Screening of biomass production of cultivated forage grasses in response to mycorrhizal symbiosis under nutritional deficit conditions

Abstract

Arbuscular mycorrhizal fungi (AMF) colonize the root systems of most natural grassland species and usually increase plant growth by enhancing nutrients provision. This effect on growth responses of cultivated forage grasses is scarcely known, particularly under nutritional deficit conditions. We examined total biomass production, aboveground and belowground biomass and tillering of three temperate and three tropical cultivated forage grasses. Seedlings of each species were inoculated with a mixture of mycorrhizal fungi and later grown for 5 months under nutritional deficit conditions. The mycorrhizal symbiosis promoted aboveground and belowground biomass production in five out of six grass species. Grass species differed in their mycorrhizal responsiveness: tropical grasses (Panicum coloratum cv. Klein = Brachiaria brizantha cv. Marandú > Paspalum dilatatum cv. Primo) responded better than temperate (Festuca arundinacea cv. Royal > Agropyron elongatum cv. Hulk), while the temperate Dactylis glomerata cv. Porto did not respond to AMF inoculation. In four of the species, the changes observed in aboveground biomass were explained by the total number of tillers, while, in P. dilatatum, changes were accounted for by the individual weight of mature tillers. On the whole, the screening of cultivated forage grasses revealed that tropical grasses were highly responsive to mycorrhizae, in contrast to a lower effect on the growth of temperate grasses.

NATIVE MICROBIOTA AND ARBUSCULAR MYCORRHIZAL FUNGI ON GROWTH OF Paspalum millegrana SCHRAD

“…The number of tillers could not be correlated to the mycorrhizal colonization of P. millegrana in all the treatments. Likewise, Cavagnaro et al (2014) confirmed that the number of tillers in P. dilatatum was not influenced by the use of AMF isolates, despite the higher tiller biomass than that of the control The mycorrhizal colonization of P. millegrana in the control, native, native + UFLA05 and native + UFLA401 treatments did not correlated to the biomass parameters (dry mass, root length and root volume). However, in the mixture treatment, a positive correlation between mycorrhizal colonization and dry shoot matter (r = 0.90, 0.1 ≤ p <0.05) and root length (r = 0.93, 0, 1 ≤ p <0.05) could be observed.…”

“…The increase of the root volume of P. millegrana with native + UFLA351 and native + UFLA372 is linked to the intense formation of fine roots, which increase the surface area for water and nutrient absorption, as observed for other species of Paspalum (CHANNABASAVA; LAKSHMAN;MUTHUKUMAR, 2015;CAVAGNARO et al, 2014).…”

“…On the other hand, P. millegrana was not responsive to the use of mycorrhizal isolates for some of the attributes, such as dry shoot mass, total dry mass, root volume and root length (Figure 1), since they indicated mycorrhizal dependence to be below 25% (MACHINESKI; BALOTA; SOUZA, 2011). Cavagnaro et al (2014) found that the AMFgrass members' interaction of tropical climate, for instance, with Panicum coloratum, resulted in an increase of 202 to 206% of the dry biomass when compared to that in the control. Whereas, P. dilatatum only had an increase of 98% with mycorrhizal addition in relation to that in the control.…”

“…The AMF-Paspalum interaction has been described only for P. natatu species in China (CUI et al, 2015), P. maximum and P. notatum in Colombia (MONROY et al, 2013), P. scrobiculatum in India (CHANNABASAVA; LAKSHMAN; MUTHUKUMAR, 2015) and P. dilatatum "Cousin" in Argentina (CAVAGNARO et al, 2014). However, no reports were found on the mycorrhizal interaction with P. millegrana, as well as the association of this grass with the native microbiota.…”

Diversity of arbuscular mycorrhizal fungi associated with Brachiaria brizantha pastures in lowlands of Oaxaca, Mexico

“…Despite the importance of B. brizantha pastures for fodder livestock, our knowledge of the AMF species diversity associated with this species is limited. These kinds of studies are essential since some researchers suggest that the presence of AMF can increase the plant species yield (Cavagnaro, Oyarzabal, Oesterheld, & Grimoldi, ), the soil maintenance and an equilibrated environment (Baum et al., ; Paterson et al., ; Pollastri et al., ). The study aimed to contribute to the knowledge of the AMF species richness in B. brizantha pastures in Oaxaca lowlands (Gulf of Mexico), Mexico and explore its relationship with soil properties.…”