Rhizobia associated with neotropical tree Centrolobium tomentosum used in riparian restoration

Abstract

Centrolobium tomentosum is a tropical legume tree indicated for functional and structural restoration of riparian areas. This study was conducted to characterize the rhizobia isolated from nodules of C. tomentosum in situ and to determine their capacity of renodulation, in an experimental area of land rehabilitation in the Rio Doce valley. Nodulation potential to inoculation with 2 selected fast-growing Rhizobium strains separately and a mixed inoculum of arbuscular mycorrhizal fungi was evaluated by the use of antibiotics resistance. Flood disturbance were observed not to affect renodulation by fast-growing strains. DNA fingerprinting RAPD (random amplified polymorphic DNA) and lipopolysaccharides (LPS) profiles were used to examine molecular relationships among field isolates, inoculants and reference strains. Maximal renodulation was exhibited by strain BHCBAb1 after 24 months after transplantation. Centrolobium tomentosum forms symbiosis with fast-and slow-growing Rhizobium strains, and it is suggested that their nursery culture could be improved by inoculation of selected strain under low nitrogen-input conditions.

Diversity of new root nodule bacteria from Erythrina velutina Willd., a native legume from the Caatinga dry forest (Northeastern Brazil)

“…In a study that examined rhizobia obtained from Centrolobium tomentosum nodules, Pagano (2008) found that the fast growing isolates were tolerant to streptomycin, chloramphenicol and ampicillin. These results are similar to those found in the present study for fast growth mulungu bacteria (ESA 0068, ESA 0069, ESA 0070 and ESA 0071) which were also tolerant to these antibiotics.…”

Plant and Soil Biota: Crucial for Mitigating Climate Change in Forests

“…2), for example, using tropical tree legumes can illustrate river-soil interaction [18]. A study of Centrolobium tomentosum, which forms symbiosis with fast-and slow-growing rhizobial strains, revealed that flood disturbances do not affect root renodulation by fast-growing Rhizobium strains; however, slow strains (Bradyrhizobium sp., also found in preserved sites) can also have an important role as they increase after flooding.…”

Mycorrhizal Interactions for Reforestation: Constraints to Dryland Agroforest in Brazil

“…Protection or regeneration of forest upstream of a threatened region has been proposed as one strategy for reducing floods. As forests can reduce flooding by acting as sponges (trapping water during heavy rainfall, and releasing it slowly into streams), which decreases the severity of floods and maintains stream flows during dry periods, several nations have invested in forest protection or reforestation [32][33][34] (Figure 1). However, some authors suggested that removal of trees does not affect large flood events [35].…”

“…Additionally, legumes can be inoculated with selected symbionts to improve survival in reforestation programs [3,33]. Since Fabaceae can support rhizobia and both EM and AM, the latter being the most frequent [70], plant performance could be favored by nitrogen (N) uptake, either by direct uptake by AM [71] or by the multiple benefits from AM [72].…”

“…For example, Machado and Bacha [81] evaluated the economic viability of the species included in their experiments, such as C. tomentosum (a nitrogen-fixing tree legume, which can be inoculated with rhizobial bacteria and AMF, being the focus of various studies) [33,34,41], and A. angustifolia (dependant on AMF) [42], but did not mention their functional type, showing a lack of biological data integration. Moreover, for several plant species indicated for reforestation, there is no report of their mycothrophy, such as B. riedelianum, popularly known as "pau marfim" [16].…”