Thirty-nine out of eighty-five barley varieties/strains survived until heading stage in the saline experimental field (0.03-0.05~%~;salt) and they were used for pollen study. Light and scanning electron microscopic observations revealed two distinctive types of barley pollens: one transparent and small in size and the other dark and larger. In addition, both types of pollens were stained with Alexander's stain and it was found that the smaller and transparent pollen was cytoplasm-devoid (CD) while the larger pollen was cytoplasm-rich (CR). Sixteen out of 39 barley varieties/lines grown in the saline soil had CR pollens, which were rarely observed in the barley plants grown in the non-saline soil. Moreover, it was observed that salt stress severely reduced seed setting in the varieties having degenerated pollens. These results suggest that salt stress affects the fertility of barley pollen. The sterile pollen was undersized and lack of cytoplasm probably due to abortion. Furthermore, a varietal difference existed in the response of pollen development to salt stress.

This study was carried out to investigate the antioxidative enzymes and isozymes between chilling-tolerant and -susceptible varieties at the booting stage under cold water stress (13~circC) in japonica rice. Total SOD, CAT, POX, and GR activities on the basis of protein were found to be important factors to defend cold water stress. Especially, SOD and CAT activities showed distinctive differences between chilling-tolerant and -susceptible varieties. Chilling-tolerant varieties were higher than chilling-susceptible varieties for SOD and CAT activities. One of eight isozyme bands for SOD was a inducible isoform. Three isozymes for CAT and one isozyme for POX were closely correlated with defense to cold water stress. Total GR activities except Stejaree 45 on the basis fresh weight and POX were increased by cold water stress, but there was no difference between chilling-tolerant and -sus­ceptible varieties.

Gahwang is an excellent chipping cultivar with yellow flesh, short oval tuber shape and mid-early maturity. Its yields were a little higher than Atlantic through the regional trials with five locations. It has a lower incidence of internal brown spot comp

Shinnamjag is a round, smooth, white-skinned, and fleshed potato cultivar with erect plant shape and early maturity. It has excellent table quality. Its yields are high, especially with prominent marketable yield compared to Superior, a leading potato cul

‘Jowon’ is a new early-maturing potato variety for table use. It has spreading growth habit with narrow oval leaves. Its tubers are attractively round with white skin and light yellow flesh color. The yielding ability of Jowon is similar to Superior. Jowo

To find out the effects of humidification and hardening of rice (Oryza sativa L. cv. Ilpumbyeo) seeds on the germination, both normal and artificially aged seeds with 60% germination rate were humidified at 40, 60, and 80% RHs and 25~circC for five weeks or hydrated for 6, 12, 18, and 24 hours at 25~circC from one to five cycles for hardening. Relative humidity and duration of humidification did not affect the germination rate of normal seeds, while reduced the time to get 50% germination rate (T50 ) by 1.0～1.6 days compared to that of normal seeds at 25~circC . Aged seeds humidified at 40 and 60% RHs did not affect the germination rate and T50 regardless of relative humidity and duration of treatment, while at 80% RH, the germination rate decreased and T50 increased significantly with the duration of humidification. Hardening of normal seeds reduced T50 by 0.7～1.1 days without changes in the germination rate. However, the germination rate and T50 of aged seeds soaked in water for 6, 12, and 18 hours were similar regardless of soaking/drying cycles, while hardening of artificially aged seeds with 1～4 cycles in 24 hours soaking increased the germination rate by 11-16% and reduced T50 by 1.4～2.0 days.