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Animal-mediated seed dispersal is important for sustaining biological diversity in forest ecosystems, particularly in the tropics. Forest fragmentation, hunting, and selective logging modify forests in myriad ways and their effects on animal-mediated seed dispersal have been examined in many case studies. However, the overall effects of different types of human disturbance on animal-mediated seed dispersal are still unknown. We identified 35 articles that provided 83 comparisons of animal-mediated seed dispersal between disturbed and undisturbed forests; all comparisons except one were conducted in tropical or subtropical ecosystems. We assessed the effects of forest fragmentation, hunting, and selective logging on seed dispersal of fleshy-fruited tree species. We carried out a meta-analysis to test whether forest fragmentation, hunting, and selective logging affected 3 components of animal-mediated seed dispersal: frugivore visitation rate, number of seeds removed, and distance of seed dispersal. Forest fragmentation, hunting, and selective logging did not affect visitation rate and were marginally associated with a reduction in seed-dispersal distance. Hunting and selective logging, but not fragmentation, were associated with a large reduction in the number of seeds removed. Fewer seeds of large-seeded than of small-seeded tree species were removed in hunted or selectively logged forests. A plausible explanation for the consistently negative effects of hunting and selective logging on large-seeded plant species is that large frugivores, as the predominant seed dispersers for large-seeded plant species, are the first animals to be extirpated from hunted or logged forests. The reduction in forest area after fragmentation appeared to have weaker effects on frugivore communities and animal-mediated seed dispersal than hunting and selective logging. The differential effects of hunting and selective logging on large-and small-seeded tree species underpinned case studies that showed disrupted plant-frugivore interactions could trigger a homogenization of seed traits in tree communities in hunted or logged tropical forests. La dispersión de semillas por animales es importante para sustentar la diversidad biológica en ecosistemas forestales, particularmente en los trópicos. La fragmentación de bosques, la cacería y la tala selectiva modifican los bosques de muchas maneras y sus efectos sobre la dispersión de semillas por animales han sido examinados en muchos estudios de caso. Sin embargo, todavía se desconocen los efectos generales de los diferentes tipos de perturbación humana sobre la dispersión de semillas por animales. Identificamos 35 artículos que proporcionaron 83 comparaciones de dispersión de semillas por animales entre bosques perturbados y no perturbados; todas las comparaciones excepto una fueron en bosques tropicales o subtropicales. Evaluamos los efectos de la fragmentación del bosque, la cacería y la tala selectiva sobre la dispersión de especies de árboles con frutos carnosos. Efectuamos un meta análisis para probar si la fragmentación del bosque, la cacería y la tala selectiva afectaban a tres componentes de la dispersión de semillas por animales: tasa de visitación de frugívoros, números de semillas removidas y distancia de dispersión de semillas. La fragmentación del bosque, la cacería y la tala selectiva no afectaron la tasa de visitación y estuvieron marginalmente asociadas con la disminución de la distancia de dispersión. La cacería y la tala selectiva, pero no la fragmentación, se asociaron con una reducción importante en el número de semillas removidas. Menos semillas de especies de árboles con semillas grandes que de semillas pequeñas fueron removidas en bosques con cacería o tala selectiva. Una explicación plausible de los efectos consistentemente negativos de la cacería y la tala selectiva sobre las especies con semillas grandes es que los frugívoros grandes, como los dispersores predominantes de especies de plantas con semillas grandes, son los primeros animales extirpados de bosques con cacería o tala. La reducción de la superficie de bosque después de la fragmentación pareció tener efectos más débiles sobre las comunidades de frugívoros y la dispersión de semillas por animales que la cacería y la tala selectiva. Los efectos diferenciales de la cacería y la tala selectiva sobre especies de árboles con semillas grandes y pequeñas sustentaron estudios de caso que mostraron que la alteración de interacciones planta-frugívoro podría detonar la homogenización de atributos de las semillas en comunidades de árboles en bosques tropicales con cacería o tala.

(Johansson & Linnaeus) (Coleoptera: Bruchidae) is a bruchid widely distributed in the New World and recently introduced to the Old World. It also has a wide host range from 11 genera in the family Arecaceae. This paper provides information on the damage caused by to the seeds of three species of the New World palm genus in Sinaloa, Mexico, which ranged between 3.48 % and 77.77 %. In addition, information is provided on the current distribution of , based on information from a collated database of museums and institutions that have specimens of bruchid species. Finally, a complete list of all host plants of is provided, including new records.

Teramnus labialis (of the Fabaceae family) is an under-utilized legume with immense potential to improve agricultural soils (through atmospheric nitrogen fixation) and for use as forage for livestock. Despite its pantropical distribution, only a limited number of studies is available to characterize germplasm of this genus. In Cuba, two cultivars are commonly grown, i.e., a light-brown and dark-brown seeded type. The current contribution reports on the phenotypic evaluation of these two cultivars in order to document and characterize plant traits. The results indicated that phenotypic differences were indistinguishable during the early phases of plant growth (up to 45 d), however, after 120–150 d, differences became apparent since the dark-brown seeded cultivar displayed a darker green leaf color and developed numerous epidermal hairs in leaves, petioles and flowers. Examination of the gross anatomical structure of harvested seeds revealed a rougher testa for the dark–brown seeded type compared with the light brown-seeded type. An additional important distinguishing feature was the extended mucro in pods of the light–brown seeded type (5.42 ± 0.13 mm) compared with that of the dark-brown seeded cultivar (3.75 ± 0.08 mm). To our knowledge, this represents the first report of morphological characterization of the two cultivars of T. labialis relevant to Cuba. This information adds to the scant body of knowledge on this under-utilized tropical legume.

This study investigated the effect of high temperature and drought (during grain-filling) on the quality and components yield of five winter wheat varieties. Drought and drought + heat were found to have a much greater influence on the yield and quality than heat stress alone. Averaged over the varieties, the yield losses were 57% after drought, 76% after drought + heat, and only 31% after heat stresses. The reductions in the unextractable polymeric protein fraction and glutenin-to-gliadin ratio indicated a poorer grain yield quality, despite the higher protein content. Quality deterioration was observed after drought or drought + heat, while high temperatures alone resulted in no change or in a better ratio of protein components. A significant negative correlation was observed between starch granule size and relative protein content after drought.

This study assessed the gross-structure, micro-structure, physical characteristics and nutritional composition of Trichilia emetica and Trichilia dregeana seeds. T. emetica and T. dregeana seeds have potential for commercialization and improved food security, yet they are under-utilized and under-researched. The gross- and micro-structure of the seeds was assessed using stereo microscopy, light microscopy (LM), confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Protein, fat, ash, and mineral content of the seeds were also assessed. T. emetica and T. dregeana seeds had lower bulk density (393.5 kgm −3 & 433.6 kgm −3 respectively) and lower porosity (55.07% & 54.38% respectively) than soybean. Geometric mean diameter (29.7 mm & 16.9 mm) and aspect ratio (1.72 and 1.85) of T. emetica and T. dregeana seeds respectively, were higher than soybean, while they had lower sphericity (0.66 and 0.66 respectively) than soybean (0.99). Microscopy analysis showed that Trichilia species had larger-sized and more round-shaped protein bodies than soybean seeds. T. emetica and T. dregeana protein contents (25.6% and 17.3% w/w, respectively) were lower than soybean (45.4%) while fat contents (49% and 51.5% w/w, respectively) were higher than soybean (20.2% w/w). Potassium (1075-1350 mg100g −1 ) and calcium (285-300 mg100g −1 ) where the main macro-minerals while iron (6.33-6.83 mg100g −1 ) and zinc (2.30-2.90 mg100g −1 ) were the main micro-minerals. The research demonstrated that the structural and nutritional characteristics of T. dregeana and T. emetica seeds could facilitate their commercial utilization and application for food security alleviation.

This study reports the incidence of the seedcorn maggot, or bean seed fly, Delia platura (Meigen) (Diptera: Anthomyiidae), as a primary pest in commercial onion and scallion plantations in Puebla, Mexico. The larvae feed on the bulbs and the basal part of leaves. We found incidences of 5 to 52% of plants in commercial fields damaged by larvae. En el presente estudio se reporta la incidencia del gusano de la semilla del maíz, o mosca de la semilla del frijol, Delia platura (Meigen) (Diptera: Anthomyiidae), como plaga primaria en plantaciones. Las larvas se alimentan de los bulbos y de la parte basal de las hojas. Se encontraron incidencias del 5 al 52% de plantas dañadas por larvas en plantaciones comerciales.

A major global effort to enable cost-effective natural regeneration is needed to achieve ambitious forest and landscape restoration goals. Natural forest regeneration can potentially play a major role in large-scale landscape restoration in tropical regions. Here, we focus on the conditions that favor natural regeneration within tropical forest landscapes. We illustrate cases where large-scale natural regeneration followed forest clearing and non-forest land use, and describe the social and ecological factors that drove these local forest transitions. The self-organizing processes that create naturally regenerating forests and natural regeneration in planted forests promote local genetic adaptation, foster native species with known traditional uses, create spatial and temporal heterogeneity, and sustain local biodiversity and biotic interactions. These features confer greater ecosystem resilience in the face of future shocks and disturbances. We discuss economic, social, and legal issues that challenge natural regeneration in tropical landscapes. We conclude by suggesting ways to enable natural regeneration to become an effective tool for implementing large-scale forest and landscape restoration. Major research and policy priorities include: identifying and modeling the ecological and economic conditions where natural regeneration is a viable and favorable land-use option, developing monitoring protocols for natural regeneration that can be carried out by local communities, and developing enabling incentives, governance structures, and regulatory conditions that promote the stewardship of naturally regenerating forests. Aligning restoration goals and practices with natural regeneration can achieve the best possible outcome for achieving multiple social and environmental benefits at minimal cost.

The alarming current and predicted species extinction rates have galvanized conservationists in their efforts to avoid future biodiversity losses, but for species extinct in the wild, few options exist. We posed the questions, can these species be restored, and, if so, what role can ex situ plant collections (i.e., botanic gardens, germplasm banks, herbaria) play in the recovery of plant genetic diversity? We reviewed the relevant literature to assess the feasibility of recovering lost plant genetic diversity with using ex situ material and the probability of survival of subsequent translocations. Thirteen attempts to recover species extinct in the wild were found, most of which used material preserved in botanic gardens (12) and seed banks (2). One case of a locally extirpated population was recovered from herbarium material. Eight (60%) of these cases were successful or partially successful translocations of the focal species or population; the other 5 failed or it was too early to determine the outcome. Limiting factors of the use of ex situ source material for the restoration of plant genetic diversity in the wild include the scarcity of source material, low viability and reduced longevity of the material, low genetic variation, lack of evolution (especially for material stored in germplasm banks and herbaria), and socioeconomic factors. However, modern collecting practices present opportunities for plant conservation, such as improved collecting protocols and improved cultivation and storage conditions. Our findings suggest that all types of ex situ collections may contribute effectively to plant species conservation if their use is informed by a thorough understanding of the aforementioned problems. We conclude that the recovery of plant species currently classified as extinct in the wild is not 100% successful, and the possibility of successful reintroduction should not be used to justify insufficient in situ conservation. Las alarmantes tasas de extinción actuales y pronosticadas han incitado a los conservacionistas a esforzarse paraevitar las futuras pérdidas de biodiversidad, pero para las especies que ya se encuentran extintas en vida silvestre existen pocas opciones. Nos preguntamos si estas especies pueden ser restauradas, y de ser así, qué papel pueden desempeñar las colecciones ex situ de plantas (es decir, jardines botánicos, bancos de germoplasma, herbarios) en la recuperación de la diversidad genética de las plantas. Revisamos la literatura relevante para evaluar la factibilidad de la recuperación de la diversidad genética perdida y la probabilidad de supervivencia subsecuente de las reubicaciones. Encontramos 13 intentos por recuperar especies extintas en vida silvestre, la mayoría de los cuales usó material preservado en jardines botánicos (12) y en bancos de semillas (2). También hubo un caso de una población eliminada localmente que fue recuperada con material de un herbario. Ocho (60%) de estos casos fueron reubicaciones exitosas o parcialmente exitosas de la especie o población focal; los otros cinco fallaron o era demasiado pronto para poder determinar el resultado. Los factores que limitan el uso de material proveniente de colecciones ex situ para la restauración de la diversidad genética de las plantas en vida silvestre incluyen la escasez de material original, la baja viabilidad y la longevidad reducida del material, la baja variación genética, la falta de evolución (especialmente para el material almacenado en herbarios y bancos de germoplasma) y los factores socioeconómicos. A pesarde esto, las prácticas modernas de colección representanuna oportunidad para la conservación de las plantas, como los protocolos mejorados de recolección y las condiciones acrecentadas de cultivo y almacenamiento. Nuestros hallazgos sugieren que todos los tipos de colecciones ex situ pueden contribuir efectivamente a la conservación de especies de plantas si su uso está respaldado por un entendimiento a fondo de los problemas antes mencionados. Concluimos que la recuperación de especies de plantas que actualmente están clasificadas como extintas en vida silvestre no es 100% exitosa y que la posibilidad de una reintroducción exitosa no debería utilizarse para justificar una conservación in situ insuficiente.

The testa of higher plant seeds protects the embryo against adverse environmental conditions. Its role is assumed mainly by controlling germination through dormancy imposition and by limiting the detrimental activity of physical and biological agents during seed storage. To analyze the function of the testa in the model plant Arabidopsis, we compared mutants affected in testa pigmentation and/or structure for dormancy, germination, and storability. The seeds of most mutants exhibited reduced dormancy. Moreover, unlike wild-type testas, mutant testas were permeable to tetrazolium salts. These altered dormancy and tetrazolium uptake properties were related to defects in the pigmentation of the endothelium and its neighboring crushed parenchymatic layers, as determined by vanillin staining and microscopic observations. Structural aberrations such as missing layers or a modified epidermal layer in specific mutants also affected dormancy levels and permeability to tetrazolium. Both structural and pigmentation mutants deteriorated faster than the wild types during natural aging at room temperature, with structural mutants being the most strongly affected.

This paper examines four key mechanisms of the seed size/number trade-off (SSNT) models to assess their relevance to a general understanding of plant community structure. Mechanism 1 is that large seeds have a greater probability of winning in competition against smaller seeds. I provide interspecific experimental evidence that there is a competitive hierarchy among seedlings based on seed size. Mechanism 2 is that a trade-off exists between the number and size of seeds produced for a given reproductive allocation. Negative correlations between seed size and number were found consistently across a range of species from a range of habitats, from published literature. Mechanism 3, that seedling-seedling competition is an important influence on species composition, was found to exist potentially in a range of environments, including annual-dominated, post-fire and gap-dynamic communities. However, there is little quantitative evidence available and this is likely to be a restrictive mechanism. Mechanism 4, that small seeds are superior colonists due to their greater number, was tested in a field experiment in a calcareous grassland community. No supporting evidence was found, suggesting that the SSNT is not an important determinant of structure in this community. Thus two of the four mechanisms can be considered to hold true generally, while the third mechanism may be valid in particular environments. The fourth mechanism did not apply in the community tested, but could be tested in a wider range of communities.