Genetic Relationship Analysis,Specific Marker Development And Fruit Quality Evaluation Of Different Nanfeng Mandarin Strains

The Nanfeng mandarin is a local citrus variety in Jiangxi province,notable for its small size,thin skin,sweet flavor,and ease of peeling.Nanfeng mandarin agriculture has a long and illustrious history,dating back over 1300 years ago.During the long-term cultivation process,a rich resource of variation of Nanfeng mandarin was formed.But due to a lack of systematic research,the relational relationship between different Nanfeng mandarin is blurred,resulting in the phenomenon of homonymy or heteronyms,which has an impact on market regularity and cause confusion among seedlings.Based on this,this study collected 20 Nanfeng mandarin and variant materials,and used SSR molecular markers and resequencing techniques to genetically identify and investigate the kinship,At the same time,the development of Kompetitive Allele Specific PCR(KASP)markers for the excellent strain of Nanfeng mandarin,in combination with the SSR marker results,provides technical support for the rapid identification of Miguang.Simultaneously,19 Nanfeng mandarin materials were tested for fruit quality,slagging,and sensory evaluation to identify Nanfeng mandarin strains with good flavor,easier slag,and greater market potential from early,medium,and late maturing Nanfeng mandarin strains,as well as providing relevant supporting data for marketing.The particular outcomes are as follows:1 Using SSR molecular markers to investigate Nanfeng mandarin kinshipA total of 58 polymorphic bands were discovered using 18 pairs of SSR primers to assess the genetic diversity of 20 Nanfeng mandarin strain resources,the findings of UPGMA clustering based on 18 pairs of SSR primers revealed that when the similarity coefficient was 0.67,the 20 Nanfeng mandarin lines could be divided into 2clusters: Xiaoyehongju and Dayehongju,and the other 18 lines of Nanfeng mandarin.When the similarity coefficient is 0.83,the 20 Nanfeng mandarin strains may be divided into 5 clusters: the first cluster is Dayehongju and Xiaoyehongju,the second cluster is Xiaoyeguangju,the third cluster is Huoju,Miguang,and Liuchengmiju,the fourth cluster is Yangxiao2-6,the fifth cluster is the other 13 Nanfeng mandarin.2.Using resequencing to investigate Nanfeng mandarin kinshipThe total amount of sequencing data gathered in this experiment was around129.561 GB,with 122.70 GB of high-quality clean data,taking the Sweet Orange Genome as the reference genome,the average matching rate was 95%,the average genome sequencing depth was 13 X,and the average coverage rate was 82%.The maximum likelihood method was used to cluster the resequenced SNP loci,revealing that the 20 Nanfeng mandarin lines could be divided into 6 clusters: the first cluster is97-1daguo;the second cluster is Liuchengmiju;the third cluster is 8 strains,including Miguang;the fourth cluster is Tezaoshu-WT,97-1xiaoguo,and Tezaoshu;the fifth cluster is five lines,including Nanfengehao;and the sixth cluster is 2007-6 and97-2xiaoguo.3.Miguang-specific markers are being developedA total of 78 pairs of KASP primers were created using SNP variant loci from the SNP difference loci database,and 34 pairs were deleted using the Sweet Orange genome differentiation test,leaving 44 pairs to be verified.Except for Guijuyihao and Huoju,a pair of high-quality KASP primers MG-B00-SNP 3 were used to differentiate Miguang from 17 Nanfeng mandarin strains.Sanger sequencing of 20 Nanfeng mandarin strains demonstrated that the Sanger sequencing results were in perfect agreement with the genotyping results of the KASP marker.Miguang was differentiated from Guijuyihao and Huoju using the SSR primers ATC09 and CAT01.Significant polymorphic bands were found between the samples using 2 sets of SSR primers.In Miguang and Huoju,the primer ATC09 amplified 3 polymorphic bands with fragment sizes of 189 bp,192 bp,and 203 bp.In Guijuyihao and Miguang,the primer CAT01 amplified 2 polymorphic bands with fragment sizes of 222 and 269 bp.4.Nanfeng mandarin strains were subjected to a comprehensive quality assessmentComprehensive quality determination and analysis of Nanfeng tangerine fruit:the 4 indices of Nanfeng mandarin were graded: weight per fruit,soluble solids(TSS)content,titratable acid(TA)content,and solid to acid ratio,the fruit is classified as "large" when it weighs 64.5 g or more per fruit;the fruit is classified as "high" when the TSS content is 16% or more;when the TA content is less than 0.587%,it is classified as "low";the fruit is classified as "high" when the solid to acid ratio is 26.2or more.In Nanfeng mandarin slagging testing,the best slagging was discovered for97-1xiaoguo,Miguang,SS-28,and Guihuadi in 2020,and Miguang,Dayehongju,and Nanfengehao in 2021.The Nanfeng mandarin strains had no significant variations in fruit form index,edibility,juice output,VC content or skin and flesh color.It’s worth noting that,in terms of weight per fruit and peel thickness,the Huoju has the heaviest single fruit weight(87 g)and the thickest skin.In Nanfeng mandarin sensory evaluation,97-1xiaoguo ranked highest overall in 2020;Miguang ranked highest overall in 2021.The fruit quality analysis,chemical residue testing,and sensory evaluation of 2 early-ripening lines,14 medium-ripening lines,and 3 late-ripening lines were combined to determine that the early-ripening lines 97-1zaoshu,the medium-ripening lines Miguang,Liuchengmiju,and the late-ripening lines 2007-6and Nanfengyihao,a total of 5 lines showed larger market development potential.