• Horticultural Science & Technology
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• v.33 no.6
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• pp.932-940
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• 2015

One of the main factors restricting production of triploid seedless watermelon is poor germination due to weak embryos, thick seed coats, and larger air spaces. This study was carried out to investigate the priming effects of different concentrations of chemicals, including hydrogen peroxide ($H_2O_2$), fusicoccin, and gibberellic acid (GA) on germination and seedling uniformity of triploid watermelon (Citrullus lanatus). Three commercial triploid cultivars, Seedless Plus, Sinus, and Sizero, were pretreated with water and different levels of $H_2O_2$ (2 and 4%), fusicoccin (FC: 1, 5, and $10{\mu}M$), and GA (1, 5, and $10{\mu}M$). The present findings helped to find optimal priming conditions for improving germination of triploid watermelon. Treatment with $5{\mu}M$ GA and hydropriming helped to break seed dormancy, enhancing the final germination percentages in all triploid cultivars and increasing the germination index in Sizero. These seed-priming treatments could be used on large scale for industrial applications. Moreover, hydropriming provides a simple, effective, and costless method to improve seed germination and seedling vigor of Sinus and Sizero varieties.

• Animal cells and systems
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• v.9 no.2
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• pp.75-78
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• 2005

Fungicides and antagonists were tested for their efficacy in the management of fungal pathogens of watermelon. The fungal species in different genera were isolated from the seeds of watermelon and their vulnerability was assessed against an array of chemicals and bioagents. Among the fungal pathogens, Fusarium species were effectively controlled by Bavistin. Topsin also showed the promising effects against all the fungal pathogens, and Dithane M-45 effectively controlled Didymella bryoniae. Seed treatment with antagonists like Trichoderma harzianum and T. viride improved the seed germination, seedling vigour and reduced the incidence of seed-borne fungal pathogens. Bavistin and Topsin among chemicals increased significantly the seed germination and vigour index. Trichoderma harzianum showed its efficacy against all Fusarium species and even stood effective than Captan and Blitox. However, Pseudomonas fIuorescens also showed promising effect against Didymella bryoniae over fungicides. Under field condition, Topsin and Dithane M-45 showed better yield than Bioagents.

• Journal of Environmental Science International
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• v.25 no.4
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• pp.557-566
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• 2016

In nine commercial watermelon cultivars, the effects of osmotic seed priming were evaluated for seed viability and seedling growth at different germination temperatures and field conditions. Generally, primed seeds showed improved germination rate and reduced time for emergence at different germination temperatures, as compared to untreated seeds. In particular, priming effect on seed germination was significantly high at $15^{\circ}C$, which is an environment normally resulting in poor germination. Depending on the watermelon cultivar, germination rate under low temperature ($15^{\circ}C$) was improved by up to 15~66% in primed seeds, as compared to untreated seeds. However, priming effect on germination was gradually reduced as the temperature reached to its optimum level for seed germination. Seed priming tended to improve the viability, fresh weight, and dry weight of watermelon seedlings, but its effect on seedling stage was not large, as compared to untreated seeds. Primed watermelon seeds showed improved emergence rate and facilitated germination in the field, but their seedling growth after 30 days from germination was not significantly affected. Our results indicated that seed priming can greatly improve the seed germination at poor temperature conditions in the watermelon.

• The Plant Pathology Journal
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• v.16 no.6
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• pp.312-317
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• 2000

The selected five plant growth-promoting rhizobacteria (PGPR) strains, WR8-3 (Pseudomonas fluorescens), WR8-6 (P. putida), WR9-9 (P. fluorescens), WR9-11 (Pseudomonas sp.), and WR9-16 (P. putida) isolated in the rhizosphere of watermelon plants were tested on their growth promotion and control effect against gummy stem rot of watermelon. Strains, WR8-3 and WR9-16 significantly increased stem length of watermelon, and there was a little increase in leaf area, fresh weight and root length when strains, WR8-3, WR9-9 and WR9-16 were treated. Generally, seed treatment was better for plant growth promotion than the soil drench, but there was no significant difference. Seed treatment and soil drench of each bacterial strain also significantly reduced the mean lesion area (MLA) by gummy stem rot, but there was no significant difference between the two treatments. At initial inoculum densities of each strain ranging from 10$^6\;to\;10^{15}$ cfu/g seed, approximately the same level of disease resistance was induced. But resistance induction was not induced at the initial inoculum density of 10$^3$ cfu/g seed. Resistance was induced by treating the strains, WR9-9, WR9-11 and WR9-16, on all of four watermelon varieties tested, and there was no significant difference in the decrease of gummy stem rot among varieties. Populations of the strains treated initially at log 9-10 cfu/g seed, followed with a rapid decrease from planting day to 1 week after planting, but the population density was maintained above log 5.0 cfu/g soil until 4 weeks after planting. Generally no or very weak in vitro antagonism was observed at the strains treated excepting WR9-11. Rifampicin-resistant bacteria which had been inoculated were not detected in the stems or leaves, which suggesting that the bacterium and the pathogens remained spatially separated during the experiment. This is the first report of rsistance induction in watermelon to gummy stem rot by PGPR strains.

• Journal of Environmental Science International
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• v.24 no.12
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• pp.1681-1689
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• 2015

This study was conducted to investigate days after anthesis (DAA) and fruit after-ripening period (FAP) for seed-harvesting of high quality watermelon seeds. Fruit weight and number of seed per fruit increased according to DAA, while those did not significant about FAP. Ratio of cotyledon at whole seed was higher about 2 to 4% compared to seed coat irrespective of DAA and FAP. Germinability of watermelon was not a significant effect by DAA, however, it had differences by FAP. Percent of germination (PB) was below 50%, when 30 days maturated fruits after anthesis was omitted ripening, while PB was increased to 92% by ripening. In addition, seeds at DAA 40 and FAP 20 were higher general seedling vigors (hypocotyl length, diameter etc.) in BP test. Results indicated that considering seed productivity, it had maximized seed viability at DAA 40 and FAP 20.

• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.46.2-46.2
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• 2007

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• Korean Journal of Food Science and Technology
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• v.19 no.4
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• pp.377-381
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• 1987

From the profiles of triglyceride composition and the fatty acid at ${\beta}-position$ of glycerol, triglyceride molecular species were found to be 26 kinds in watermelon seed oil. The major triglyceride molecular species in watermelon seed oil were $C_{18:1}{\cdot}C_{18:2}{\cdot}C_{18:1}$ OLO; 6.4%, $C_{18:0}{\cdot}C_{18:2}{\cdot}C_{18:2}$ SLL; 7.1%, $C_{18:1}{\cdot}C_{18:2}{\cdot}C_{18:2}$ OLL; 16.6%, $C_{16:0}{\cdot}C_{18:2}{\cdot}C_{18:2}$ PLL; 19.6% and $C_{18:2}{\cdot}C_{18:2}{\cdot}C_{18:2}$ LLL; 27.6%, Triglyceride molecular species of watermelon seed oil characterized that LLL species existed more than 27% of the total triglyceride molecular species.

• Journal of Life Science
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• v.16 no.2 s.75
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• pp.219-224
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• 2006

Inter-simple sequence repeat (ISSR) analysis were used to assess genetic diversity among 18 genotypes of watermelon (Citrullus lanatus Thunb.) including breeding lines and commercial varieties. The 21 ISSR primers selected from 100 primers were showed the amplification of 105 reproducible fragments ranging from about 200 bp to 5000 bp. A total of 58 DNA fragments were polymorphic with an average 2.7 polymorphic bands per primer. The polymorphic primers were divided into 18 anchored primers and 3 non anchored primers. All of the anchored primers were di-nucleotide repeat motif, and was more polymorphic than non anchored primers. Eighteen watermelon genotypes were classified into two large groups. Clustering was in some accordance with the division of fruit shape into 18 watermelon. Therefore, ISSR markers may be suitable for variety discrimination and for constructing a linkage map of watermelon.

• Journal of the Korean Society for Nondestructive Testing
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• v.36 no.1
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• pp.35-44
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• 2016

Seed viability is one of the most important parameters that is directly related with seed germination performance and seedling emergence. In this study, a hyperspectral imaging (HSI) system having a range of 1000-2500 nm was used to classify viable watermelon seeds from nonviable seeds. In order to obtain nonviable watermelon seeds, a total of 96 seeds were artificially aged by immersing the seeds in hot water ($25^{\circ}C$) for 15 days. Further, hyperspectral images for 192 seeds (96 normal and 96 aged) were acquired using the developed HSI system. A germination test was performed for all the 192 seeds in order to confirm their viability. Spectral data from the hyperspectral images of the seeds were extracted by selecting pixels from the region of interest. Each seed spectrum was averaged and preprocessed to develop a classification model of partial least square discriminant analysis (PLS-DA). The developed PLS-DA model showed a classification accuracy of 94.7% for the calibration set, and 84.2% for the validation set. The results demonstrate that the proposed technique can classify viable and nonviable watermelon seeds with a reasonable accuracy, and can be further converted into an online sorting system for rapid and nondestructive classification of watermelon seeds with regard to viability.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.412-419
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• 2009

In order to study the inheritance of watermelon seed size, we used six watermelon lines of different seed sizes as parental lines. Six lines include three accessions, 'PI525088' with giant seed (GS), 'Charleston Gray' with big seed (BS), and 'NT' with normal medium size seed (NS), and three near isogenic lines, 'NTss' with small seed (SS), 'NTms' with micro seed (MS) and 'NTts' with tomato seed size (TS) bred by crosses between accession 'NT' of normal seed size and accession 'TDR' of the smallest seed size,. We inspected $F_1$, $F_2$, $BC_1F_1$ (P1), $BC_1F_1$ (P2) populations from the crosses between the adjacent seed size materials like $GS{\times}BS$, $BS{\times}NS$, $NS{\times}SS$, and $MS{\times}TS$, and two crosses between parental lines showing relatively big difference in seed size such as $GS{\times}TS$ and $NS{\times}TS$. Partial single dominant inheritance patterns were observed between $GS{\times}BS$, $NS{\times}SS$, and $MS{\times}TS$ and inheritance patterns based on two genes or more than two genes were speculated between $BS{\times}NS$. A very wide segregation range was observed from the population of $GS{\times}TS$ indicating many quantitative genes involved in the seed sizes. Overall, we speculated that more than six genes are involved in between the biggest and smallest seed size watermelon and three major genes between the normal seed size and the smallest seed size watermelon.