（3）The physiological substances of the five grape varieties were quite different.Glutamate,aspartic acid and tyrosine were the most abundant amino acids in the wound fluid,with a total amount of 220.36-698.93.79 μg/mL;When the protein content is 1.75-8.05mg/ml,Midknight Beauty is the highest;Phosphorus P,potassium K and calcium CA with high content of mineral elements are 125.88-489.93 mg/L;Among the four cytokinins TZR,ZT,IP and IPA,the content of IPA was the highest,and the total amount was 212-1096 ng/L;The content of GA4 in GA1,GA3,GA4 and GA7 gibberellins was relatively high,but the total amount was much lower than that of cytokinin;The total sugar content of Summer Balck is the highest and zuijinxiang is the lowest.Glucose accounts for most of the total sugar,with a total amount of 179.46-908.99 mg/L;The total acid content of Midknight Beauty is the highest and that of Golden Finger is the lowest.Oxalic acid accounts for most of the total acid,with a total amount of 1760.25-2848.08 mg/L.There is a certain relationship between the concent of bleeding fluid and the source of strain.（4）The content of physiologically substances in the bleeding fluid has a certain relationship with the position.The total amount of amino acids,sugars and acids was the highest in the three-year-old branches,but the protein showed no obvious regularity.It was also found that the content of glucose was the highest in the annual branches.Combined with the analysis of conduit structure,the higher the water conveyance efficiency of branches,the higher the content of organic matter in tree sap.