• Journal of Aquaculture
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• v.8 no.3
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• pp.159-170
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• 1995

Triploid abalone, Haliotis discus hannai, was induced by the cold $(0^{\circ}C\;and\;3^{\circ}C)$ or the heat $(35^{\circ}C\;and\;40^{\circ}C)$ shock procedure with fertilized eggs, 12 min. or 32 min. post fertilization with the various time intervals of shock duration. Fertilization rate of each experimental group was not significantly different from that of corresponding diploid control (P>0.05). However hatching rates and normality rates of triploid larvae were significantly different from those of corresponding diploid control (P <0.05). In heat shock groups at $40^{\circ}C$, fertilization rate of eggs was extremely low $(0\~2.7\%)$ and hatched larvae were not detected in these treatment groups. Incidence of triploidy was confirmed by chromosome count and the highest rates of triploid $(84.0\%)$ revealed in cold $(3^{\circ}C)$ shock with 15 min. treatment duration 12 min. after fertilization. The number of diploid chromosome was 2n: 36, and that of tiploid was 3n=54.

• Journal of Aquaculture
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• v.10 no.2
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• pp.123-131
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• 1997

Growth of triploid abalone, Haliotis discus hannai induced by cody (3$^{\circ}C$) shock and its feed efficiency were investigated from larva to adult for 51 months. After 51 months from triploidy induction, the triploid abalones have outgrown to diploid abalones in shell length and total weight. Triploid abalones with inhibition of extrusion of first polar body (3n-1pb) were outgrown to diploid abalones, however, triploid abalones with inhibition of extrusion of second polar body (3n-2pb) were not significantly different from diploid controls in shell length and total weight through the whole rearing period (P<0.05), because of their heterozygosity differences. Daily feeding rates and feed conversion rates decreased with the growth of abalones and both rates had no differnce between two experimental groups. After 51 months from inducing triploid, conditin index of triploid abalone (64.1%) was higher than that of diploid control (59.4%) (P<0.05). Survival rate was 63.0% in triploid group (3n-1pb 62.0%, 3n-2pb 64.0%) and 62.0% in diploid group during the experimental period.

• The Korean Journal of Malacology
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• v.29 no.2
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• pp.105-111
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• 2013

The gonadal development of triploid and diploid Pacific abalones, Haliotis discus hannai was histologically investigated in spawning season. Diploid abalones had matured oocytes and spermatozoa, but most triploid had spermatocytes or developing oocytes that was slightly retarded in gonadal development compared to diploid abalones. In spawning experiment of triploid and diploid abalones, spawning rates of diploid male and female were 100%, but those of triploid female was 50% and male was 25% respectively. Investigation of spawned abalone eggs and spermatozoa revealed that length of diploid sperms head were 17.47 ${\mu}m$, breadth of head were 10.31 ${\mu}m$, length of spermatozoa were 130.72 ${\mu}m$, but those of triploid spermatozoa were 11.83 ${\mu}m$, 7.89 ${\mu}m$ and 103.36 ${\mu}m$ respectively. Triploid spermatozoa were significantly small to diploid spermatozoa (p < 0.05). The eggs of diploid and triploid were not different in size. The cross experiment between oocytes produced by triploids and spermatozoa by diploids ($3n{\times}2n$ cross) revealed that no fertilization were occurred, and $2n{\times}3n$ cross also revealed same result.

• Korean Journal of Ichthyology
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• v.2 no.2
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• pp.203-210
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• 1990

The cobitid hybrid complex of C. sinensis and C. longicorpus occurs commonly in the upper streams of the Nakdong River, Korea where it is sympatric with the bisexual species, C. sinensis and C. longicorpus.The specimens of hybrid complex which are all females accounted for approximately 40% of all cobitid fish observed. These cobitid complex having the unique cloudy specks on body sides appeared to be morphologically intermediate between C. sinesis and C. longicorpusus. The chromosomes of hybrid complex were composed of both diploid form of 49 and triploid form of 73. This forms are tentatively presumed to be a unisexual complex originating from hybrid between C. sinensis and C. longcorpus.

• Korean Journal of Plant Taxonomy
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• v.35 no.2
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• pp.129-142
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• 2005

Somatic chromosome numbers of 19 taxa of Korean Rubus was investigated. Subg. Anoplobatus (2 species), subg. Cylactis (1 species), subg. Idaeobatus (15 taxa) and subg. Malachobatus (1 species) are found in Korea. All taxa belonging to subg. Idaeobatus except for R. parvifolius which shows tetrapolid and hexaploid are diploid. The basic chromosome number of the genus was x=7. New chromosome numbers for 5 taxa were reported here: R. hongnoensis of Jeju-island endemic species, 2n=14; R. longisepalus, 2n=14; R. longisepalus var. tozawai, 2n=14; R. parvifolius, 2n=28; R. parvifolius var. taquetii, 2n=28. The rest 12 taxa except for R. coreanus Miq was well counted as 2n=14 and well consistent with previous reports from China and Japan. Our new chromosome level for R. parvifolius as 6x may indicate that speciation by polyploidization has occurred within Korean population. Unlikely to Japanese population (2n=42), Korean population of R. buergeri has same ploidy level with Taiwanese population as 2n=56.

• Horticultural Science & Technology
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• v.30 no.5
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• pp.543-548
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• 2012

Morphological characters of Baemoochae, xBrassicoraphanus are mostly intermedium of the both parents, Chinese cabbage, Brassica rapa ssp. pekinensis and radish, Raphanus sativus. The upper and lower parts of the leaf resemble the shape of Chinese cabbage and radish, respectively. The midrib of the leaf is round like to that of radish, but very big more than 3 cm in diameter and white in color like that of Chinese cabbage. The root was changed from the swollen type like that of radish to the enlarged taproot like that of the land race of Chinese cabbage after attaining genetical stability. The flower is white. The seed pod is divided into 2 different parts; the upper part is radish and about 4 cm in length and holds 3-4 seeds and the lower part is Chinese cabbage and about 3 cm in length and holds 7-8 seeds. The color of seed is brown, weight per 1.000 seeds is 5.5 g and the number of seeds per mL is 120. The matured plant in the fall season is around 5 kg in weight and outer leaves are very vigorous and stiffly and inner leaves are erect and form a loose head. The leaf and the root contain a high level of sulforaphene which is well known as a functional substance for anti-cancer and anti-super-bacteria. Baemoochae is an amphidiploid and does not have the self incompatibility function. It has a high level of cross compatibility with Chinese cabbage as the female parent, but not the male parent. It is cross incompatible to cabbage, B. oleracea, black mustard, B. nigra and radish. However it is highly compatible to oil seed rape, B. napus, yellow mustard, B. carinata and partial compatible to muatard, B. juncea in the reciprocal cross.

• Horticultural Science & Technology
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• v.19 no.1
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• pp.54-59
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• 2001

The objective of this research was to develop a screening system for selection of grape downy mildew (Plasmopara viticola)-resistant grape cultivars or seedlings under greenhouse condition. Inoculum concentrations ranging from $10^4$ to $10^5spores/mL$ for screening of resistance were evaluated and $5{\times}10^4spores/mL$ was optimum. Of the tested 14 grape cultivars, Campbell Early and Niagara were resistant to grape downy mildew, Sheridan and Cheongsoo were moderate resistant, while Kaiji, Red Queen and Ruby Okuyama were susceptible under both greenhouse and field conditions. Vitis vinifera grape cultivars were more susceptible to grape downy mildew than V. vinifera-labrusca hybrids and V. vinifera-labrusca-aestivalis hybrids. In V. vinifera-labrusca hybrids, tetraploid grape cultivars were more susceptible than diploid culivars. The evaluated results of grape downy mildew resistance under greenhouse condition were in accordance with those of field condition. Results of this study indicated that both greenhouse and field procedures could be used to screen grape cultivars and seedlings for downy mildew resistance.

• Development and Reproduction
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• v.7 no.1
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• pp.29-34
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• 2003

Anatomical and histological observations were used to examine the morphological differentiation and development of the digestive tract during ontogenesis in tiger puffer, Taklyugu rubripes. Before hatching, the digestive tract was located between yolk sac and notochord of embryo. Newly hatched larvae had a straight tubular digestive tract. The larval mouth opened at 2 days after hatching (DAH). At 4 DAH, sphincters separated the digestive tract into the esophagus, anterior intestine, mid-intestine and rectum, and the anus was opened. At 5 DAH, the larval intestine bent between the anterior and intermediate parts and mucous cells developed in the esophageal epithelium. At this time yolk sac was absorbed completely. At 6 DAM, the digestive tract was differentiated into the U type with expansion of the anterior intestine toward the head of the larvae. At 10 DAH, the expanding anterior intestine became wider and a elliptical. At 15 DAH, the anterior intestine was divided into two portions by invagination of dorsal epithelium and the mid-intestine was convoluted dorsally. At 21 DAM, the frontal portion of the anterior intestine formed a differentiated expansion sac. At 24 DAH, the second convolution was observed in the anterior part of the posterior intestine. At 30 DAH the expansion sac was extended longitudinally and the digestive tract took on the form seen in adult fish.

• Horticultural Science & Technology
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• v.34 no.2
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• pp.305-313
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• 2016

Brassica juncea (2n = 4x = 36, AABB genome, 1,068 Mb) is a U's triangle species and an amphidiploid derivative of B. rapa and B. nigra. Fifteen varieties were used to study the ITS (internal transcribed spacer) regions of ribosomal DNA and MITEs (miniature inverted-repeat transposable elements) with a view of developing specific molecular markers. ITSs and MITEs are an excellent resource for developing DNA markers for genomics and evolutionary studies because most of them are stably inherited and present in high copy numbers. The ITS (ITS1 and ITS2) sequence was compared with the consensus sequence of B. rapa and B. nigra. Variation in ITS1 created two separate groups among 15 varieties, with 10 varieties in one group and 5 in the other. Phylogenetic analysis revealed two major clusters for those 10 and 5 varieties. Among the 160 different MITE primers used to evaluate the selected 15 varieties of B. juncea, 70 were related to the Stowaway, 79 to the Tourist, 6 to the hAT, and 5 to the Mutator super-families of MITEs. Of 160 markers examined, 32 were found to be polymorphic when fifteen different varieties of B. juncea were evaluated. The variety 'Blackgat' was different from the other mustard varieties with respect to both phenotype and genotype. The diversity of 47 additional accessions could be verified using eight selected molecular markers derived from MITE family sequences. The polymorphic markers identified in this study can be used for varietal classification, variety protection, and other breeding purposes.