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This study investigated the factors influencing in vitro flowering of gherkin (Cucumis anguria L.). Multiple shoots were efficiently regenerated from cotyledonary node and axillary bud explants of C. anguria within 15 days on MSB5 medium containing 3% sucrose and supplemented with 1.5 mg l-1 6-benzyladinine (BA). The elongated shoots were excised and transferred to MSB5 medium containing 4% sucrose supplemented with 0.5 mg l-1 gibberellic acid (GA3) and 1.0 mg l-1 indole-3-butyric acid (IBA) induced maximum number of flowers (9.5 flowers/plant) and root induction (16.5 roots/plant). Factors that influence the in vitro flowering were optimizing pH, photoperiod and temperature. In vitro flowering was significantly early and higher number of flowers produced at pH (5.8), photoperiod (12/12 h) and room temperature (28 °C). In vitro developed flowers were less viable (80 ± 1.0%) compared to control plants (90 ± 2.0%). Our in vitro flower induction procedures provide an extremely effective method for further research on flowering regulation mechanisms in C. anguria. These plantlets were successfully transferred to the soil where they grew well for 3 to 5 weeks with 90% survivability. Plants grew normally and produced flowers with viable pollen and fertile seeds. [ABSTRACT FROM AUTHOR]

With 7 figures and 6 tables Garlic is widely consumed for its culinary and medical benefits. Six hundred and thirteen accessions of garlic and its relatives with diverse origin were evaluated for genetic diversity at eight recently novel simple sequence repeat loci in this study. A total of 113 alleles were detected, the average allelic richness was 14.1 alleles per locus. Using a heuristic approach, a core set of 95 accessions was successfully developed, which showed 100% coverage of alleles with minimum redundancy. The model‐based structure analysis here revealed the presence of four subpopulations in the selected core set, which was basically consistent with clustering based on the genetic distance. The analysis of molecular variance based on this core set showed that between‐population component of genetic variance is <15.6% in contrast to 84.4% for the within population component. Overall FST value was 0.1560, indicating a moderate differentiation among the four groups. These results will provide an effective aid for future allele mining, association genetics, mapping and cloning gene(s), germplasm conservation, and improvement programs. [ABSTRACT FROM AUTHOR]

In attempts to control weeds in rice, much effort has been focused on rice allelopathy research for more than 30 years. Among screening methods that have been developed, some estimate the allelopathic potential of various rice cultivars in a limited time and space, which is less costly and can be conducted year round. Rice allelopathy activity is variety dependent and origin dependent, where Japonica rice shows greater allelopathic activity than Indica and Japonica–Indica hybrids. Allelopathic characteristics in rice are quantitatively inherited and several allelopathy-involved traits have been identified. Numerous phytotoxins such as cytokinins, diterpenoids, fatty acids, flavones, glucopyranosides, indoles, momilactones (A and B), oryzalexins, phenols, phenolic acids, resorcinols and stigmastanols have been identified and determined as growth inhibitors in rice. However, the fate and actual modes of action of these compounds as well as other potent rice phytotoxins in nature are not well understood. The question of which compounds play a major role in rice allelopathy has remained obscure; however, rice allelopathy might be attributable to the interaction of all present allelochemicals. Despite locating genes determining or involving allelopathy in rice having attracted much effort, the introduction of these genes into target rice cultivars has not yet been achieved. Success in breeding new rice cultivars having good weed-suppressing ability would benefit farmers in rice-cultivating countries and play an important role in sustainable agricultural production. [ABSTRACT FROM AUTHOR]

In August 2002, Typhoon RUSA hit Korea with severe gale and storm, causing extensive damage throughout the whole country and especially in the Gangneung area. Even on a single day, Typhoon RUSA recorded up to 879.5mm of rainfall in the Gangneung area. Quantitative and qualitative analyses of the scale of Typhoon RUSA are performed in this study. Most of the inland affected by RUSA in the Korean Peninsula recorded heavy rainfall, equivalent to a return period of more than 200 years. Especially, rainfall of 24 h duration exceeded the maxima observed so far. Although areal rainfall showed a rapidly decreasing trend with increasing area, it reached 96 percent of the existing PMP within a 2000 km² area and recorded the maximum observed value of Korea according to a DAD analysis of rainfall. Re-estimated PMP values obtained from a hydro-meteorological approach compared with existing PMP estimates revealed a discrepancy between the two values, which showed that re-estimated PMP values of 12 to 24 h duration within 2000 km² exceeded the existing PMP estimates of Korea. Therefore, modification of the existing PMP is required, which is used as a design hydrological variable of hydraulic structure. [ABSTRACT FROM AUTHOR]