• Korean Journal of Plant Resources
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• v.4 no.2
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• pp.47-49
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• 1991

In an attempt to analyse the variation of chromosome numbers in Cododopsis lanceolate, 28 species of Deo-Deong have been examined for determination of chromosomenumbers. Tlle somatic chromosone numbers were counted to be 2n=16 of C. lanceolata.

• Journal of Korean Society of Forest Science
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• v.77 no.1
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• pp.53-64
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• 1988

The idiogram of pine chromosomes was obtained from the length, the ratio of the long and short arm, and the position of the secondary constriction. The descending order of the long arm was found by analyzing the idiogram for 6 species of hard pines and 5 species of soft pines growing in Korea. The basic chromosome number of the genus Pinus was n=12, of which the ten chromosomes were the M-type showing similar S/L ratio, and the other two short chromosomes were the heterobrachial SM-type and the sub-median centric SM-type. The interspecific identification was able to made by comparing the number and the position of the secondary constriction, and the pattern of descending order of the long arm. The intraspecific variation was also able to be identified by comparing the long arms Descending order among the provenaces. Some differences were found in the chromosomal structures between the hard- and the soft-pines. However, the differences were not apparent as much as those in the morphological characteristics. The results might not be exactly reproducible because of the variable responses of chromosomes depending on concentration of the chemicals, the temperatures and time of the treatments, and the analytical errors during the preparateur preparation.

• Korean Journal of Animal Reproduction
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• v.21 no.1
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• pp.47-52
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• 1997

The objective of this study was to investigate the in vitro / in vivo embryonic development after vitrification of mouse zygotes and the chrom osomal normality of delivered live young after embryo transfer. Mouse IVF zygotes were cryopreserved by vitrification using vitrification solution, EFS40 (40% ethylene glyc이, 30% Ficoll a and 0.3 M sucrose in phosphate buffer saline c containing 10% FBS ) . After mouse zygotes were exposed to EFS40 at 25"C for 30 sec., they were immediately plunged into LN$_2$. Vitrified thawed mouse zygotes were cultured upto bIastocysts in M16 for 4 days. The rates of in vitro development were 71.5% under this condition. Cultured blastocysts were transferred to recipients (3 day of pseudopregnant) on one or both uterus horns (6-8 embryos per a uterus horn). And all recipients were allowed to produce litters. The results obtained in these experiments were summarized as follows: The pregnancy rates and in vivo survival rates, live fetus rates, for vitrified zygotes (80.0, 39.6%) were not significantly difference in those of control zygotes (77.8%, 50.0%). Also, all of live-born young mice were chromosomally normal (n=40). This results suggested that proposed rapid vitrification procedures can be effectively use in 1-cell mouse zygotes cryopreservation.