International Journal of Agricultural Policy and Research
Vol. 2 (2), pp. 041-048, February 2014
Article 13/ID/ Article ID JPR117, 08 page
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Original Research Paper
Excess soil water impact on colonization and extraradical mycelium biomass production of arbuscular mycorrhizal fungi in soybean field
Accepted 4 December, 2013
Rintaro Hattori, Atsushi Matsumura*, Kenji Yamawaki, Arata Tarui, and Hiroyuki Daimon
Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Naka, Sakai, Osaka 599-5831, Japan.
*Corresponding author E-mail: firstname.lastname@example.org
In Japan, soybean plants at early growth stage, mainly cultivated in upland fields converted from paddy, are often stressed by excess soil water. Although, symbiotic relationships between soybean and arbuscular mycorrhizal (AM) fungi play a crucial role in increasing nutrient uptake, few studies have considered the occurrence and roles of AM fungi in soybean under these conditions. In the present study, we established different soil water plots (control plot and wet plot), and assessed the effect of excess soil water during early growth stage of soybean on AM colonization, AM extraradical mycelium (ERM) biomass production and soybean growth in an upland field converted from paddy through two years field experiment. Our results showed that the excess water treatment negatively affected soybean growth (P < 0.05), and reduced AM colonization (P < 0.05). The ERM biomass at vegetative stage of soybean in wet plot was much lower (P < 0.05) compared with that in control plots in both years. However, the ERM biomass in wet plot recovered similar to that in control plots at the reproductive stage of soybean. These results indicate that the production and spread of ERM are severely suppressed by excess water conditions. It may be pointed out that one of the reasons for the growth inhibition of soybean cultivated in upland fields converted from paddy is the negative effects on the AM symbiotic relationship by excess soil water.
Key words: fatty acid, Glycine max (L.) Merrill., root length density, soil water content