Native Legumes Research Articles

Standards‐based evaluation inform ecological restoration outcomes for a major mining activity in a global biodiversity hotspot

The International Principles and Standards for the Ecological Restoration and Recovery of Mine Sites were used to assess the restoration quality of one of the world's largest mines, located in the world's most biodiverse temperate forest. Quantitative analysis of longitudinal data spanning 35 years scored restoration quality at 2‐stars against a 5‐star forest ecosystem restoration target, with little indication of improvements from adaptive management. Two‐thirds of indicator plants were significantly under‐represented in early‐stage restoration and declined with age. Most plant species were effectively absent, including key structural species. Invasive plants and native legumes were persistently overabundant. Time required for the maturation of tree species will prevent the production of fundamental ecosystem features for well over a century (e.g. hollows and fallen logs), inhibiting functional fauna return (reptiles, bats, and conservation priority cockatoos in particular). The significantly different outcome compared with previous assessments is due to the age of restoration assessed and previous assumptions that early‐stage success indicate that restoration is on the correct, prolonged trajectory toward full ecological restoration. However, previous assessment methods did not consider many key metrics of the standards, nor accurately predict future restoration trajectory. In particluar, initial plant species richness (the only measure of biodiversity in the company's restoration completion criteria) did not reflect future restoration quality. These substandard restoration outcomes may result from removing the deep, multi‐layered bauxitic substrate on which the ecosystem evolved and establishing restoration on shallow topsoil over a more homogenized, impervious substrate. This study demonstrates the value of a robust, adaptable multi‐factor framework and methodology to evaluate restoration outcomes.

Nutritional and Functional Value of Andean Native Legumes and Their Potential Industrial Application.

Legumes are edible seeds that have high nutritional and functional value. Their cultivation and consumption turn out to be an alternative to hunger and guarantee food security in vulnerable populations. This manuscript explores the nutritional and functional properties and potential uses of native Andean legumes such as Pajuro, Tarhui, Common bean, and Lima beans. They contain macro and micronutrients and bioactive compounds with antioxidant, antimicrobial, antidiabetic, and antihypertensive that benefit consumer health. These compounds are particular proteins, peptides, polyphenols, alkaloids, vitamins, minerals, and among others. Moreover, Andean legumes have shown industrial potential due to their technological properties that could be useful in adding value to other food products. These properties are due to their content of starch, oil, fiber, and protein that could facilitate their processing and obtain products with adequate sensory characteristics. Andean legumes have good nutritional and functional value and have the potential to be included in daily diets. Given the accumulated evidence, we believe that the consumption of Andean legumes in nature and processed should be strongly encouraged.

An efficiently biological nitrogen fixation of non-native Lotus tenuis justifies its key role in the flooding Pampas (Argentina)

Forage production is a major challenge in the Salado River basin, Argentina (also denominated “Flooding Pampas”), the largest livestock raising area. The successful naturalization of the European legume Lotus tenuis (native from Mediterranean area) has been of productive and environmental relevance to the region. The main objective of this work was to quantify the efficiency of L. tenuis through its ability to fix nitrogen biologically and thus strengthening their strategic role in the region. The 15N natural abundance method was used to evaluate the Biological Nitrogen Fixation (BNF) of L. tenuis in soil plots. Non-leguminous weed species in the same plots were utilized as reference plants. Simultaneously, evaluations were carried out in the greenhouse and the relative reproducibility of the field experiments. The results showed that L. tenuis promotion was accompanied by an increase in forage quality improving the Crude Protein (CP) content and the Digestibility of Dry Matter (DDM). Moreover, its contribution to N inputs to the system through BNF in symbiosis with native rhizobia was about 80%, a highly relevant percentage for these constrained agroecosystems where the presence of native legumes is very scarce. In conclusion, this study supports the hypothesis that L. tenuis promotion plays a strategic role in ecosystem sustainability in the Salado River basin, especially in soil constrained areas. Together with previously published data, including information on ruminant management, the results obtained contribute to supporting the idea that the naturalized legume plays a strategic role in the sustainability of marginal agricultural soils.

Sorghum–Legume Mixtures to Improve Forage Yield and Nutritive Value in Semiarid Regions

In a continued search for legumes to grow with forage sorghum (FS) [Sorghum bicolor (L.) Moench] in semi-arid environments, studies in 2019 and 2022 at New Mexico State University Rex E. Kirksey Agricultural Science Center at Tucumcari, NM USA, evaluated FS mixed with cowpea [Vigna unguiculata (L.) Walp.], lablab (Lablab purpureus L.), both previously evaluated, and a native legume, big-pod sesbania (Sesbania macrocarpa), for yield and nutritive value in four randomized complete blocks each year. At harvest legume proportions of approximately 15% of the dry matter yield, there were no differences in the yield (mean = 15.97 Mg ha−1, p > 0.40) or land equivalency ratio between sole FS and any mixture or among mixtures; however, the crude protein of FS+Lablab was greater than sole FS, with FS+Cowpea and FS+Sesbania intermediate (67, 77, 87, and 79 g kg−1 for sole FS, FS+Cowpea, FS+Lablab, and FS+Sesbania, respectively; 5% LSD = 14). The neutral detergent fiber digestibility of FS+Sesbania was less than all other treatments (p = 0.0266). Although the sesbania did not improve forage yield or nutritive value when grown with FS and harvested near sesbania maturity, perhaps growing with a shorter season grass and harvesting earlier may show benefit, as sesbania’s nutritive value is known to be greater at earlier stages.

Influence of Temperature and Water Availability on Seed Germination of Cicer Milkvetch (Astragulus Cicer L.) and Purple Prairie Clover (Dalea Purpurea Vent. Var. Pupurea)

Global warming may leads a decrease in plant diversity and increased risk for some plant extinction does exist. The effect of temperature and water availability on seed germination were investigated in many plants, and are two of the most important factors on seed germination, for the plant survival that can result in a loss or increase under global climate change scenarios, by affecting a plant's recruitment success. Therefore, research on how climate change affects seed germination is essential for our research and ability to predict the risk for plants. To examine the possible effect of climate change on two commonly grown legumes a greenhouse experiment was run at at AAFC-SPARC. One was an introduced legume, cicer milkvetch, and the other a native legume, purple prairie clover. Our findings were: the experiment with warmer temperature and decreased soil moisture to research seed germination, the result is that reduction in the total both seed germination rate occurs, and showed the seed germination of purple prairie clover is better for the more stressful temperatures and water potentials examined in this experiment. For both legumes were examined on the control water potential the best temperature range is from 20℃ to 30℃ .

High freezing sensitivity of legumes relative to other herbaceous species in northern temperate plant communities.

Reduced snow cover and increased air temperature variability are predicted to expose overwintering herbaceous plants to more severe freezing in some northern temperate regions. Legumes are a key functional group that may exhibit lower freezing tolerance than other species in these regions, but this trend has been observed only for non-native legumes. Our aim was to confirm if this trend is restricted to non-native legumes or whether native legumes in these regions also exhibit low freezing tolerance. First, we transplanted legumes (five non-native species and four native species) into either an old field (non-native) or a prairie (native) and used snow removal to expose the plots to increased soil freezing. Second, we grew plants in mesocosms (old field) and pots (prairie species) and exposed them in controlled environment chambers to a range of freezing treatments (control, 0, -5 or -10 °C) in winter or spring. We assessed freezing responses by comparing differences in biomass, cover and nodulation between freezing (or snow removal) treatments and controls. Among legume species, lower freezing tolerance was positively correlated with a lower proportion of nodulated plants and active nodules, and under controlled conditions, freezing-induced reductions in above-ground biomass were lower on average in native legumes than in non-native legumes. Nevertheless, both non-native and native legumes (except Desmodium canadense) exhibited greater reductions in biomass in response to increased freezing than their non-leguminous neighbours, both in controlled environments and in the field. These results demonstrate that both native and non-native legumes exhibit low freezing tolerance relative to other herbaceous species in northern temperate plant communities. By reducing legume biomass and nodulation, increased soil freezing could reduce nitrogen inputs into these systems.

Increased dependence on nitrogen-fixation of a native legume in competition with an invasive plant

Suppression of roots and/or their symbiotic microorganisms, such as mycorrhizal fungi and rhizobia, is an effective way for alien plants to outcompete native plants. However, little is known about how invasive and native plants interact with the quantity and activity of nutrient-acquisition agents. Here a pot experiment was conducted with monoculture and mixed plantings of an invasive plant, Xanthium strumarium, and a common native legume, Glycine max. We measured traits related to root and nodule quantity and activity and mycorrhizal colonization. Compared to the monoculture, fine root quantity (biomass, surface area) and activity (root nitrogen (N) concentration, acid phosphatase activity) of G. max decreased in mixed plantings; nodule quantity (biomass) decreased by 45%, while nodule activity in N-fixing via rhizobium increased by 106%; mycorrhizal colonization was unaffected. Contribution of N fixation to leaf N content in G. max increased in the mixed plantings, and this increase was attributed to a decrease in the rhizosphere soil N of G. max in the mixed plantings. Increased root quantity and activity, along with a higher mycorrhizal association was observed in X. strumarium in the mixed compared to monoculture. Together, the invasive plant did not directly scavenge N from nodule-fixed N, but rather depleted the rhizosphere soil N of the legume, thereby stimulating the activity of N-fixation and increasing the dependence of the native legume on this N source. The quantity–activity framework holds promise for future studies on how native legumes respond to alien plant invasions.

Enhancing Pisum sativum growth and symbiosis under heat stress: the synergistic impact of co-inoculated bacterial consortia and ACC deaminase-lacking Rhizobium

The 1-aminocyclopropane-1-carboxylate (ACC) deaminase is a crucial bacterial trait, yet it is not widely distributed among rhizobia. Hence, employing a co-inoculation approach that combines selected plant growth-promoting bacteria with compatible rhizobial strains, especially those lacking ACC deaminase, presents a practical solution to alleviate the negative effects of diverse abiotic stresses on legume nodulation. Our objective was to explore the efficacy of three non-rhizobial endophytes, Phyllobacterium salinisoli (PH), Starkeya sp. (ST) and Pseudomonas turukhanskensis (PS), isolated from native legumes grown in Tunisian arid regions, in improving the growth of cool-season legume and fostering symbiosis with an ACC deaminase-lacking rhizobial strain under heat stress. Various combinations of these endophytes (ST + PS, ST + PH, PS + PH, and ST + PS + PH) were co-inoculated with Rhizobium leguminosarum 128C53 or its ΔacdS mutant derivative on Pisum sativum plants exposed to a two-week heat stress period.Our findings revealed that the absence of ACC deaminase activity negatively impacted both pea growth and symbiosis under heat stress. Nevertheless, these detrimental effects were successfully mitigated in plants co-inoculated with ΔacdS mutant strain and specific non-rhizobial endophytes consortia. Our results indicated that heat stress significantly altered the phenolic content of pea root exudates. Despite this, there was no impact on IAA production. Interestingly, these changes positively influenced biofilm formation in consortia containing the mutant strain, indicating synergistic bacteria-bacteria interactions. Additionally, no positive effects were observed when these endophytic consortia were combined with the wild-type strain. This study highlights the potential of non-rhizobial endophytes to improve symbiotic performance of rhizobial strains lacking genetic mechanisms to mitigate stress effects on their legume host, holding promising potential to enhance the growth and yield of targeted legumes by boosting symbiosis.

Lespedeza potaninii Vass seed yield response to plant density and phosphate fertilization in Northwest China

Lespedeza potaninii Vass is a highly drought-resistant China native legume plant, which plays an important role in animal husbandry and ecological restoration. However, there are few reports on the agricultural practices of its seed production. We evaluated the effect of four plant densities (33,333, 44,444, 66,666, and 133,333 plants ha−1) and five phosphate fertilizer rates (0, 45, 90, 135, and 180 kg ha−1) on seed yield, seed yield components and agronomic traits from the year 2020–2022. Correlation and structural equation model (SEM) analyses were used to determine the contribution of yield components to seed yield per plant. Year, plant density, phosphorus fertilizer rate and their interaction (P<0.05) significantly influenced the seed yield of L. potaninii Vass. The maximum average seed yield over 3 years (570 kg ha−1) occurred at the plant density of 44,444 plants ha−1 and phosphate fertilizer rate of 90 kg/ha. All the yield components, except 1000-seed weight, were significantly correlated with seed yield per plant. The racemes per stem, florets per raceme and pods per raceme had significant positive correlation, and stems per square meter and biomass had significant negative correlation with seed yield per plant. Increasing phosphorus fertilizer increased seed yield per plant. However, increasing plant density decreased seed yield per plant. Our findings enable further understanding of the mechanism of seed yield response to plant density and phosphorus fertilization in L. potaninii Vass and provide a reference for appropriate agronomic measures to improve seed yield of L. potaninii Vass and similar shrubs.

Legume (Fabaceae) and seed beetle (Coleoptera, Chrysomelidae, Bruchinae) species of Europe: distribution and host specialization

The paper investigates the distributions of legumes (Fabaceae) and their associated seed beetle species (Bruchinae) across vegetation zones and regions of Europe and evaluates the host range and specialization of seed beetles. 1584 legume species/subspecies/varieties were included in the study and ca. 16% of these serve as known hosts by the 175 seed beetle species found in Europe. Both plant and seed beetle species richness increased from the Boreal to Mediterranean zones/regions. 717 legume species occurred only in single zones/regions and only 4.7% of these (34 species) were hosts for 38 bruchine species specific to a zone/region. Europe has 664 native legume species and 381 of these are Eu-endemics. There were 52 alien legume species found. Similarities in plant species composition by the Sørensen index were pronounced between the Central-European and the Mediterranean, between the Transcaucasian and Mediterranean, and between the Colchis-Caucasian and the Pontic-Caspian areas. The most species-rich genus is Astragalus L. with 334 species and 16 subspecies. Of the two major pre-dispersal seed predator genera, Bruchidius Schilsky species are sensu lato oligophagous, using a wide range of leguminous tribes as hosts, but restricted to few host species within a tribe. In contrast, members of the Bruchus L. genus are sensu stricto oligophagous species and, despite being constrained to the Fabeae tribe, most of them feed on several Lathyrus L. and Vicia L. species. The ways annual and perennial life cycles as well as chemical constituents of legumes might affect the colonization success of the seed beetles are discussed.

Environmental Effects during Early Life-History Stages and Seed Development on Seed Functional Traits of an Australian Native Legume Species.

Understanding how seed functional traits interact with environmental factors to determine seedling recruitment is critical to assess the impact of climate change on ecosystem restoration. This study focused on the effects of environmental factors on the mother plant during early plant life history stages and during seed development. Desmodium brachypodum A. Gray (large tick trefoil, Fabaceae) was used as a model species. Firstly, this study analyzed seed germination traits in response to temperature and moisture stress. Secondly, it investigated how seed burial depth interacts with temperature and soil moisture to influence seedling emergence traits. Finally, it determined if contrasting levels of post-anthesis soil moisture could result in changes in D. brachypodum reproductive biology and seed and seedling functional traits. The results showed that elevated temperature and moisture stress interacted to significantly reduce the seed germination and seedling emergence (each by >50%), while the seed burial improved the seedling emergence. Post-anthesis soil moisture stress negatively impacted the plant traits, reducing the duration of the reproductive phenology stage (by 9 days) and seed production (by almost 50%). Unexpectedly, soil moisture stress did not affect most seed or seedling traits. In conclusion, elevated temperatures combined with low soil moisture caused significant declines in seed germination and seedling emergence. On the other hand, the reproductive output of D. brachypodum had low seed variability under soil moisture stress, which might be useful when sourcing seeds from climates with high variability. Even so, a reduction in seed quantity under maternal moisture stress can impact the long-term survival of restored plant populations.

Complete genome sequences of Rhizobium sp. strain SL42 and Hydrogenophaga sp. strain SL48, microsymbionts of Amphicarpaea bracteata

This study comprehensively analyzed two distinct rhizobacterial strains, Rhizobium sp. SL42 and Hydrogenophaga sp. SL48, through whole genome de novo sequencing. Isolated from root nodules of Amphicarpaea bracteata, a native legume related to soybean, they were selected to explore beneficial rhizobacteria from native plant relatives. Utilizing Illumina and Nanopore sequencers and MaSuRCA assembly, their complete genetic information was elucidated. Rhizobium sp. SL42 has a 4.06 Mbp circular chromosome and two plasmids with 60% GC content, while Hydrogenophaga sp. SL48 exhibits a 5.43 Mbp circular chromosome with 65% GC content. Genetic analysis identified them as new species, supported by ANI values (77.72% for SL42 and 83.39% for SL48) below the threshold. The genomic analysis unraveled a plethora of genes encoding diverse metabolic functions, secretion systems for substance transport, quorum sensing for coordination, and biosynthetic gene clusters suggesting the production of bioactive compounds. These functional properties contribute to plant growth stimulation, reflecting the symbiotic relationship of rhizobacteria with plants, potentially involving nitrogen fixation and growth-promoting compounds. This research contributes valuable knowledge about plant-microbe interactions and plant growth promotion by these two strains of rhizobacteria.

Land use is a stronger determinant of ecological network complexity than the number of trophic levels.

Land modification causes biodiversity loss and ecosystem modification. Despite many studies on the impacts of this factor, there is little empirical evidence on how it affects the interaction networks of plants, herbivores and their natural enemies; likewise, there is little evidence on how those networks change due to differences in the complexity of the communities they comprise. We analyzed the effects of land use and number of trophic levels on the interaction networks of exotic legume species and their associated arthropods. We collected seedpods from five exotic legume species (one of them invasive) in four land use types (urbanization, roadside, L. leucocephala plantation, wooded pasture) on Santa Cruz Island in the Galapagos, and obtained all arthropods that emerged from the seeds. Then, we built and analyzed the interaction networks for each land use at two community scales, each with different numbers of trophic levels: (1) three levels: plant-seed beetle-parasitoid (PSP), and (2) more than three levels: plant-seed beetle-parasitoid-predator and other trophic guilds (PSPP). Land use was more relevant than number of trophic levels in the configuration of species interactions. The number of species and interactions was highest on roadsides at PSPP and lowest in plantations at PSP. We found a significant effect of land use on connectance and interaction evenness (IE), and no significant effect of number of trophic levels on connectance, diversity or IE. The simultaneous analysis of land use and number of trophic levels enabled the identification of more complex patterns of community structure. Comparison of the patterns we found among islands and between exotic and native legumes is recommended. Understanding the structure of the communities analyzed here, as well as the relative contribution of their determinants of change, would allow us to develop conservation plans according to the dynamics of these neo-ecosystems.

Mapping pathogenic bacteria resistance against common antibiotics and their potential susceptibility to methylated white kidney bean protein.

As antibiotics cannot inhibit multidrug-resistant bacteria (MDR), continuous research is mandatory to find other antibacterials from natural resources. Native legume proteins and their modified forms exhibited broad spectra of high antimicrobial activities. Sixteen bacterial isolates were mapped for antibiotic resistance, showing resistance in the range of (58-92%) and (42-92%) in the case of the Gram-negative and Gram-positive bacteria, respectively. White native Phaseolus vulgaris protein (NPP) was isolated from the seeds and methylated (MPP). The MIC range of MPP against 7 MDR bacteria was 10-25 times lower than NPP and could (1 MIC) considerably inhibit their 24h liquid growth. MPP showed higher antibacterial effectiveness than Gentamycin, the most effective antibiotic against Gram-positive bacteria and the second most effective against Gram-negative bacteria. However, MPP recorded MICs against the seven studied MDR bacteria in the 1-20µg/mL range, the same for Gentamycin. The combination of Gentamycin and MPP produced synergistic effects against the seven bacteria studied, as confirmed by the Transmission Electron Microscopic images. The antimicrobial activity of MPP against the seven MDR bacteria remained stable after two years of cold storage at 8-10°C as contrasted to Gentamycin, which lost 20-72% of its antimicrobial effectiveness.

Which native legume or non-legume nitrogen-fixing tree is more efficient in restoring post-landslide forests along an environmental gradient?

Under climate change, heavy precipitation is predicted to trigger frequent shallow landslides. To accelerate vegetation recovery after landslides, planting nitrogen (N)-fixing trees is a promising technique. However, a comparison of the performance of non-legume and legume N-fixing species planted across a wide range of environments after landslides has not been conducted, which is problematic for determining the most efficient tree species for restoration. We planted the seedlings of a native legume (Lespedeza bicolor) and a native non-legume (Alnus hirsuta) tree species and monitored their survival in 15 landslide forests artificially established across a variety of environments in northern Japan. The landslides were mimicked by removing standing trees and surface soil with heavy machinery from the sites. There was a significant difference in the survival rate of seedlings between the two species. The survival rate was significantly higher for L. bicolor than for A. hirsuta. Furthermore, the performance of the two species differed along the environmental gradient of post-landslide forests. Interestingly, L. bicolor seedlings survived better in the steeper post-landslide forests, probably due to less exposure to ungulate herbivory. On the other hand, the warmer air temperature and serpentine soil negatively influenced the survival of A. hirsuta, which indicates different environmental preferences of N-fixing plants in post-landslide forests. Our results suggest that for efficient forest restoration after landslides, careful selection of N-fixing plants based on slope conditions is essential.

Towards inoculant development for Bambara groundnut (Vigna subterranean (L.) Verdc) pulse crop production in Namibia.

The globally expanding population, together with climate change, poses a risk to the availability of food for humankind. Bambara groundnut (BGN) (Vigna subterranea (L.) Verdc) is a neglected, relatively drought-tolerant native legume of Sub-Saharan Africa that has the potential to become a successful food crop because of its nutritional quality and climate-smart features. Nitrogen fixation from root nodule symbiosis with climate-adapted rhizobial symbionts can contribute nitrogen and organic material in nutrient-poor soil and improve yields. However, high soil temperature and drought often reduce the abundance of native rhizobia in such soil. Therefore, the formulation of climate-smart biofertilizers has the potential to improve the farming of BGN at a low cost in a sustainable manner. The effect of seven Bradyrhizobium spp. strains native to Namibia, including B. vignae and B. subterraneum, were tested on three Namibian BGN varieties (red, brown, cream) in greenhouse pot experiments in Namibia, using soil from the target region of Kavango. Each variety was treated with a mixed inoculant consisting of seven preselected strains ("MK") as well as with one promising single inoculant strain. The results revealed that in all three varieties, the two inoculants (mixed or single) outperformed the non-inoculated cultivars in terms of shoot dry weight by up to 70%; the mixed inoculant treatment performed significantly better (p < 0.05) in all cases compared to the single inoculant used. To test whether the inoculant strains were established in root nodules, they were identified by sequence analysis. In many cases, the indigenous strains of Kavango soil outcompeted the inoculant strains of the mix for nodule occupancy, depending on the BGN variety. As a further preselection, each of the individual strains of the mix was used to inoculate the three varieties under sterile conditions in a phytotron. The agronomic trait and root nodulation response of the host plant inoculations strongly differed with the BGN variety. Even competitiveness in nodule occupancy without involving any indigenous strains from soil differed and depended strictly on the variety. Severe differences in symbiont-plant interactions appear to occur in BGN depending on the plant variety, demanding for coupling of breeding efforts with selecting efficient inoculant strains.

Natural nodulation and nitrogen fixation of Acacia Auriculiformis grown in technosol eco-engineered from Fe ore tailings

AimsNitrogen deficiency in eco-engineered technosol from iron (Fe) ore tailings limits the productivity of colonising soil microbes and pioneer plants, which are critical to further development of the technosol. Symbiotic biological N2 fixation may be a strategy to supply N in the moderately alkaline early technosols since native legumes such as Acacia auriculiformis are tolerant of saline and alkaline soil conditions as those in the technosol. It is hypothesized that tolerant native legume A. auriculiformis could form functional nodules to fix N2 when grown in early eco-engineered technosols.MethodsA. auriculiformis growth and root nodulation in the early tailing technosols were investigated using a glasshouse experiment, and plant N2 fixation was evaluated using the 15 N natural abundance isotope method. Key factors influencing root nodulation and N2 fixation have also been evaluated, including water supply and phosphorous nutrition.ResultsThe results indicated that A. auriculiformis grew well in the tailing technosols and naturally formed nodules with rhizobia. The nodules were functional in N2 fixation, leading to improved plant N nutrition. The nodulation and N2 fixation were severely limited by water deficiency stress. Improved phosphorous supply favoured nodulation and N2 fixation by A. auriculiformis plants under water deficiency stress.ConclusionsThese findings suggested that A. auriculiformis could grow in early tailings technosols and fixed N2, and proper water and phosphorous fertilizer management could improve Acacia plant’s performance and N2 fixation functions. It is possible to introduce tolerant native legumes such as A. auriculiformis to improve N supply in the early technosols.

Preliminary Evaluation of Four Legume and Grass Species to Compose Roadside Revegetation in Piauí, Brazil

A trial was conducted to investigate the growth and production characteristics of four plant species, marking the initiation of research on roadside revegetation processes in the southern region of Piauí state, Brazil. The trial was conducted in greenhouse conditions to evaluate the response of the species—two native legumes (Arachis pintoi and Stylosanthes macrocephala) and two grasses (Brachiaria humidicula—non-native and Paspalum notatum—native)—under different fertilization and irrigation treatments. Data were collected in two harvest operations, measuring the following variables: total plant height, population density per pot, number of live leaves, plant moisture content, total forage biomass, and root biomass. The results suggested that fertilization and irrigation caused no significant effect on the major species development characteristics that allay with the highway agency interests. Arachis pintoi showed the best results with the lowest height (24.1 cm in Experiment 1 and 19.2 cm in Experiment 2) and the greatest total forage biomass yield (6.4 g plant−1 in Experiment 1 and 4.1 g plant−1 in Experiment 2). Thus, we recommend that the results found in this study should be extended to field experiments and long-term research. Because our study did not explore mixed-species designs, adopting such evaluation could offer advantages in achieving more comprehensive and resilient revegetation outcomes and help decision-making regarding target species to compose the roadside revegetation operations.

Impact of Hydrochloric acid on breaking seed dormancy and germination enhancement in native Alhagi graecorum Boiss ( Al-Agool ).

Despite the great importance of legumes plants, most of them have a hard and impermeable testa, which causes physical dormancy of the seeds and prevents germination even when environmental conditions are favorable. This is considered one of the major problems in successful seed germination. Alhagi graecorum plant is a wild native legume. It has a hard and impermeable testa, which causes physical dormancy of seeds, and to overcome hard coat imposed dormancy, softening the hard seed coat by soaking Hydrochloric acid ( HCl ). The present study was conducted to evaluate various duration of soaking seeds in HCL to breaking physical dormancy for A.graecorum in 10, 20, and 30 minutes. The results showed that, final germination percentage (FGP) in treated seeds significantly increased when compared with the control were 55, 62 and 68 % respectively, while in control was only 12 %. Seed germination influenced by HCL is due to its capability to break the hard seed coat that leads to water absorption and imbibition of seeds. As for the mean daily germination ( MDG ), the results revealed that, there were significance increased in seventh day of sowing in germination between the treated seeds in duration of soaking 20 and 30 min were 23 and 24 % respectively, as they were most effective in germination, while the germination in the control stopped in the fifth day of sowing at 12 %. While the mean germination time (MGT), the results indicated that the seeds soaked in acid recorded 9.66, 9.13, and 8.62 days, respectively. The minimum MGT for treated seeds was detected in 30 min., 8.62 days. The reason for the long period of the mean germination time may be due to the use of a low concentration of hydrochloric acid, so I recommend using higher concentrations of acid to obtain a lower mean germination time.

Can legume seeds establish after land degradation by buffelgrass? Evidence to initiate restoration in Central Sonora, Mexico

AbstractBuffelgrass (Pennisetum ciliare) has been introduced in many localities of northwestern Mexico for cattle grazing. Recent studies have documented how the conversion of natural vegetation to buffelgrass pastures affects several ecological processes that result in high levels of desertification and the subsequent abandonment of lands. However, no previous study has documented successful restoration in these habitats. In this paper we report the results of several experiments focused on the restoration of these areas using native legume species of the region. We selected a degraded buffelgrass pasture considered unproductive by local ranchers in central Sonora. We carried out experiments to evaluate seed removal, seedling emergence, and seedling establishment of native legumes species (Prosopis glandulosa, Parkinsonia microphylla and P. praecox). Our results showed that P. microphylla had greater emergence (10%) than the other two species despite the high seed removal recorded. In addition, P. microphylla was the species with the highest survival (1.4%). Thus, our results show that ecological recovery using native species is possible in desertified buffelgrass pastures. Considering the ecological benefits of P. microphylla in the Sonoran Desert (i.e., nurse plant, positive associations, plant‐growth promoting), this species could be considered highly valuable in restoration procedures.