Efectos del pretratamiento con Trichoderma y Bacillus en la germinación de semillas de Agave victoriae-reginae T. Moore

La aplicación de tratamientos pregerminativos es fundamental para mejorar las tasas de germinación de las semillas de especies forestales, entre los cuales el uso de microorganismos es uno de ellos. En este estudio se evaluó el porcentaje de germinación de semillas de Agave victoriae-reginae tratadas con Trichoderma spp. y Bacillus spp. Se probaron tres tratamientos: T1 (Trichoderma), T2 (Bacillus) y T3 (Testigo), con tres repeticiones de 100 semillas cada una. Las semillas se sumergieron en una solución de 1 × 106 UFC (tratamientos T1 y T2), y en agua corriente (T3), luego se sembraron sobre Sphagnum peat moss y se registró el porcentaje de germinación diariamente. La germinación comenzó a los 5 días después de la siembra, lo que significa que las semillas no presentaron latencia. Entre el 8° y 12° día se registró un aumento acelerado de la germinación en los tres casos, hasta que la el proceso finalizó a los 26 días, con 85 % de germinación total para semillas tratadas con Trichoderma, 86.7 % con Bacillus y 74 % con el testigo. Se observó un efecto significativo del tratamiento sobre el porcentaje de germinación; incluso el uso de ambos microorganismos aceleró el proceso de germinación con respecto al testigo. Estos resultados sugieren que el uso de Trichoderma spp y Bacillus spp. como tratamientos pregerminativos puede mejorar la germinación de A. victoriae-reginae y su conservación a largo plazo, lo que contribuye a la permanencia de esta especie en peligro de extinción.

Natural selection on a carbon cycling trait drives ecosystem engineering by Sphagnum (peat moss)

Sphagnum peat mosses have an extraordinary impact on the global carbon cycle as they control long-term carbon sequestration in boreal peatland ecosystems. Sphagnum species engineer peatlands, which harbour roughly a quarter of all terrestrial carbon, through peat accumulation by constructing their own niche that allows them to outcompete other plants. Interspecific variation in peat production, largely resulting from differences in tissue decomposability, is hypothesized to drive niche differentiation along microhabitat gradients thereby alleviating competitive pressure. However, little empirical evidence exists for the role of selection in the creation and maintenance of such gradients. In order to document how niche construction and differentiation evolved in Sphagnum , we quantified decomposability for 54 species under natural conditions and used phylogenetic comparative methods to model the evolution of this carbon cycling trait. We show that decomposability tracks the phylogenetic diversification of peat mosses, that natural selection favours different levels of decomposability corresponding to optimum niche and that divergence in this trait occurred early in the evolution of the genus prior to the divergence of most extant species. Our results demonstrate the evolution of ecosystem engineering via natural selection on an extended phenotype, of a fundamental ecosystem process, and one of the Earth's largest soil carbon pools.

Evaluation of Sugarcane Agroindustrial Wastes as Substrate in Soilless Cultivation of Tomato (S. lycopersicum Linnaeus): Effect of Substrate Composition on Yield Production

Traditionally, biochar is generally proposed to substitute Canadian Sphagnum peat moss. Sugarcane bagasse, filter press mud and sugarcane bagasse ash were mixed in different ratios and proposed as an alternative to substitute commercial Sphagnum peat moss (SPM) for the soilless cultivation of tomato (S. lycopersicum Linnaeus). The choice of the agroindustrial waste ratio was performed from physical-chemical sample characterization. During vegetable production, an adequate ratio was evaluated based on plant height, substrate pH, number of leaves, yield, and fruit size. The addition of essential macro- and micro-nutrients was performed manually. The results show that as-received materials contain different minerals with a structure that corresponds to the quartz, cristobalite, and feldspar phases. A morphology composed of lamellate structures was observed for sugarcane bagasse, whereas the filter press mud and the sugarcane bagasse ash presented compact agglomerates with a surface area of 1.60, 3.78, and 1.07 m2 g−1, respectively. The properties of each component promote the water adsorption, retention and releasing capacity. Important differences were observed as the quantity of filter press mud increased, but also it is required an amount of sugarcane bagasse above of 18 wt% to reach a superior performance. This work demonstrated that, in adequate quantities, agroindustrial wastes can be used as a soilless substrate for growing tomatoes in greenhouse, reducing their disposal problems.

Comparison of Water Capture Efficiency through Two Irrigation Techniques of Three Common Greenhouse Soilless Substrate Components

Substrate wettability is an important factor in determining effective and efficient irrigation techniques for container-grown crops. Reduced substrate wettability can lead to lower substrate water capture, excessive leaching and poor plant growth. This research examined substrate water capture using surface and subirrigation under three initial moisture contents (IMC). Sphagnum peat moss, coconut coir, and pine bark were tested at IMCs of 67% 50%, and 33%. Substrate water capture was influenced by both IMC and irrigation technique. Surface irrigation increased the water capture of coir and peat, regardless of IMC, whereas IMC influenced pine bark water capture more than irrigation method. Surface-irrigated coir at or above 50% IMC provided the greatest water capture across all treatments. The first irrigation had the highest capture rate compared to all other events combined. Container capacities of pine bark and coir were unaffected by IMC and irrigation type, but the CC of peat was less by ~ 40% volumetrically under low IMC conditions. Coir, had the greatest ability to capture water, followed by pine bark and peat, respectively. Moisture content, irrigation type and component selection all influence the water capture efficiency of a container substrate.

INVESTIGATION OF QUALITY CHARACTERISTICS OF UNIVERSAL SORBENTS USED AT UFA REFINERIES

Determined the efficiency of use and capacity of oil absorption of natural large-dispersed hydrophilic isotropic-porous universal sorbent “Canadian Sphagnum Peat Moss” and organic finely-dispersed coarse hydrophilic isotropic-porous sorbents: “Profsorb”, “Lessorb”, “STsN-2” in relation to various environments and products of oil refining. The quantitative analysis method was carried out according to GOST 33627-2015. The obtained results showed that the high absorption capacity when bottling gasoline, kerosene and drying oil sorbents “Lessorb” and “STsN-2”, when bottling oil sorbents No. 1, “Lessorb” and “STsN-2”, when bottling benzene, p-xylene and o-xylene – sorbents “Profso”, “STsN-2”.

Adsorptive-removal of Bromothymol Blue as Acidic-dye Probe from Water Solution Using Latvian Sphagnum Peat Moss: Thermodynamic Assessment, Kinetic and Isotherm Modeling

A green and environmental–friendly method for the removal of the hazardous bromothymol blue from aqueous solution was considered applying a hydrophilic, biocompatible and biodegradable natural sorbent of Latvian sphagnum peat moss, applying shaking-dispersive solid-phase extraction. First, the influence of shaking speed was evaluated at 300, 600, 900 U. Furthermore, the optimum conditions of dye-adsorption, such as pH, adsorption-equilibrium contact time, adsorbent mass, and adsorbate initial concentration were investigated. In addition, the adsorption equilibrium isotherms, thermodynamics, and kinetics were studied. Thus, the optimum removal of bromothymol blue was concluded at a shaking speed of 600 U. Regarding the dye adsorption at different pH, bromothymol blue showed two removal maxima at acidic (pH 2.5) and almost neutral (pH 7.5) media, reaching dye % removal of 80.8 and 88.2 %, respectively, in 120 min of adsorption equilibrium contact time. Moreover, the dye removal improved reasonably by increasing the concentration and the sphagnum dose. Additionally, the equilibrium isotherm plot correlated comparably to Langmuir's and Freundlich's models. Also, the adsorption kinetic study demonstrated a better correlation to pseudo-secondorder plot than to pseudo-first-order one. Finally, excellent reproducibility in % removal was demonstrated with RSD values of 2.2 and 2.7% at pH of 7.5 and 2.5, respectively.

Evaluation of Soybean Plant Introductions for Traits that can Improve Emergence under Varied Soil Moisture Levels

When drought occurs during the soybean (Glycine max L. Merr.) sowing period, emergence will most likely be affected. We evaluated a diverse panel of 373 plant introductions under controlled environmental conditions for primary root length (PRL) (at 100, 80, 60, 40, and 20% pot water holding capacity (PWHC); pots filled with potting soil that contained Sphagnum peat moss (>50%), bark, and perlite), and time taken for radicle emergence (TRE). The PRL decreased ≥75% at 40% PWHC, compared to 100, 80, and 60% PWHC. No genotypes germinated at 20% PWHC. We identified superior genotypes in terms of PRL and TRE, and found a positive relationship between PRL and emergence that became stronger with decreases in soil moisture levels. This indicates the importance of PRL in improving emergence, which becomes greater with decreases in soil moisture levels or increases in severity of drought. Seed weight was not related to PRL and emergence, indicating that larger seeds will not necessarily have longer PRL and better emergence. As the soybean panel used in this study was previously assessed for traits associated with drought tolerance at the late-vegetative and flowering stages, and the present study assessed it for putative traits related with emergence under various soil moisture conditions, the panel will become an important resource for soybean improvement.