: A total of 67 watermelon accessions which include 37 accessions from Korean and 27 accessions from Turkish germplasm and 3 accessions of other related species from USA were investigated for morphological characteristics. The UPOV descriptor list for 56 characters (6 seedlings, 4 plants, 11 leaves, 5 flowers, 23 fruits and 7 seeds) was used in characterization. In addition, eight quantitative characters, hypocotyl length, cotyledon width, cotyledon length, fruit weight, fruit length, fruit width, thickness of outer layer of pericarp and soluble solid content were also measured. The 56 qualitatively scored characters were analyzed by principle coordinate analysis (PCoA) while the eight quantitative ones were subjected to principle component analysis (PCA). Morphological characterization result demonstrated that the accessions displayed high morphological diversity(how much percent?). A high level of phenotypic diversity was observed from the results of morphological characterization. However, plant growth habit and leaf blade flecking showed constant characters for all of the accessions. The Korean and Turkish watermelon genotypes are diverse groups and can be separated by both multivariate analysis of morphological characters although the grouping was more apparent in PCoS results.

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This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. high resistance to M. cannonballus. A total of four accessions, 'K134068', 'K133069', 'Wondae' and 'PI 414723', showing resistance to both pathogens were selected as candidates for melon rootstock. Yield and quality of fruits harvested from 'Earl's elite' (Muskmelon, Reticulatus Group) grafted onto the selected melon rootstocks were found comparable to or better than those of non-grafted melons.Nearly negligible incidence of fruit fermentation was observed when 'Homerunstar' (Honeydew type, Inodorus Group) was grafted with the selected melon rootstocks, unlike when it was grafted onto 'Shintozwa' (Cucurbita spp.) rootstock. The selected melon accessions with resistance to Fusarium wilt and Monosporascus root rot are considered to be potential and valuable genetic resources for breeding program of melon.

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Abstract. Five isolates of Tomato yellow leaf curl virus (TYLCV) collected from various regions of Korea were amplified using PCR and determined the sequences of full-length genome, respectively. The PCR-amplified DNA of each TYLCV isolate was introduced into a binary vector to construct infectious clone containing 1.9 copies of the corresponding viral genome. Various cultivars and breeding lines of tomato were inoculated with Agrobacterium tumefaciens harboring infectious clone of each TYLCV isolate to assess resistance against TYLCV. Susceptible cultivar 'Super-sunread' revealed typical yellowing and narrowing of the upper leaves. In contrast, breeding linesTY12, GC9, GC171, and GC173, which contained the TY-1 and/or TY-3 genes that confer resistance against TYLCV in nature, were completely symptomless, suggesting that the lines were resistant to challenging TYLCV isolates. Symptoms of TYLCV in susceptible tomato cultivars are significantly different from those of TYLCV in the resistant tomato cultivars at 30 days after agroinfiltration. Although genomic DNAs of TYLCV were detected from the breeding lines TY12, GC9, GC171, and GC173 using real-time PCR analysis with specific primers, levels of TYLCV DNA accumulation in the resistant breeding lines were much lower than those of TYLCV DNA accumulation in susceptible tomato cultivars. Similar symptom severity and levels of TYLCV DNA accumulation were observed from TYLCV infections mediated by Bemisia tabaci in the resistant and susceptible tomato cultivars. Concentration of agrobacterium did not affect the response of tomato cultivars against TYLCV inoculation. Taken together, these results suggest that TYLCV inoculation via agroinfiltration is as effective as inoculation through Bemisia tabaci and is useful for breeding programs of TYLCV-resistant tomato.