Pollination-constant Astringent Research Articles

Analysis of the Correlation between Persimmon Fruit-Sugar Components and Taste Traits from Germplasm Evaluation.

Persimmon fruits are brightly colored and nutritious and are fruits that contain large amounts of sugar, vitamins, mineral elements, and phenolic substances. The aim of this study was to explore the differences in fruit-sugar components of different persimmon germplasms and their relationships with phenotypic and flavor indices through the determination of phenotypes and sugar components and through electronic-tongue indices, which provided the basis and inspiration for the selection of different sugar-accumulating types of persimmon fruits and the selection of high-sugar persimmon varieties. Our results showed that persimmon germplasm fruit-sugar components were dominated by sucrose, glucose and fructose and that the remaining sugar components were more diverse but less distributed among the various germplasm types. Based on the proportion of each sugar component in the fruit, persimmon germplasms can be categorized into sucrose-accumulating and reduced-sugar-accumulation types. Sucrose-accumulating types are dominated by sucrose, galactose, fucose and inositol, while reduced-sugar-accumulation types are dominated by glucose, fructose, mannose-6-phosphate, and xylose. The content of sugar components in the germplasm persimmon of fruits of different types and maturity periods of also differed, with significant differences in sugar components between PCNA (pollination-constant non-astringent) and PCA (pollination-constant astringent) fruits. Cluster analysis classified 81 persimmon germplasms into three clusters, including cluster I-A, with low glucose and fructose content, and cluster I-B, with medium glucose, fructose, and sucrose contents. Cluster II was high in sucrose and fructose. Cluster III had high contents of glucose and fructose and low contents of sucrose and inositol.

Comparative Metabolomic and Transcriptomic Analyses Reveal Distinct Ascorbic Acid (AsA) Accumulation Patterns between PCA and PCNA Persimmon Developing Fruit.

Persimmon fruit has a high nutritional value and significantly varies between pollination-constant astringent (PCA) and pollination-constant non-astringent (PCNA) persimmons. The astringency type affects sugar, flavonoids, and tannin accumulation and is well known in persimmon fruit. However, the impact of the fruit astringency type on ascorbic acid (AsA) accumulation is limited. In this study, typical PCA varieties ('Huojing' and 'Zhongshi5') and PCNA varieties ('Yohou' and 'Jiro') of persimmon fruit were sampled at four developing stages (S1-S4) to provide valuable information on AsA content variation in PCA and PCNA persimmon. Persimmon fruit is rich in ascorbic acid; the AsA content of the four varieties 'Zhongshi5', 'Huojing', 'Jiro', and 'Youhou' mature fruit reached 104.49, 48.69, 69.69, and 47.48 mg/100 g. Fruit of the same astringency type persimmon showed a similar AsA accumulation pattern. AsA content was significantly higher in PCA than PCNA fruit at S1-S3. The initial KEGG analysis of metabolites showed that galactose metabolism is the major biosynthetic pathway of AsA in persimmon fruit. There were significant differences in galactose pathway-related metabolite content in developing PCA and PCNA fruit, such as Lactose, D-Tagatose, and D-Sorbitol content in PCA being higher than that of PCNA. Combined gene expression and WGCNA analyses showed that the expression of the GME (evm.TU.contig4144.37) gene was higher in PCA-type than in PCNA-type fruit in S1-S3 and exhibited the highest correlation with AsA content (r = 690 **, p < 0.01). Four hub genes, including the DNA methylation gene, methyltransferase gene, F-box, and Actin-like Protein, were identified as potential regulators of the GME gene. These results provide basic information on how astringency types affect AsA accumulation and will provide valuable information for further investigation on AsA content variation in persimmon fruit.

Multiple Introduction Events of Cultivated Diospyros Kaki L. of and Native Diospyros Species in Taiwan Inferred by Low Copy Nuclear Markers

Diospyros kaki L. is one of the most important fruits in Taiwan. Cultivated D. kaki cultivars are classified into four types, according to their loss of astringency in ripening fruit and their change in flesh color, namely the Pollination-Constant Non-Astringent (PCNA), the Pollination Variant Non-Astringent (PVNA), the Pollination Variant Astringent (PVA) and the Pollination Constant Astringent (PCA). Recently, persimmon breeders are paying more attention to rootstock selection for successful grafting and agricultural production. To identify suitable rootstock and to trace the origins of extant native Diospyros species in Taiwan, the 10 known native Diospyros species together with four D. kaki cultivars were analyzed by using two low-copy, nuclear-encoded DNA markers, ncpGS and PHYA. There was moderate to strong support for the major nodes within the phylogenetic tree, obtained from both the Maximum-likelihood or the Bayesian inference methods. The constructed D. kaki phylogeny using Maximum Likelihood (ML) and Bayesian Inference (BI) algorithms formed three clades. The most basal clade (clade A) comprised species distributed in the South East Asia , then species distributed in East Asia (clade B), and then D. kaki cultivars (clade C). The extant native Taiwan Diospyros species nested into clade A and B, suggesting a northward migration pattern of native Taiwan Diospyros species. In addition, the species D. oldhamii formed a sister clade with the D. kaki cultivars, suggesting that D. oldhamii may be a compatible rootstock. Lastly, D. kaki cultivars sampled from growers that were acquaintances formed corresponding subclades within clade C (C-1, C-2 and C-3), suggesting a high discrimination ability of the ncpGS and PHYA molecular markers used here.

Population Genetic Analysis in Persimmons (Diospyros kaki Thunb.) Based on Genome-Wide Single-Nucleotide Polymorphisms.

This study investigated the genetic diversity and population structure of a persimmon (Diospyros kaki Thunb., 2n = 6x = 90) collection in South Korea by evaluating 9751 genome-wide single-nucleotide polymorphisms (SNPs) detected using genotyping-by-sequencing in 93 cultivars. The results of neighbor-joining clustering, principal component analysis, and STRUCTURE analysis based on SNPs indicated clear separation between cultivar groups (pollination-constant nonastringent (PCNA, 40 cultivars), pollination-constant astringent (PCA, 19), pollination-variant nonastringent (PVNA, 23), and the pollination-variant astringent type (PVA, 9)) based on the astringency types, while separation between PVA and PVNA-type cultivars was unclear. Population genetic diversity based on SNPs showed that the proportions of polymorphic SNPs within each group ranged from 99.01% (PVNA) to 94.08% (PVA), and the PVNA group exhibited the highest genetic diversity (He = 3.86 and uHe = 0.397). F (fixation index) values were low ranging from -0.024 (PVA) to 0.176 (PCA) with an average of 0.089, indicating a deficiency of heterozygosity. Analysis of molecular variance (AMOVA) and Fst among cultivar groups indicated that variation within individuals was higher than that among the groups. Pairwise Fst values among the groups ranged from 0.01566 (between PVA and PVNA) to 0.09416 (between PCA and PCNA), indicating a low level of cultivar type differentiation. These findings highlight the potential application of biallelic SNPs in population genetics studies of allopolyploids species and provide valuable insights that may have significant implications for breeding and cultivar identification in persimmon.

Transcriptome and Metabolome Reveal Distinct Sugar Accumulation Pattern between PCNA and PCA Mature Persimmon Fruit.

Persimmon (Diospyros kaki) fruit have significant variation between pollination-constant non-astringent (PCNA) and pollination-constant astringent (PCA) persimmons. The astringency type affects not only the soluble tannin concentration but also the accumulation of individual sugars. Thus, we comprehensively investigate the gene expression and metabolite profiles of individual sugars to resolve the formation of flavor differences in PCNA and PCA persimmon fruit. The results showed that soluble sugar, starch content, sucrose synthase, and sucrose invertase were significantly different between PCNA and PCA persimmon fruit. The sucrose and starch metabolism pathway was considerably enriched, and six sugar metabolites involving this pathway were significantly differentially accumulated. In addition, the expression patterns of diferentially expressed genes (such as bglX, eglC, Cel, TPS, SUS, and TREH genes) were significantly correlated with the content of deferentially accumulated metabolites (such as starch, sucrose, and trehalose) in the sucrose and starch metabolism pathway. These results indicated that the sucrose and starch metabolism pathway maintained a central position of sugar metabolism between PCNA and PCA persimmon fruit. Our results provide a theoretical basis for exploring functional genes related to sugar metabolism and provide useful resources for future studies on the flavor differences between PCNA and PCA persimmon fruit.

Comparative transcriptomic and metabolomic analyses reveal differences in flavonoid biosynthesis between PCNA and PCA persimmon fruit.

The fruit of the persimmon (Diospyros kaki.) has high economic and nutritional value and is rich in flavonoids. Flavonoids are essential secondary metabolisms in plants. The association between persimmon astringency and changes in the proanthocyanidins (a flavonoid subclass) content is well-known. However, information on the relationships between different astringency types and other flavonoid subclasses and biosynthetic genes is more limited. In this study, an initial correlation analysis between total flavonoids and fruit astringency type, and KEGG analysis of metabolites showed that flavonoid-related pathways were linked to differences between mature pollination-constant non-astringent (PCNA) varieties ('Jiro' and 'Yohou') and pollination-constant astringent (PCA) fruit varieties ('Zhongshi5' and 'Huojing'). Based on these findings, variations in the expression of genes and metabolites associated with flavonoid biosynthesis were investigated between typical PCNA ('Jiro') and PCA ('Huojing') persimmons during fruit development. The flavonoid concentration in 'Huojing' fruit was significantly higher than that of 'Jiro' fruit, especially, in levels of proanthocyanin precursor epicatechin and anthocyanin cyanidin derivatives. Combined WGCNA and KEGG analyses showed that genes such as PAL, C4H, CHI, CHS, F3H, F3'5'H, FLS, DFR, ANR, ANS, and UF3GT in the phenylpropanoid and flavonoid biosynthesis pathways may be significant factors impacting the proanthocyanin precursor and anthocyanin contents. Moreover, interactions between the R2R3MYB (evm.TU.contig7272.598) and WD40 (evm.TU.contig3208.5) transcription factors were found to be associated with the above structural genes. These findings provide essential information on flavonoid biosynthesis and its regulation in the persimmon and lay a foundation for further investigation into how astringency types affect flavor components in PCNA and PCA persimmons.

Diversidade genética, produtividade e qualidade de frutos de caqui nos trópicos

Abstract The objective of this work was to determine the genetic diversity, yield, and fruit quality of persimmon genotypes grown in the tropics, in order to select promising genetic materials. DNA extraction was performed on young leaves of 19 persimmon genotypes. For pomological characterization, 15 genotypes were selected. From each genotype, 50 fruit at the physiological maturity stage were harvested in the morning, in order to determine the following parameters: physicochemical characteristics; and the productive variables number of fruit per plant, average fruit fresh mass, average yield, and estimated average yield in two seasons. Twenty SSR markers were tested, out of which 12 were selected to evaluate genetic similarity, which allowed of the identification of distinct groups. The mean genetic diversity value found was 0.41, which is an indicative of low diversity among the analyzed persimmon genotypes. The 'Guiombo', 'Iapar 125', 'Kakimel', 'Mikado RJ', 'Rama Forte Tardio', and 'Taubaté' genotypes show a high yield. The genotypes classified as pollination-constant astringent ('Pomelo', 'Regina', 'Rubi', and 'Taubaté') and those classified as pollination-variant astringent ('Rama Forte', 'Guiombo', and 'Cereja') are potential materials for selection and genetic breeding programs due to their excellent fruit physicochemical characteristics. The investigation through molecular markers is an efficient approach to study the genetic diversity of persimmon genotypes grown in the tropics.

Assessment of Fruit Quality and Genes Related to Proanthocyanidins Biosynthesis and Stress Resistance in Persimmon (Diospyros kaki Thunb.)

Persimmon (Diospyros kaki Thunb.) is becoming a fruit that is used worldwide because it contains high nutritional and medicinal value. However, the trait evaluation of persimmon is still needed and is critical for marketing and breeding, especially in China. Here, we evaluated thirteen quality indicators (fruit weight, horizontal length, vertical length, firmness, titratable acid content, vitamin C content, flavonoid content, anthocyanin content, soluble sugar content, pectinase activity, soluble protein content, tannin content, and tannin cell size) in six Chinese pollination-constant, astringent (PCA) persimmon cultivars (‘Jinxi 3′, ‘Ganfang 1′, ‘Poyang 5′, ‘Poyang 6′, ‘Yifeng 1′, and ‘Yifeng 3′) and a Japanese pollination-constant non-astringent (PCNA) persimmon cultivar (‘Youhou’). The quality indicator data were normalized and subjected to variant analysis and principal component analysis (PCA). The results showed that 10 of 13 indicators among the seven persimmon cultivars were significantly different, and the contribution rates of the first principal component reached 40.582%. The principal component comprehensive scores for ‘Poyang 5′ and ‘Ganfang 1′ ranked second and third, respectively, and were clustered with that of ‘Youhou.’ In addition, we also measured the expression levels of three stress resistance genes and three proanthocyanidin (PA, also called condensed tannins) pathway genes in these persimmon cultivars by quantitative reverse transcription PCR (qRT—PCR). The qRT—PCR analysis of DkCBF and DkWRKY3/8 showed low resistance to cold in ‘Ganfang 1′ but stronger resistance to anthracnose. Moreover, the expression of the PA pathway genes demonstrated that the PA content in ‘Ganfang 1′ was at a moderate level in the seven varieties. Together, our study revealed relatively comprehensive profiles of persimmon quality evaluation and demonstrated that ‘Ganfang 1′ may have the potential to be used as a breeding parent for future persimmon breeding programs.

Molecular Assisted Selection for Pollination-Constant and Non-Astringent Type without Male Flowers in Spanish Germplasm for Persimmon Breeding

Persimmon (Diospyros kaki Thunb) species is a hexaploid genotype that has a morphologically polygamous gyonodioecious sexual system. D. kaki bears unisexual flowers. The presence of male flowers resulted in the presence of seeds in the varieties. The fruits of persimmon are classified according to their astringency and the pollination events that produced seeds and modify the levels of astringency in the fruit. The presence of seeds in astringent varieties as pollination variant astringent (PVA), pollination variant non-astringent (PVNA) and pollination constant astringent (PCA) resulted in fruits not marketable. Molecular markers that allow selection of the varieties according to the type of flowers at the plantlet stage would allow selection of seedless varieties. In this study, a marker developed in D. lotus by bulk segregant analysis (BSA) and amplified fragment length polymorphism (AFLP) markers, named DlSx-AF4, has been validated in a germplasm collection of persimmon, results obtained agree with the phenotype data. A second important trait in persimmon is the presence of astringency in ripened fruits. Fruits non-astringent at the ripen stage named pollination constant non-astringent (PCNA) are the objective of many breeding programs as they do not need removal of the astringency by a postharvest treatment. Astringency in the hexaploid persimmon is a dominant trait. The presence of at least one astringent allele confers astringency to the fruit. In this paper we checked the marker developed linked to the AST gene. Our goal has been to validate both markers in germplasm from different origins and to test the usefulness in a breeding program.

Genetic diversity among wild androecious germplasms of Diospyros kaki in China based on SSR markers

Abstract A lack of male flowers strongly restricts controlled pollination in persimmons. To address this problem, we collected and conserved male persimmon resources from various provinces in China in 5 successive years, from 2012 to 2017. Approximately 120 wild androecious persimmons and 10 monoecious persimmons were collected in Hubei, Jiangxi, Jiangsu, Hunan, Shaanxi, and Henan Provinces as well as Guangxi Zhuang Autonomous Region in China. To determine the genetic diversity and relationships among these androecious persimmons, as well as the relationship among Chinese persimmons, Japanese persimmons and closely related species, 47 wild androecious, 2 wild andromonoecious, 10 monoecious, and 1 female persimmons from China, 12 Japanese persimmons and 15 closely related species, were analyzed based on simple sequence repeat (SSR) markers. A total of 179 alleles and 456 genotypes were obtained from 15 loci, with a mean of 11.93 alleles and 30.40 genotypes per locus. The 87 persimmon resources investigated in this study were divided into XIII clusters using the unweighted pair group method with arithmetic mean average (UPGMA) and the androecious persimmons were distinguished completely from their closely related species. The androecious persimmons originating from the same provinces displayed a close genetic relationship and most Japanese resources could be classified into a same cluster exclusively. A C-PCNA type called ‘Baohuatianshi’ was genetically closely related to three Chinese androecious persimmons (“Macheng Yeshi-1″, “Zhanfanghou-male” and “Qinghua-male”) and two monoecious pollination-constant astringent (PCA) type (‘Xiangyang Niuxinshi’ and “Laojianshan-5″). These results provide useful information for the effective conservation and utilization of androecious persimmons.

Analysis of genetic diversity among a set of accessions from the IVIA’s persimmon collection

In Spain, persimmon (Diospyros kaki Thunb.; 2n=6x=90) production has become an alternative to producing major fruit crops. The aim of the Instituto Valenciano de Investigaciones Agrarias's (Valencia, Spain) persimmon breeding program is to increase the range of available cultivars. Genetic resources collections are an important tool for breeding. Knowledge of the germplasm's genetic structure is valuable for improving the management of plant materials in a breeding program. Here, 47 new accessions having different origins and two rootstock species were studied using 18 polymorphic microsatellite markers. Genetic structures were estimated using a Bayesian-based model clustering method, while a Neighbor-Joining phylogenetic tree was constructed to visualize the genetic relationships among the samples. Evanno's test of the Bayesian-based model estimation found that three populations were the most informative. Persimmon cultivars are classified in four types, pollination-constant non-astringent, pollination-variant non-astringent, pollination-constant astringent and pollination-variant astringent, based on their astringency. Using these types, most of the pollination-constant and pollination-variant non-astringent accessions were grouped separately from the pollination-constant and pollination-variant astringent accessions, regardless of their origin.

ADH and PDC genes involved in tannins coagulation leading to natural de-astringency in Chinese pollination constant and non-astringency persimmon (Diospyros kaki Thunb.)

Pollination constant non-astringency (PCNA)-type persimmons are the most desirable cultivar because the fruit loses astringency naturally and does not require any treatments for edibility. The mechanism of natural astringency loss in Chinese PCNA (C-PCNA)-type persimmon is probably related to the coagulation of soluble tannins into insoluble tannins, which is quite different from that in the Japanese PCNA (J-PCNA) type. In this work, three types of persimmon cultivars were sampled: ‘Luotian-tianshi’ (C-PCNA), ‘Maekawa-jirou’ (J-PCNA), and ‘Mopanshi’ (pollination constant astringent (PCA)) were sampled. Three DkADH and four DkPDC genes were isolated from C-PCNA plants. Three candidate genes for soluble tannins coagulation identified in C-PCNA fruit (DkADH1, DkPDC1, and DkPDC2) were characterized through combined analysis of spatiotemporal expression patterns and tannin and acetaldehyde contents during fruit development. Transient over-expression in persimmon leaves showed that DkADH1 and DkPDC2 led to a significant decrease in the levels of soluble tannins in infiltrated leaves. These results indicated that DkADH and DkPDC genes should be considered key genes for natural astringency loss in C-PCNA types.

Persimmon breeding in Japan for pollination-constant non-astringent (PCNA) type with marker-assisted selection.

Oriental persimmon (Diospyros kaki) originated in Eastern Asia, and many indigenous cultivars have been developed in China, Japan, and Korea. These cultivars are classified into four groups based on their natural astringency loss on the tree and seed formation: pollination-constant non-astringent (PCNA), pollination-variant non-astringent (PVNA), pollination-constant astringent (PCA), and pollination-variant astringent (PVA). PCNA is the most desirable type because the fruit can be eaten without any postharvest treatment; therefore, one of the goals of our persimmon breeding programs is to release superior PCNA cultivars. The PCNA genotype is recessive to the other three non-PCNA genotypes, and PCNA-type F1 offspring are obtained exclusively from crosses among PCNA genotypes. Moreover, the number of superior PCNA cross-parents have been limited. In the late 1980s, inbreeding depression became obvious, especially in terms of fruit size, tree vigor, and productivity. To mitigate the inbreeding, a backcross program using PCNA [(non-PCNA × PCNA) × PCNA] was started in 1990. This process, however, was inefficient because only 15% of the offspring were PCNA, and all offspring had to be grown to the fruiting stage. Therefore, molecular markers linked to the PCNA locus were developed for discriminating PCNA offspring. A molecular marker linked to Chinese PCNA has also been developed.

Development of Molecular Markers Linked to the Allele Associated with the Non-astringent Trait of the Chinese Persimmon (Diospyros kaki Thunb.)

Persimmon cultivars are classified into four types depending on the nature of astringency loss of the fruit, namely pollination constant non-astringent (PCNA), pollination variant non-astringent (PVNA), pollination variant astringent (PVA), and pollination constant astringent (PCA). Among these four types, PCNA is the most important cultivar for persimmon breeding due to the stable loss of natural astringency on the tree. The trait of natural astringency loss is recessive in Japanese PCNA cultivars, while that in the Chinese PCNA cultivar, ‘Luo tian tian shi’, is dominant and the latter locus, termed CPCNA, is different from that in Japanese cultivars. In order to develop a molecular marker for the selection of the CPCNA-type cultivar, we performed amplified fragment length polymorphism (AFLP) in combination with bulked segregant analysis for F1 offspring derived from ‘Luo tian tian shi’, which was used as the maternal parent. A total of 384 primer combinations were tested, and three AFLP markers, namely EACT-MCCC-222 (RO1), EGGC-MCTC-309 (RO2), and EGCC-MCGA-105 (RO3), linked to the CPCNA dominant allele were obtained. Among these markers, EGGC/MCTC-309 (RO2) was converted into a sequence-characterized amplified region (SCAR) marker. PCR analysis using F1 offspring (n = 264) revealed that the relevance ratio of the SCAR marker was 94%. The polymorphism of the RO2 marker, which was strongly linked to the CPCNA dominant allele, was detected in only two Chinese PCNA cultivars, namely ‘Luo tian tian shi’ and ‘Tian bao gai’, among the Chinese, Korean, and Japanese cultivars tested. These results indicate that the RO2 marker contributes to marker-assisted selection for breeding programs of new PCNA cultivars having the CPCNA trait.

GENE EXPRESSIONS INVOLVED IN FLAVONOID BIOSYNTHETIC PATHWAY IS ASSOCIATED WITH TANNIN ACCUMULATION IN JAPANESE PERSIMMON (DIOSPYROS KAKI THUNB.) FRUIT

Japanese persimmons (Diospyros kaki Thunb.) are classified into the following four types depending on the effect of pollination on flesh colour and whether the fruit lose astringency on the tree: 1) pollination-constant non-astringent (PCNA), 2) pollination-variant non-astringent (PVNA), 3) pollination-variant astringent (PVA), and 4) pollination-constant astringent (PCA). Among these four types, PCNA-type is the most desirable persimmon for fresh consumption, since the fruit can be eaten always while firm without any postharvest treatments. The PCNA-type appeared uniquely in Japan probably due to the loss of the ability of tannin accumulation. PCNA-type fruit stops accumulating tannins at an early stage of fruit development. However, the molecular mechanism controlling tannin accumulation in persimmon is not so clear. Persimmon tannins are categorized into condensed tannins consisted of polymeric proanthocyanidins, which are synthesized via flavonoid biosynthetic pathway. So, we investigated varietal and seasonal changes in expressions of five genes involved in flavonoid biosynthesis (PAL, CHS, CHI, F3H, and DFR). The expressions of these genes were high until late stages of fruit growth in astringent-type, whereas those disappeared at an early stage of fruit growth in PCNA-type fruit. The relationship between transcripts of these genes and tannin accumulation in the fruit is discussed.

초위성 마커를 이용한 감(Diospyros kaki Thunb.)의 유연관계 분석

총 20개의 감 SSR primer set을 사용하여 완전단감(PCNA) 12품종, 불완전단감(PVNA) 13품종, 불완전 떫은감(PVA) 15품종, 완전 떫은감(PCA) 8품종 등, 총 48개 유전자원의 유전적 연관성을 분석하였다. 획득된 114개의 다형성 밴드를 이용하여 UPGMA 방식으로 유사도 및 집괴분석을 수행한 결과 48개 품종들은 크게 2개의 그룹(cluster)으로 나뉘어졌으며, 제 1 cluster는 다시 4개의 subcluster를 형성하였다. 이는 탈삽의 특성을 기준으로 분류한 품종군과 대체로 일치 함을 알 수 있고, 품종군간의 유연관계에 있어서는 완전단감군은 불완전 단감군과, 그리고 완전 떫은감은 불완전 떫은감군과 유연관계가 더욱 높은 것으로 관찰되었다. 평균 유사도의 값은 0.499였고 품종간 가장 높은 유사도 값(0.954)를 나타낸 것은 '청도반시'와 '함안반시'였고, 가장 낮은 유사도 값(0.192)를 나타낸 것은 '대마반'과 '애탕'이었다. 본 연구에 사용된 2SSR primer 들은 유럽 감품종으로부터 개발되어 보고되었지만, 일본 및 국내 품종의 연구에서도 효과적으로 사용될 수 있었고, 이들 마커들을 통해, 48개 품종 중 청도반시(Cheongdo-Bansi)와 경산반시(Gyeongsan-Bansi)를 제외한 모든 품종간 구별이 가능하였다. 이는 향후 신품종 개발시 품종보호를 위한 품종 특이적 마커로 효율적으로 사용될 수 있음을 보여준다. The genetic diversity among 48 persimmon (Diospyros kaki Thunb.) accessions, indigenous in Korea and introduced from Japan and China, was evaluated by using simple sequence repeat (SSR) markers. From 20 SSR primer sets, a total of 114 polymorphic markers were detected among 12 pollination-constant non-astringent (PCNA), 13 pollination-variant non-astringent (PVNA), 15 pollination-variant astringent (PVA), and 8 pollination-constant astringent (PCA) cultivars. Analysis of pair-wise genetic similarity coefficient (Nei-Li) and unweighted pair-group method with arithmetic averaging (UPGMA) clustering revealed two main clusters and four subclusters for cluster I. The subclustering pattern was in accordance with the classification of persimmon cultivars based on the nature of astringency loss. Phenetic relationships among the subclusters showed a closer relatedness of the PCNA group with the PVNA group, and the PVA with the PCA group. Genetic similarity co-efficiency was 0.499 on average and the highest (0.954) similarity was observed between 'Cheongdo-Bansi' and 'Haman-Bansi'. The similarity was lowest (0.192) between 'Damopan'and 'Atago'. Identification of each cultivar with the execption of 'Cheongdo-Bansi' and 'Gyeongsan-Bansi' was possible based on the SSR fingerprints, suggesting that these SSR markers are a useful tool for protecting intellectual property on newly developed cultivars.

Segregations of Astringent Progenies in the F1 Populations Derived from Crosses between a Chinese Pollination-constant Nonastringent (PCNA) `Luo Tian Tian Shi', and Japanese PCNA and Pollination-constant Astringent (PCA) Cultivars of Japanese Origin

Pollination-constant and nonastringent (PCNA) is one of the most desirable traits in persimmons as this type of cultivar loses its astringency while still on the tree before harvest. Among Japanese PCNA cultivars, the trait is qualitatively inherited and recessive to pollination-constant, astringent (PCA), pollination-variant, nonastringent (PVNA), and pollination-variant, astringent (PVA) types. However, in a previous trial, both astringent and nonastringent types segregated in the F1 population that resulted from a cross between a Chinese PCNA `Luo Tian Tian Shi' and a Japanese PCNA cultivar. Because of the unusual segregation, in this study, we crossed another Japanese PCNA `Okugosho' with `Luo Tian Tian Shi' to confirm the segregation of astringent types by measuring the tannin cell size and tannin concentration at harvest. Previously, we found that astringent types have larger tannin cells than PCNA-type. The F1 hybrid progenies from the cross segregated into both PCNA and astringent-type individuals in approximately 1:1 ratio. Likewise, the F1 population from the astringent-type `Yotsumizo' and `Iwasedo' × `Luo Tian Tian Shi' were ascertained to contain both PCNA and astringent types, which indicates that the PCNA trait of `Luo Tian Tian Shi' was dominant. Thus, this Chinese cultivar has the potential to become an important parental material for future breeding of PCNA persimmons.

Segregation of Astringency in F1 Progenies Derived from Crosses between Pollination-constant, Nonastringent Persimmon Cultivars

Japanese persimmon (Diospyros kaki Thunb.) cultivars are classified into four types depending on the nature of astringency loss of the fruit. The pollination-constant, non-astringent (PCNA) persimmons lose their astringency on the tree as the fruits develop. This PCNA trait is qualitatively inherited and recessive to the other three types, pollination-constant, astringent (PCA), pollination-variant, nonastringent (PVNA), and pollination-variant, astringent (PVA). In fact, crosses among Japanese PCNA cultivars yield only PCNA type in F1 generation as shown in recent breeding programs at the National Institute of Fruit Tree Science. Despite these previous results, we demonstrated here that non-PCNA (PVNA, PVA, and PCA) type offspring were derived at relatively high rates in the F1 generation from a cross between `Luo Tian Tian Shi', a PCNA accession from China, and the Japanese PCNA cultivar, `Taishu', despite the fact that `Luo Tian Tian Shi' was confirmed to be a true PCNA type by measuring tannin cell size, a principal morphological characteristic to distinguish PCNA cultivars from non-PCNA ones. When segregations of tannin cell size and tannin content in three progenies of the breeding populations derived from Chinese PCNA `Luo Tian Tian Shi' × Japanese PCNA `Taishu', Japanese PCNA `Shinshu' × Japanese PCNA `Taishu', and Japanese PVNA (non-PCNA) `Kurokuma' × Japanese PCNA `Taishu' were investigated, all offspring between Japanese PCNA cultivars contained only small tannin cells and were PCNA types, and those between Japanese PVNA × PCNA cultivars contained only large tannin cells and were non-PCNA types. However, hybrids between `Luo Tian Tian Shi' and `Taishu' segregated into populations of small and large tannin cells, indicating that `Luo Tian Tian Shi' is likely heterozygous for astringency. Therefore, Chinese PCNA `Luo Tian Tian Shi' should be different from Japanese PCNA cultivars in genetic makeup.

日本原産のカキ品種における果実成熟期, 果実重及び可溶性固形物含量の変異

One hundred and eighty-eight cultivars of oriental persimmon (Diospyros kaki Thunb.) native to Japan were evaluated for fruit ripening time (FRT), fruit weight (FW), and soluble solids content (SSC). A high heritability for each of these traits was conserved in this population; the overall mean and SD of FRT, FW and SSC were early to mid-November and 15 days, 200 g and 72 g, and 17.0% and 1.7%, respectively. Subgroups of PCA (pollination constant-astringent) and PVNA (pollination variant-nonastringent) showed wide variations for each trait. As to mean values, the PVNA group had slightly earlier FRT and higher SSC than the PCA group but their FW were similar. PCNA (pollination constant-nonastringent) group showed the latest FRT and the SSC was intermediate between those of PCA and PVNA groups; whereas, PVA (pollination variant-astringent) had the earliest FRT with the lowest SSC. The PCNA and PVA groups had larger fruits than the PCA and PVNA groups. Variations in FRT and SSC of PCNA were characteristically small, which suggest that these cultivars evolved later than the others.There is a weak, negative correlation between FW and SSC and a weak, positive one between FRT and FW. The percentage of early ripening cultivars was higher in cultivars which originated in the northern areas of Japan in contrast to those developed in southern regions.

カキの甘渋の遺伝

Inheritance of astringency in Japanese persimmon (Dyospiros kaki Thunb.) was investigated using data collected over 30 years in Okitsu Horticultural Research Station.PCNA (pollination constant non-astringent) and non-PCNA were qualitatively inherited. The former was recessive to the latter. Backcrosses between PCNA and the progeny (PCA) derived from the cross of PCNA×non-PCNA yielded PCNA of approximately 15 percent.Inheritance of astringency in non-PCNA seemed to be quantitative. Few PVNA (pollination variant non-astringent) progenies occured from crosses among PCA (pollination constant astringent) cultivars. Many PCA progenies occured from crosses among PVNA cultivars.In crosses between PCNA and PCA, more PVNA or PVA (pollination variant astringent) progenies were obtained between ‘Fuyu(PCNA)’ and PCA cultivars, compared to crosses between other PCNA cultivars and PCA cultivars.