This study was conducted to obtain the basic breeding information of Colocasia esculenta Schott. Effect of supplemental plant growth regulators and genotype difference were investigated on dormant bud tissue for proliferation. The plant regeneration ratio, plant height and root length were the best upon mixed treatment of 0.8mg/L IAA and 2.0mg/L zeatin. Both leaf weight and root weight were heavy upon culture in a dark condition. The leaf and root weights were heaviest in 6Pie sucrose concentrations. In several collected area the heaviest one was Binnangxin and then in the order of Suwon, Wanju and Puan. Genotype differences of tuber diameter and tuber weight were found in Suwon. Tuber weight was found in the order of Suwon (862mg) >Wanju(723mg) >Puan(649mg) >Binnangxin (424mg).

A rapid and sensitive assay for specific detection and identification of barley yellow mosaic virus(BaYMV) was set up using the reverse transcriptase polymerase chain reaction(RT-PCR). A couple of primers was select to discriminate the viruses. PCR fragments of BaYMV(ca.0.9 kb) were obtained by using the method designed for BaYMV capsid protein. RT-PCR fragments were cloned with vector pT7 Blue and the resulting clones were sequenced. Capsid protein of BaYMV consisted of 297 amino acids and 891 nucleotides. The capsid protein sequence of BaYMV showed that 98% of nucleotides and 99% of amino acids homology.

Twenty two varieties of pecan including wild types were classified based on 6 characters measured by principal component analysis score distance. The results are summarized as fellow. Twenty two varieties were classified into 5 groups based in PCA score distance. Five groups were distinctly characterized by many morphological characters. Total variation could be explained by 51%, 95%, 99% with first, third and fifth principal components respectively. Varimax rotation of the factor loading of the first factors indicated that the first component was highly loaded with leaf characters, the second component with fruit characters, but fruit length was negative loaded. The second, the third and the fourths groups of cultivars had very close genetic parentage similarity.

Sixteen isolates showing relatively strong antagonicity against the ginger rhizome rot pathogen, Pythium zingiberum, were selected among the 155 isolates from ginger rhizome surfaces and rhizospheres of ginger cultivation fields in Wanju, Chonbuk. The isolate, 'HB 26-5'showing the strongest antagonicity was finally selected by testing duration of inhibition effect and pathogenicity to ginger. The isolated antagonistic microorganism, 'HB 26-5' was rod shape, gram positive and formed endospore. The isolate produced acids utilizing glucose, arabinose, xylose and mannitol, and acetoin at VP test, and grew anaerobically. Temperature range for growth was from 10 to 40℃ . Reaction to catalase and gelatin, hydrolysis were positive, and casein hydrolysis and indol production were negative. Based on the mycological characters and the fatty acid composition, it was identified as Bacillus polymyxa. The pathogenicity test of isolated Bacillus polymyxa 'HB 26-5'on 22 crop cultivars resulted that only the lettuce was influenced in germination, and the others were not affected.

These experiments were conducted to evaluate the variability of seed germination and seedling growth with different levels of polyethylene glycol(PEG 6,000) solution in onion seed. Average germination percentage of seed primed in PEG solution with 1.00 and 0.75 MPa was higher than control, and that of seed primed in 1.50MPa was lower than unprimed control. Germination percentage(GP) of seed primed for 5 days was highest, and as the primed days become long, the GP was decreased. The GP of airation seed during the primed was higher than that of unairation seed, about 5% , respectively. The GP of washed seed after primed was higher than that of unwashed seed, but that of redried seed after primed was lower than that of the others. The highest GP cultivar was Chunjoogoohyung and the lowest GP cultivar was Seouldego in unredried seed after primed, but Chunjoojoonggo was highest and Jungpoonwhang was the lowest cultivar in redried seed after primed. As the PEG concentration increased, the seedling length(SL) was shortened, and seed primed for 15 days was longer than other treatments. The SL of primed seed was similar to GP. The SL of washed seed after primed was longer than that of others, but that of redried seed after primed was shortest among the others. The SL of Chunjoojoonggo and Nongwoodego was longest and Seouldego was shortest among the cultivars in unredried seed after primed, but that of Chunjoogoohyung and Chunjoojoonggo was longest and Seouldego was the shortest cultivars in redried seed after primed.

Through the research of tracheophytes type around Mt. Daedun, we are aiming at figuring out the habitat condition of useful resource plants by the classification of vegetation units and communities using the Z-M phyto-sociological method in the basis of the traits of species composition and by the analysis of vegetation and environment by way of coincidence method. Tracheophytes in our research sites was classifid into 117 family, 475 genus 797, species 102 variety,18 breed, in total to 917 kinds. The forest around Mt. Daedun district was classified into 6 communities, 12 groups, 2 sub-groups according to feature species group, differential species group and differential. Judging the result from the examination of community classification factors by the coincidence method, vegetation unit was decided by altitude and topography.

This study was carried out to investigate the morphological characteristics of the plants and seeds of Ainsliaea acerifolia and to determine the optimum condition for producing sprouts from the seeds. Plant height, flower stalk length, and pod number were higher in natural habitat than in campus farm. Average 1.2 seeds per pod was set but only 0 to 2 seeds per plant was set in plants with the enveloped flower stalks, indicating that this is an outcrossing species. Most of seeds were 9-11mm long and 1.1-1.4mm wide. Fresh weight of seeds was ranged from 10mg to 17mg. Seeds germinated well at 15℃ and 20℃. Mean germination period was 11.5 day at 15 to 25℃. Sprouts grown at 15℃ was longest(5.4cm) and heaviest(738mg/10 sprouts). Chlorophyll content was 333mg per fresh weight 110g. Protein, Fe, vitamin Bl, vitamin B2, and vitamin C were respectively 23.7mg, 6.4mg, 1.82mg, 0.49mg, and 10..7mg.

Many higher fungi were collected at Pyonsan penisula Mt.Odae, Korean Highway Cororation Arboretum, Mt.Moak, Yaksan island from 1996 to 1998. They were identified and according to the results, Hygrocybe coccineocrenata, Collybia neofusipes, Marasmius wettsteinii, Amanita esculenta, Lepiota fuscipes, Leucocoprinus subglobisporus, Cystoderma japonicum and Coprinus narcoticus are newly to Korea. They were designed Korean common name by author.