• Korean journal of applied entomology
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• v.44 no.4 s.141
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• pp.299-306
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• 2005

Soybean seed injury was analyzed in the experiments that soybean pods were allowed to be sucked by adults of the bean bug, R. clavatus, and were picked with a specimen pin. While attack by the bean bug at podding stage of soybean caused the increase of empty pods and completely-undeveloped seeds, attack at full seed stage caused the increase of seeds wi distinct injury mark on seed-coat. The ratio of deformed seed was lower than those of injury-marked seed and undeveloped seed when attacked during all stages. In at full bloom stage hardly produced injury-marked seeds and deformed seeds. When the injured seeds were dyed with acid-fuchsine solution, stylet sheaths of R. clavatus formed on seed-coat were observed in 83% of undeveloped seeds formed under attack during podding stage and in 91% of injury-marked seeds formed during full seed stage. In pods injured with a specimen pin at full seed and full maturity stages, no healthy seeds could be obtained from the pods. And the more picked at full seed stage, the more deformed seeds were produced and the higher weight reduction of injury-marked seed occurred. However, pin-injury at full maturity stage didn't give rise to weight reduction of seeds.

• Korean journal of applied entomology
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• v.49 no.4
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• pp.357-362
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• 2010

Soybean seed injury was analyzed in the experiments in which the bean bug, Riptortus pedestris(Hemiptera: Alydidae), was released into screen-caged pots containing full seed stage(R6) of soybean. When the different stages of insects, from the 3rd instar nymphs to adults, were released into pots during 8 days in soybean R6 stage, soybean seeds with injury marks (B-type seeds) increased. The weight reduction ratio in B-type seeds was highest in the injury by the 5th instar nymphs, while the daily-produced number ratio of B-type seeds was small in the treatment. In the injury by the different number of adult released into pots, 4, 8, 16 adults caused a significant increase of B-type seeds, while 16 adults caused the significant increase of the deformed (C-type) seeds. In the injury by the different release period of adults, the total number of pods was not significantly different among treatments, while the total seed number harvested was significantly small in the release for 48 days. The release for 8 and 16 days caused a significant increase of B-type seeds, while the release for 48 days caused the increase of C-type seeds. The results indicated that injury of soybean R6 stage by the bean bug produced soybean seeds with distinct injury marks at relatively low density and during short term attack period, while it produced deformed seeds at high density and during long attack period.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.512-515
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• 2004

The purpose of this experiment was to obtain informations about variation of anthocyanin content within black-seeded soybean testa according to cultivation and harvest time. Three varieties, Ilpumgeomjeongkong, Geomjeongkong 2, Tawonkong were tested in this experiment. Seeds were planted on April 15 (early planting), May 15 (optimum planting), and June 15 (late planting), respectively. Harvest time was R6 (full seed), R7 (physiological maturity), and R8 (harvest maturity), respectively. The content of delphinidin-3-glucoside (D3G), cyanidin-3-glucoside (C3G), petunidin-3-glucoside (Pt3G), and total anthocyanin (TA) had all increased gradually from April 15 to June 15 as well as R6 to R8. There was no varietal difference in D3G, but C3G and TA of Geomjeongkong 2 were higher than other two varieties. Pt3G was the highest Tawonkong of varieties. The value of L as anthocyanin color difference had gradually decreased from April 15 to June 15 and R6 to R8, Geomjeongkong 2 among three varieties was the lowest. The value of a was the highest on May 15 and increased gradually from R6 to R8, Geomjeongkong 2 was the lowest. The value of b was the highest on June 15 as late planting and was the highest Geomjeongkong 2 of varieties. The value of b had increased gradually from R6 to R8. D3G, C3G, Pt3G, and TA contents showed mutually high positive correlation and these four characters were represented high negative correlation with L value but showed high positive correlation with a and b values. The value of L showed high negative correlation with a and b values. The value of a showed high positive correlation with b value.