The role of community and population ecology in applying mycorrhizal fungi for improved food security.

The global human population is expected to reach ∼9 billion by 2050. Feeding this many people represents a major challenge requiring global crop yield increases of up to 100%. Microbial symbionts of plants such as arbuscular mycorrhizal fungi (AMF) represent a huge, but unrealized resource for improving yields of globally important crops, especially in the tropics. We argue that the application of AMF in agriculture is too simplistic and ignores basic ecological principals. To achieve this challenge, a community and population ecology approach can contribute greatly. First, ecologists could significantly improve our understanding of the determinants of the survival of introduced AMF, the role of adaptability and intraspecific diversity of AMF and whether inoculation has a direct or indirect effect on plant production. Second, we call for extensive metagenomics as well as population genomics studies that are crucial to assess the environmental impact that introduction of non-local AMF may have on native AMF communities and populations. Finally, we plead for an ecologically sound use of AMF in efforts to increase food security at a global scale in a sustainable manner.

Post-market environmental monitoring of Bt maize in Spain: Non-target effects of varieties derived from the event MON810 on predatory fauna

The Spanish Government has established post-market environmental monitoring (PMEM) as mandatory for genetically modified (GM) crop varieties cultivated in Spain. In order to comply with this regulation, effects of Bt maize varieties derived from the event MON810 on the predatory fauna were monitored for two years in northeast and central Spain. The study was carried out with a randomized block design in maize fields of 3-4 ha on which the abundance of plant-dwelling predators and the activity-density of soil-dwelling predators in Bt vs. non-Bt near-isogenic varieties were compared. To this end, the plots were sampled by visual inspection of a certain number of plants and pitfall traps 6 or 7 times throughout two seasons. No significant differences in predator densities on plants were found between Bt and non-Bt varieties. In the pitfall traps, significant differences between the two types of maize were found only in Staphylinidae, in which trap catches in non-Bt maize were higher than in Bt maize in central Spain. Based on the statistical power of the assays, surrogate arthropods for PMEM purposes are proposed; Orius spp. and Araneae for visual sampling and Carabidae, Araneae, and Staphylinidae for pitfall trapping. The other predator groups recorded in the study, Nabis sp. and Coccinellidae in visual sampling and Dermaptera in pitfall trapping, gave very poor power results. To help to establish a standardized protocol for PMEM of genetically modified crops, the effect-detecting capacity with a power of 0.8 of each predator group is given.

The impact of breeding on fruit production in warm climates of Brazil

Brazil is a very large country with a diverse climate. This fact allows a diversity of plants to grow ranging from tropical rainforest in the Amazon, passing through Atlantic Forest along the coast, the cerrados (Brazilian savannah) in the Central West region, and semi-arid area in the Northeast. Latitude ranges from 5º N to 33º S, with most of this territory in the tropical region. There are enough reasons to plant breeders devoting great amount of their effort to improve plants suitable for warm climates, though. Among fruit crops, results of breeder's work have been noticed in several species, especially on peaches, grapes, citrus, apples, persimmons, figs, pears and others not so common, such as acerola, guava, annonas (sour sop, sugar apple, atemoya, cherimoya) and passion fruit. Peach tree introduced at low latitude (22 ± 2ºS) requires climatic adaptation to subtropical conditions of low chilling. In Brazil, the first peach breeding program aiming adaptation of cultivars to different habitats was developed by Instituto Agronômico de Campinas (IAC) beginning in the end of the 40's. Apple low chill requirement cultivars obtained in a South state, Paraná, are now been planted at low latitudes. Banana and pineapple breeding programs from Embrapa units along the country are successfully facing new sanitary problems. Petrolina/Juazeiro, in the Northeastern region (9ºS), is the main grape exporting region with more than 6,000 ha. Grape growing in the region is based in the so called "tropical" rootstocks released by IAC, namely: IAC 313 'Tropical', IAC 572 'Jales'. Recently, Embrapa Grape and Wine released tropical grape seedless cultivars that are changing table grape scenario in the country.

Female sterility associated with increased clonal propagation suggests a unique combination of androdioecy and asexual reproduction in populations of Cardamine amara (Brassicaceae).

BACKGROUND AND AIMS: The coexistence of hermaphrodites and female-sterile individuals, or androdioecy, has been documented in only a handful of plants and animals. This study reports its existence in the plant species Cardamine amara (Brassicaceae), in which female-sterile individuals have shorter pistils than seed-producing hermaphrodites. METHODS: Morphological analysis, in situ manual pollination, microsatellite genotyping and differential gene expression analysis using Arabidopsis microarrays were used to delimit variation between female-sterile individuals and hermaphrodites. KEY RESULTS: Female sterility in C. amara appears to be caused by disrupted ovule development. It was associated with a 2.4- to 2.9-fold increase in clonal propagation. This made the pollen number of female-sterile genets more than double that of hermaphrodite genets, which fulfils a condition of co-existence predicted by simple androdioecy theories. When female-sterile individuals were observed in wild androdioecious populations, their ramet frequencies ranged from 5 to 54 %; however, their genet frequencies ranged from 11 to 29 %, which is consistent with the theoretically predicted upper limit of 50 %. CONCLUSIONS: The results suggest that a combination of sexual reproduction and increased asexual proliferation by female-sterile individuals probably explains the invasion and maintenance of female sterility in otherwise hermaphroditic populations. To our knowledge, this is the first report of the coexistence of female sterility and hermaphrodites in the Brassicaceae.

Fruit size and quality of pineapples cv. Vitória in response to micronutrient doses and way of application and to soil covers

The objective of this study was to evaluate the effects of foundation and leaf fertilization with micronutrients on fruit size and quality of pineapple cv. Vitória under the environmental conditions of the Baixo Acaraú irrigated perimeter in Northern Ceará State, Brazil, under two covers (bagana and black plastic) of the sandy soil of low fertility. The experimental design was a randomized split blocks one with four levels of soil dressing and four levels of foliar fertilization, with five replications. Micronutrient soil dressing was studied as FTE-12 at doses of 0, 60, 120 and 180 kg ha-1. The four levels of foliar fertilization were: LF0 (without fertilizer), LF 1 (15 leaf fertilization, using the amount of 1158.75 g Fe ha-1, 844.65 g Mn ha-1, 391.5 g ha-1 Zn, 322.65 g ha-1 Cu and 216 g ha-1 B), LF2 (15 leaf fertilization, using twice the quantities of level LF1) and LF3 (15 leaf fertilization, using three times the amount of level LF1). At 13 months after planting the micropropagated plantlets was carried out the floral induction treatment and five months later the fruit harvest determining the following variables: fruit weight and median diameter, soluble solids content (SS) and titratable acidity (TA). Both fruit weight and diameter increased with increasing doses of micronutrients applied to the soil and to the leaves, of plants grown both on bagana soil cover and plastic mulch. On the other hand fruit pulp quality was little affected by the treatments studied. There were a small increase of SS contents for plants grown on bagana soil cover and a small decrease of titratable acidity for those grown on plastic mulch, in both cases just in response to micronutrient foliar application.

Strawberry yield submitted to different root pruning intensities of transplants

This study aimed to evaluate the growth of plants and the precocity of strawberry production under different root pruning intensities at planting time. Bare roots plants with 12 millimeters crown diameter produced in nurseries from the Patagonia region, Argentina were used. The planting was carried out on May 12th 2010 into experimental plots with non-fumigated soil. The treatments consisted of three cultivars (Camarosa, Florida Festival and Camino Real) and three pruning intensities (1/3, 2/3 and no pruning) on the total root length of the plants. The experimental design used was a randomized block design in a 3x3 factorial arrangement with three replications and 12 plants per plot and density of 11.1 plants m-2. Mature fruits were harvested from July 15th to December 14th 2010 and the production of fresh fruit was determined. There was no significative interaction between cultivars and pruning intensity. 'Camarosa' and 'Florida Festival' plants showed precocity and had the most abundant and heavier fruits during the precocity period. The different root pruning intensities did not affect the assessed variables. It was concluded that, in order to facilitate strawberry planting of the cultivars Camarosa, Florida Festival and Camino Real root pruning is possible, with no damages on plant growth and development, precocity and early fruit production.

Three-step pathway engineering results in more incidence rate and higher emission of nerolidol and improved attraction of Diadegma semiclausum

The concentration and ratio of terpenoids in the headspace volatile blend of plants have a fundamental role in the communication of plants and insects. The sesquiterpene (E)-nerolidol is one of the important volatiles with effect on beneficial carnivores for biologic pest management in the field. To optimize de novo biosynthesis and reliable and uniform emission of (E)-nerolidol, we engineered different steps of the (E)-nerolidol biosynthesis pathway in Arabidopsis thaliana. Introduction of a mitochondrial nerolidol synthase gene mediates de novo emission of (E)-nerolidol and linalool. Co-expression of the mitochondrial FPS1 and cytosolic HMGR1 increased the number of emitting transgenic plants (incidence rate) and the emission rate of both volatiles. No association between the emission rate of transgenic volatiles and their growth inhibitory effect could be established. (E)-Nerolidol was to a large extent metabolized to non-volatile conjugates.

Growth and production of irrigated vitória pineapple grown in semi-arid conditions

This study aimed to evaluate the growth characteristics of irrigated Vitória pineapple plants grown in semi-arid conditions and determine its developmental stages based on those characteristics. It was used a randomized block design with four replicates. The experimental treatments were: plant harvest at 270, 330, 390, 450, 510, 570, 690, 750, and 810 days after planting (DAP). The following variables were determined: plant height, stem diameter, D-leaf length, D-leaf fresh and dry mass, biomass production of plants and plant parts (organs), and vegetative biomass. Five phenological stages are proposed based on vegetative biomass production: < 20% biomass production (V1); 21-40% (V2); 41-60% (V3); 61-80% (V4); and > 80% (V5). The maximum growth rate for plant height, D-leaf length, and stem diameter was observed at the end of the phenological stage V1 (390-411 DAP), and at the end of stage V5 these plant traits had average values of 106, 82, and 7 cm, respectively. The maximum biomass accumulation rates were observed at stages V4 and V5, resulting in a final fruit yield and total fresh biomass of 72 t ha-1 and 326 t ha-1, respectively. Finally, we estimated that 80% of the accumulated biomass may remain in the field after fruit and slip harvest, and could be incorporated as plant residue into the soil.

Phylogeny and biogeography of Primula sect. Armerina: implications for plant evolution under climate change and the uplift of the Qinghai-Tibet Plateau.

BACKGROUND: The historical orogenesis and associated climatic changes of mountain areas have been suggested to partly account for the occurrence of high levels of biodiversity and endemism. However, their effects on dispersal, differentiation and evolution of many groups of plants are still unknown. In this study, we examined the detailed diversification history of Primula sect. Armerina, and used biogeographic analysis and macro-evolutionary modeling to investigate a series of different questions concerning the evolution of the geographical and ecological distribution of the species in this section. RESULTS: We sequenced five chloroplast and one nuclear genes for species of Primula sect. Armerina. Neither chloroplast nor nuclear trees support the monophyly of the section. The major incongruences between the two trees occur among closely related species and may be explained by hybridization. Our dating analyses based on the chloroplast dataset suggest that this section began to diverge from its relatives around 3.55 million years ago, largely coinciding with the last major uplift of the Qinghai-Tibet Plateau (QTP). Biogeographic analysis supports the origin of the section in the Himalayan Mountains and dispersal from the Himalayas to Northeastern QTP, Western QTP and Hengduan Mountains. Furthermore, evolutionary models of ecological niches show that the two P. fasciculata clades have significantly different climatic niche optima and rates of niche evolution, indicating niche evolution under climatic changes and further providing evidence for explaining their biogeographic patterns. CONCLUSION: Our results support the hypothesis that geologic and climatic events play important roles in driving biological diversification of organisms in the QTP area. The Pliocene uplift of the QTP and following climatic changes most likely promoted both the inter- and intraspecific divergence of Primula sect. Armerina. This study also illustrates how niche evolution under climatic changes influences biogeographic patterns.

Study of selenocompounds from selenium-enriched culture of edible sprouts

Selenium is recognised as an essential micronutrient for humans and animals. One of the main sources of selenocompounds in the human diet is vegetables. Therefore, this study deals with the Se species present in different edible sprouts grown in Se-enriched media. We grew alfalfa, lentil and soy in a hydroponic system amended with soluble salts, containing the same proportion of Se, in the form of Se(VI) and Se(IV). Total Se in the sprouts was determined by acidic digestion in a microwave system and by ICP/MS. Se speciation was carried out by enzymatic extraction (Protease XIV) and measured by LC-ICP/MS. The study shows that the Se content of plants depends on the content in the growth culture, and that part of the inorganic Se was biotransformed mainly into SeMet. These results contribute to our understanding of the uptake of inorganic Se and its biotransformation by edible plants.

Fifty years after Ehrlich and Raven, is there support for plant-insect coevolution as a major driver of species diversification?

Since Ehrlich & Raven's seminal paper 50 years ago, coevolution has been seen as a major driver of species diversification. Here, we review classical and more recent case studies on the coevolution of plants and associated insects, to examine whether the coevolutionary component holds as an explanation of their current diversity. We discuss the main dogmas in coevolution and argue that coevolutionary processes should not be considered as major drivers of diversification in plants and insects. Instead, we suggest that coevolution essentially occurs through relatively short 'interludes', making the pattern difficult to detect. We also criticize the use of comparative phylogenetics to investigate coevolutionary processes, as coevolution may not necessarily produce congruent phylogenies among interacting lineages and, in turn, other processes may produce patterns of codivergence. Finally, we propose new lines of investigation for future research.

Capillarity and fibre types in locomotory muscles of wild yellow-legged gulls (Larus cachinnans)

This study analyzes the capillarity and fibre-type distribution of six locomotory muscles of gulls. The morphological basis and the oxygen supply characteristics of the skeletal muscle of a species with a marked pattern of gliding flight are established, thus contributing to a better understanding of the physiology of a kind of flight with low energetic requirements. The four wing muscles studied (scapulotriceps, pectoralis, scapulohumeralis, and extensor metacarpi) exhibited higher percentages of fast oxidative glycolytic fibres (>70%) and lower percentages of slow oxidative fibres (<16%) than the muscles involved in nonflight locomotion (gastrocnemius and iliotibialis). Capillary densities ranged from 816 to 1,233 capillaries mm(-2), having the highest value in the pectoralis. In this muscle, the fast oxidative glycolytic fibres had moderate staining for succinate dehydrogenase and relatively large fibre sizes, as deduced from the low fibre densities (589-665 fibres mm(-2)). All these findings are seen as an adaptive response for gliding, when the wing is held outstretched by isometric contractions. The leg muscles studied included a considerable population of slow oxidative fibres (>14% in many regions), which suggests that they are adapted to postural activities. Regional variations in the relative distributions of fibre types in muscle gastrocnemius may reflect different functional demands placed on this muscle during terrestrial and aquatic locomotion. The predominance of oxidative fibres and capillary densities under 1,000 capillaries mm(-2) in leg muscles is probably a consequence of an adaptation for slow swimming and maintenance of the posture on land rather than for other locomotory capabilities, such as endurance or sprint activities.

Efeito da aplicação foliar de ácidos graxos na "Via das Lipoxigenases" de plantas de soja

The involvement of lipoxygenase isozymes in several physiological processes of plants has been described but their role is not well understood and more biochemical studies are needed to elucidate the role of the "Lipoxygenase Pathway" in plant physiology. Thus, the biochemical and kinetic characterization of a lipoxygenases "pool" from soybean leaves was carried out. Two genotypes were used: IAC-100 (a normal variety having lipoxygenases in the seeds) and IAC-100 TN (genetically modified genotype, which is devoid of lipoxygenases in the seeds). The plants were submitted to the application of fatty acids (lipoxygenase substrates) on leaves. The results of the biochemical and kinetic studies of lipoxygenase isozymes from leaves of the two genotypes analysed showed that genetic removal of lipoxygenase from seeds did not affect the response of the plant to the treatment, since both genotypes showed similar results.

Back to the island of calm: mallorcan human traditional medicine and ethnobotany

This study reveals that a successful ethnobotanical survey can take place still nowadays, even close to one of the hotspots of tourism in the Mediterranean coast. This is the first approach in this field entirely based on interviews with local people in Mallorca. An amount of 235 informants has been inquired from all the 53 municipalities of the island. The data collected have been analyzed from the botanical and ethnographical points of view, and managed using the online platform of our research team (details at www.etnobiofic.cat). The Mallorcan ethnopharmacopoeia includes 255 plant taxa referring more than 150 medicinal use categories. Ethnomedical queries as the one here presented contribute to the knowledge of the traditional use of plants of the island and appreciate the benefits of this knowledge, applied to the present and future of its society.

Back to the island of calm: Mallorcan human traditional medicine and ethnobotany

This study reveals that a successful ethnobotanical survey can take place still nowadays, even close to one of the hotspots of tourism in the Mediterranean coast. This is the first approach in this field entirely based on interviews with local people in Mallorca. An amount of 235 informants has been inquired from all the 53 municipalities of the island. The data collected have been analyzed from the botanical and ethnographical points of view, and managed using the online platform of our research team (details at www.etnobiofic.cat). The Mallorcan ethnopharmacopoeia includes 255 plant taxa referring more than 150 medicinal use categories. Ethnomedical queries as the one here presented contribute to the knowledge of the traditional use of plants of the island and appreciate the benefits of this knowledge, applied to the present and future of its society.