Studies On Introduction, Regionalization And Storage Technique Of Rabbiteye Blueberry In Southern Part Of China

Based on the summarization of the significance of the blueberry development in China and the situation of worldwide blueberry production and researches,the results of studies on the introduction,cultivar comparison of blueberry in the southern China have been presented in this paper.Studies included mainly two aspects:1) researches on the comparison of climatic,soil type and some biological characters among cultivars between native and introduction regions;2) the storability of fresh fruits.1.Studies on suitable growing regions and some biological characters of Rabbiteyes blueberry in southern China1.1 Studies on the introduction and suitable growing regions of Rabbiteyes blueberryAccording to the theory of "Ecological Factor Analysis Method",the ecological conditions of blueberry growing areas in China have been analyzed and the situation of introduction has been reviewed.It has been suggested that there was a greater potentiality for the development of blueberry in the southern of China than that in other regions.With the comparisons of the ecological factors between native and introduction regions of Rabbiteyes blueberry and the biological characters of the flowering and fruiting,it was pointed out that:1) the subtropical red and yellow soil regions in southern China were suitable area for Rabbiteyes blueberry growing.The regions included the plains in middle and lower reaches of Yangtze River,the hilly areas on the south of Yangtze River,the mountainous areas in Zhejiang and Fujian Provinces,the middle and northern parts of Guangxi,the northern part of Guangdong, the Sichuan Basin,some parts of the Yunnan-Guizhou Plateau at the elevation of about 2000m;2) both the drought season in the hilly areas in southern part of Yangtzi River and the less sunshine hours in Guizhou region were not the restrict factors for blueberry growing and 3) owing to the huge territory for blueberry growing and the complexity of climatic conditions and the various types of soil,it was necessary to have many experimental plots over a wide range of geographic features.The advantages of development of Rabbiteyes blueberry was emphasized as well as the ecological security of blueberry growing were discussed.1.2 The total anthocyanins qualitative & quantitative analysis of Rabiteyes blueberries produced in China1.2.1 The comparative researches on the content of total anthocyanins of rabiteye blueberriesThe quality & quantity of total anthocyanins of 12 Rabbiteyes blueberry cultivars introduced from the US were determined by ultraviolet spectrometry.The result showed that there was an obvious difference among cultivars,cultivars 'Centurion', 'Delite' and 'Woodard' presented higher quantity than the others.1.2.2 The comparative researches on the components of total anthocyanins of rabiteye blueberriesThe comparative research on the components of total anthocyanins of Rabiteyes blueberries produced in China and the bilberry,'Myrtocyan',native products from Europe,were analyzed by HPLC method.The result showed that there were 16 components were found from bilberry,'Myrtocyan'.Among them there were 14 components also found in Rabbiteyes blueberries except peonidin-3-o-arabinoside and another unknown one.Besides,there were also two unknown components from Rabbiteyes blueberry that could not found in bilberry,'Myrtocyan'.It came out the conclusion that the elements of anthocyanins of Rabbiteyes blueberry produced in China were basically similar to bilberry,'Myrtocyan',but the quantity was much less.1.3 Evaluation on fruit quality of artificial hybrids and studies on its distinction and identification of genetic relationship of cultivar germplasm by ISSR marker1.3.1 Evaluation on fruit quality of selections generated from complicatedly hybrid cultivarsFruit quality including total sugar,total acids and sugar acid ratio,contents and composition of mineral elements and amino acids were determined on six promising selections generated from complicatedly hybrid cultivars and these selections have been considered as ecologically adaptive ones.The result showed that the fruit quality of the selections has basically reached the level of commercial cultivars. Among them the NJ1 and NJ8 with high sugar content,13.91%and 8.64% respectively,could be used as fresh cultivars.The NJ9 with high acid content,1.12%, could be used for processing purposes.The NJ4 could be used as parental material in breeding program for high amino acids content in the future.1.3.2 Distinction and identification of genetic relationship of cultivar germplasm by ISSR markerSeven southern highbush blueberry cultivars(V.darrowi x corymbosum),nine promising selections from southern highbush blueberry and Rabbiteyes blueberry seedlings,and 12 Rabbiteyes blueberry cultivars(V.ashei),totally 28 genotypes, were examined by ISSR markers to construct DNA fingerprinting figure to distinguish these genotypes and analyze there genetic relationship.There were 98 bands obtained by ten primers,of which 37 were polymorphic.The percentage of polymorphic bands was 37.8%.Then 17 polymorphic bands from eight premiers were chosen to construct a DNA fingerprinting figure to distinguish among the genotypes.POPGENE 1.31 software was used to calculate the Nei's genetic distance and a dendrogram was constructed based on UPGMA cluster analysis.The cultivar groups were grouped out separately as expected.The result indicated also that the genetic distances among promising selections from seedlings were relatively higher than that of common cultivar group,and seven selections were grouped with highbush blueberry group.On the other hands,two were included in Rabbiteyes blueberry group.However,estimation of relative genetic distance between genotypes within one cultivar group did not agree well with known pedigree data and,thus,it indicated that the data of ISSR markers used in this study did not accurately assess the genetic relationships within the cultivar group.2.Studies on fruit storage technique2.1 Effect of different packaging treatments on physiology and storage period of blueberry fruitsIn order to investigate the physiological changes on the storage period of blueberry fruits produced in the southern China,and to provide scientific basis for suitable packaging materials,the quantity changes of the total soluble solids,vitamin C, acetaldehyde,ethanol,protopectin,total anthocyanins,respiration rate,the activity of polygalacturonase(PG) and pectinesterase(PE),the percentage of weight loss and the percentage of fruit rotten were treated by different packaging plastic membrane under 2℃.The results showed that plastic membrane packaging used in this experiment obviously decreased the percentage of weight loss and the percentage of fruit rotten.These packaging methods also decreased to a certain extent the respiration rate and slow down the reduction of anthocyanin content as well as inhibiting polygalacturonase(PG) and pectinesterase(PE) activitiy.But the decreasing of the contents of total soluble solid,vitamin C and protopectin were slightly affected by packaging membrane.In general,the 0.08 mm polyethylene membrane bag was comparatively suitable packaging material for 30 days storage.2.2 Studies on suitable storage temperatureThe effect of storage experiments of blueberries packed with 0.05 mm polyethylene(PE) membrane by using chemicals of CT₁,CT₂ and CT₅ and sodium diacetate with two cultivars,'Tifblue' and 'Brightwell',were conducted under three different temperatures,-1℃,0℃and 2℃.The result showed that for 90 days storage under -1℃the percentage of fruit rotten could be controlled at 4.8%.There were difference of storage period between cultivars and cultivar,the 'Tifblue' was better than that of 'Brightwell'.3.Scientific guide for the development of blueberry growingIt was extremely important to extend blueberry growing in order and scientifically. The lesson of so-called "valley emotion" of blueberry growing in the early days in Florida,USA should be keep in our mind and carefully avoided.Commercial growing in large scale and quality guarantee were essentials for smooth and rapid development of blueberry growing.It is important,at first,to have model orchards to show the cultivated practice to the farmers before growing blueberries properly.