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

본 실험은 한국 재배종과 재래 수집종을 포함하는 36개 보리 품종을 공시하여 비가림 플라스틱 하우스의 포장 조건에서 실시하였다 대조구는 전 생유기간에 걸쳐서 토양 수분 포텐셜이 -0.05㎫이 유지되도록 관개를 하였고, 한발 처리구는 월동 후 재생기부터 수확기까지 곤개를 하지 않았다. 한발 처리구의 토양 수분 포텐셜은 최저 -0.29㎫까지 저하하였고 처리기간 중 평균은 -0.15㎫이었다. 처리에에 따른 생장, 수량 및 수량구성요소, 잎의 상대수분함량(RWC), 삼투포텐설(OP), 삼투조정(OA), 13C discrimination(A), 등의 변화를 조사하여 다음과 같은 결과를 얻었다. 1. 공시한 품종 중 한발 처리에 따른 건물 중과 수량 저하 가 작아서 한발 저항성이 강한 품종은 동보리1호. 찰보리, 창영재래, 삼도보리, 월성87-31 등이었으며, 상록보리 , 송학보리, 수원맥360 등은 한발저항성이 낮았다. 2. 건물중 및 수량의 한발피해지수(한발처리구/대조구 비)와 한발조건하 RWC와는 높은 정의 상관이, 한발조건하 OP 및 OA는 매우 높은 부의 상관관계가 있었으며, 대조구의 δ 와는 유의한 정의 상관관계가 있었다. 3. OP δ 및 RWC의 한발지수(한발처리구/대조구 비)는 건물중, 천립중 및 수량의 한발피해지수와 매우 높은 정의 상관 관계를 나타내었다. 4. 이상의 결과를 종합해 보면 한발 저항성이 큰 품종은 삼투 조정능력이 커서 잎의 수분함량을 높게 유지하는 특성을 가지고 있어서 한발 처리 조건에서 OP와 RWC는 보리의 한발저항성 선발지표로 이용될 수 있을 것으로 판단되었다. 그러나 δ 와 한발 저항성간의 관계에 대해서는 보다 구체적인 연구가 필요한 것으로 생각된다.서는 백수발생시 평균 3.4-7.0cm, 부분퇴화가 4.2-5.2cm, 퇴화가 0.4-5.4cm, 줄기 고사가 0.4-0.6cm로 차이를 보였다. 제1절간장은 보리, 밀 각각 0.3-8.4cm, 0.2-24.2cm로 신장정도에서 저온에 따른 변이를 보였고, 지엽-이삭간 거리도 보리 -2.5∼-7.4cm, 밀 -0.6-11.5cm로 신장정도에 차이가 컸다.d from a constant temperature to a temperature cycle under DD. These results suggest that per/sup 01/ and tim/sup 01/ flies have a temperature-entrainable weak oscillatory mechanism. The fact that dClk/sup Jrk/ and cyc/sup 01/ flies did not show any sign of the endogenous oscillation suggests that the per-less oscillatory mechanism may require CLK and CYC.out to investigate the reactants between cement hydrates and chemical ions and some crystalline such as gypsum ettringite and Fridel′s salt were confirmed.ng for others, 3. Virtue of "forgiveness other′s mistakes"(from 3.32 to 3.65 for experimental group and from 3.33 to 3.25 for comparison group) in domain of kindness, concession, forgiveness, and virtue of "volunte

To identify the new source of breeding materials for rice salt tolerance, the salinity tolerance of thirty-four varieties was evaluated under 0.5% saline condition at seedling stage. The salinity score showed highly significant correlations to dry weight and dead leaf ratio. The tested varieties were classified into three groups by visual score, reduction ratio of dry weight, and dead leaf ratio. Eighteen varieties were classified as the highly tolerant group (salinity scores of 1.3-3.7), seven varieties were fallen into the tolerant group (salinity scores of 4.2-5.8), and others were susceptible (salinity scores of 6.7-9.0). In highly tolerant group, most indica varieties including Getu, Dikwee and Kuatic Putic, didn't exsert a panicle under the Korean climate. But six varieties, Xiangcho V, Annapuruna, HP 3319-2wx-6-3-1, Giza 175, and GZ 2447-S-17, GZ 4255-6-3 were suitable to the Korean climate, and their heading date (6-16, August) and culm length (65-78㎝) were similar to the Korean varieties. Accordingly, these varieties can be utilized as crossing materials for the salt tolerance in japonica rice.

Molecular markers were used to map and characterize quantitative trait loci (QTLs) for traits related to cold tolerance in an intrasubspecif ic backcross population of r ice. The parents of the cross were a cold susceptible Tongil-type cultivar 'Milyang23

Nonghobyeo', was derived from a mutant of Milyang 95, by pure line selection method, which was developed from the single cross between Chukei 1016 and Milyang 79, by the rice breeding team of National Yeongnam Agricultural Experiment Station (NYAES) in 19

In order to examine the mechanistic basis for differential sensitivities to chilling and subsequent recovery between two rice (Oryza sativa L.) cutivars, a chilling-tolerant japonica type (Ilpumbyeo) and a chilling-susceptible indica type (Taebaekbyeo), changes of physiological responses and antioxidant enzymes were investigated. Both cultivars at 3 leaf stage were exposed at a low temperature of 5~circC for 3 days and subsequently recovered in a growth chamber at a 25~circC for 5 days with 250 mmol m-2 s-1 . Physiological parameters such as leaf fresh weight, relative water content, cellular leakage, lipid peroxidation, and chlorophyll a fluorescence showed that the chilling tolerant cultivar had a high tolerance during chilling. However, the chilling-susceptible cultivar revealed severe chilling damages. The chilling-tolerant cultivar was also faster in recovery than the chilling-susceptible cultivar in all parameters examined. We analyzed the activity and isozyme profiles of four antioxidant enzymes which are: superoxide dismutase (SOD), caltalase (CAT), ascorbate peroxidase (APX), and glutation reductase (GR). We observed that chilling-tolerance was due to a result of the induced or higher antioxidant enzyme system, CAT and APX in leaves and SOD, CAT, APX, and GR in roots. Especially, we observed the most significant differences between the chilling-tolerant cultivar and -susceptible cultivar in CAT and APX activity. Also in isozyme profiles, CAT and APX band intensity in the chilling-tolerant cultivar was distinctively higher than in the chilling-susceptible cultivars during chilling and recovery. Thus, the cold stability of CAT and APX are expected to contribute to a tolerance mechanism of chilling in rice plants. In addition, the antioxidative enzymes activity in roots may be more important than in that of leaves to protect chilling damage on rice plants.