Arbuscular mycorrhizal fungi improve the growth of olive trees and their resistance to transplantation stress

Two native Algerian mycorrhizal fungi (Glomus mosseae and Glomus intraradices) were tested for their effect on the growth of micropropagated olive tree (Olea europaea L.). The effect of inoculation of plantlets with G. mosseae was also compared with chemical fertilization using osmocote. Specific molecular techniques were then used to detect the presence of the two fungi. Highly significant increases in growth were evident for inoculated plants compared with uninoculated ones. For a slightly lower shoot growth, G. mosseae doubled the root growth of the inoculated plantlets, compared to that of the fertilized plants. This change in the root: shoot ratio permitted greater utilization of soil resources and strengthened the plant’s capacity to resist transplantation shock and water stress. The abundance of the two fungi in the roots of wild olives just as in the inoculated olives is indicative of thepredominance of G. intraradices when the natural microflora is present

Biological control of arbuscular mycorrhizal fungi and Trichoderma harzianum against Fusarium oxysporum and Verticillium dahliae induced wilt in tomato plants

Abstract Background Arbuscular mycorrhizal fungi (AMF) and Trichoderma harzianum are effective bioagents against Fusarium oxysporum and Verticillium dahliae in tomato plants. The objective of the research was to evaluate the in vivo antagonistic activity of AMF and T. harzianum against Verticillium and Fusarium wilt by enhancing the growth and resistance of tomato plants. A completely randomized experimental design was used, consisting of twelve treatments with nine replicates for each treatment. The treatments included combinations of AMF and T. harzianum inoculation, infection or non-infection by F. oxysporum and V. dahliae, while also considering individual and combined treatments. Mycorrhization rates, growth parameters, disease severity, disease progression, and the impact on disease mitigation were evaluated. Results The study revealed the superiority of AMF over T. harzianum, resulting in a significant enhancement in the overall extent of mycorrhizal colonization in tomato plants co-inoculated with T. harzianum. Moreover, AMF treatments and the AMF + T. harzianum consortium contributed to the improvement in growth among all plants infected with V. dahliae and F. oxysporum. Both AMF and T. harzianum significantly reduced the progression of Fusarium wilt, resulting in reductions of 45.14 and 44.91%, respectively, than the untreated plants infected with F. oxysporum (initial disease severity of 75.54%). T. harzianum demonstrated greater efficacy in reducing V. dahliae infection, with a reduction of 34.45% compared to 28.26% for AMF, starting from an initial disease severity of 69.85%. Thus, T. harzianum demonstrated greater effectiveness in controlling disease, particularly Verticillium wilt. Conclusion The target application of disease control methods in tomato plants revealed the effectiveness of both AMF and T. harzianum in mitigating Fusarium wilt. Furthermore, T. harzianum demonstrated a higher level of effectiveness against Verticillium wilt. These findings emphasize the potential of AMF and T. harzianum as sustainable alternatives in agriculture, providing a viable option to decrease dependence on fungicides

Arbuscular mycorrhizal fungi improve the growth of olive trees and their resistance to transplantation stress

International audienceTwo native Algerian mycorrhizal fungi (Glomus mosseae and Glomus intraradices) were tested for their effect on the growth of micropropagated olive tree (Olea europaea L.). The effect of inoculation of plantlets with G. mosseae was also compared with chemical fertilization using osmocote. Specific molecular techniques were then used to detect the presence of the two fungi. Highly significant increases in growth were evident for inoculated plants compared with uninoculated ones. For a slightly lower shoot growth, G. mosseae doubled the root growth of the inoculated plantlets, compared to that of the fertilized plants. This change in the root: shoot ratio permitted greater utilization of soil resources and strengthened the plant’s capacity to resist transplantation shock and water stress. The abundance of the two fungi in the roots of wild olives just as in the inoculated olives is indicative of the predominance of G. intraradices when the natural microflora is present

Arbuscular mycorrhizal fungi improve the growth of olive trees and their resistance to transplantation stress

International audienceTwo native Algerian mycorrhizal fungi (Glomus mosseae and Glomus intraradices) were tested for their effect on the growth of micropropagated olive tree (Olea europaea L.). The effect of inoculation of plantlets with G. mosseae was also compared with chemical fertilization using osmocote. Specific molecular techniques were then used to detect the presence of the two fungi. Highly significant increases in growth were evident for inoculated plants compared with uninoculated ones. For a slightly lower shoot growth, G. mosseae doubled the root growth of the inoculated plantlets, compared to that of the fertilized plants. This change in the root: shoot ratio permitted greater utilization of soil resources and strengthened the plant’s capacity to resist transplantation shock and water stress. The abundance of the two fungi in the roots of wild olives just as in the inoculated olives is indicative of the predominance of G. intraradices when the natural microflora is present

Avaliação da interação micorrízica em cultivares de oliveira (Olea europea L.)

A maioria dos estudos com oliveira no Brasil e no mundo tem sido direcionada à produção e ao manejo. Apesar da importância para o crescimento vegetal e resistência a estresses diversos, não há estudos sobre a ocorrência de associação micorrízica em oliveira, no Brasil. O objetivo do presente trabalho foi avaliar a interação micorrízica em cultivares de oliveira na Fazenda Experimental de Maria da Fé - MG (FEMF - EPAMIG), a qual serve como ponto de partida na produção de inoculantes comerciais de fungos micorrízicos arbusculares para a cultura. Amostras de solo e de raízes de sete cultivares de oliveira foram coletadas para determinação do comprimento de micélio extrarradicular ativo e total e avaliação da percentagem e intensidade de colonização micorrízica, bem como da densidade e diversidade de esporos. Nas rizosferas das cultivares de oliveira, foram isoladas nove espécies de fungos micorrízicos: Acaulospora denticulata, Acaulospora scrobiculata, Acaulospora sp1, Acaulospora sp2, Entrophospora sp1, Gigaspora sp1, Glomus mosseae, Scutellospora pellucida e Scutellospora sp1. Os resultados comprovaram o micotrofismo da espécie. No entanto, não houve efeito das cultivares na distribuição dos propágulos de FMAs, os quais estiveram homogeneamente distribuídos nas diferentes rizosferas

Olive Genetic Resources

UMR AGAP - équipe AFEF - Architecture et fonctionnement des espèces fruitièresAs one of the most important and ancient fruit crops in the Mediterranean Basin, olive is characterized by a huge genetic patrimony, represented by cultivated and wild germplasm, ancient trees and related forms. The richness of this germplasm represents an unusual case among horticultural crops, due to species longevity, lack of new better performing genotypes, and the millennial tradition of cultivation. Focusing on a wide spectrum of genetic resources, their conservation, characterization, and management, this chapter tries to give an insight into the achievements and the necessities of this type of works in olive. Knowledge of existing diversity among the olive genetic resources is essential to maximize their conservation, safeguard, and exploitation