• Title/Summary/Keyword: varietal difference

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Effective Screening Method for Viviparous Germination of Rice

  • Ju, Young-Cheoul;Han, Sang-Wook;Park, Joong-Soo;Park, Kyeong-Yeol
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.45 no.2
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    • pp.103-107
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    • 2000
  • The viviparity of 28 rice varieties was tested at 25 days after heading(DAH), 35DAH, and 45DAH in the laboratory and field condition for 12 days. The incubation temperature was 20/l$0^{\circ}C$ (day/night), 25/15$^{\circ}$C$ and 30/20$^{\circ}$C$ in the laboratory test, and under field water conditions in the field test. The biggest varietal difference of viviparity was found in the laboratory test when examined at 45DAH with the 6-day incubation under 25/15$^{\circ}$C$ . At this conditions the mean viviparous ratio was 32.1 % with the range of 53.9 and the variance of 259.5. In the field test, the significant varietal difference in the viviparity was also found in the lodging treatment at 45 DAH for 6 days. Correlation coefficient analysis between the field and laboratory tests was highly significant from 4 days after incubation at 45 DAH and after 6-day incubation at 35 DAH, and correlation coefficient was higher as incubation days in the laboratory and submerged days under field water became longer. Considering the correlation between the field and laboratory tests, varietal difference of viviparity and convenience of testing, the laboratory test at 45 DAH for 6-day incubation under 25/15$^{\circ}$C$ was the most efficient evaluation method for the viviparity of rice cultivar.

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Varietal Difference of Resistance to Ozone Injury in Rice Plant (벼 품종별 오존 피해 저항성 차이)

  • 손재근;이상철
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.3
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    • pp.338-343
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    • 1997
  • The response of seventy-five rice cultivars to ozone (O$_3$) were tested in the open-top chamber with ozone producing and monitoring system to determine the varietal difference of resistance to $O_3$ stress. Ozone was produced by electrostatic discharge in oxygen and was monitored by UV absorption ozone analyzer. Difference in response of rice to ozone was more clearly appeared on rice plants treated for 2 to 4 hours at 0.3 ppm concentration of $O_3$. Varietal resistance of rice to ozone was more distinctly classified at 21- to 35-day seedlings compared with 14-day rice plants. Most of indica and Tongil(indica$\times$japonica) type rice cultivars were more resistant than that of japonica cultivars based on the leaf injury to $O_3$. Eight Korean cultivars belong to japonica groups showed highly resistant reaction to $O_3$. Ozone exposure during booting stage caused lower grain fertility than exposures during seedling, maximum tillering and heading stages of rice.

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Varietal Difference in Retrogradation of Cooked Rice and Its Association with Physicochemical Properties of Rice Grain

  • Choi, Hae Chune;Hong, Ha Cheal;Cho, Soo Yeon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.44 no.4
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    • pp.355-363
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    • 1999
  • The experiments were carried out to elucidate the varietal variation of retrogradation in aged cooked rice and its association with some physicochemical properties of milled rice. The fifteen rice materials were selected from forty-three low-amylose japonica and Tongil-type rice cultivars based on palatability and retrogradation of cooked rice stratified by preliminary sensory evaluation of warm and cooled cooked rice. One japonica glutinous rice variety was included for comparison of retrogradation of cooked rice. The $\alpha$-amylase-iodine method was adopted for checking the varietal difference in retrogradation of cooked rice. The desirable checking time for evaluating the varietal difference in deterioration of aged cooked rice was four hours after storing in room temperature and two hours after preserving in refrigerator based on the largest coefficients of variations in degree of retrogradation of cooked rice. The rice cultivars revealing the relatively slow retrogradation in aged cooked rice were Ilpumbyeo, Chucheongbyeo, Sasanishiki, Jinbubyeo and Koshihikari. A Tongil-type rice, Taebaegbyeo, and a japonica cultivar, Seomjinbyeo, showed the relatively fast deterioration of cooked rice. The retrogadation index represented by the percentage of retrogradation difference between warm and cooled cooked rice to original estimates of warm cooked rice was significantly affected by the degree of retrogradation of cooled cooked rice. Generally, the better rice cultivars in eating quality of cooked rice showed less retrogradation and much sponginess in cooled cooked rice. Also, the rice varieties exhibiting less retrogradation in cooled cooked rice revealed higher hot viscosity and lower cool viscosity of rice flour in amylogram. The sponginess of cooled cooked rice was closely associated with magnesium content and volume expansion of cooked rice. The hardness-changed ratio of cooked rice by cooling was negatively correlated with solids amount extracted during boiling and volume expansion of cooked rice. The major physicochemical properties of rice grain closely related to the palatability of cooked rice may be directly or indirectly associated with the retrogradation characteristics of cooked nce. The varietal difference in retrogradation of cooked rice can be effectively classified by scatter diagram on the plane of upper two principal components based on some retrogradation properties of cooked rice. The deteriorated structural change in cooled cooked rice by observing through the scanning electron microscope was more conspicuous in the fastly retrograded cooked rice than in the slower one.

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Varietal Difference in Salinity Tolerance during Germination Stage of Rice

  • Lee, Kang-Soo;Choi, Sun-Young;Choi, Won-Yul
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.43 no.1
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    • pp.11-14
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    • 1998
  • This study was conducted to find out a desirable screening condition for the salinity tolerance in germination of rice. Seeds of 33 rice varieties were tested in NaCl solutions with various concentration levels. The germination percentage had a decreasing tendency with increasing NaCl concentration and inhibition concentration of 50% germination was 320mM. Standard deviation of germination percentage was highest (28.6) under 300mM NaCl. There was a highly significant correlation between the 50% germination concentration and the germination percentage at 20th day after seeding in 300mM NaCl. Also in 300mM NaCl, the germination percentage at 20th day after seeding was significantly correlated with the germination percentage at the 6th day after seeding. The salinity tolerance on the basis of germination percentage at 6th day after seeding in 300mM NaCl, was strong in 'Hyangnambyeo', 'Ilmibyeo', 'Kancheogbyeo', and 'Namwonbyeo', while weak in 'Ansanbyeo', 'Odaebyeo', 'Nonganbyeo', 'Dasanbyeo', and 'Namcheonbyeo'.

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Interrelation between Physicochemical Properties of Milled Rice and Retrogradation of Rice Bread during COld Storage (쌀의 이화학적 특성과 저장 쌀빵의 노화성과의 관계)

  • 강미영;최영희;최해춘
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.5
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    • pp.886-891
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    • 1997
  • The interrelation between physicochemical properties of milled rice and retrogradation of rice bread during cold storage was examined to compare the varietal difference in maintenance of rice bread quality. Twelve rice materials showed big varietal difference on physicochemical properties of rice starch such as amylose content(0.0~29.2%), gel consistency(20~98mm), and alkali digestion value(2.0~7.0). Rice bread made from milled rice of Jungwonbyeo, AC 27 and IRAT 177 exhibited soft texture and late retrogradation of rice bread during cold storage(4$^{\circ}C$). The amylose content of milled rice was closely associated with gel consistency negatively and with springiness of rice bread positively. The retrogradation of rice bread texture during cold storage was correlated with gel consistency of rice flour positively and with alkali digestion value of milled rice negatively.

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Varietal Difference in the Occurrence of Grey Leaf Tobacco (연초grey엽 발생의 품종간 차이)

  • 이철환;진정의
    • Journal of the Korean Society of Tobacco Science
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    • v.17 no.2
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    • pp.120-125
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    • 1995
  • Varietal difference in the occurrence of grey leaves in upland diverted from paddy field were investigated with several flue-cured tobacco varieties in Korea. Grey leaves caused by Fe, Mn and Cl toxicity were occurred in all varieties used in this experiment. The variety, NC82 and KF113, however, were more sensitive than other varieties to the toxicity. It's revealed that grey leaves had little effects on the contents of total sugar, nicotine and total nitrogen. NC82 and KF113 were increased in the ratio of occurrences in the paddy soils which had a tendency to concrete with the passage of days after transplanting. NC82 showed high occurrences of grey leaves in each of variety used and it was estimated that this variety had a traits of easy occurrences of grey leaves, and it might be presumed that there would be a close connection between the ratio of occurrence and amounts of absorbed causal materials accumulated in plants and tobacco varieties on the occurrence of grey leaf tobacco.

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