The objective of this study was to examine the effect of caffeine and sodium bicarbonate in a fertilization medium on the fertilizability of boar spermatozoa that were frozen in straws. Boar spermatozoa were extended with Beltsville F5 extender and frozen in 0.25‐ml straws. In vitro matured porcine oocytes were fertilized in vitro (IVF) with frozen‐thawed boar spermatozoa for 6 h in a modified tris‐buffered medium (mTBM) or in its modified medium by substituting the tris with 25 mM sodium bicarbonate (modified bicarbonate‐buffered medium; mBBM). Some of inseminated oocytes were fixed and stained for examination of sperm penetration. IVF embryos were cultured in a North Carolina State University‐23 medium for embryo development. The percentage of live sperm was 47±4% and morphological abnormality of acrosome was found in 14±3% of spermatozoa. Optimal sperm concentration for IVF was 0.75～1.0×106 sperms/ml when mTBM containing 5 mM caffeine was used as the fertilization medium. Sperm penetration was significantly (p<0.05) stimulated by increasing caffeine concentration in the IVF medium. In addition, mBBM significantly (p<0.05) increased sperm penetration (92%) compared to mTBM (65%). More (p<0.05) blastocysts (22% vs. 32%) developed from the oocytes that were fertilized in mBBM containing 1 mM caffeine than from those fertilized in mTBM with 5 mM caffeine. Our results indicate that boar spermatozoa can be frozen successfully in straws with holding their normal fertilizability and that caffeine and sodium bicarbonate stimulates sperm penetration in vitro.

The techniques of IVM, IVF and IVC of canine oocytes may provide useful information for gamete salvage programs and the conservation of endangered canidae. This investigation has been made to determine the efficiency of in vitro maturation (IVM) as a basic experiment to study the development of canine oocytes after in vitro fertilization (IVF). The rate of oocytes developing to the MII stage was higher in the hormone treated group (10 IU/ml hCG+eCG, 14.7%, p<0.05) than in the control group (0 IU/ml hCG+eCG, 10.0%). The monospermy and pronuclear rates of canine oocytes were investigated after caffeine treatment on IVF. Canine oocytes were fertilized in the Fert‐TALP medium supplemented with 0, 10, 20 or 30 mM caffeine (Fert I, Fert II, Fert III or Fert IV, respectively). The highest pronuclear formation rate was obtained in the Fert I for 24 h IVF (6.7%, 6/89). Therefore, it is believed that unlike in other mammals, caffeine in canine IVF does not increase the efficiency of fertilization rate, and is not an important factor.

치커리와 쑥갓에 있어 기내 파종 시 발아 및 무균묘 생산을 증진시키기 위한 적절한 방법을 제안하기 위해 일련의 실험들이 수행되었다. NaOCl의 적정 처리농도와 시간 검정을 통해 치커리 'Precole'과 'Chiavari' 및 쑥갓 'Okiku 3' 모두 Naocl 5%로 15분간 처리하는 것이 발아 및 유묘형성을 촉진시키고 오염발생을 억제하는 것으로 관찰되었다. 배지조성에 있어 MS와 1/2 MS처리구들의 발아반응성은 뚜렷이 차이가 나타나지 않았으며, sucrose 농도가 높아짐에 따라 발아 및 유묘형성이 지연되었다. 배양용기에 따른 반응성의 차이는 치커리 'Precole'의 경우 petri-dish에서 양호한 발아율 및 유묘형성율을 보여주었지만, 치커리 'Chiavari'와 쑥갓 'Okiku 3'에서는 용기에 큰 영향을 받지 않았다. 초음파 처리는 치커리의 발아율 및 유묘형성율을 증가시켰지만, 쑥갓 'Okiku 3'에서는 초음파 처리효과가 나타나지 않았다. 따라서 치커리와 쑥갓 모두에서 NaOCl 5%, 15분간 종자소독하고, sucrose가 무첨가된 1/2 MS 배지로 petri-dish를 이용하며, 초음파 처리는 NaOCl 5% 용매에서 120분간 하는 것이 기내 발아향상에 적당한 조건으로 선정되었다.