• Proceedings of the Korean Society of Crop Science Conference
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• 1986.06a
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• pp.24-25
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• 1986

• Proceedings of the Korean Society of Crop Science Conference
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• 1986.06a
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• pp.22-23
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• 1986

• Korean Journal of Breeding Science
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• v.42 no.2
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• pp.169-180
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• 2010

This study was conducted to investigate characteristics of panicle traits which are important factors affecting yield and grain quality of rice. Twelve panicle traits in 178 Korean rice varieties composed of 160 Japonica type varieties and 18 Tongil type varieties were investigated. Tongil type varieties had longer panicle and thicker neck node than Japonica type varieties. Other traits such as number of total spikelets, total rachis-branches, secondary rachis-branches (SRBs) per panicle, total spikelets on SRBs per panicle, mean number of spikelets on a SRB, and mean number of SRBs per primary rachis branch (PRB) in Tongil type varieties were also higher than in Japonica type varieties. On the other hand, Japonica type varieties were shown to have well exserted panicle and little more mean number of spikelets on a PRB than Tongil type varieties. According to cluster analysis based on 12 panicle traits, 178 varieties were divided into four main groups. Group I had 133 Japonica type varieties and was characterized by relatively well exserted short panicle, small thickness of neck node, few rachis-branches and little sink size than other group. Group II was composed of 24 Japonica type varieties and 6 Tongil type varieties showing medium value and range between Group I and III. Group III included 11 Tongil type varieties and 1 Japonica type variety 'Baegjinju1' characterized by relatively poor exserted long panicle, big thickness of neck node, many rachis-branches and large sink size. Group IV was solely composed of 'Nongan', which had well exserted long panicle, big thickness of neck node, many rachis-branches and large-sink size. In correlation analysis, number of total spikelets per panicle showed very high correlation with the number of total rachis-branches per panicle (r=0.975), number of spikelets on SRBs per panicle (0.962), number of SRBs per panicle (0.959), mean number of SRBs per PRB (0.746) and mean number of spikelets on SRBs (0.738).

• Applied Biological Chemistry
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• v.28 no.2
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• pp.106-109
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• 1985

Gelatinization of Japonica(30 varieties) and J/Indica(22 varieties) rice flours in 0.2N NaOH was examined. J/Indica rice flours were easily gelatinized and showed higher viscosities at all reference points than Japonica counterparts. Viscosity development rate was not correlated with protein or amylose content. Only J/Indica rice varieties showed positive correlation between hydration rate and viscosity development rate.

• Korean Journal of Food Science and Technology
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• v.18 no.2
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• pp.110-113
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• 1986

Effect of defatting on the hydration rate of Akibare (Japonica) and Milyang 30 (J/lndica) rice was investigated. Relative crystallinity of rice starch and width of the rice grain were decreased by defatting, which was more pronounced for Milyang 30. The moisture gain at $10^{\circ}{\sim}40^{\circ}C$ for 80 min and the hydration rate of the defatted Milyang 30 rice were lower and higher than those of the defatted Akibare rice, respectively. The activation energy for hydration of rice was not affected by defatting.

• Applied Biological Chemistry
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• v.28 no.2
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• pp.62-67
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• 1985

Hydration rate of 35 Japonica and 24 J x Indica rice varieties at $23^{\circ}C$ was investigated and an attempt was made for a tentative classification of milled rice into six groups based on hydration rate. Each rice variety had characteristic value for hydration rate. In general, J x Indica rice hydrated at a faster rate than Japonica rice. Hydration rate was negatively correlated with the ratio of length to width of rice grain. No correlation was found between hydration rate and protein, amylose, surface area, volume or initial water grain.

• Journal of Biosystems Engineering
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• v.14 no.3
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• pp.181-187
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• 1989

The mechanical and rheological properties of agricultural materials which influence the machine design or handling are not completely understood. Agricultural materials do not react in a purely elastic manner, and their responses when subjected to stress and strain appear a combination of elastic and viscous behavior. Many researchers have studied the mechanical and rheological properties of the various agricultural materials, but those properties are available mostly for foreign varieties of agricultural products. Rheological properties of rice seedlings become important to formulate the principles governing their mechanical behavior. The objectives of this study were to experimentally determine the creep and recovery behavior of rice seedlings of one japonica-type and one Indica x japonica hybrid in the transplanting age. The results of this study are summarized as follows; 1. The compression creep and recovery behavior of mat-type seedlings could be described by 4-element Burger's model. 2. The steady-state creep appeared at the stress larger than 0.8 MPa and the logarithmic creep appeared at the stress smaller than 0.8 MPa. 3. In the compression creep test of the rice seedlings, the instantaneous elastic modulus of Burger's model showed the range from 20 to 40 MPa. The higher value of absolute viscosity for the rice seedling explained that the rice seedlings were viscoelastic materials. 4. In the recovery test of the rice seedlings, there was a tendency that the higher permanent strain of all samples was observed under the smaller stress being appeared, and the larger permanent strain in Dongjin was observed than in Samkang.

• 한국전자현미경학회:학술대회논문집
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• 2005.05a
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• pp.26-26
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• 2005

• Proceedings of the Korean Society of Crop Science Conference
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• 1996.10a
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• pp.20-21
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• 1996

• Proceedings of the Korean Society of Crop Science Conference
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• 1996.10a
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• pp.22-23
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• 1996