• Journal of Crop Science and Biotechnology
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• v.11 no.2
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• pp.111-118
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• 2008

Soybean is sensitive to waterlogging stress, leading to reduce their growth and yield significantly. The objective of this study was to characterize the relative sensitivities of biomass accumulation and specific nodule activity under waterlogging stress between supernoduating mutants, 'SS2-2' and 'Sakukei 4' and their wild-type soybeans, 'Sinpaldalkong 2' and 'Enrei', respectively. Flooding treatment was performed to soybean plants grown in a pot by waterlogging for 15 days from the beginning bloom(R1) stage under natural light. The nodule number and weight were considerably decreased by waterlogging stress. The bleeding sap rate of waterlogging soybean plants was decreased by 78-80% in supernodulating mutants and 65-74% in their wild types compared to control plants. The relative ureide-N content was also decreased by waterlogging and the reduction was high in supernodulating mutants. This may cause the massive reduction of shoot and root dry weight and leaf area in waterlogged soybean plants. There was a varietal difference in response to the waterlogging stress. During the waterlogging, supernodulating mutants maintained higher spad value than their wild types. Particularly, the difference between soybean varieties was clear in low rank leaves from the top. Also, supernodulating mutants showed a weak waterlogging tolerance than their wild types. Under waterlogging conditions, massive nodules were considerably destroyed and specific nodule activity after waterlogging may not be recovered when compared to their wild-type soybeans. Supernodulating mutants showed lower seed yield than their wild types in waterlogging conditions.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.4
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• pp.370-374
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• 1988

The study was objected to compare the differential responses in photosynthesis and resipiration by selected cultivars as tolerant or susceptible to oxyfluorfen and bensulfuron-methyl. Clark-typed oxygen elect rude system (Rank Brothers Co., Bottisham. UK.) was used to detect the releasing oxygen from the leaf disks. By increasing oxyfluorfen concentrations. both cultivars were disposed to decrease in photosynthetic O$_2$ generation and increase in respiratory O$_2$ generation. Comparing of both rice cultivars. cv. Mushakdanti (selected at 10$\^$-3/M as the susceptible) failed down in photosynthetic O$_2$ generation as lower as 43% of the control but cv. Aichiasahi to 55%, respectively. However. no significant difference in respiratory O$_2$ generation were detected between both cultivars. As for bensulfuron-methyl. almost same tendency was conferable with general responses on O$_2$ generation between both selected cultivars, namely cv. IR 1846 failed down in photosynthetic O$_2$ generation as lower as 55% of the control but cv. Chinsurah Boro II to 77%. respectively.