Abstract
Vigorous shoot growth in native soybean cultivar ‘Misato-zairai’ in Mie Prefecture often reduces seed production due to vigorous vegetative growth. We compared plant length, total dry weight and leaf area of Misato-zairai and Fukuyutaka grown in wet and dry soil conditions for two weeks at the vegetative growth stage (soil water treatment) for 3 years to examine the mechanism of vegetative growth of Misato-zairai. The plant length of Misato-zairai for two weeks of wet soil condition was significantly longer than that of Fukuyutaka due to longer stem length. Leaf area was similar in the two cultivars in the dry soil condition, but the wet soil condition increased leaf area of Misato-zairai significantly through the increase in node number on the main stem and increase in average specific leaf area. There were no significant differences in total dry weight after soil water treatment, plant growth rate, relative growth rate and net assimilation rate between cultivars between the two soil conditions, but SPAD value, which shows the mesophyll photosynthetic capacity, was lower in Misato-zairai grown in wet soil condition.
