외국에서 도입한 블루베리의 내한성을 평가하고, 목재수분계측기가 월동 중 블루베리 가지의 동해피해를 간편하고 신속하게 진단하는데 활용할 수 있는지를 알아보기 위하여 수행되었다. 월동 중 블루베리의 가지의 고사율은 0~100%로 다양하게 나타나 품종별 내한성의 차이가 컸다. 블루베리 가지의 저온처리에 따른 TTC 검정에서 품종별 OD값은 -40℃ 〈 -21℃ 〈 4℃ 순으로 처리온도가 낮을수록 낮게 나타났다. 블루베리 가지의 저온처리에 따른 가지절단면의 색의 검정은 가지고 사율에 의한 내한성과 다른 결과와 차이가 있었다. 목재수분계측기에 의해 측정된 살아있는 블루베리 가지의 월동 중 최저 수분함량은 약 15%였으며, 월동 중 블루베리 가지의 위치별 수분함량은 나무 아랫부분일수록 높고 가지 끝으로 갈수록 낮았으나, 봄으로 접어들면서 가지 끝의 수분함량이 점점 높아져 20~40% 범위로 측정되었다. 월동 중 동해피해를 받은 가지는 점점 건조되어 수분함량이 5% 이하로 낮아졌다. 동해를 받은 블루베리 가지의 수분함량은 14% 수준 이하일 것으로 추정되며, 목재수분계측기가 블루베리 가지의 동해피해를 현장에서 신속하게 진단하는데 활용될 수 있을 것으로 기대된다.

This study was performed to investigate the characteristics within ages and freezing tolerance of spermatozoa in Jindo Dog. Experimental animals were selected 12 herds within 1～8 year’s old and collected semen for 2 times in a week. Collected semen was evaluated whole volume and sperm number with CASA system (SIAS, Medical Supply, Korea). Then seminal plasma were separated and diluted with modified Tris-egg yolk extender and added 4, 6 and 8% glycerol for 4 times to final concentration and equilibrated for 1.5 hrs. Before and after freezing, equilibrated semen were evaluated the survival rates. Total volume of sperm at 1～2 year old group is as 5.2×108 cells/ ml largest and there were no significance among groups. The motility of 1～2 year old group is highest as 90.9% and there were significance among groups. Abnormal sperm showed similar among groups. The survival rate in terms of pre-freezing and post-freezing were decreased all levels of glycerol and reveled 87.0% to 64.5% in 4%, 87.5% to 51.9% in 6% and 73.4% to 29.7% in 8%, there were significant difference among the groups (p<0.05). These results suggest that the optimal sperm-freezing methods in Jindo Dog are utilized with modified Tris egg-yolk extender with 4% glycerol and were improve the reproductive activity by these methods.

Anthocyanins are responsible for vivid colors of flowers, fruits and vegetative tissues and biosynthesis of it is primarily controlled by several structural and regulatory genes. The regulatory mechanism of this pathway is still unknown. This study identified 19 transcription factors of Brassica rapa and investigated their regulatory function in anthocyanin biosynthesis pathway genes and cold and/or freezing tolerance in B. rapa. Expression analysis of these genes in the pigmented and non-pigmented portion of leaves of different lines of B. rapa revealed that BrMYB2-2 and BrTT8 showed responses contrasting with anthocyanin accumulation and cold stress. Sequences of these genes were analyzed and compared with similar gene sequences from other species and a high degree of homology with their respective functions was found. Co-regulated cis -elements were found in promoters of BrPAL1, BrCHS, BrF3H1, BrF3’H1, BrFLS, BrBAN, BrDFR8, BrANS1, and BrMYB2-2 and BrTT8 had binding sites of the promoters of those structural genes. Thus, the above results suggest the association of BrMYB2-2 and BrTT8 with regulation of anthocyanin biosynthesis pathway genes and cold and freezing stress tolerance and might be useful resources for development of cold resistant Brassica crops with desirable colors as well.

Overwintering capacity, closely related to winter hardiness, of Chinese milk vetch planted with different sowing times and sowing practices was investigated to improve the incorporation into cropping system in Korea. The tolerance to low temperature was evaluated with LT50 using leaf disc leaching method. Dry weight of CMV was reduced remarkably with delayed planting from Sep. 5 to Oct. 20. The differences in tolerance to freezing temperature were not conspicuous among CMV genotypes, however, the differences between genotype (collections at different regions) were due to the plant architecture, mainly to the leaf angle. The crouching genotype collected at central region of Korean peninsula, which showed excellent freezing tolerant, has planophile leaves. The feature of internal constituents of CMV genotypes did not show any noticeable differences with respect to the freezing tolerance which evaluated by leaf disc leaching experiment. To overcome the poor overwintering capacity, tolerant genotype should be developed by selection with considering the plant architecture. The reduction of CMV growth during overwintering period was ameliorated with furrow-sowing under late-sown condition, therefore, when the CMV is inevitably sown late after recommended time, the seeds should be sown on furrow to overcome the cold stress.

In order to measure an antifreezing tolerance, antifreeze proteins accumulated upon cold acclimation in apoplast were analyzed. As Dongborilho were cold-acclimated for 3 to 74 days there was an abrupt increase in apoplastic proteins up to 30 days and then decrease to the similar levels. Among the known antifreeze proteins, CLP produced in E. coli. and TLP purified from apoplast were used to generate antisera that allow to measure and localize the proteins in leaves of barley. The CLP of 27.7 kDa and TLPs of 6, 26, 27, 30, and 31 kDa were increased in their amounts in apoplast as cold treatment being longer. There was a correlation among the amounts of those proteins accumulated in apoplast and freezing tolerance as shown in field and ion leakage tests for five cultivars. The deposit of CLP was localized in the marginal area and the area adjacent to leaf vescular bundle cells in an increasing manner according to duration of cold acclimation but no variation was observed in terms of it's distribution. Based on the close correlation between levels of antifreeze proteins and degrees of freezing tolerance, the immunological methods was to develop to estimate a freezing tolerance in barley

One of the most attractive short-term possibilities for increasing freezing tolerance of winter crops may be the application of chemicals. This research was conducted to determine the effect of two plant growth regulators. Terpal-C and Cerone on freezing tolerance and winter survival of canola. Three cultivars were planted on the michigan state University Agronimy Farm at East Lansing. MI. on Sept. 10. 1992 and 1993 Chemicals were applied to one-month-old plants when they reached the 5 leaf stage. Ion leakage tests for freezing tolerance were conducted before and after chemical treatment. Winter survival was evaluated by counting the plant standing in the fall and spring. Neither of the chemicals. Terpal-C. inhibited natural cold hardening.

파종시기는 작물의 월동율에 가장 중요한 영향을 미치는데, 본 실험은 케놀라의 파종시기에 따른 내동성의 증가형태 및 이러한 내동성이 궁극적으로 월동율에 미치는 영향을 구명하기 위하여 수행되었다. 여섯 가지의 케놀라 품종을 8워 25일, 9월 10일과 9월 25일의 세 파종시기로 구분하여 포장에 파종하였으며, 파종 후 15일 간격으로 11월 중순까지 잎 표본을 채취하여 실험실에서 elec-troleakage test 법에 의하여 내동성을 측정하였으며, 월동율은 포장상태에서 가을과 봄에 걸쳐 살아있는 개체수를 세어서 산정하였는 바 그 결과는 다음과 같았다. 1. 내동성이 증가하는 형태는 파종시기에 따른 양태를 보였는데, 일찍 파종할수록 생육기 전반에 있어서 내동성의 증가가 일어나지 않는 반면 일찍 파종한 구에서는 꾸준한 증가세를 유지하였는데 이는 식물체의 생장정도에 따라 저온에 반응하여 내동성을 증가시키는 능력에 차이가 있는 것에 기인된다고 생각된다. 2. 세 파종시기에 있어서 공히 내동성의 급격한 증가를 보이는 기간은 기온이 케놀라의 저온적응에 알맞은 2∼5일 때임을 미루어 볼 때 식물체의 저온적응에 영향을 미치는 여러 가지 환경요인 중 저온의 중요성을 시사한다고 하겠다. 3. 내동성과 월동율은 긴밀한 상관관계를 보였으며, 이는 내동성이 월동율을 결정하는데 있어서 가장 중요한 요인의 하나이며 이러한 실내에서의 내동성측정이 월동율 향상을 위한 육종도구로 쓰일 수 있는 가능성을 확인할 수 있었다.