The post-thaw survival of mouse embryos of the various developmental stages was determined after cryopreservation by vitrification in a solution containing ethylene glycol, Ficoll and sucrose (EFS). All the embryos were equilibrated for 2 minutes just prior to freezing. The number of blastomeres during in vitro development was counted by nuclei higher rates of post-thaw survival were obtained from the embryos of 2-cell(92.2%), 8-cell(77.2%) or morula stage(90.0%) than those of blastocyst stage(62.7%). The number of blastomeres per embryo following in vitro culture for 24 hours was significantly(P<0.05) smaller as 66.0f22.3 in vitrified and thawed morulae than fresh morulae(91.712.2).

These experiments were carried out to determine the effect of pregnancy in bisected embryo. The embryos of ICR mouse were microsurgically bisected at morula and blastocyst stage using microsurgical blade attached a micromanipulator. These bisected embryos without zona pellucida were cultured up to blastocyst stage and cell count and diameter of stained blastomere, and transferred pseudopregnant mice. And the development of these bisected embryos was compared with the results of production of young of the corresponding intact embryos or cell stage. When the bisected mouse embryos were cultured in vitro for 20 to 24 hours in morula stage(77.2%) or 3 to 6 hours in blastocyst stage(84.1%), them were developed to the expanded blastocyst stage. There were no significant(P<0.05) differences in the development rate of bisected embryos between in morula and blastocyst stages. The embryo size of blastocyst developed in vitro from bisected embryo was small(P<0.05)than intact embryo. However, the number of blastomeres with bisected embryo (24.7+1.3and 21.5+1.2 respectively) were significantly(P<0.05) reduced, compared with that of intacted embryos(36.3+1.1 and 41.4+1.2 respectively). When compared with the result of pregnancy rate(63.6%) after surgical transfer of bisected morulae, a similar result(65.4%) was obtained with bisected blastocyst stage(P< 0.05). However, production of youngs (38.8%) after transfer of bisected morula, a similar result (38.1%) was obtained with bisected blastocyst stage (P<0.05).

This study was conducted to determine the characteristics of fertilization process and embryo development of Astragalus membranaceus Bunge (Astragali Radix) to provide basic data needed in its breeding. A. membranaceus showed poor seed setting when self-pollination was induced. When artificial pollination was induced, it showed less than 5% bearing in late August, but more than 13% bearing from the beginning of September 4th. The flower size was about 17.0 mm×4.0 mm and pistils and stamens had the same length of 15.0mm at flowering stage. When self-pollination or cross-pollination was induced, pollen tubes extended to an ovule. While pollen tube was extending to the ovule, reproductive cell split and formed two male generative nuclei and a vegetative nucleus. In the case of self-pollination, fertilized embryo was not observed, but was formed in the case of cross-pollination. A. membranaceus is noted to have zygote self-incompatibility. In the case of cross-pollination, fertilization was observed in 6 to 8 h after pollination, where apical cell derivatives split after fertilization. A spherical pro-embryo was then formed three days after fertilization. The seed attained full shape with a seed coat showing its distinctive contour 15 days after fertilization. Thus, A. membranaceus in Leguminosae family is found to have zygote selfincompatibility although its flower shape is shown to match the self-compatibility plant.

도축 소의 난소를 이용하여 체외에서 수정란 생산과 이식이 산업화에 접어들고 있지만, 그 기원이 되는 난소의 자질은 검토되어 있지 않고, 생산된 송아지의 자질 또한 의문시 되고 있는 실정이다. 본 실험에서는 도축 한우의 육질과 육량에 따른 배발달율을 조사하여 고품질 체외수정란의 생산에 기초를 확립 하고자 실시하였다. 한우 난소는 도축 직후에 개체별로 paper에 싸서, 0.9%생리식염수 (25-)가 들어있는 보온병에 담아 실험실로 운반하였다. 운반된 난소

아미노산은 수정란의 체외생산에 있어서 배발달에 유효하게 작용한다. 이러한 이유로 체외배양 단계에 아미노산 첨가에 관한 보고는 많지만, 체외성숙 단계에서의 아미노산 효과와 관련된 보고는 소수이다. 본 실험에서는 먼저 체외성숙 배지에 NEAA와 EAA군들의 첨가 농도가 PB 출현율, 배발달율 그리고 생산된 배반포의 세포수에 미치는 영향과 더불어 새로운 아미노산원으로 LAH의 효과를 검토하였다. 체외성숙을 위한 난포란은 도축 한우 난소에서 2-8mm의 가시난

수분후 시기별 배발달 상태와 종자형질의 생장, 개갑 및 발아특성을 연관시켜 조사 연구하여 인삼종자의 채종가능시기와 채종적기를 구명하였던 바 그 결과를 요약하면 다음과 같다. 1. 수분후 열매, 종자 및 배유의 크기는 초기생장이 빨라 20일경에는 성숙한 종자 크기와 큰 차이가 없어 조기채종종자와 완숙종자간에만 유의차가 인정되었으나 종자중은 시기가 경과할 수록 점차 무거워지는 경향이었다. 2. 수분후 20일경에 채종한 종자는 전혀 개갑이 되지 않았으나 30일 후에 채종한 종자는 개갑과 발아가 비교적 양호하여 수분 30일 후면 종자채종이 가능한 시기로 사료되었다. 3. 인삼의 채종적기는 중앙부위의 소화 적심시 수분후 약 50일경의 완숙기에 채종하는 것이 바람직하였다. 4. 배의 발아시기는 수분후 약 10일경으로 추측되었으며 배의 생장속도는 초기단계에서 빠른 경향을 보여 채종가능시기인 수분후 30일경의 배장은 200mu extrmm 이상으로 자엽조직이 분화하기 시작하였다.