• Korean Journal of Breeding Science
• /
• v.42 no.1
• /
• pp.100-108
• /
• 2010

This study was carried out to confirm the chromosome constitution and homoeologous recombination of progenies derived from various cross combination using tetraploid OA interspecific hybrid originated from mitotic chromosome doubling. Based on the chromosome analysis of progenies crossed reciprocally, there were only triploid progenies when crossed with diploid Asiatics as male or female parent. While only tetraploid progenies were produced when crossed tetraploid Asiatics or tetraploid OA hybrid with tetraploid OA hybrid, respectively. However, two types of progenies, that is, diploid and triploid plants, were produced from cross combinations between diploid Oriental hybrid and tetraploid OA hybrid. From the GISH analysis of OA hybrid, it was confirmed that diploid $F_1$ OA hybrid was consisted of 24 chromosomes (12 Oriental and 12 Asiatics) showing authentic OA hybrid. On the other hand, it was notified that triploid plants (3x=36) were consisted of 24 Asiatics lily chromosomes and 12 Oriental lily chromosomes by analysis of backcross progenies derived from either $A{\times}OA$ or $OA{\times}A$ crosses. In cross between tetraploid OA and OA, all the progenies were tetraploid with equal number of chromosomes without any homoeologous recombination, i.e. each 24 chromosomes of Oriental and Asiatics. In 2x-4x ($O{\times}OA$) cross combination, some progenies had 2x=24 chromosomes originated from only Oriental hybrid, and other progenies had 3x=36 chromosomes derived from 24 chromosomes of Oriental hybrid and 12 chromosomes of Asiatic hybrid. Only tetraploid Asiatics chromosomes without any Oriental one were produced in all the progenies from 4x-4x ($AA{\times}OA$) cross combination.

• Proceedings of the Korean Society of Developmental Biology Conference
• /
• 2004.07a
• /
• pp.34-35
• /
• 2004

• Journal of Sericultural and Entomological Science
• /
• v.3
• /
• pp.59-60
• /
• 1963

It was prved by the author that : 1. The Smear Method with the buds of mulberry just before sprouting, can be used as one of the best methods in observation of the chromosome number. 2. The chromosome number of the Korean native mulberry is 28 in all (2n=28). 3. Triploid in mulberry can never occur under natural weather condition.

• Korean Journal of Ichthyology
• /
• v.6 no.1
• /
• pp.71-78
• /
• 1994

Fertilized eggs of red seabream, Pagrus major were subjected to cold shock with various initial treatment times and durations. Cold shocks at $3^{\circ}C$ for 20 minutes and 30 minutes at 6 minutes after fertilization yielded the highest triploid incidence with 100%. Triploidy was confirmed by erythrocyte measurements and chromosome counts. Diploid ad 48 acrocentric chromosomes. while triploid had 72 acrocentrics. Triploids revealed increased erythrocyte size compared to their diploids and early growth rates of triploids from 10 days to 34 days after hatching were slightly lower than that of their controls.

• Journal of Animal Reproduction and Biotechnology
• /
• v.35 no.3
• /
• pp.223-231
• /
• 2020

Karyotype analysis is a major work in the process of triploid abalone production for the purpose of productivity and quality improvement. However, the metaphase spreads for karyotype analysis have been prepared just from the larvae at trochophore stage, which has restricted the spectrum of sample correction inhibiting more efficient analysis. Here, we investigated the feasibility of preparing metaphase spreads from the larvae at veliger stage that is the next developmental stage of trochophore. For this, diploid and triploid larvae at trochophore and veliger stages from Pacific abalone (Haliotis discus hannai) were subjected to metaphase spread preparation and its efficiencies were measured and compared each other. As the results, although the efficiencies of metaphase spread preparation were significantly lower in the larvae at veliger stage compared to the ones at trochophore stage regardless of ploidy status, we found that the preparation of metaphase spreads, which showed the clear chromosomal images containing the normal number of chromosomes, was possible from the veliger stage larvae. On the other hands, all larvae used in this study regardless of developmental stage and ploidy did not show colchicine sensitivity. Moreover, no significant difference was observed in cell cycle distribution of the cells comprising larvae between two developmental stages regardless of ploidy status. These suggested that the details of protocol to prepare metaphase spreads from abalone larvae should be optimized depending on its developmental stages. Taken together, we demonstrated the feasibility of preparing metaphase spreads from H. discus hannai veliger stage larvae for karyotype analysis.

• Molecules and Cells
• /
• v.25 no.2
• /
• pp.163-171
• /
• 2008

The genus Cynodon comprises ten species. The objective of this study was to evaluate the genetic diversity of Korean bermudagrasses at the morphological, cytological and molecular levels. Morphological parameters, the nuclear DNA content and ploidy levels were observed in 43 bermudagrass ecotypes. AFLP markers were evaluated to define the genetic diversity, and chromosome counts were made to confirm the inferred cytotypes. Nuclear DNA contents were in the ranges 1.42-1.56, 1.94-2.19, 2.54, and 2.77-2.85 pg/2C for the triploid, tetraploid, pentaploid, and hexaploid accessions, respectively. The inferred cytotypes were triploid (2n = 3x = 27), tetraploid (2n = 4x = 36), pentaploid (2n = 5x = 45), and hexaploid (2n = 6x = 54), but the majority of the collections were tetraploid (81%). Mitotic chromosome counts verified the corresponding ploidy levels. The fast growing fine-textured ecotypes had lower ploidy levels, while the pentaploids and hexaploids were coarse types. The genetic similarity ranged from 0.42 to 0.94 with an average of 0.64. UPGMA cluster analysis and principle coordinate analysis separated the ecotypes into 6 distinct groups. The genetic similarity suggests natural hybridization between the different cytotypes, which could be useful resources for future breeding and genetic studies.

• Development and Reproduction
• /
• v.21 no.2
• /
• pp.181-191
• /
• 2017

A comparison of the growth, hematological values, fatty acids, and gonadal and growth hormonal changes of river puffer, Takifugu obscurus, tiger puffer, T. rubripes, their hybrids (river puffer ${\times}$ tiger puffer) and hybrid triploids was performed during 3 months of their early growth period. Several features were observed during these 3 months: hybrids showed the highest levels of specific growth rate, 1.48%; hybrid triploids showed the smallest change in viscera fat (P<0.05), but GSI was not significantly different among groups (P>0.05). Considering hematological parameters, hybrid triploids had increased mean corpuscular volume and mean corpuscular hemoglobin (P<0.05), but other parameters were not significantly different between groups (P>0.05). With respect to fatty acids, puffer fish, hybrids and hybrid triploids contained fatty acids such as SFAs, MUFAs, n-3 PUFAs and n-6 PUFAs. There were significantly different amounts of total fatty acids between groups (P<0.05), however, rates of changes in fatty acids did not differ significantly between groups (P>0.05). Gonadal hormone (estradiol and testosterone) changes in the river puffer and tiger puffer were significantly higher than that observed in hybrids and hybrid triploids. The hybrids and tiger puffers had higher amounts of growth hormone (thyroid stimulating hormone and thyroxine) than the hybrid triploids and river puffers (P<0.05).

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.44 no.3
• /
• pp.259-266
• /
• 2011

To produce cupped oyster sprat consistently, we investigated the efficiency of nine settlement substrates using selective breeding of Pacific oyster Crassostrea gigas, with the goal of popularizing off-bottom culture on the west coast of Korea. We also compared the growth and survival of selectively bred sprat (diploid) with triploid sprat from an off-bottom culture system. Considering, the attachment rate and detachment efficiency, producing cupped oyster in a polypropylene gunny bag proved to be the most effective method. There were no differences in shell growth or total weight between the diploids from selective breeding and triploids from off-bottom culture for 5 months. However, the survival rate was 8 times higher in the diploids than the triploids. Transplanting sprat from selective breeding is one way to restore oyster farms and nurture off-bottom culture along the west coast.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.27 no.1
• /
• pp.83-88
• /
• 1994

For the purpose of genetic stock indentification of three species of salmonid fishs and their hybrid, lactate dehydrogenase(LDH), malate dehydrogenase(MDH), isocitrate dehydrogenase(IDH), a-gylycerophosphate dehydrogenase(a-GPDH), malic enzyme(ME), 6-phospho-gluconate dehydrogenase(6-PGD), phosphoglucose isomerase(PGI) and phospho-glucomutase(PGM) from skeletal muscle, liver, heart and gill tissues in all three species were analyzed. Chum and masu salmon showed no polymorphic patterns in all isozyme loci, however rainbow trout were found to have polymorphic patterns at MDH-B, LDH and IDH loci. Especially, significant differences were found at MDH-B loci between the three species and the IDH patterns of rainbow trout were also different from the other two species. These loci therefore can be utilized as efficient genetic markers for the identification of hybrids and improve the efficiency of fish breeding. There was no difference except PGI between diploid and triploid isozyme patterns but PGI showed some potential as a marker for triploid in masu salmon.

• Korean Journal of Plant Taxonomy
• /
• v.39 no.3
• /
• pp.216-219
• /
• 2009

The somatic chromosome of two taxa, Galium elegans Wall. ex Roxb(Sect. Cymogaliea Pobed) and Galium asperifolium Wall. ex Roxb(Sect. Leptogalium Lang), in Yunnan, China were investigated. The taxa were reported for the first time. The somatic chromosome numbers of G. elegans was 2n = 22(X = 11), diploid, from two regions, Mt. Canghsan and Hutiaoxia Valley. Those of G. asperifolium were found as 2n = 33, 44, 55(X = 11) with triploid, tetraploid, pentaploid. Most of G. elegans in the Yunnan were confirmed as diploid. The somatic chromosome number of G. asperifolium was found polyploidy, and the investigation revealed that triploid and tetraploid are living together as mixed population in the Mt. Canghsan.