Matching of Nitrogen Enhancement and Photosynthetic Efficiency by Arbuscular Mycorrhiza in Maize (Zea mays L.) in Relation to Organic Fertilizer Type

Abstract

In the present study, Funneliformis mosseae (FM), Claroideoglomus etunicatum (CE), and Acaulospora foveata (AF) were inoculated to hybrid maize (Zea mays L. cv. CP888^®). Upregulation of nitrogen levels were dependent on the type of mycorrhiza (AMF). Photosynthetic efficiency (F_v/F_m) and water content in FM- and AF-inoculated plants were elevated, resulting in promotion of leaf area and shoot biomass. N content in the shoot and root tissues of the FM-inoculated plants increased by 21% and 30% over the control. A positive correlation between biochemical, physiological, and morphological parameters using Pearson's coefficient was demonstrated. A decline in lipid peroxidation was noticed in the FM-inoculated plants. In addition, we investigated the potential of N fertilizer application in combination with FM inoculation in maize plants. The FM-inoculated plants with organic O_LT, a chicken manure fertilizer, increased N content in the host shoots by 73% over the control, leading to improved F_v/F_m as a physiological adaptation strategy. The FM and the O_LT on the regulation of the N enhancement and photosynthetic efficiency of the hybrid maize should further be validated in field trials in different environments for sustainability.

Keywords: arbuscular mycorrhizal fungi; maize; nitrogen content; organic fertilizer; photosynthetic efficiency.

Figure 1

Morphological characters and root colonization of arbuscular mycorrhizal fungi: (a) Funneliformis mosseae (FM); (b) Acaulospora foveata (AF); (c) Claroideoglomus etunicatum (CE); (d) control (Con) in the hybrid maize host. ¹ Mean ± SE. The different letters indicate significant data at p ≤ 0.01 using Duncan’s new multiple range test.

Figure 2

Box plots showing N content in the shoots (a) and roots (b) of the hybrid maize inoculated with Funneliformis mosseae (FM), Acaulospora foveata (AF), and Claroideoglomus etunicatum (CE) and the uninoculated control (Con). Data sorted by means.

Figure 3

Pearson correlation coefficient matrices depicting relationship between N content and total chlorophyll content, photosynthetic efficiency (F_v/F_m) of the hybrid inoculated with (a) Funneliformis mosseae (FM), (b) Acaulospora foveata (AF), and (c) Claroideoglomus etunicatum (CE) and the (d) uninoculated control (Con). Scale from a −1 to 1 coefficient. Data were significant at ** p ≤ 0.01 and * p ≤ 0.05 using Duncan’s new multiple range test.

Figure 4

Box plot showing malondialdehyde (MDA) content in the shoots of the hybrid maize inoculated with Claroideoglomus etunicatum (CE), Acaulospora foveata (AF), and Funneliformis mosseae (FM) and the uninoculated control (Con). Data sorted by means.

Figure 5

Heat map clustering (as Z-score values) of shoot and root N content, fresh weight, water content, total chlorophyll content, photosynthetic efficiency, and reversed MDA content of the hybrid maize inoculated with Funneliformis mosseae (FM), Claroideoglomus etunicatum (CE), and Acaulospora foveata (AF) and the uninoculated control (Con).

Figure 6

Box plots representing relative changes in N content (a) and photosynthetic efficiency (F_v/F_m) (b) in the shoots of the hybrid maize plant inoculated with Funneliformis mosseae (FM) with/without organic fertilizers (i.e., O_LT and O_UMJ), chemical fertilizer (i.e., C_UR), and the uninoculated control (Con). Data sorting by means. Different letters indicate significant differences at p ≤ 0.05 applying Duncan’s new multiple range test.