Effects of arbuscular mycorrhizal fungi on seed and protein yield under water-deficit stress in mung bean

Abstract

Arbuscular mycorrhizal fungi are considered to have the potential to increase the tolerance of host plants to water-deficit stress. This is due to their apparent role in water and nutrient uptake and transfer to their host plants. To evaluate the effects of mycorrhizal fungi species and water-deficit stress on mung bean [Vigna radiata (L.) R. Wilczek var. radiata] plants, a 2-yr split-plot experiment based on a randomized complete block design with three replications was conducted in the field in 2009 and 2010. Treatments were the application of various irrigation levels (irrigation after 50, 100, 150, and 200 mm of evaporation from a Class A pan as the main plot) and inoculation with two mycorrhizal fungal species (Glomus mosseae, G. intraradices, and uninoculated plants as subplots). Our results from 2 yr of experiment indicates that the highest (1833.51 and 479.15 kg ha−1) and lowest (1139.56 and 333.99 kg ha−1) seed and protein yield were obtained from plants irrigated after 50 and 200 mm of evaporation, respectively; however, the maximum (0.60 kg m−3) and minimum (0.32 kg m−3) ecosystem water use efficiency was observed in plants irrigated after 200 and 50 mm of evaporation, respectively. Seed yield, biological yield, leaf P, leaf N, protein percentage, protein yield, harvest index of protein, and ecosystem water use efficiency were improved in mycorrhizal plants compared with the non-mycorrhizal plants. Our results suggest that both G. mosseae and G. intraradices significantly improved the yield (seed and protein) and reduced the water-deficit stress in mung bean plants in the field.