Evaluation Of The Important Fruit Characters About Hawthorn Germplasm Resources

Hawthorn(Crataegus L.)belongs to Maloideae of Rosaceae,the dungarunga or deciduous shrub,originated in cretaceous century or the new generation of the third century,and is widely distributed in Asia,Europe and Northern America.In this study,233 accessions of Crataegus L.from Shenyang national germplasm hawthorn repository were selected as materials,which include eight species,e.g.Crataegus pinnatifida Bge.,Crataegus pinnatifida Bge.var.major N.E.Br.,Crataegus brettschneideri Schneid,Crataegus hupehensis Sarg.,Crataegus mespilus,Crataegus laevigata Poir.Crataegus crus-galli L.Crataegus cuneata Sieb.et Zucc.and Crataegus phaenopyrum Medic.The changes of hawthorn fruit quality were analyzed,furthermore,the important fruit characters of hawthorn resources were evaluated,and the main findings are as follows:1.The soluble sugar content,titratable acid content and vitamin C content in hawthorn fruits were determined by different methods.The results showed that the content of soluble sugar in hawthorn fruit was determined by NY/T 1278 method.The content of titratable acid in hawthorn was determined by GB/T12456 method.These methods were more objective and accurate than others,and it was suitable for the determination of fruit quality of hawthorn resources.2.The hawthorn fruit intrinsic quality during the fruit ripening period and storage were analyzed with 3 cultivars named ’Liaohong’,’Qiujinxing’ and ’Mengyin Dajinxing’.The results showed that the hawthorn fruit weight increased significantly during the first 10 days,the fruit shape index and fruit hardness gradually reduced.The content of titratable acid was decreased by about 25%and the content of soluble sugar decreased less than 10%in 30 days when the fruits were storaged at 4℃.The content of vitamin C in hawthorn fruit increased before harvest and decreased by 17.24%,11.5%and 21.3%after storage respectively for 3 cultivars.3.The diversity of different hawthorn resources was analyzed.The fruit weight was varied from 2.54g to 13.20g and the variation coefficient was 29.55%.Fruit hardness and shape index were 24.64-47.ION and 0.91-1.17 respectively and the variation coefficient were 7.99%and 6.96%respectively.Soluble sugar content was varied from 2.43%to 14.26%and the coefficient of variation was 30.14%.Titratable acid content was varied from 0.63%to 2.69%and the coefficient of variation was 21.12%.The content of Vitamin C was 19.93-135.38mg/100g,with a mean of 88.94mg/100g and the variation coefficient was 23.64%.In addition,Fruit hardness of Crataegus brettschneideri was smaller and the fruit weight was lower compared with Crataegus pinnatifida,however,soluble sugar content was more than 36.7%.4.The total soluble sugar,acid and components in fruits were analyzed by HPLC method.The content of total soluble sugar ranged significantly from 0.94-20.97mg/g FW.The sugar in hawthorn fruit mainly includes glucose,fructose and sucrose.The mean content of glucose was 5.26mg/g FW which is the highest in 3 certain kinds of sugars,and accounted for 47.05%in the total sugar content.Fructose content was smaller than glucose,and the mean was 3.78 mg/g FW.Sucrose content was the lowest in total sugars and the mean was 2.47mg/g FW.The content of fructose in total soluble sugar was accounted for 33.3%in nearly 87.5%in the total cultivars,and the proportion was stable.The content of sucrose in different cultivars varied greatly,and the proportion accounted for total sugar was 0-65.58%.The organic acids in hawthorn fruit mainly included malic acid,citric acid,oxalic acid and tartaric acid.Citric acid was mainly organic acids of the investigated Hawthorn resources,whose content ranged from 0.21 mg/g FW to 37.43mg/g FW.Secondly,malic acid ranged from 0 mg/g FW to 35.88mg/g FW.The content of tartaric acid and oxalic acid were less,accounting for 2.25%and 1.69%in the total acid content,respectively.The ratio of critic/malic acid more than 1 was about 93.8%in total hawthorn germplasm resources,including Crataegus pinnatifida Bge.(’Yidu Changkou’,’Qingyuan Mopan’ etc.),Crataegus mespilus,Crataegus cruss-galli L.,which were classified as citric-dominant types.The ratio of critic/malic acid less than 1 was about 6.2%in total hawthorn germplasm resources,including C.cuneata Sieb.et Zucc.,C.phaenopyrum Medic.,Crataegus laevigata Poir.and some Crataegus brettschneideri;which were classified as malic-dominant types,ekinds of hawthorn varieties were screened and about storability through tgehe of mtrong ature hawthorn fruit5.By the investigation for the storability at 4℃,68 hawthorn accessions were preliminary determined as the strong storage resources,such as ’Huixian Dahong’,’Jinxian Xiaoye’ and ’Pingyi Fuhongzi’ etc.Of 185 hawthorn resources,39.0%resources were lower than 20%in the pod borer insect fruit rate;3 hawthorn varieties were high resistance to the insect with less than 5%of insect fruit rate,including ’Yidu Changkou’,’Jingduan 1 Hao’ and’Pingyi Fuhongzi’.