Plant health status effects on arbuscular mycorrhizal fungi associated with Lavandula angustifolia and Lavandula intermedia infected by Phytoplasma in France

Abstract

We investigated root communities of arbuscular mycorrhizal fungi (AMF) in relation to lavender (Lavandula angustifolia) and lavandin (Lavandula intermedia) health status from organic and conventional fields affected by Phytoplasma infection. The intensity of root mycorrhizal colonization was significantly different between diseased and healthy plants and was higher in the latter regardless of agricultural practice. This difference was more pronounced in lavender. The root AMF diversity was influenced by the plant health status solely in lavender and only under the conventional practice resulting in an increase in the AMF abundance and richness. The plant health status did not influence the distribution of root AMF communities in lavandin unlike its strong impact in lavender in both agricultural practices. Finally, among the most abundant molecular operational taxonomic units (MOTUs), four different MOTUs for each plant species were significantly abundant in the roots of healthy lavender and lavandin in either agricultural practice. Our study demonstrated that the plant health status influences root colonization and can influence the diversity and distribution of root AMF communities. Its effects vary according to plant species, can be modified by agricultural practices and allow plants to establish symbiosis with specific AMF species.

Diversity of Endomycorrhizas in Falcataria moluccana (Miq.) Barneby & J.W. Grimes Affected by Gall Rust Disease in Laguna, Philippines

“…This is true in the most diseased trees of T1 (Table5) and in Figure4, which shows a positive correlation of disease severity with Shannon and Simpson's indices. A study byBinet et al (2020) on Lavandula spp. infected by phytoplasma demonstrated that health status influences AMF diversity, abundance, and richness.…”

The Mycorrizal Status in Vineyards Affected by Esca

“…New studies are now required to understand what appears to be a paradox. Usually, clear relationships between root-associated fungal communities’ composition and plant health status were demonstrated in several plant-mycorrhizae-pathogen interactions involving both woody perennial crops and annual crops [ 21 , 37 , 57 , 58 , 59 ]. Studies comparing different fungal species highlighted that the degree of protection is highly dependent on the AMF inoculated [ 60 ].…”

“…This is an easy and fast method for analyzing the whole root’s mycorrhizal status, including the presence and distribution of key features such as arbuscules, processing a large number of samples but without discriminating the AMF species [ 33 , 36 ]. Recently, the omics approach has allowed researchers to quantify the abundance of mycorrhiza in both plant roots and soil [ 17 , 37 , 38 ]. For high throughput sequencing, the operational taxonomic units (OTUs) technique was used in several works according to rRNA (SSU rRNA) [ 39 ], or internal transcribed spacer (ITS) region, this last as universal barcode for fungi marker genes clustered into OTUs according to nucleotides’ similarity [ 40 ].…”

Current Trends for Lavender (Lavandula angustifolia Mill.) Crops and Products with Emphasis on Essential Oil Quality

“…Studies show that arbuscular mycorrhiza inoculation can increase lavender growth and photosynthetic pigments [ 67 ] and significantly increase linalyl acetate content in lavender essential oil [ 68 ]. Because mycorrhizal colonization level was shown to be significantly influenced by lavender plant health status, and could be modified by agricultural practices [ 69 ], there are more studies needed to elucidate the stability of symbiosis in order to identify ways to assist lavender crops in benefiting from these microorganisms. As an environmentally friendly approach, this should be pursued further.…”