Kaki Thunb Research Articles

Validation of a male‐linked gene locus (OGI) for sex identification in persimmon (Diospyros kaki Thunb.) and its application in F1 progeny

AbstractIt is crucial to develop a rapid technique for identifying sexuality in the seedling stage of persimmon (Diospyros kaki Thunb.), and the elimination of male progeny has been regarded as an important strategy for enhancing breeding efficiency. In this study, phenotype characterization and genotyping of the male‐linked OGI marker were carried out using 205 accessions, including persimmon cultivars, F1 progeny and nine related Diospyros species. All persimmon cultivars displayed consistent results regarding OGI amplification and sex phenotype. A total of 143 F1 progeny were derived from 11 crosses, among which 95 individuals had flowered. In the flowering full‐sib families, the amplification of the OGI marker in agreement with the sex phenotype was obtained in 85 plants (89.5%). The segregation of OGI in ‘Huashi 1’ × ‘Luotian Tianshi’ and ‘Huashi 1’ × Male 3 F1 populations fit a 1 : 1 ratio. Furthermore, high OGI transferability was observed in nine related species. Overall, the results indicated that the OGI locus could be used to distinguish male from female persimmon plants at an early stage.

Anti-Inflammatory Effects and Mechanisms of Action of Coussaric and Betulinic Acids Isolated from Diospyros kaki in Lipopolysaccharide-Stimulated RAW 264.7 Macrophages.

Diospyros kaki Thunb. is widely distributed in East Asian countries, its leaves being mainly used for making tea. In this study, coussaric acid (CA) and betulinic acid (BA), both triterpenoid compounds, were obtained from D. kaki leaf extracts through bioassay-guided isolation. CA and BA showed anti-inflammatory effects via inhibition of the nuclear factor-κB (NF-κB) pathway, providing important information on their anti-inflammatory mechanism. Furthermore, they markedly inhibited nitric oxide (NO) and prostaglandin E2 (PGE2) production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages, and suppressed tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) levels. Furthermore, they decreased protein expression of inducible nitric oxide synthase and cyclooxygenase-2. Pre-treatment with CA and BA inhibited LPS-induced NF-κB. We further examined the effects of CA and BA on heme oxygenase (HO)-1 expression in RAW 264.7 macrophages: BA induced HO-1 protein expression in a dose-dependent manner, while CA had no effect. We also investigated whether BA treatment induced nuclear translocation of Nrf2. BA inhibited LPS-induced NF-κB-binding activity, as well as pro-inflammatory mediator and cytokine production (e.g., NO, PGE2, TNF-α, IL-1β, IL-6), by partial reversal of this effect by SnPP, an inhibitor of HO-1. These findings further elucidate the anti-inflammatory mechanism of CA and BA isolated from D. kaki.

Population dynamics of mites (Acari) on Diospyros kaki Thunb. and Diospyros lotus L. (Ebenaceae) trees in Ordu, Turkey

Populations of mites (Phytoseiidae, Stigmaeidae, Cunaxidae, Cheyletidae, Tenuipalpidae, Tarsonemidae, Tydeidae, Acaridae) were monitored on Diospyros kaki Thunb. and Diospyros lotus L. (Ebenaceae) in Ordu, Turkey during 2012 and 2013. Phytoseiid, tydeid and acarid populations were higher on D. kaki (both seasons). Cunaxid populations were higher on this species in 2012. Tenuipalpids (2012) and stigmaeids (2013) were significantly more abundant on D. lotus . Populations of pest mites did not reach high levels in persimmon trees not exposed to pesticides. A significant positive correlation between rainfall and tenuipalpid (both persimmon species in 2013) and cunaxid ( D. lotus , 2013) populations. There was also a significant negative correlation between relative humidity and tydeid ( D. kaki in 2012) and cunaxid ( D. kaki in 2013) populations. Temperature showed generally a positive correlation with mite populations, however, a significant negative correlation was detected in tenuipalpid (both species in 2012, D. kaki in 2013) and cheyletid populations ( D. kaki in 2012).

Efficiency of Sequence Characterized Amplified Region Markers for Selecting Non-Astringent Persimmon (Diospyros kaki Thunb.)

Persimmon (Diospyros kaki Thunb.) is classified into four types based on the fruit traits, astringency and flesh color. Of the four types, the pollination-constant non-astringent (PCNA) fruit is typically most desirable for consumption. In the present study, we used five sequence characterized amplified region (SCAR) markers associated with astringency in persimmon fruit, namely E4/E9r, E4/A2r, 7H9F/AST-R, AST-F/AST-R, and AST-F/PCNA-F/5R3R, to improve the efficiency of PCNA-type persimmon breeding via marker-assisted selection (MAS). A total of 84 cultivars of the four types and their segregating F1 progeny were used to evaluate the association of SCAR markers with the fruit astringency phenotype. Polymerase chain reaction evaluation of each SCAR marker showed that E4/E9r combined with AST-F/PCNA-F/5R3R was appropriate for selecting the ast allele responsible for PCNA-type fruit, as the phenotype-genotype match percentages of these two markers were 94% and 99%, respectively. This MAS was verified by the successful use of AST-F/PCNA-F/5R3R to select 107 PCNA-type individuals from 609 F1 hybrid progeny derived from various crosses.

Selection of Suitable Reference Genes for RT-qPCR Normalization under Abiotic Stresses and Hormone Stimulation in Persimmon (Diospyros kaki Thunb).

The success of quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR) to quantify gene expression depends on the stability of the reference genes used for data normalization. To date, systematic screening for reference genes in persimmon (Diospyros kaki Thunb) has never been reported. In this study, 13 candidate reference genes were cloned from 'Nantongxiaofangshi' using information available in the transcriptome database. Their expression stability was assessed by geNorm and NormFinder algorithms under abiotic stress and hormone stimulation. Our results showed that the most suitable reference genes across all samples were UBC and GAPDH, and not the commonly used persimmon reference gene ACT. In addition, UBC combined with RPII or TUA were found to be appropriate for the "abiotic stress" group and α-TUB combined with PP2A were found to be appropriate for the "hormone stimuli" group. For further validation, the transcript level of the DkDREB2C homologue under heat stress was studied with the selected genes (CYP, GAPDH, TUA, UBC, α-TUB, and EF1-α). The results suggested that it is necessary to choose appropriate reference genes according to the test materials or experimental conditions. Our study will be useful for future studies on gene expression in persimmon.

Molecular cloning and functional characterization of DkMATE1 involved in proanthocyanidin precursor transport in persimmon (Diospyros kaki Thunb.) fruit

Persimmon fruits accumulate a large amount of proanthocyanidins (PAs) in “tannin cells” during development that cause the sensation of astringency due to coagulation of oral proteins. Pollination-constant non-astringent (PCNA) is a spontaneous mutant persimmon phenotype that loses its astringency naturally on the tree at maturity; while the more common non-PCNA fruits remain rich in PAs until they are fully ripened. Here, we isolated a DkMATE1 gene encoding a Multidrug And Toxic Compound Extrusion (MATE) family protein from the Chinese PCNA (C-PCNA) ‘Eshi 1’. Expression patterns of DkMATE1 were positively correlated with the accumulation of PAs in different types of persimmons fruits during fruit development. An analysis of the inferred amino acid sequences and phylogenetic relationships indicated that DkMATE1 is a putative PA precursor transporter, and subcellular localization assays revealed that DkMATE1 is localized in the vacuolar membrane. Ectopic expression of the DkMATE1 in Arabidopsis tt12 mutant supported that DkMATE1 could complement its biological function in transporting epicatechin 3′-O-glucoside as a PAs precursor from the cytoplasm to vacuole. Furthermore, the transient over-expression and silencing of DkMATE1 in ‘Mopanshi’ persimmon leaves resulted in a significant increase and a decrease in PA content, respectively. The analysis of cis-elements in DkMATE1 promoter regions indicated that DkMATE1 might be regulated by DkMYB4, another well-known structural gene in persimmon. Overall, our results show that DkMATE1 may be an essential PA precursor membrane transporter that plays an important role in PA biosynthesis in persimmon.

In vitro shoot multiplication and ex vitro rooting of Eustoma grandiflorum by shoot tips using 2,4-D and BAP

An Agrobacterium-mediated transient transformation system was established for gene functional analysis in persimmon (Diospyros kaki Thunb.) utilizing sonication followed by vacuum infiltration of seedlings in vitro. The optimal vacuum conditions for agroinfiltration of persimmon were evaluated by monitoring expression of GUS reporter gene. The technique was further applied to evaluate five different genotypes. Among the genotypes examined in vitro, ‘Xiaoguo-tianshi’ (Chinese PCNA type) produced the highest expression levels of both GUS and GFP, and was the most ideal genotype. Furthermore, the developed system was successfully utilized for DkLAR (leucoanthocyanidin reductase) gene transient silencing. DMACA (4- dimethylaminocinnamaldehyde) staining and the Folin-Ciocalteau assay revealed that the proanthocyanidins (PAs) levels was markedly decrease in ‘Xiaoguo-tianshi’ and ‘Mopanshi’ (Chinese PCA type) leaves. These results confirmed that DkLAR plays an important role in the accumulation of PAs in persimmon. In conclusion, based on the Agrobacterium-mediated vacuum infiltration, we developed a reliable and highly efficient transient transformation system that can be used for gene functional analysis through the seedlings in vitro.

Characterization of a highly polymorphic region closely linked to the AST locus and its potential use in breeding of hexaploid persimmon (Diospyros kaki Thunb.)

The pollination-constant, non-astringent (PCNA) type of persimmon is ideal for production because its fruits lose astringency at harvest regardless of seed formation. The PCNA trait in Japanese persimmons is controlled by a single locus, AST, and is recessive to the non-PCNA trait. Because cultivated persimmon is hexaploid, only the homozygous genotype with six recessive alleles is PCNA. A region tightly linked to AST has been used as a DNA marker for breeding. Three non-PCNA (A) alleles have been reported. Here, we show that the region linked to AST is highly polymorphic and includes microsatellites. By analyzing the size of PCR-amplified fragments, we distinguished 12 different A alleles from 14 non-PCNA cultivars and a Chinese PCNA ‘Luotian-tianshi.’ Then, using A fragment size, we assessed A allele inheritance in six non-PCNA × PCNA populations by analyzing segregation of each A allele in a population and segregation of progeny genotypes. By using A allele segregation analysis, we were able to estimate the copy number of each A allele in five non-PCNA parents but not in ‘Amahyakume.’ By analyzing progeny genotype segregation, we were able to estimate the ‘Amahyakume’ genotype. Our approach can be used not only for the selection of PCNA individuals in populations, but also for estimation of the copy number of A alleles in a possible non-PCNA parent. This would enable us to select non-PCNA parents with fewer A alleles, which would segregate more PCNA individuals in crosses with PCNA cultivars.

Secoiridoids and lignans from the leaves of Diospyros kaki Thunb. with antioxidant and neuroprotective activities

The leaves of persimmon (LP) have been used for centuries in China, Korea and Japan as a delicate, pleasant beverage and an effective herbal remedy. Phytochemical investigations of LP have resulted in the discovery of two new secoiridoid glucosides, named persimmonoid A and B (1–2), together with ten known ones. Antioxidant and neuroprotective assays of all compounds were carried out, and compounds (+)-medioresinol (5), (+)-pinoresinol (7), (+)-pinoresinol-β-D-glucoside (10) and (−)-(7′S,8S,8′R)-4,4′-dihydroxy-3,3′,5,5′-tetramethoxy-7′,9-epoxylignan-9′-ol-7-one (12) were found to exhibit significant activity in the ABTS radical scavenging assay, while compounds (+)-syringaresinol (6), (+)-pinoresinol (7) and (+)-isolariciresinol (11) displayed stronger activity than the positive control in the FRAP assay. In addition, some of these compounds showed statistically significant neuroprotective activities. The HPLC-QQQ-MS/MS method was successfully applied to quantify twelve compounds from LP and fruits of persimmon (FP). The bioactive studies supported LP potential for development as a new antioxidant and neuroprotective functional food.

Effect of split applications of oil cake on leaf nutrient contents, tree growth, and fruit quality in non-astringent persimmon trees

ABSTRACTOil cake, widely used as an organic source of nutrients in horticultural production in South Korea, is a by-product when oil is extracted from various oilseeds. Split applications of oil cake were supplied to evaluate their effects on tree growth and fruit production in organic, non-astringent persimmon (Diospyros × kaki Thunb.) trees in 2009 and in 2010. Treatments included a single annual application of oil cake at 150 kg N ha−1 in April (single application), two applications in April and July (105 and 45 kg N ha−1, respectively; two-split application), or three applications in April, June, and August (60, 45, and 45 kg N ha−1, respectively; three-split application), as well as zero application of oil cake (control). All applications of oil cake significantly increased the amount of ground-cover vegetation compared to the control. The single and two-split applications increased soil organic matter (OM), K2O, CaO, and MgO concentrations, and cation exchange capacity to a soil depth of 0–30 cm in 2010. Oil cake applications increased soil porosity in 2010, as well as overall chlorophyll (SPAD values) and macronutrient concentrations in leaves in 2009 and 2010. Single and two-split applications stimulated water-sprout development, reduced the light intensity inside the tree canopy, and increased fruit drop. Fruit yield was higher in the two-split [24.7 metric tonnes (MT) ha−1] and three-split application trees (25.0 MT ha−1) compared to zero application control trees (19.8 MT ha−1) and single application trees (21.0 MT ha−1) in 2010. A single application resulted in soft fruit and slow skin colouration during maturation. Total soluble solids contents were higher in the control and three-split application trees in both years. The three-split application in 2010 increased the estimated production income by approx. 21% compared to the zero application, and by approx. 33% compared to a single application of oil cake.

Enhanced Microbial, Functional and Sensory Properties of Herbal Yogurt Fermented with Korean Traditional Plant Extracts.

This study evaluated the effects of two Korean traditional plant extracts (Diospyros kaki THUNB. leaf; DK, and Nelumbo nucifera leaf; NN) on the fermentation, functional and sensory properties of herbal yogurts. Compared to control fermentation, all plant extracts increased acidification rate and reduced the time to complete fermentation (pH 4.5). Supplementation of plant extracts and storage time were found to influence the characteristics of the yogurts, contributing to increased viability of starter culture and phenolic compounds. In particular, the increase in the counts of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus was highest (2.95 and 1.14 Log CFU/mL respectively) in DK yogurt. Furthermore, supplementation of the plant extracts significantly influenced to increase the antioxidant activity and water holding capacity and to produce volatile compounds. The higher antioxidant activity and water holding capacity were observed in NN yogurt than DK yogurt. Moreover, all of the sensory characteristics were altered by the addition of plant extracts. Addition of plant extracts increased the scores related to flavor, taste, and texture from plain yogurt without a plant extract, as a result of volatile compounds analysis. Thus, the overall preference was increased by plant extracts. Consequently, supplementation of DK and NN extracts in yogurt enhanced the antioxidant activity and physical property, moreover increased the acceptability of yogurt. These findings demonstrate the possibility of using plant extracts as a functional ingredient in the manufacture of herbal yogurt.

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.

Isolation and Characterization of DkPK Genes Associated with Natural Deastringency in C-PCNA Persimmon.

Chinese pollination-constant non-astringent (C-PCNA) persimmon (Diospyros kaki Thunb.) is considered to be an important germplasm resource for the breeding of PCNA cultivars, though its molecular mechanisms of astringency removal remain to be elucidated. Previously, we showed that the abundance of pyruvate kinase gene transcripts increased rapidly during astringency removal in C-PCNA persimmon fruit. Here, we report the full-length coding sequences of six novel DkPK genes from C-PCNA persimmon fruit isolated based on a complementary DNA (cDNA) library and transcriptome data. The expression patterns of these six DkPK genes and correlations with the soluble proanthocyanidin (PA) content were analyzed during various fruit development stages in different types of persimmon, with DkPK1 showing an expression pattern during the last stage in C-PCNA persimmon that was positively correlated with a decrease in soluble PAs. Phylogenetic analysis revealed that DkPK1 belongs to cytosolic-1 subgroup, and subcellular localization analysis confirmed that DkPK1 is located in the cytosol. Notably, tissue expression profiling revealed ubiquitous DkPK1 expression in different persimmon organs, with the highest expression in seeds. Furthermore, transient over-expression of DkPK1 in persimmon leaves resulted in a significant decrease in the content of soluble PAs but a significant increase in the transcript levels of pyruvate decarboxylase genes (DkPDC1, -3, -4, -5), which catalyze the conversion of pyruvate to acetaldehyde. Thus, we propose that an acetaldehyde-based coagulation effect reduces the content of soluble PAs. Taken together, our results suggest that DkPK1 might be involved in the natural removal of astringency at the last developmental stage in C-PCNA persimmon. This is the first report to identify several novel full-length DkPK genes as well as their potential roles in the natural loss of astringency in C-PCNA persimmon.

Antioxidant potential in non-extractable fractions of dried persimmon (Diospyros kaki Thunb.)

Dried fruits of persimmon (Diospyros kaki Thunb.) are a traditional food in Japan and contain large quantities of tannins. In this study, we investigated the in vitro and in vivo antioxidant potentials of non-extractable fractions from dried persimmons. Hydrolysed non-extractable fractions showed the highest antioxidant activities in vitro. In subsequent experiments, the plasma oxygen radical absorbance capacity (ORAC) values in rats supplemented with a 5% non-extractable fraction were approximately 1.5times higher than those in control rats after 1week in vivo. Furthermore, using an in vitro model of the gastrointestinal tract, the ORAC values of the non-extractable fraction were significantly increased with colonic fermentation in the large bowel stage. These data indicate that non-extractable fractions may possess significant antioxidant potential in vitro and in vivo.

Development of a Transient ihpRNA-induced Gene Silencing System for Functional Analysis in Persimmon (Diospyros kaki Thunb.)

A transient ihpRNA-induced gene silencing system based on Agrobacterium-mediated injection infiltration has been established to evaluate candidate genes involved in proanthocyanidin (PAs) biosynthesis in persimmon (Diospyros kaki Thunb.). We chose DkPDS (phytoene desaturase) as a gene-silencing target to evaluate the newly developed transient gene silencing system. Our qRT-PCR analysis indicated that two ihpRNA constructs (pHG-PDS5’ and pHG-PDS3’) targeted DkPDS, which also led to significantly reduce expression of DkPDS in ‘Mopanshi’ persimmon leaves. To further confirm the reliability of the system, we successfully utilized it for DkLAR (leucoanthocyanidin reductase) gene silencing. The expression levels of DkLAR in ‘Mopanshi’ and ‘Eshi 1’ leaves were ca. 6-fold and ca. 5-fold lower than those in leaves harboring empty vector (pHG-GFP), respectively. DMACA (4-dimethylaminocinnamaldehyde) staining and the Folin-Ciocalteau assay showed that the accumulation of PAs was markedly inhibited in ‘Mopanshi’, ‘Eshi 1’ and ‘Youhou’ leaves. These results indicate that DkLAR plays an important role in the accumulation of PAs in persimmon. The transient ihpRNA-induced gene silencing method developed in this study is a highly efficient and useful tool for functional analysis of persimmon genes involved in PA biosynthesis.

경상북도 지방의 기상환경 변화에 따른 상주둥시 감나무의 과실특성 및 수확량

Division of Special-purpose Trees, Korea Forest Research Institute, Suwon 16631, Korea(Received September 11, 2015; Revised October 29, 2015; Accepted December 3, 2015)ABSTRACTThis study was conducted to analyze the relationship between climate factors and fruit characteristicsof ‘Sangjudungsi’ persimmon (Diospyros kaki THUNB) has been mainly cultivated in Sangju ofKorea. We has been surveyed the yield and fruit characteristics such as fruit weight and soluble solidsof ‘Sangjudungsi’ persimmon from 2010 to 2015 for five years. Also, as major meteorological factor,mean air temperature, cumulative temperature and days, the data of sunshine duration, diurnalrange, and rainfall were collected from Sangju Regional Meteorological Administration. As result ofthat, the annual variation of fruit weight was affected by sunshine duration for April and Octoberrelated starting point of fruit weight increase. The content of soluble solids was affected by sunshineduration for April and October similarly with fruit weight and was negatively correlated with thenumber of days with precipitation in the year. These results indicate the characteristics related to fruitquality like the above were affected by the sunshine duration and precipitation which is critical factorfor the intensity of radiation during rapid growth period (April and October). Fruit number and yieldper tree was commonly affected by mean air temperature of April and cumulative temperature daysof October. These results also indicate that temperature for period of rapid growth stage ofpersimmon may have an important role in the fruit number and yield per tree.Key words: Climate factor, Diospyros kaki THUNB, Fruit weight, Soluble solids, Yield

Removal of Cd(II) from Water System Using Novel Biosorbent Derived from Persimmon Fallen Leaves

A biosorbent was prepared by treating the persimmon (Diospyros kaki Thunb.) fallen leaves with sodium hydroxide (NaOH). The NaOH concentration and stirring period for the preparation of the biosorbent were adjusted to optimise the Cd(I) adsorption capacity of the biosorbents. Removal of highly toxic Cadmium metal ions from water system using the optimal biosorbent named ‘NPFL’ was investigated using a mimic industrial column. The result showed that NPFL could remove Cd(II) in large quantities from aqueous solution with coexisting metal ions. The raw material, NPFL and Cd(II) loaded NPFL were characterized by SEM-EDS. The reusability of NPFL was also studied by batch adsorption-desorption test.

Browning inhibition and microbial control in fresh-cut persimmon (Diospyros kaki Thunb. cv. Rojo Brillante) by apple pectin-based edible coatings

The aim of this study was to develop new edible coatings based on apple pectin with a combination of antioxidants and antimicrobial agents to control enzymatic browning and microbial growth of fresh-cut ‘Rojo Brillante’ persimmon. The survival of important food-borne human pathogens artificially inoculated on fresh-cut fruit was also assessed. Potassium sorbate (PS) at 2 or 4gkg−1, sodium benzoate (SB) at 4gkg−1, or nisin (NI) at 500IUmL−1, were added to apple pectin coatings containing 10gkg−1 citric acid and 10gkg−1 calcium chloride as antioxidants. Persimmon slices were dipped in the coatings, the aqueous antioxidant solution (citric acid and calcium chloride) or water (control), packed in an ambient atmosphere and stored at 5°C for up to 9 days. Microbial growth, colour, firmness, polyphenol oxidase (PPO) activity, visual quality and overall sensory flavour were measured during storage. Coated samples and those dipped in the antioxidant aqueous solution presented lower a* values than control samples, which indicated effective browning inhibition. Persimmon slices treated with coatings containing PS and SB reached the limit of marketability after 7 days of storage. At the end of storage, the overall fruit flavour was ranked above the limit of acceptability. Antimicrobial coatings inhibited growth of mesophilic aerobic bacteria, and those containing SB and NI were the most effective. No growth of moulds, yeasts and psychrophilic aerobic bacteria was detected during storage. All the treatments effectively reduced the populations of Escherichia coli and Salmonella enteritidis, NI-coating being the most effective. For Listeriamonocytogenes, only the NI-coating effectively reduced the bacterial population.

Breeding of ‘Partner’ (Diospyros kaki Thunb.) Astringent Persimmon with High Quality as a Pollinizer

Breeding of ‘Partner’ (Diospyros kaki Thunb.) Astringent Persimmon with High Quality as a Pollinizer

Preliminary results of fruit selection and induced parthenocarpy of mabolo (Diospyros blancoi A. DC.)

The fruits of Diospyros blancoi A. DC., commonly known as velvet apple or mabolo, vary greatly in size. The aims of our study are to clarify the feasibility of large fruit selection and investigate the parthenocarpic nature of mabolo in order to better understand the potential applicability of mabolo in large and seedless fruit production. To conduct an initial selection for large fruits in Taiwan, three individuals (code named SYD, KKN, and YKC) with an average fruit size of more than 200 g were selected. The largest fruits were collected from SYD, the fruit had an average weight of 218.6 ± 61.9 g and an average pulp weight of 193.8 ± 55.1 g (after deducting the weight of seeds). These results were significantly different from those recorded for the entire population, which had an average fruit weight of 103.9 ± 34.0 g and pulp weight of 78.6 ± 29.1 g (after deducting the weight of seeds). As in persimmons (Diospyros kaki Thunb.), parthenocarpic seedless fruits can also be obtained in D. blancoi through manipulation. Parthenocarpic seedless fruits were induced in SYD using either bagging or the stigma removal method. The fruit-set rate and average fruit weights were 49 % and 122.6 ± 24.7 g, and 76 % and 109.3 ± 18.7 g for bagging and the stigma removal method, respectively. SYD fruits had not only fewer seeds and lesser seed weight but also the highest average pulp weight compared to the other two selections, showing that D. blancoi has good parthenocarpy nature and SYD has the best large fruit characteristic for potential commercialization of mabolo.