| Jujube(Ziziphus jujuba Mill.),belonging to the genus of Ziziphus in Rhamnaceae,is an unique economic fruit tree in China.According to the different regional distribution,it can be divided into northern and southern cultivation floras.In recent years,the study of southern fresh jujube has been gradually deepened,but few studies have been conducted on the characteristics of flowering and fruiting in southern fresh jujube.In this study,the field investigation,electron microscope scanning,in vitro culture method,acid-anthrone method,3,5-dinitrosalicylic acid method,anthrone method,2,6-Dichlorophenolindo-phenol sodium method,coomassie brilliant blue method,national standard method and elisa were used to compare and analyze botanical characteristics,the performance of budding,flowering and fruit setting,morphological characteristics at different developmental stages of flowers,pollen viability,fruit quality and endogenous hormone content.That more reasonable cultivation and management measures would work out to provide a theoretical basis for regulating flowering and bearing of southern fresh jujube.The main conclusions were as follows:(1)Leaf color,leaf shape,shape of leaf apex,leaf base and leaf margin of bearing branch Ⅰ～Ⅲ were basically the same.The bearing branch length,leaf length and breadth of were bearing branch I the largest,and the thickness of bearing branch II was significantly larger than that of bearing branch I,III.Besides,the bearing branch length,thickness,leaf length and breadth of bearing branch III were the least.(2)The trends of bearing branch Ⅰ～Ⅲ in budding,flowering and fruit setting were similar,showing the trend of increasing first and then decreasing.The number of buds of bearing branch I-III reached the maximum at 28,35 and 112 days after budding respectively.The flowers of bearing branch Ⅰ～Ⅲ reached the maximum at 21,28 and 91 days after anthesis respectively.The fruit bearing number of jujube bearing branch Ⅰ～Ⅲreached the maximum at 28,35 and 70 days after fruiting respectively,and became relatively stable at 45,56 and 91 days after fruiting respectively.There were differences in the number of buds,flowers and fruit setting at different nodes of bearing branch Ⅰ～Ⅲ.With the increase of nodes,the number of buds,flowers and fruit setting of bearing branch I and III showed the trend of increasing first and then decreasing,but bearing branch II decreased gradually.The number of buds and flowers of bearing branchⅠ～Ⅲwere the highest at nodes 6,1 and 6,respectively,and fruit setting number reached the maximum at nodes6,1 and 5 respectively.The results of bearing branch Ⅰ～Ⅲ were significantly different,which were 4,7 and 2 respectively.The nodes of results also showed significant differences,concentrating in tail,the upper and middle,the middle nodes respectively.There were significant differences in the total number of buds,flowers,fruit setting,results,flowering rate,bearing rate and resulting rate.The total number of buds,flowers,fruit setting of bearing branch I were the largest,and flowering rate,bearing rate and resulting rate of jujube bearing branch II were significantly larger,but total number of buds,flowers,fruit setting and results were generally low.(3)The morphological characteristics of flower organs of bearing branch Ⅰ～Ⅲwere the same,but the size of flower organs was different.The flower diameter,flower radius,radius of honeycomb,filament length and the ratio of the radius of the honeycomb to flower radius of bearing branch II were the largest,then was bearing branch I,and bearing branch III was the last.(4)The sub-micromorphological characteristics of flower organs of bearing branchⅠ～Ⅲ were different.At bud squaring period,the pollen was observed for the first time in bearing branch Ⅰ.At inflorescence period,there were a large number of early pollen grains observed of bearing branch I and II,indicating that pollen were mainly formed from the inflorescence period.From the beginning of bud flat period,the abnormal anthers were found in bearing branch I and III,and the stigma and the apical development were not symmetrical of flower organs of bearing branch I.The enlargement of the apical stigma was not obvious.The pollen size of bearing branchⅠ～Ⅲ was different.The polar axis and equatorial axis of bearing branch II were the longest,then was bearing branch I,and bearing branch III was the last.(5)There were differences in the single pollen grains of bearing branch Ⅰ～Ⅲ.The single pollen grains of flower organs of bearing branch I were the most,then was bearing branch Ⅱ,and bearing branch III were the least.(6)The pollen germination rates of bearing branch Ⅰ～Ⅲ were different.With the increase of sucrose and boric acid concentration,the germination rates of bearing branchⅠ～Ⅲ increased first and then decreased.The pollen germination rate of bearing branch II was highest,followed by bearing branch I,and finally was bearing branch III.The pollen germination rate of bearing branch I and III reached the highest at 75.OOmg/L boric acid + 12.50%sucrose,while the germination rate of bearing branch II was 75.00mg/L boric acid + 15.00%sucrose to reach the maximum.(7)The germinated pollen tube length of bearing branch Ⅰ～Ⅲ were different.The germinated pollen tube length of bearing branch Ⅱ was the longest,and bearing branchⅢ was the shortest.The germinated pollen tube length of bearing branch I and III reached the longest at 75.OOmg/L boric acid + 12.50%sucrose,while the germination rate of bearing branch Ⅱ was 100.00mg/L boric acid + 15.00%sucrose to reach the longest.(8)The appearance characteristics of bearing branch Ⅰ～Ⅲ were basically the same,but the fruit weight,fruit vertical length,fruit cross diameter,the length of carpopodium,stone weigh,fruit shape index and edible rate were different.The fruit diameter and length of carpopodium of bearing branch I were dominant,but the fruit vertical length,fruit shape index and edible rate of bearing branch II were the largest.The contents of soluble total sugar,reducing sugar,starch,vitamin C and soluble protein of bearing branch I-III were different.At white crisp mature period,the contents of soluble sugar,starch and soluble protein of bearing branch II were significantly lower than that of bearing branch I and III,but the content of reducing sugar and vitamin C were higher.At crisp mature period,the reducing sugar of bearing branch I was significantly lower than that of bearing branch II and III,but the others were not significant There were differences in the contents of eight kinds of minerals of bearing branch Ⅰ～Ⅲ At white crisp mature period,the contents of K,Mg,Ca,Na,Fe and Zn in fruits of bearing branch I were significantly higher than those of bearing branch II and III,but the contents of Mn and Cu in bearing branch Ⅲwere the highest.At crisp mature period,the contents of K,Ca,Fe and Cu in fruits of bearing branch I were the highest,but the contents of Mg,Na,Mn and Zn in bearing branch Ⅲwere the highest.The trend of endogenous hormones and there balance of bearing branch Ⅰ～Ⅲ were consistent.In fruits of bearing branch II,there were higher levels of GA,IAA,CTK and lower levels of ABA,ABA/GA,ABA/IAA,ABA/CTK,GA/IAA,which could contribute to flowering and fruit setting. |
