Responses of root growth characters to waterlogging in soybean [Glycine max (L.) Merrill].

摘要

Stress from excess water is one of the most harmful limiting factor in soybean yield during the wet season under the climate conditions. Soybean is very sensitive to excess water compare to other crops. This experiment was carried out to identify the growth responses for establishing a screening system related to waterlogging tolerance in soybean from 2003 to 2004. The root dry weight accumulation rate of per day for 21 days after waterlogging at V5 stage was the highest in Pungsannamulkong (47-56% of control) and was the lowest in Jangyeobkong (26-27% of control). The nodules dry weight recovery rate was the highest in Pungsannamulkong (83-91% of control), while the lowest in Myungjunamulkong (48-66% of control). After waterlogging, recovery rate of roots was high, which increased the root/shoot ratio of Pungsannamulkong, which also produced significantly more adventitious roots than in Jangyeobkong. The percentage of adventitious roots fresh weight to the total roots fresh weight was the lowest in Myungjunamulkong (14%), while the highest in Pungsannamulkong (38%). This results implies that the water and nutrients absorbing ability of Pungsannamulkong is more higher than that of Myungjunamulkong during late growth period.