Hymenasplenium volubile: documentation of its gametophytes and the first record of a hemiepiphyte in the Aspleniaceae.

BACKGROUND AND AIMS: Through careful field examination of the growth habit of the gametophytes and sporophytes of Hymenasplenium volubile across an ontogenetic series, we aim to understand better the evolution of epiphytism in this poorly understood group of ferns. METHODS: We made field observations of H. volubile sporophytes and gametophytes, and brought specimens back to the lab for microscopic analysis. In the field, sporophytes at each ontogenetic stage were photographed to document the species' growth habit. We used an existing phylogeny to optimize growth form of New World Hymenasplenium. KEY RESULTS: Young sporophytes were at first fully epiphytic and produced one or two long feeding roots that extend to the soil where they branch profusely. The feeding roots remain in contact with the soil throughout the life of the plant. Thus, H. volubile is a hemiepiphyte. While immature, gametophytes are appressed to the tree trunk, but, as their gametangia mature, their lower margin lifts upward, imparting a shelf-like appearance to the thallus. The thallus attaches to the substrate by branched rhizoids produced along the margin of the thallus in contact with the substrate. CONCLUSIONS: Hemiepiphytes are a key link in the evolution of epiphytic ferns and may act as a bridge between the forest floor and the canopy. Our finding is the first report of hemiepiphytism in Aspleniaceae, a large lineage with many epiphytic and terrestrial taxa. This work serves as an important model to understand the evolution of epiphytism in this group specifically and in ferns in general. The majority of our understanding of fern gametophyte biology is derived from laboratory studies. Our efforts represent a fundamental contribution to understanding fern gametophyte ecology in a field setting.

Molecular basis of angiosperm tree architecture.

The architecture of trees greatly impacts the productivity of orchards and forestry plantations. Amassing greater knowledge on the molecular genetics that underlie tree form can benefit these industries, as well as contribute to basic knowledge of plant developmental biology. This review describes the fundamental components of branch architecture, a prominent aspect of tree structure, as well as genetic and hormonal influences inferred from studies in model plant systems and from trees with non-standard architectures. The bulk of the molecular and genetic data described here is from studies of fruit trees and poplar, as these species have been the primary subjects of investigation in this field of science.

How Nutritious Are French Beans (Phaseolus vulgaris L.) from the Citizen Science Experiment?

French beans are tender, immature, edible pods that are harvested early in the plant's growth cycle and are usually eaten cooked. The growth habits of French beans were studied for the first time in a Citizen Science experiment, and 19 pod samples were collected for further nutritional analysis. Various macronutrients (e.g., protein, ash, fat, carbohydrates, amino acids) and multi-element profiles were determined. A survey of their growing habits revealed that beans are usually planted once or twice a year in May and June at a length of 5-10 m, with a predominance of dwarf beans cultivation over climbing varieties, and pest resistance and stringless pods are the most important characteristics when deciding on a bean. Homogenised freeze-dried pod samples contained 16.1-23.1% protein, 4.5-8.2% ash, 0.1-1.1% fat, and 62.0-70.6% carbohydrates and had a caloric value of 337-363 kcal/100 g. Of the 17 free amino acids identified, 8 were essential (histidine, threonine, methionine, valine, lysine, isoleucine, leucine, phenylalanine) and 9 were non-essential (cysteine, aspartic acid, serine, glutamic acid, glycine, arginine, alanine, proline, tyrosine); meanwhile, of the 12 elements, 5 were macroelements and 7 were microelements. The predominant free amino acids were aspartic acid, glutamic acid, and serine. In the multiple comparisons (Box and Whisker plot), the parameters caloric value and iron showed the strongest response. A very strong positive significant Pearson correlation (≥0.95) was found for five pairs of variables within the free amino acids. Comparison of the nutrient data obtained in the pods showed near-perfect or high complementarity (85.2-103.4%) with the food composition databases for half of the parameters, suggesting that the home-grown French beans from the Citizen Science experiment are a highly nutritious vegetable.

Nontoxic KBBF Family Member Zn2BO3(OH): Balance between Beneficial Layered Structure and Layer Tendency.

The conflict between beneficial layered structure for performances and layered growth habits in KBe2BO3F2 (KBBF) always restricts its practical applications. A beryllium-free KBBF family member, Zn2BO3(OH), is explored to feature the same topological layer with KBBF by replacing [BeO3F]5- with [ZnO3(OH)]5- and excellent UV performances. It exhibits a second harmonic generation response of about 1.5 × KH2PO4 with the UV cutoff edge of 204 nm. The birefringence of Zn2BO3(OH) in the visible region is about 0.067, which is larger than those of commercial UV crystals LiB3O5, CsB3O5, and CsLiB6O10. Additionally, it has excellent thermal and water-resistant stabilities. Owing to the removal of interlayer cations, Zn2BO3(OH) shows better growth habits than KBBF while achieving the balance between beneficial layered structure and layer tendency.

Recruiting Conventional Tree Architecture Models into State-of-the-Art LiDAR Mapping for Investigating Tree Growth Habits in Structure.

Mensuration of tree growth habits is of considerable importance for understanding forest ecosystem processes and forest biophysical responses to climate changes. However, the complexity of tree crown morphology that is typically formed after many years of growth tends to render it a non-trivial task, even for the state-of-the-art 3D forest mapping technology-light detection and ranging (LiDAR). Fortunately, botanists have deduced the large structural diversity of tree forms into only a limited number of tree architecture models, which can present a-priori knowledge about tree structure, growth, and other attributes for different species. This study attempted to recruit Hallé architecture models (HAMs) into LiDAR mapping to investigate tree growth habits in structure. First, following the HAM-characterized tree structure organization rules, we run the kernel procedure of tree species classification based on the LiDAR-collected point clouds using a support vector machine classifier in the leave-one-out-for-cross-validation mode. Then, the HAM corresponding to each of the classified tree species was identified based on expert knowledge, assisted by the comparison of the LiDAR-derived feature parameters. Next, the tree growth habits in structure for each of the tree species were derived from the determined HAM. In the case of four tree species growing in the boreal environment, the tests indicated that the classification accuracy reached 85.0%, and their growth habits could be derived by qualitative and quantitative means. Overall, the strategy of recruiting conventional HAMs into LiDAR mapping for investigating tree growth habits in structure was validated, thereby paving a new way for efficiently reflecting tree growth habits and projecting forest structure dynamics.

Association Mapping of Flowering Time QTLs and Insight into Their Contributions to Rapeseed Growth Habits.

Plants have developed sophisticated systems to adapt to local conditions during evolution, domestication and natural or artificial selection. The selective pressures of these different growing conditions have caused significant genomic divergence within species. The flowering time trait is the most crucial factor because it helps plants to maintain sustainable development. Controlling flowering at appropriate times can also prevent plants from suffering from adverse growth conditions, such as drought, winter hardness, and disease. Hence, discovering the genome-wide genetic mechanisms that influence flowering time variations and understanding their contributions to adaptation should be a central goal of plant genetics and genomics. A global core collection panel with 448 inbred rapeseed lines was first planted in four independent environments, and their flowering time traits were evaluated. We then performed a genome-wide association mapping of flowering times with a 60 K SNP array for this core collection. With quality control and filtration, 20,342 SNP markers were ultimately used for further analyses. In total, 312 SNPs showed marker-trait associations in all four environments, and they were based on a threshold p-value of 4.06 × 10(-4); the 40 QTLs showed significant association with flowering time variations. To explore flowering time QTLs and genes related to growth habits in rapeseed, selection signals related to divergent habits were screened at the genome-wide level and 117 genomic regions were found. Comparing locations of flowering time QTLs and genes with these selection regions revealed that 20 flowering time QTLs and 224 flowering time genes overlapped with 24 and 81 selected regions, respectively. Based on this study, a number of marker-trait associations and candidate genes for flowering time variations in rapeseed were revealed. Moreover, we also showed that both flowering time QTLs and genes play important roles in rapeseed growth habits. These results will be applied to rapeseed breeding programs, and they will aid in our understanding of the relation between flowering time variations and growth habits in plants.

Riqueza total de especies de plantas vasculares en un bosque andino de la Cordillera central de Colombia / Total richness of vascular plant species in an Andean forest of the Central Cordillera, Colombia

Resumen Los reportes sobre diversidad de plantas en los bosques tropicales suelen estar restringidos a árboles u otros grupos de plantas leñosas por encima de cierto diámetro del tallo. Sin embargo, otros estudios que incluyen todas las formas de vida sin restricciones de tamaño de los individuos, indican claramente que las plantas no leñosas son igual de importantes. En este estudio se reporta la Riqueza total de especies de plantas vasculares (RTE) en una parcela de una hectárea en un bosque andino del noroccidente de Colombia (6º12'48"N & 75º29'32"O); adicionalmente evaluamos la contribución de los diferentes hábitos de crecimiento a la RTE y el efecto del tamaño de las plantas. Se censaron todos los individuos con diámetro del tronco (D) ≥ 5 cm en 1 ha, y todas las plantas vasculares de todos los tamaños, incluyendo epífitas, en una muestra de 0.25 hectáreas. Se registró un total de 14 545 individuos distribuidos en 318 especies, 72 familias (considerando Pteridophyta como un solo grupo) y 171 géneros. El 99.7 % de las especies son menores de 10 cm de (D) y el 94.4 % son menores a 2.5 cm de (D). Las especies no arbóreas (hierbas terrestres, epífitas y escandentes) representan el 54.3% del total de especies registradas en la parcela, lo que indica que son un componente clave de la estructura, composición y riqueza de este bosque montano neotropical. Estos resultados confirman reportes similares para otros bosques tropicales. Concluimos que para conocer con más detalle la diversidad de florística de un sitio es recomendable: 1) ampliar el rango de tamaño de las plantas considerado comúnmente en los inventarios florísticos y 2) incluir las especies no leñosas; esta información es crucial para tomar mejores decisiones en los esfuerzos de conservación a escala local y global.

Abstract Studies of plant diversity in tropical forests are usually restricted to trees or other groups of woody plants above a certain stem diameter. However, surveys that include all forms of live plants with no restrictions on their sizes, clearly indicate that non-woody plants are equally important. In this study, we reported the total species richness of vascular plants species (TSR) in one hectare plot in an Andean forest in Northwestern Colombia (6º12'48"N & 75º29 32"W). We evaluated the relative contribution of the different growth habits and the effect of the plant size, to TSR. We measured all individuals with diameter (D) ≥ 5 cm in the hectare and all the vascular plants of all sizes, including epiphytes, in a subsample of 0.25 ha. A total of 14 545 individuals distributed in 318 species, 72 families (considering Pteridophyta as one group) and 171 genera were registered. Most of the species showed a (D) < 10 cm (99.7 %) and < 2.5 cm (94.4 %). The no-arboreal species (ground herbs, epiphytes and vines) represented 54.3 % of the total species reported in the plot, indicating that they are important in the structure, composition and species richness of this montane forest. Our results coincide with similar studies in other tropical forests. We concluded that to get a more detailed knowledge of the floristic diversity of a site, it is advisable to: 1) amplify the size range of the plants generally considered in the floristic inventories and 2) to include non-woody species. This information is crucial for making better decisions in local and global conservation efforts. Rev. Biol. Trop. 66(1): 227-236. Epub 2018 March 01.

Efeito da dessecação em estádios fenológicos antecipados na cultura da soja / Effects of early desiccation in phenological phases in soybean

O Estado do Mato Grosso detém a maior área plantada de soja, mas perdas de produtividade vêem ocorrendo nessas áreas, não sendo consideradas as que ocorrem por manejo no momento da dessecação, cujos critérios dependem do conhecimento da cultura. Objetivou-se com este trabalho determinar a perda de produtividade de grãos ocorrida pela dessecação em estádios fenológicos antecipados, em cultivares de soja com diferentes tipos de crescimento, em relação ao tratamento sem dessecação. O experimento foi instalado na safra 2008/2009, no município de Lucas do Rio Verde, em delineamento de blocos casualizados, em esquema fatorial (4x5), representado por quatro cultivares (TMG123 RR, NK7074 RR, P98Y11 e SYN9070 RR) em quatro estádios de dessecação (R6, R6+2DD, R6+4DD e R7), além do tratamento testemunha sem dessecação. As plantas colhidas foram divididas em terço superior (TS) e terço médio e inferior (TMI), debulhadas manualmente e depois determinada a massa de 100 grãos. Concluí-se que os valores de maior massa foram obtidos nas cultivares de crescimento determinado e estes decresceram com a dessecação antecipada, aumentando linearmente com o atraso da dessecação. Existem diferentes respostas para cada cultivar causadas pela dessecação, com perdas de rendimento, sendo o terço superior o mais afetado pela dessecação, causando até 15% de perda de produtividade na cultura.

State of Mato Grosso has the largest soybean area planted, yield losses occurring in these areas, not considering the ones that occur by handling during the desiccation, the criteria adopted depend on the knowledge of the culture. The goal of this study was to determine the loss occurred by desiccation in early stages, when compared with no desiccation in soybean fields. The experiment was installed in 2008/2009 season, in the municipality of Lucas do Rio Verde, in a randomized block design in a (4x5) factorial arrangements, represented by four varieties (TMG123 RR, NK7074 RR, P98Y11 and SYN9070 RR) in four stages desiccation (R6, R6+2DD, R6+4DD and R7), and controls without desiccation. The harvested plants were divided into upper third (TS) and medium and lower third (TMI) and manually threshed and after determined the mass of 100 grains. Concluded that the values of the higher mass were obtained in cultivars of determinate growth habit, and these decreased with early desiccation, and increased linearly with the delay of desiccation. There are different answers for each cultivar caused by desiccation, with yield losses, being the upper third the most affected by desiccation, which can causing up to 15% to loss of crop productivity.