The direct use of mutation is a valuable approach to generate variability in crops. The electron beam, one of the ionizing radiations, has been applied to evaluate its effect on seed germination and early seedling growth of creeping bentgrass (Agrostis palustris Huds., cv Penn-A1). The mature dry seeds were irradiated with various electron beam energies (0.3, 1.0, 1.3, and 2 MeV) and current levels (0.03 and 0.06 mA). Although large variability was existed within each dose, distinct difference of germiability and seedling vigor were not found at 0.3 MeV / 0.03 mA and 0.3 MeV / 0.06 mA beam condition. However, 1.0 MeV / 0.06 mA application most effectively inhibited and retarded seed germination and most severely restricted cotyledon and root growth in early seedling growth. The direct use of electron beam would be a valuable supplementary approach to generate mutants suitable for breeding purposes.

Systemic acquired resistance is an important component of the disease resistance repertoire of plants. A novel syntheticchemical, Benzo (1,2,3) thiadiazole-7-carbothioic acid S-methyl ester (BTH), was shown to induce acquired resistance in wheat.BTH prote

In order to develop molecular markers related to stay green phenotype, AFLP analysis was conducted using near-isogenic lines for either stay green or non stay green trait. Both lines have characteristics of multi-ear and tillers (MET). Two out of 64 primer combinations of selective amplification identified three reproducible polymorphic fragments in MET corn with stay green. Both of E+AGC/M+CAC and E+AAG/M+CAA primer combinations produced two and one specific polymorphic fragments linked to stay green trait, respectively. For the conversion of AFLPs to sequence tag sites (STSs), primers were designed form both end sequences of each two polymorphic fragments. One fragment, which was amplified with E+AAG/M+CAA primer combinations, possessed 298 bp long and showed a 91~% homology with maize retrotransposon Cinful-l. One out of two polymorphic fragments produced with E+AGC/M+CAC primer combination had 236 bp long and matched a 96~% homology with an intron region of 22kDa alpha zein gene cluster in Zea mays. One out of two PCR fragments amplified with MET2 primer set in the stay green MET was not produced in the non-stay green MET. The developed AFLP and STS marker could be used as an efficient tool for selection of the stay green trait in the MET inbred.

The Hessian fly, Mayetiola destructor (Say), is known to be one of the major insect herbivores of wheat worldwide. In order to provide molecular events on interactions of the NIL with H21 and larvae of Hessian fly biotype L, the TaCR1 gene, Triticum aestivum cytokinin repressed 1, was isolated through the suppression subtractive hybridization, which was constructed using stems of the NIL with H21 at 6 days after infestation as tester and stems of the recurrent parent Coker797 without H21 at 6 days after infestation as driver. Transcript levels of TaCR1 mRNA in the NIL with H21 were highest at 6 days after infestation but in the Coker797 without H21 until 8 days were similar with those of non-infested plants. Expression of the TaCR1 gene was decreased at early time and then recovered after wounding or H2O 2 treatment as well as 6-BAP treatment. Transcripts levels of the TaCR1 gene was changed after MeJA, SA, ethephone, or ABA treatment. In drought treatment, the TaCRl gene were increased at early stage of stress and then decreased at late stage. Expression of the TaCRl gene was continued to decrease through 24 h in the cold treatment. Although the TaCRl gene is increased through infestation in NIL with H21, further study was required to elucidate a role on resistance against larvae of Hessian fly. However, the TaCR1 gene could be used as marker gene on response of plants against abiotic stresses as well as application of plants with several hormones.

Immature and mature embryos of 18 Korean wheat genotypes were cultured in vitro to develop an efficient method of callus formation and plant regeneration, and to compare the responses of both embryo cultures. Immature and mature embryos were placed on a solid agar medium containing the MS salts and vitamins, 30g/l maltose, 2 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D), and amino acids. The developed calli were maintained on regeneration medium containing MS salts and B5 vitamins, 20 g/l sucrose, and the combination of two plant growth regulators, 6-benzylaminopurine (BAP) and indole-3-acetic acid (IAA). Immature embryos in most genotypes showed high efficiency of callus induction except three genotypes; Eunpamil, Chunggemil, and Namhaemil, and significant differences among the genotypes. Plant regeneration of calli induced from immature embryos showed high efficiency in Geurumil (56.5%), Tapdongmil (50.5%), Gobunmil (45.5%), and Urimil(42.2%). The analysis of variance showed significant differences for regeneration frequency among the genotypes. Mature embryos showed low callus induction frequency compared with that in immature embryos, and significant differences among the genotypes. Plant regeneration of calli induced from mature embryos showed high efficiency in Keumkangmil (33.33%), Tapdongmil(28.13%), and Geurumil (27.78%). The analysis of variance showed significant differences for plant regeneration frequency among the genotypes.

Cereal grains are rich in phenolic compounds that give beneficial effect in human health. Although several research works have been reported on the effects of phytochemicals of plant origin, such as fruits, vegetables, few studies have examined the antioxidative effects of whole cereal grains. The objective of this study was to determine total antioxidant capacity of 80% ethanolic extracts of cereal grains by testing the ability of the extracts to inhibit UV -induced lipid peroxidation in vitro using linoleic acid in comparison to well-known antioxidant such as ascorbic acid and tannic acid. The total phenolic content of the cereal grain (80% ethanolic extracts) investigated in this study varied from 2.1 mg/g (wheat cv. Olgeurumil) to 10.4 mg/g (barely cv. Seodunchalbori). Highly positive relationship between total phenol compounds and antioxidant activity was found. When the antioxidant activities of all investigated extracts were measured with application of same quantity of phenol compounds, oat grain extracts showed similar antioxidant activity of barely cultivars. However, barely extract appeared as the most potent antioxidant activity of inhibition of UV -induced lipid peroxidation. This indicated that factors such as phenolic compound composition and their individual antioxidant activity could playa crucial role in the total antioxidant activity of cereal grains.