Rural Development Administration

About: Rural Development Administration is a government organization based out in Jeonju, South Korea. It is known for research contribution in the topics: Gene & Population. The organization has 4372 authors who have published 4919 publications receiving 94318 citations.

Mapping of Quantitative Trait Loci for Cold Tolerance in Weedy Rice

Abstract: A quantitative trait locus (QTL) analysis was carried out with a recombinant inbred line (RIL) population to identify the chromosomal regions responsible for cold tolerance of rice (Oryza sativa L.). The RIL population, consisting of 80 lines, was developed from a cross between the indica cultivar, Milyang 23 and the japonica weedy rice, Hapcheonaengmi 3. The population was genotyped with 2 morphological and 132 DNA markers, providing an average interval size of 11.3 cM, and was also evaluated for traits related to agricultural performance in cold water and in control plots. The RILs showed delayed heading and reduced culm length in the cold water plot and the differences in heading date and culm length between two plots were statistically significant. Cold tolerance was measured as days to heading, culm length, spikelet fertility, leaf discoloration, and panicle exsertion in the cold water plot, and difference in days to heading and the reduction ratio of culm length between two plots. A total of 14 QTLs for 7 traits were identified using single point and composite interval analysis. The number of QTLs per trait ranged from one to three. Phenotypic variation associated with each QTL ranged from 5.8 to 32.8%. No digenic interaction was detected. Several QTLs associated with cold tolerance were clustered in a few chromosomal blocks. For 11 (78.6%) of the QTLs identified in this study, the Hapcheonaengmi 3-derived alleles contributed desirable effects and favorable alleles were detected for difference in days to heading, spikelet fertility, panicle exsertion and leaf discoloration. From this study, it can be concluded that weedy rice is useful as a source of valuable alleles for breeding cold tolerance in rice.

Chryseobacterium kwangjuense sp. nov., isolated from pepper (Capsicum annuum L.) root.

Abstract: The yellow-pigmented, Gram-stain-negative, rod-shaped bacterium KJ1R5T was isolated from the root of a pepper plant grown in a field in Kwangju, Korea. Strain KJ1R5T was characterized by physiological, biochemical, and molecular genetic analyses. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain KJ1R5T was most closely related to members of the genus Chryseobacterium , and that the strain exhibited the highest similarities with type strains of Chryseobacterium vrystaatense (97.0 %) and Chryseobacterium rhizosphaerae (97.1 %). DNA–DNA hybridization reassociation values between strain KJ1R5T and type strains of C. vrystaatense KACC 11675T and C. rhizosphaerae KACC 14918T were 46.9 and 38.4 %, respectively. The DNA G+C content of KJ1R5T is 40.2 mol%. The predominant respiratory quinone of KJ1R5T was menaquinone MK-6; major cellular fatty acids were iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), iso-C17 : 1ω9c, and iso-C17 : 0 3-OH. On the basis of these phenotypic and genotypic characteristics, the strain significantly differed from representative strains belonging to the genus Chryseobacterium . Thus, we propose that strain KJ1R5T represents a novel species of the genus Chryseobacterium , named Chryseobacterium kwangjuense sp. nov. The type strain is KJ1R5T ( = KACC 13029T = JCM 15904T).