• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.101-105
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• 2008

The germplasm of 246 rice cultivars was analysed for iron and zinc contents using a Inductively Coupled Argon Plasma (ICP) at International Rice Research Institute (IRRI) Philippines. Iron contents ranged from 2.0 to 12.0, and zinc ranged from 10.0 to 33.0 (mg/kg), showing with the mean values of 4.3 and 22.8 (mg/kg), respectively. In genotypes tested, there was approximately a two-fold difference in iron and zinc concentrations, suggesting a genetic potential to increase these micronutrients in rice grain. A highly significant positive correlation ($r^2=0.503$) was found between iron and zinc contents. Iron contents decreased drastically as polishing time increased, whereas zinc decreased only slightly. In the interaction between genotype and environment on iron contents, genotype (G), environment (E), and the G ${\times}$ E interactions accounted for 69%, 5% and 26% of the sums of squares, respectively. Indicating that genotype is would be the most significant factor for the to improve iron contents of rice in rice breeding, suggesting that therefore identifying genotypes with relatively stable performance across various environments is important as staple food crops.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.2
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• pp.136-140
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• 2004

Twenty-one lowland rice genotypes were evaluated for their stability parameters with respect to grain yield in a multi locational trial at five different sites of Eastern India viz. CRRI, Cuttack (Orissa); OUAT, Bhubaneswar (Orissa); CRS, Masodha (UP); RAU, Pusa (Bihar) and RARS, North Lakhimpur (Assam). Pooled analysis of variance reflects existence of genotype x environment interactions and contribution of both linear and nonlinear components to genotype (G) x environment (E) interactions. Through stability parameter analysis it was found that Rayda $\textrm{B}_3$, CR 778-95 and CR 661-236 were suitable for over all environments where as Sabita, OR 1334-16 and OR 1358-RGA-4 were suitable for rich environments. PSR 1209-2-3-2, CR 780-1937, Ambika, OR 877-ST-4-2 and CR 662-2211 were identified for poor environments.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.342-342
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• 2017

Rice seeds are a home to endophytic bacterial communities which serve as a source of the plant's endophytes. As rice undergo physiological and adaptive modifications through cross breeding in the process of attaining salinity tolerance, this may also lead to changes in the endophytic bacterial community especially those residing in the seeds. This study explores the community structure of seed bacterial endophytes as influenced by rice parental lineage, genotype and physiological adaptation to salinity stress. Endophytic bacterial diversity was studied through culture dependent technique, cloning and Terminal-Restriction Fragment Length Polymorphism (T-RFLP) analysis. Results revealed considerably diverse communities of bacterial endophytes in the interior of rice seeds. The richness of ribotypes ranges from 5-14 T-RFs corresponding to major groups of bacterial endophytes in the seeds. Endophytic bacterial diversity of the salt-sensitive IR29 is significantly more diverse compared to those of salt-tolerant cultivars. Proteobacteria followed by Actinobacteria and Firmicutes dominated the overall endophytic bacterial communities of the indica rice seeds based on 16S rDNA analysis of clones and isolates. Community profiles show common ribotypes found in all cultivars of the indica subspecies representing potential core microbiota belonging to Curtobacterium, Flavobacterium, Enterobacter, Xanthomonas, Herbaspirillum, Microbacterium and Stenotrophomonas. Multivariate analysis showed that the bacterial endophytic community and diversity of rice seeds are mainly influenced by their host's genotype, physiological adaptation to salt stress and parental lineage.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.10
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• pp.1435-1440
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• 2008

An experiment was carried out to investigate whether a local breed of cattle is better adapted than European breed crosses to low quality feeds and to variations in their supply. Four Red Chittagong (RC) and four Holstein cross Sahiwal (Hx) cattle were used to compare the intake and digestibility of German grass (Echinocloa crusgalli) and rice straw with four regimes of feed supply. These were; a choice of German grass and rice straw each offered ad libitum on the same day (A); German grass and rice straw offered ad libitum on alternate days (B); rice straw offered ad libitum for 5 days followed by German grass ad libitum for 5 days (C); and German grass offered ad libitum for 5 days followed by rice straw ad libitum for 5 days (D). Each breed was offered the treatments in a $4{\times}4$ Latin Square design. The German grass intake and total dry matter intake per kg metabolic live weight were significantly higher for the Hx than for RC, but there were no significant effects of genotype on digestibility of nutrients or live weight. Treatment A had the highest proportion of German grass relative to rice straw in the total DM intake, and had the highest total DM intake and apparent digestibility of nutrients compared with treatments B, C and D. It was concluded that there was no significant evidence that the RG cattle were better adapted to a variable supply of low quality feed than Hx cattle, and that the variable feed supply reduced the ability of cattle to select a preferred diet and consequently nutrient intake was depressed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.4
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• pp.425-430
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• 1983

Rice (Oryza sativa L.) anthers collected from different genotypes were cultured to investigate the priority to increase callus production rate among several factors affecting on callus formation. Rice varieties, F$_1$ hybrids and F$_2$ plants differed greatly in their abilities to produce callus from anthers, and it was confirmed that the culturability of rice anther was a heritable characteristic. Cold shock treatment before plating anthers promoted callus formation rate, but combined effect with genotype having high culturability was more significant. The response to sucrose concentration in culture medium in callus induction rate was different between rice genotypes, but combined effect with genotype was not significant. Single supplement of NAA to R$_2$ medium increased callus production rate remarkably only in rice genotype having high culturability. Conclusively selection of genotypes is most important to increase callus initiation frequency from rice anthers.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.5
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• pp.316-321
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• 2000

Blast severity data of 39 rice varieties at 11 sites in Korea from 1997 to 1999 were analyzed using AMMI model and pattern analysis. Genotype x Environment (G$\times$E) interaction sum of squares (SS) accounted for 12 % of the total SS. Eight genotype groups and seven location groups were identified based on blast reaction pattern. The data obtained from over 21 sites with 44 test varieties from 1981 to 1996 were also considered. These were compared with the 1997-1999 data using the G$\times$E analysis results. Majority of the variability in the Korean Rice Blast Nursery (KRBN) were attributable to variations due to genotypes. Variations of G$\times$E interaction were maintained though test sites were reduced from 21 to 11 sites. Broadly compatible biological discriminative varieties identified were Nagdongbyeo and Akibare while broadly incompatible biological discriminative varieties identified were Hangangchalbyeo and Seogwangbyeo. Key sites for future evaluation work could be selected from location groups. Each location group should be represented by the site with the strongest interaction pattern. Blast responses in Cheolwon, Gyehwa, Suwon, Iksan, and Icheon showed different patterns from other locations.

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.10b
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• pp.268-269
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• 2005

• Proceedings of the Korean Society of Crop Science Conference
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• 1995.05a
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• pp.46-47
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• 1995

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.252-252
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• 2022

Genotype-by-environment interaction (GEI) refers to the comparative response of genotypes to different environments conditions. Thus, understanding GEI is a fundamental component for selecting superior genotypes for breeding programs. The significance of utilizing early maturing cultivars not only provides flexibility in planting dates, but also serves as an effective strategy to reduce methane emission from the paddy fields. In this study, we conducted multi-environment trials (METs) to evaluate yield-related traits such as culm length, panicle length, panicle number, spikelet per plant, and thousand grain weight. A total of eighty-one Korean commercial rice cultivars categorized as early maturing cultivars, were cultivated in three regions, two planting seasons for two years. The genotype main effect plus genotype-by-environment interaction (GGE) biplot analysis of yield-related traits and grain yield explained 70.02-91.24% of genotype plus GEI variation, and exhibited various patterns of mega-environment delineation, discriminating ability, representativeness, and genotype rankings across the planting seasons and environments. Moreover, simultaneous selection using weighted average of absolute scores from the singular value decomposition (WAASB) and multi-trait stability index (MTSI) revealed six highly recommended genotypes with high stability and crop productivity. The winning genotypes under specific environment can be utilized as useful genetic materials to develop regional specialty cultivars, and recommended genotypes can be used as elite climate-resilient parents to improve yield-potential and reduce methane emission as part to accomplish carbon-neutrality.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.96-96
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• 2017

Rice is a staple food for nearly half of the world's population, with more than 10,000 rice varieties providing almost one-quarter of the global per capita dietary energy supply. Grain size, panicle size and branch number, grain number in a panicle are directly associated with rice productivity. Recently several genes which increase grain yield were identified through map-based cloning. Gn1a, Cytokinin oxidase, is a major grain number QTL and regulates grain number per panicle. Dep1 increases panicle branching and reduced rachis length. SCM2 (APO1) was identified by a QTL for culm strength and increased spikelet number. OsSPL16 (GW8) controls grain size and shape and then increases 1000-weight of seed. In here, to identify genotype of genes related to yield in 400 of rice germplasms possessed in National Institute of Crop Science, we had first chosen 4 of well-known genes related to yield; Gn1a, Dep1, SCM2, and OsSPL16. Among these germplasms, 195, 382, 165, and 353 of germplasms harbored the dominant type of Gn1a, Dep1, SCM2, and OsSPL16, respectively. We grouped these germplasms into a total of 10 groups using genotypes of Gn1a, Dep1, SCM2 and OsSPL16. Most rice germplasms belong to group 1, harbored Gn1a, dep1, gw8 and APO1, and group 10, harbored gn1a, Dep1, GW8 and apo1. Hanareum2 is the highest productive cultivar in Korea but do not have dominant type OsSPL16, so belong to group 1. On the other hand, in the case of Unkwang, belongs to group 10, which has dominant type of OsSPL16 but do not have the remaining genes. We can grasp the differences in rice germplasms through the Profiling of genes related to these grain yield, which will be useful for cross-breeding to integrate grain yield genes. We are continuously observing the genotype and phenotype of rice that possesses grain yield genes.