Callus cultures from leaf explants of Gypsophila paniculata L. cv. 'Bristol Fairy' have been tested their growth and morphogenic capacity on Murashige and Skoog medium supplemented with 0.l, 0.5, 1 and 3 mg/L 2,4-D. The frequency of callus formation ranged from 43.3% to 100%. The optimal 2,4-D concentration for promoting callus formation and growth was 0.5 to 3 ㎎/L. 4.2∼ 5.6% of adventitious roots were obtained with the use of 0.1 and 0.5 mg/L 2,4-D. Calli grown well on 1.0 mg/L 2,4-D was the heaviest among the calli grown in various concentrations.

This study was conducted to assess the allelopathic potentiality of Korea traditional seventy-nine rice (Oryza sativa L.) cultivars on barnyardgrass (Echinochloa crus-galli P. Beauv. var. oryzicola Ohwi) and to identify possible allelopathic compounds from selected rice cultivars, such as Seogandodobyeo, Huadobyeo and Heugbalbyeo. In the straw mixture, Seogandodobyeo showed the greatest inhibition (67.07%) on total emergence percentage. The greatest inhibition on total seedling length and dry weight of barnyardgrass occurred in Huadobyeo (58.32 %) and Heugbalbyeo (81.20%), respectively. An HPLC analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compound depend upon the cultivars. Four compounds including Ο-coumaric acid in Seogandodobyeo extracts, four compounds including p-coumaric acid in Huadobyeo extracts, and seven compounds including Ο-coumaric acid in Heugbalbyeo were detected, respectively. Ο-coumaric acid (0.97 mg/g) in Seogandodobyeo, p-coumaric acid (0.92mg/g) in Huadobyeo and Ο-coumaric acid (1.02 mg/g) in Heugbalbyeo was detected as the highest amounts, respectively. The preliminary identification by HPLC analysis resulted in peaks with retention times close to those of standards which were confirmed with EI/MS. The mass spectra of p-coumaric, and Ο-coumaric acids showed molecular ions (m/z) at 164 and 164, and their base peaks (m/z) at 164 and 118, respectively.

Chong, Song-Yun. 1999. The Alternation of Liquid Sounds and Syllable Structure. Studies in Modern Grammar 17, 1-14. The erratic alternation of liquid sounds in English sound production is one of the recalcitrant problems for Korean students. This problem is caused by the differences in phonemic distribution between Korean and English languages. I will argue that the differences in phonemic system(other than the range of its distribution) between these languages hardly explicate the reason why in one position the lateral([l]) is replaced by flapping([r]) and in certain other position the flapping is replaced by lateral. This fact, as I have observed, has nothing to do with phonemic inventory (or system) of both languages. This alternation can be recognizable by analyzing the differences of syllable structure along with the syllable constituents between Korean and English. Incidentally, the (re)syllabification setting up by Korean in English sound production is crucial to account for the erroneous substitution of [l] for [r] or vice versa. I am going to use, therefore, the binary branching syllable structure and justify that the erratic alternation can be normalized by relocating the lateral/flapping sounds in syllable constituents.

Carbohydrate metabolism and partitioning are dependent on relationships between sources and sinks which can be affected by rates of photosynthesis and respiration. Fructan, the major form of stored carbohydrate in tall fescue (festuca arundineacea Schreb.), changes in concentration during growth and in response to the environment. Objectives of this study were i) to examine the content and the composition of carbohydrates in five tissues (mature leaf blade, immature leaf blade, leaf elongation zone, terminal meristem, and root tips) of two tall fescue genotypes, one with high yield per tiller (HYT) and one with low yield per tiller (LYT), and ii) to compare the reserved and utilized carbohydrates among above five different tissues, particularly between the leaf elongation zone and root tips. The established vegetative tillers of the HYT and LYT genotypes were grown in a controlled-environment growth chamber. Water-soluble carbohydrate (WSC) in the leaf elongation zone was about 22% of dry weight in the HYT and about 19% in the LYT genotype. The root tip also had high WSC, about 12% of dry weight in the HYT and 6% in the LYT genotype. Hexoses and sucrose were the major components of total WSC in all tissues except the leaf elongation zone. The growing tissues (sinks), i.e., the leaf elongation zone and root tip, had a high proportion of low degree of polymerization fructan, i.e., 3 to 8 hexose units.

The conductivity test is a measure of electrolytes leakage from plant tissue. The shorter the maturation period after heading was the greater electrical conductivity (EC) of rice seed. The polymer-coated seed was not different in EC compared with non-coated seed. As soaking time of rice seed increased, EC increased gradually. The EC varied from 9.9 to 20.7~mu S cm-1g-l for control plots and from 21.3 to 41.7~mu S cm-1g-l for heat-killed seeds which were produced by autoclaving seeds at 121~circC for 20 minutes. The germination speed (the rate of 5th day) of rice seed was 94% at control plot, 83% at low temperature and 20% at high temperature. Besides, germination percentage was 95% for the control, 92% for the low temperature treatment and 39% for the high temperature treatment. The EC was negatively correlated (r=-0.771** ) with germination percentage at low temperature. Water uptake in seeds of 30, 40, 50 days after heading (DAH) was greater than that of 20 DAH. Plant height of seedlings was 9.84 cm for the control but 4.32 cm for the high temperature treatment, and the tallest for polymer-coated seed. Dry weight of seedlings was 0.841 g for the control and 0.287 g at high temperature. Besides, the polymer-coated seed was heavier than non-coated seed. The number of roots was largest from 40 to 50 DAH and polymer-coated seed, but was decreased from 20 to 30 DAH. The length of roots was 20.52 cm at control plot and 19.89 cm polymer-coated seed but 8.68 cm for the low temperature treatment and 7.28 cm for the high temperature treatment.

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.

Effects of acute anoxia on carbohydrate hydrolytic enzyme activities and free amino acid contents in malt were examined. Malts were prepared with barley grains germinated for 7 days which contained the highest levels of amylolytic and(1-3,1-4)-β -glucanase activities. α -Amylase and β -amylase activities in malts were not significantly affected by anoxia for 5 or 10 h.(1-3,1-4)-β -Glucanase activity, however, decreased about 7 to 10% by anoxia for 5 or 10 h. Alanine and ~gamma -aminobutyric acid content changed drastically. Alanine contents in malts increased by 2.2- and 2-fold, and ~gamma -aminobutyric acid contents by 1.4- and 1.9-fold under anoxia for 5 and 10 h, respectively.

분리한 보리호분층을 이용하여 (1-3)-β-glu-canase 와 (1-3,1-4)-β-glucanase 의GA3 에 대한 반응특성을 조사하였다 GA3 처리에 의해 호분충과 배양액 내의 단백질 함량, (1-3)-β-glucanase및(1-3,1-4)-β-glucanase 활성 등이 모두 증가하였다. 그러나 GA3 처리에 의한 효소활성 및 효소분비 증가 정도는 효소에 따라 큰 차이를 보였다. (1-3,1-4)-β-glucanase 가(1-3)-β-glucanase 보다 효소활성 증가 정도와 분비증가 정도 모두 컸다. 이와 같은 결과는 발아초기 (1-3,1-4)-β-glucanase 의 중요한 생리작용과 관계가 있을 것으로 생각되었다

(1-3)-β-glucanase 동위효소의 발현 양상을 등 전점 전기영동 젤에서 직접 검출 확인할 수 있는 방법을 개발하였다. 개발된 방법은 시판되고 있는 (1-3)-β-glucanase활성 측정용 염료착색 기질을 이용하였다. 본 방법은 신속, 간편하며 보리 종자에서 발현되는 것으로 알려져 있는 모든 (1-3)-βglucanase 동위효소를 검출할 수 있을 정도로 민감하고 특이적이었다. 시판되고 있는 Penicillium(1-3)-β-glucanase에 대한 활성 검출 한계단위는 50 u U 정도로 추정되었다. 따라서, 본 방법은 특별한 시설이나 연구 인력을 확보하고 있지 않는 연구실에서 식물체의 (1-3)-β-glucanase발현에 대한 단백질 수준에서의 연구를 수행하는데 유용하게 이용될 수 있을 것으로 생각된다