| Pomelo(Citrus grandis Osbeck)is one of the most important cultivated fruits in China.As one of the birthplaces of pomelo,China has abundant pomelo germplasm resources.Hainan is the largest tropical province in China,there are many germplasm resources of pomelo,but there are no detailed records and related studies on it.In order to protect and efficiently use these pomelo germplasms,the study was carried out to collect,describe and identify a number of excellent pomelo germplasm resources.And a genetic relationships and genetic diversity of Hainan pomelo germplasm resources were further studied at the molecular level.(1)62 varieties of pomelo completed variety certification(identification,protection,etc.)in China were counted,and analyzed in terms of year,maturity period,breeding methods,etc.,and the main pomelo varieties and their derived varieties(lines)were analyzed with emphasis.The results show that the number of breeding has been on the rise since 1985,and has increased obviously since 2010.The main breeding methods were bud transformation and seed breeding.The mature period is mainly concentrated in September to November.It was mainly white meat,followed by red meat,and yellow meat was the least.Find out the three backbone parents of "Shatin pomelo","Guanxi honey pomelo" and "Anjiang sweet pomelo".(2)16 Hainan pomelo germplasms’ 21 botanical traits,such as tree pose,tree form,spring shoot length,leaf length,leaf width etc.were used Euclian-type genetic distance cluster analysis and principal component analysis.The clustering results showed that the maximum genetic distance was 10.478 and the shortest was 2.832.Principal component analysis found a total of five principal components,including 13 main characters.(3)The fruit quality of 6 varieties of grapefruit collected in Hainan was determined,and the fuzzy comprehensive evaluation of fruit internal quality was carried out with seedless pomelo.The results showed that the fruit quality of germplasm HN-3,HN-7 and HN-8 was better than that of seedless pomelo,but there was a certain gap.(4)The fruit quality of normal seedless pomelo and navel pomelo were compared.It was found that the fruit shape index of normal fruit and umbilical grapefruit had no difference.The umbilical grapefruit had higher edible rate and thinner skin.The content of soluble solids,Vc and soluble protein were significantly different,while the content of titratable acid,soluble total sugar,solid to acid ratio and sugar to acid ratio were not significantly different.(5)The storage test of seedless pomelo showed that the fruit quality was kept the best and the storage period was the longest under 10℃,which could reach more than90 days.(6)SSR markers were used to identify the genetic relationships between 16 collected grapefruit germplasm and 34 known grapefruit germplasm.A total of 87 polymorphic bands were amplified from 50 germplasm using 7 pairs of primers,with an average of 12.4 bands per pair of primers.Cluster analysis results showed that the50 germplasm could be clustered into 3 groups when the similarity coefficient was0.675,and all germplasm could be clustered into 10 groups when the similarity coefficient was 0.76.The collected pomelo germplasm was distributed into 5 groups,among which HN-7,HN-8 and Sanhong pomelo were clustered into one group.HN-1,HN-2,HN-3,HN-6,HN-11,HN-12 and HN-14 are grouped with yellow grapefruit,HN-10 is grouped with red grapefruit,HN-5,HN-9,HN-13,HN-15,HN-16 is grouped with Ping Mountain grapefruit,Vietnam red skin red grapefruit,red skin red flesh grapefruit and mountain orchid grapefruit.HN-4 is a class by itself.The results of genotype genetic structure analysis of the collected pomelo germplasm resources showed that the collected pomelo germplasm could be divided into 5 groups,which indicated that the 16 pomelo germplasm had a certain degree of differentiation among each other. |
PDF Full Text Request