• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.2
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• pp.155-165
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• 1992

Experiments were conducted to determined the development of the vascular bundles in the peduncle of different tillers on its development in order to improve the vascular system and possibly increase grain yield. The development of the vascular bundle in the leaf, stem and panicle is an important aspect of assimilate translocation and differentiation of panicle characters. Two cultivars were used in this study: IR58, an indica type, and Unbong 7, a japonica type. The main culm(M) had more and bigger vascular bundles in the peduncle and those vascular bundle decreased with tiller order and tiller development. In the primary tillers, P1 had more large and small vascular bundles than P5 in both cultivars. IR58 developed more large vascular bundles compared to Unbong 7, but the small vascular bundle in unbong 7 was more than in IR58. The cross sectional area of phloem and xylem in large vascular bundle decreased with tiller order in both cultivar. Larger area of phloem and xylem in the early formed tillers more efficient transport of assimilates. The number of spikelets, the weight of panicle and grain yield per panicle were highest in the main culm followed by the order of their initiation or emergence. The number of primary and secondary branches to be positive associated with the number and area of vascular bundles. Furthermore, the number of vascular bundles in the peduncle was highly correlated with the peduncle thickness which in turn was correlated with the number of primary and secondary branches on the panicle. These results showed tillers that are initiated early and have relatively ation usually have more vascular bundles, larger peduncle, more spikelets spike let filling and ultimately higher yield.

• Korean Journal of Plant Resources
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• v.30 no.4
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• pp.427-434
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• 2017

This experiment was conducted to investigate the aspect of tiller occurrence, growth and yield of sorghum according to planting distance and sowing date. The object of this experiment is to get basic data to inhibit non-productive tillers uneconomical and cumbersome for mechanical harvesting. Also another object was to evaluate optimum planting distance and sowing date in central district area. Total number of tillers was more in 80 cm ridge than 60 cm ridge and it was increased as the planting distance was wider from 15 cm to 30 cm on the each ridge. Ratio of effective tillers was higher in 60 cm ridge than 80 cm ridge and it was decreased as planting distance was wider from 15 cm to 30 cm. The lower the planting distance, the more increased total number of tillers, whereas effective tillers was decreased as planting distance was high. Average of total number of tillers of three varieties was higher in sowing date of May 2 (1st sowing date), whereas ratio of effective tillers was the highest in sowing date of May 23 (2nd sowing date). Hwanggeumchal showed the highest total number of tillers (1.2 tillers), while Moktaksusu had the lowest total number of tillers (0.8 tillers) among three varieties. There were no significant difference between planting distance and days to heading and ripening date from seeding. Culm length increased as planting distance was high, but ear length, grains per ear and 1000 grain weight were decreased on the other hand. The highest yield of sorghum per 10a was obtained from $60{\times}20cm$ planting distance among 6 planting distances.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.91-91
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• 2017

Drought is the most serious abiotic stress limiting rice production. However, little progress has been made in the genetic analysis of drought tolerance, because it is a complex trait controlled by a number of genes and affected by various environmental factors. In here, we screened 218 rice genetic resources for drought tolerance at vegetative stage and selected 32 highly drought tolerant varieties in greenhouse. Under rain-fed conditions, Grain yield of Nagdong was decreased by 53.3% from 517 kg/10a to 241 kg/10a when compare to irrigation condition. By comparison, grain yield of Samgang was decreased by 23.6% from 550 kg/10a to 420 kg/10a. The variety Samgang exhibited strong drought tolerance and stable yield in rain-fed conditions and was selected for further study. To identify QTLs for drought tolerance, we examined visual drought tolerance (VDT) and relative water content (RWC) using a doubled haploid (DH) population consisted of 101 lines derived from a cross between Samgang (a drought tolerance variety) and Nagdong (a drought sensitive variety). Three QTLs for VDT were located on chromosomes 2, 6, and 11, respectively, and explained 41.8% of the total phenotypic variance. qVDT2, flanked by markers RM324 and S2016, explained 8.8% of the phenotypic variance with LOD score of 3.3 and an additive effect of -0.6. qVDT6 was flanked by S6022 and S6023 and explained 12.7% of the phenotypic variance with LOD score of 5.0 and an additive effect of -0.7. qVDT11, flanked by markers RM26765 and RM287, explained 19.9% of the phenotypic variance with LOD score of 7.1 and an additive effect of -1.0. qRWC11 was the only QTL for RWC to be identified; it was in the same locus as qVDT11. qRWC11 explained 19.6% of the phenotypic variance, with a LOD score of 4.0 and an additive effect of 9.7. To determine QTL effects on drought tolerance in rain-fed paddy conditions, seven DH lines were selected according to the number of QTLs they contained. Of the drought tolerance associated QTLs, qVDT2 and qVDT6 did not affect tiller formation, but qVDT11increased tiller number. Tiller formation was most stable when qVDT2 and qVDT11 were combined. DH lines with both of these drought tolerance associated QTLs exhibited the most stable tiller formation. These results suggest that qVDT11 is important for drought tolerance and stable tiller formation under drought stress condition in field.

• Korean Journal of Soil Science and Fertilizer
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• v.5 no.2
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• pp.75-82
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• 1972

The proposed hypothesis that the effects of climatic factors during ripening period (from 10 days before heading to 30 days after heading) on ripened grain ratio are equal on the level of canopy and on the level of tiller in that canopy of rice plant appeared to be agreeable. The followings were found according to the analysis of ripening structure at tiller level. 1. The optimum ripening temperature (mean air temperature during ripening period) was $21^{\circ}C$ for Jinheung and $22^{\circ}C$ for IR667-Suwon 214. 2. The minimum mean solar radiation ($cal\;cm^{-2}\;day^{-1}$) of ripening period was not greater than 240 for Jinheung and greater than 270 for IR 667-Suwon 214. 3. The ripened grain ratio was not different from main culm to first tillers of second order of main culm in Jinheung but greatly decreased from 4th tiller of first order of main culm in IR667 and the number of grain per main culm was greater in IR667 than in Jinheung indicating that yield of IR667 could be increased by increasing the number of main culm. 4. The last heading date insuring optimum ripening period appeared to be 25th in August for Jinheung and 30th in August for IR667 in Suweon.

• Molecules and Cells
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• v.42 no.12
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• pp.858-868
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• 2019

Shoot branching is an essential agronomic trait that impacts on plant architecture and yield. Shoot branching is determined by two independent steps: axillary meristem formation and axillary bud outgrowth. Although several genes and regulatory mechanism have been studied with respect to shoot branching, the roles of chromatin-remodeling factors in the developmental process have not been reported in rice. We previously identified a chromatin-remodeling factor OsVIL2 that controls the trimethylation of histone H3 lysine 27 (H3K27me3) at target genes. In this study, we report that loss-of-function mutants in OsVIL2 showed a phenotype of reduced tiller number in rice. The reduction was due to a defect in axillary bud (tiller) outgrowth rather than axillary meristem initiation. Analysis of the expression patterns of the tiller-related genes revealed that expression of OsTB1, which is a negative regulator of bud outgrowth, was increased in osvil2 mutants. Chromatin immunoprecipitation assays showed that OsVIL2 binds to the promoter region of OsTB1 chromatin in wild-type rice, but the binding was not observed in osvil2 mutants. Tiller number of double mutant osvil2 ostb1 was similar to that of ostb1, suggesting that osvil2 is epistatic to ostb1. These observations indicate that OsVIL2 suppresses OsTB1 expression by chromatin modification, thereby inducing bud outgrowth.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.4
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• pp.326-333
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• 2003

Transgenic rice plants expressing a Bacillus subtilis protoporphyrinogen oxidase (Protox), the last shared enzyme of the porphyrin pathway in the expressed cytoplasm or the plastids, were compared with non-trangenic rice plants in their growth characteristics such as tiller number, plant height, biomass, and yield. Transgenic rice plants of $\textrm{T}_3$ generation had 8 to 15 % and 25 to 43% increases in tiller number compared to non-transgenic rice plants at 4 and 8 weeks after transplanting(WAT); similar values were observed for $\textrm{T}_4$ generation at 4 and 8 WAT. However, the plant height in both $\textrm{T}_3$ and $\textrm{T}_4$ generations was similar between transgenic rice plants and non-transgenic rice plants at 4 and 8 WAT. Transgenic rice plants had 13 to 32% increase in above-ground biomass and 9 to 28% increase in grain yield compared to non-transgenic rice plants, demonstrating that biomass and yield correlate with each other. The increased grain yield of the transgenic rice plants was closely associated with the increased panicle number per plant. The percent of filled grain, thousand grains and spikelet number per panicle were similar between transgenic and non-transgenic rice plants. Generally, the growth and yield of transgenic generations ($\textrm{T}_2$, $\textrm{T}_3$, and $\textrm{T}_4$) and gene expressing sites (cytoplasm-expressed and plastid-targeted transgenic rice plants) were similar, although they slightly varied with generations as well as with gene expressing sites. The transgenic rice plants had promotive effects, indicating that regulation of the porphyrin pathway by expression of B. subtilis Protox in rice influences plant growth and yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.143-148
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• 1999

Soil moisture condition is an important limiting factor in growth and yield in rice culture. The purpose of this study was to compare the influence on the growth, yield and Quality of rice subjected to soil moisture stress (SMS) at different growth stages. Ajaponica rice cultivar, Dongjinbyeo, was cultured under flooded conditions in a plastic container filled with silty loam soil. The container was subjected to SMS until the initial wilting point (IWP) coincided with about 10% in soil moisture content and about-200 kPa in soil matric potential, and was then irrigated again, at 6 and 5 of main growth stage in 1996 and 1997, respectively. At maturity, the plant height, tiller number, leaf area and top dry weight were decreased more in SMS treatments at the early stage than the late stage. The averaged yield index of SMS to control in both years was lowest at meiosis (62.5%), which primarily resulted from lower percent ripened grain and 1,000 grain weight, and second＇ reduced the spikelet number per panicle and panicle number per hill, and followed at tillering stage (68.5%) which resulted from the lower production in tiller number and top dry matter during and after SMS treatment. The percent-age of read rice in SMS plants varied with the treatment stage as order of lower at meiosis (44.0%), heading (53.9%), panicle initiation (70.1%), tillering (72.1%), ripening (75.8%) and 5 days after transplanting (DAT) (79.0%). Protein content in brown rice was slightly larger in SMS at late growth stage than the control, while the contents of fat and ash differed very little between SMS and control. Contents of Mg and K and Mg/K in brown rice with SMS were lower at some treatment stages such as at ripening or panicle initiation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.14 no.3
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• pp.195-200
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• 1994

This experiment was undertaken to study the relationship between dry weight of plant(DW) and yield components. varietal differences in seasonal production at each of three cutting. and to classiQ them into some patterns of seasonal production in tall fescue varieties. The varieties examined were Barvetia. Fuego, Demeter. Safe, Barcel. Forager, Johnstone. Enforcer and Stef. The results obtained were as follows : 1. The Fuego and Barcel with high number of tiller per plant(NT) which had more dry wieght of plant(DW) than those of varieties with low number of tillers per plant(NT) at each cutting. 2. The dry weight of plant(DW) in 1st cutting indicated positive significant correlation with the number of tillers per plant(NT) and dry weight of a tiller(WT). But there was only positive correlation between the number of tillers per plant(NT) and dry weight of plant(DW) in 2nd and 3rd cutting. 3. Mean relative yield of each cutting were 3 1 %. 29.7% and 39.3% in 1st. 2nd and 3rd cutting, respectively. 4. Tall fescue varieties could be classified into 3 different seasonal growth patterns according to their mode of relative yield at each cutting. Barvetia, Fuego, Johnstone. Enforcer and Stef belong to the group of ABA with high relative yield in 1st and 3rd cutting. Demeter, Safe and Forager belong to the group of CBA with relative yield increased linearly up to 3rd cutting. And, Barcel belong to the group of BAB with high relative yield in 2nd cutting.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.4
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• pp.469-473
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• 2007

With the aim to analyze stability performance of six promising barley genotypes, eleven yield related characters were evaluated employing varied irrigation treatments under the tropical climate of Northern part in Bangladesh. Analysis of variance(ANOVA), phenotypic index, regression co-efficient(bi) and deviation from regression($s^2_d$) of the individual genotypes were estimated to evaluate the stable performance of the genotypes. A significant interaction was observed between the genotypes and irrigation period($G{\times}T$). Among all the genotypes, BSH-2 showed stable performance for plant height under different irrigation period, where $P>\bar{X},\;bi{\sim}1\;and\;s^2_d{\sim}0$. High phenotypic index, lower bi value and low deviations from regression were observed in case of spikelet number per spike and grain number per spike for genotype BSH-2 and plant height, spike length and harvest index per plant for BB-2 which suggest that those parameters were not usually affected by irrigation. On the other hand the genotype BSH-2 for tiller number and BB-1 for the fertile tiller number were not suitable for favorable moisture content, where $P<\bar{X},\;bi>1.0\;and\;low\;s^2_d$. Thus we suggest that genotype BSH-2 might have transmit high mean and increased phenotypic stability to the next progenies, which may consider as an ideal genotype for developing improved barely cultivars.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.2
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• pp.41-46
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• 2000

This experiment was carried out to find out the responses of the growth characteristics to various air temperature in a high yielding indica/japonica rice cultivar, 'Dasanbyeo'. Five different transplanting dates with 30 day-old seedlings were tried to induce various environmental conditions, starting from 10th May to 19th June in the interval of 10 days at National Crop Experiment Station, in 1998. Planting densities with different plants per hill but same hill spacing were tested. The daily mean air temperature during 30 days after transplanting was 19.0, 20,8, 21.9, 24.4 and 25.2$^{\circ}C$ when transplanted on the 10th May, the 20th May, the 30th May, the 9th June and 19th June, respectively. The number of tillers per hill at 30 days after transplanting was affected by the daily mean air temperature during 30 days after transplanting. The higher the daily mean air temperature, the more tillers per hill at 30 days after transplanting were. The growth duration from transplanting to heading was greatly changed according to the transplanting dates. It was shortened as the transplanting date was delayed until transplanted on the 9th June, but it was prolonged when transplanted on the 19th June compared to that of the 9th June. The number of panicles per hill increased with the increase of the transplanted plants per hill up to 7 plants per hill. The number of panicle per unit area was closely related to the number of tillers per unit area at maximum tillering stage. It was found that the average effective temperature during first 10 tiller formation related to the days to the tenth tiller formation with the relationship of y = 1.071x$^2$ - 37.307x + 342.38($R^2$ = 0.9823).