PRODUCTION OF Colubrina glandulosa SEEDLINGS WITH DIFFERENT MYCORRHIZAL INOCULA

Abstract

Colubrina glandulosa has potential for reforestation of disturbed areas. Seedlings inoculated with arbuscular mycorrhizal fungi (AMF) can be produced with biosolids from Sewage Treatment Plants. This study aimed to evaluate the response of Colubrina glandulosa seedlings to isolated or mixed inoculation of different AMF species on a biosolid-based substrate under greenhouse conditions. The experimental design was completely randomized, with 32 replicates (seedlings)/treatment and five treatments: (1) control or absence of inoculation (CT); (2) inoculation with Dentiscutata heterogama (DH); (3) inoculation with Gigaspora margarita (GM); (4) inoculation with Rhizophagus clarus (RC); (5) inoculation with the mixture of the three AMF species (MT). We evaluated height and collar diameter of the seedlings at 30, 60, 90, 120, and 140 days after the experiment installation. We evaluated shoot dry biomass (SDM), root dry biomass (RDM), and total dry biomass; SDM / RDM ratio; Dickson Quality Index; relative increments in height, collar diameter, and shoot biomass; nutrient content (N, P, K) in the shoots and roots; efficiency of absorption and utilization of nutrients; rate of root mycorrhizal colonization, at 140 days. In general, the highest values of growth and nutrition variables occurred in the MT treatment, which was recommended, in comparison with CT, DH, GM, and RC. Colonization rates were low (≤ 20 %), regardless of the mycorrhizal inoculum, due to the high levels of phosphorus in the biosolid.

A Mixture of Arbuscular Mycorrhizal Fungi Favors Brazilian Pepper Seedlings Under an Intermediate Level of Soil Phosphorus

“…Root colonization was extremely reduced at the highest dose of P (650 mg kg -1 ), not exceeding 5% in all treatments. We expected this pattern, as it has been widely reported for other forest species, such as Toona ciliata (LIMA et al, 2015), Eugenia uniflora (DALANHOL et al, 2016), Apuleia leiocarpa (OLIVEIRA JÚNIOR et al, 2017), and Colubrina glandulosa (CAMARA et al, 2017;SILVA et al, 2020), as well as for plants of agronomic interest, such as Zea mays L. (NOVAIS et al, 2014) and coffee (MOREIRA et al, 2019).…”

“…Plants are known to exhibit different degrees of mycorrhizal dependence, and even in soils with high levels of available phosphorus, the species that benefit from the mycorrhizal association are considered highly dependent on this symbiosis (OLIVEIRA JÚNIOR et al, 2017). Different AMF species can distinctly affect the efficiency of this relationship, and some studies have shown that the symbiotic efficiency was higher in seedlings that were inoculated with a mixture of AMF species than those that received an isolated fungus (NOVAIS et al, 2014;OLIVEIRA JÚNIOR et al, 2017;SILVA et al, 2020). These studies show the importance of investigating the effect of the inoculation of forest species seedlings with different AMF symbionts, either alone or in a mixture.…”