In order to breed the useful mutants in black raspberry, cultivated in Gochang-gun, leaf-petiol explants from shoot-proliferating culture was regenerated after irradiated with 30, 50 and 70 Gy gamma-ray. The LD50 dose of leaf-petiol explants was identified as 30Gy after two months. Morphological characteristics of the variants were observed such as stem variation, existence and nonexistence of spine, spine color, anthocyanin content, width of leaf, thick of leaf compared with donor cultivar. Of the 701 mutants, 14 lines with the useful mutant characters were selected and random amplified polymorphic DNA(RAPD) was carried out to confirm mutation state at the molecular level with 20 primers. There are many bands be revealed only in mutants and disappear in mutants reversely. RAPD analysis revealed a high level of genetic diversity among Control and mutants. Compared to Control, No. 14 mutant showed the highest genetic diversity. Also, the co-dominant SSR markers have allowed the evaluation of heterozygosity. Valuable mutants obtained will be useful for developing new cultivars and studying gene function in molecular level.

Biomass crops have potential as a source of renewable CO2-neutral energy to ease concerns about fossil fuel consumption. Therefore, there is an increasing interest in high biomass crops such as switchgrass (Panicum virgatum L.). Switchgrass is a perennial C4 grass that requires low cost for biomass production. In the previous study, we evaluated forty switchgrass germplasms for biomass yield and classified the germplasms into the high-, medium-, and low-yielding groups. In this experiment, we evaluated response of switchgrass accessions to fertilizer applications. A recommended level of fertilizer was applied to the field and responses of morphological and agronomic characteristics affecting biomass productivity (panicle length, clum length, leaf width, thickness, tiller numbers, effective tiller numbers, seed weight, plant weight) were analyzed. Also, the composition of organic compounds (crude protein, crude fat, ash, glucose, xylose) and mineral elements were analyzed for the two selected lines from each biomass yield group by the levels of exchangeable cations in the soil. Positive correlations were found between biomass yield and content of crude protein, crude fat, ash, T-N, glucose, and xylose. However, no relations were found between biomass yield and mineral elements such as Na, P, K, Fe and Zn. Biomass yield was increased by 1.9-fold by the fertilizer application and the traits most significantly affected by fertilizer application were effective tiller number and plant weight. The accessions that showed less than 10% increase in biomass productivity by the fertilizer application were accession 26, 29, 13, and 18. This study was supported by Technology Development Program for New Bioenergy (subject number-20070301030016), Rural Development Adiministration, Republic of Korea.

The salt adversely affects normal growth and development by the toxic effects of sodium ion (Na+) absorbed from plants. In different plant species, the difference of salt-tolerance degree is related to ion homeostasis, osmolytes biosynthesis, scavenge of harmful operator and water transportation. This intend that salt-tolerance is a quantitative trait controlled by amount of genes. In the previous study, we selected several tolerant cultivars and landraces from over 1,000 barley germplasms which were screened in a high salt (0.4 %, w/w) reclaimed soil. Among the selected germplasms, we selected a salt-tolerant variety from Tunisia (T76) and a salt-susceptible variety Gwandongpi 41 (G41) in germination and early growth stages. In order to develop salt-tolerant segregating population, we performed the development of a new interspecific barley recombinant inbred line population of PB 71 lines deriving from an interspecific cross between Tunisia 76 (T76) and Gwandongpi 41 (G41). The F1 hybrid was progressed by F4 generation. Germination and seedling growth of the F4 generation (a total of 710 lines) were screened for salt-tolerance in 200 mM NaCl solution for 10 days. Ten days after incubation, salt-tolerance was scored on a scale from 1 (sensitive) to 5 (tolerant). In germination screening for evaluation of salt tolerance, the T76 and G41 as parent pants showed all 100 % germination ratio in control or saline conditions. In addition, the whole F4 generations also showed normal germination ratio over 90 % in control condition, while the only 70.42 % of the that showed germination ratio over 90 % in 200 mM NaCl stress condition. The average score of salt tolerance at the seedling stage of parent plants showed that the salt-tolerant cultivar T76 was 5 and the salt-sensitive cultivar G41 was 3 in saline condition. The average score frequency of F4 generations showed that five (7.04 %) among the PB71 lines possessed the highest score 5 and 40 lines possessed the score 3 (26.76 %) and 2 (29.58 %), respectively. This work was supported by grant (KRF-2007-521-F00002) from Korea Research foundation.

In order to breed the useful mutants in black raspberry, cultivated in Gochanggun, leaf-petiol explants from shootproliferating culture was regenerated after irradiated with 30, 50 and 70 Gy gamma-ray and seeds were irradiated with 100, 130, 150, 170 and 200 Gy gamma-ray. The LD50 dose of leaf-petiol explants and seeds in black raspberry was identified as 30 and 150 Gy after two months and one month, respectively. The mutants such as leaves with increasing width, chlorophyll content and increasing anthocyanin were selected in regenerated explants and seeds irradiated. The increased rate of leaves width and chlorophyll were 33.3% and 23.1% compared to the control. Also, antocyanin concentration in leaf of mutnats from irradiated seeds was increased till 17.3%. For the breeding of black raspberry, valuable mutants obtained will be expected for improving photosynthesis efficiency and functional components, and will be useful for developing new cultivars.

Growth and quality of rice are affected by various factors including the location of cultivation. This study was conducted to investigate the effects of altitudinal locations on the growth and yield-related components of rice. Nineteen Japonica type varieties were grown at Iksan (altitude, 10 m), Imsil (altitude, 150 m), Jinan (altitude, 275 m) and Jangsu (altitude, 430 m) at a similar latitude in Jeonbuk province in the south western Korea. Minimum air temperature showed a strong negative correlation with altitude. The morphological traits and yield-and quality-related components were analyzed. Longer days to heading was required at higher altitudes. However, culm length, panicle length, panicle number, grain number and rice yield were reduced at higher altitudes. Protein content of brown rice increased but fatty acid content decreased at higher altitudes. Amylose content was affected by neither the altitude nor the ecotype. Palatability of polished rice tends to be improved at higher altitudes and in early-maturing ecotypes but its relationships with altitude and ecotype were not significant. Head rice ratio was lower at higher altitudes but broken rice ratio vise versa. These results indicate that growth and quality of rice are affected significantly by changes in temperatures at the locations of different altitude. Also, the characters related to yield and quality of rice often respond incompatibly to the changes in altitudes. These results could provide valuable information for the strategic planning of rice production in geographically diverse areas

Superoxide dismutases (SOD) are metalloenzymes that convert O2- to H2O2. Rehmannia glutinosa is highly tolerant to paraquat-induced oxidative stress. The primary objective of this study was to characterize regulation of SOD gene expression in R. glutinosa in response to oxidative stresses and hormones. A full-length putative SOD clone (RgCu-ZnSOD1) was isolated from the leaf cDNA library of R. glutinosa using an expressed sequence tag clone as a probe. RgCu-ZnSOD1 cDNA is 777 bp in length and contains an open reading frame for a polypeptide consisted of 152 amino acid residues. The deduced amino acid sequence of the clone shows highest sequence similarity to the cytosolic Cu-ZnSODs. The two to three major bands with several minor ones on the Southern blots indicate that RgCu-ZnSOD1 is a member of a small multi-gene family. RgCuZnSOD1 mRNA was constitutively expressed in the leaf, flower and root. The expression of RgCu-ZnSOD1 mRNA was increased about 20% by wounding and paraquat, but decreased over 50% by ethylene and GA3. This result indicates that the RgCu-ZnSOD1 expression is regulated differentially by different stresses and phytohormones at the transcription level. The RgCu-ZnSOD1 sequence and information on its regulation will be useful in investigating the role of SOD in the paraquat tolerance of R. glutinosa.

Rehmannia glutinosa shows a high level of resistance to the non-selective herbicide paraquat. To characterize the antioxidant enzyme system of R. glutinosa, we comparatively examined the responses of antioxidant enzymes to UV, wounding and a general elicitor yeast extract in R. glutinosa and soybean. The levels of enzyme activities of the two plant species were drastically different between those per fresh weight (general activity) and per protein (specific activity) bases. The general activities of superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), and glutathione reductase (GR) were lower, but that of ascorbate peroxidase (APX) was higher in R. glutinosa than in soybean. The specific activities of the enzymes, however, were about two- to seven-fold higher in R. glutinosa than in soybean, except that of CAT, which was about 12-fold higher in soybean. The general and specific enzyme activities of R. glutinosa relative to those of soybean showed a consistent increase in responses to the stresses only in SOD. The specific activities of SOD and APX were higher in R. glutinosa in all stress treatments. The results might suggest a relatively higher contribution of SOD and APX to the stress tolerance.

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.

Water deficit is a serious constraint to soybean [Glycine max L. (Merr.)] production in rainfed regions of Asia, Africa, and America. This study was conducted to develop a simple and effective screening method for drought tolerance in soybean. Fifteen soybean cultivars, eight identified to be drought-tolerant and seven drought-sensitive in previous studies, were used for the evaluation of drought tolerance under the new screening conditions. The seedling screening method was consisted of a treatment in a PEG solution and drought treatment in parafilm-layered pots. 5-day-old seedlings were treated in a 18% PEG solution for 4 days and their wilting and hypocotyl browning were recorded. Three seedlings grown in a parafilm-layered pot containing peat moss were drought-stressed by withholding water from the third day after seedling emergence, and root and seedling growth were examined. Degree of drought tolerance were rated based on seedling vigor in the PEG solution and drought-stressed parafilm-layered pots, and also on the penetration ability of roots through parafilm layer. Most of seedlings of the drought-tolerant cultivars showed higher vigour and root penetration than those of the drought-sensitive cultivars under the new screening conditions. Our results indicate that the new method can be used as a simple and effective screening procedure for drought tolerance in soybean breeding programs.