Greenhouse Evaluation of Indigenous AMF Inoculums Isolated from High Land and Low Land Areas in Improving Growth and Survival of Seedlings of the Green Legacy Program of Ethiopia

Abstract

Ethiopia has been carrying out national tree seedling planting campaigns since its millennium. The low level of seedlings’ survival and establishment has been a bottleneck to the realization of the national restoration target. Poor field survival and establishment of trees were caused by low moisture and nutrient content of soils at the planting site. This study is aimed at evaluating the potential of native AMF inoculums isolated from highland and lowland areas in improving the growth and survival of seedlings of the Green Legacy Program of Ethiopia. The study was carried out in three stages. (1) Rhizosphere soil samples were collected from the selected sampling areas, (2) AMF was propagated in trap culture in greenhouse conditions, and (3), the culture of AMF was inoculated onto selected seedlings trees, Delonix regia, Sesbania grandflora, Cassia fistula, and Azodichta indica. Four treatments were set up: AMF inoculum from A.seyal, AMF inoculum from A.tortilis, AMF inoculum from A. abyssinica, and without inoculum (-ve control). The growth parameters like shoot height and root height, fresh and dry mass of root and shoot, and the number of leaves; percentage of root colonization, and spore density were measured and analyzed by ANOVA. The results showed that the growth of the trees significantly increased by inoculation of the AMF over that of non-inoculated (control) (p< 0.05). AMF spore density and root colonization rate showed the highest in trees treated by AMF from A.seyal among the treatments and followed by A.abyssinica and A.tortilis. Moreover, the highest root colonization and mycorrhizal dependency were observed in S. grandflora and spore density in C. fistula among the selected trees. Furthermore, Pearson’s correlation analysis showed that significant positive correlations were observed between the parameters. All of these results suggested that inoculation of native AMF could improve the growth and survival rate of seedlings. However, the application of present findings required to be confirmed by further studies under field conditions.