Affordable and robust phenotyping framework to analyse root system architecture of soil-grown plants.

The phenotypic analysis of root system growth is important to inform efforts to enhance plant resource acquisition from soils; however, root phenotyping remains challenging because of the opacity of soil, requiring systems that facilitate root system visibility and image acquisition. Previously reported systems require costly or bespoke materials not available in most countries, where breeders need tools to select varieties best adapted to local soils and field conditions. Here, we report an affordable soil-based growth (rhizobox) and imaging system to phenotype root development in glasshouses or shelters. All components of the system are made from locally available commodity components, facilitating the adoption of this affordable technology in low-income countries. The rhizobox is large enough (approximately 6000 cm2 of visible soil) to avoid restricting vertical root system growth for most if not all of the life cycle, yet light enough (approximately 21 kg when filled with soil) for routine handling. Support structures and an imaging station, with five cameras covering the whole soil surface, complement the rhizoboxes. Images are acquired via the Phenotiki sensor interface, collected, stitched and analysed. Root system architecture (RSA) parameters are quantified without intervention. The RSAs of a dicot species (Cicer arietinum, chickpea) and a monocot species (Hordeum vulgare, barley), exhibiting contrasting root systems, were analysed. Insights into root system dynamics during vegetative and reproductive stages of the chickpea life cycle were obtained. This affordable system is relevant for efforts in Ethiopia and other low- and middle-income countries to enhance crop yields and climate resilience sustainably.

The impact of the rhizobia-legume symbiosis on host root system architecture.

Legumes form symbioses with rhizobia to fix N2 in root nodules to supplement their nitrogen (N) requirements. Many studies have shown how symbioses affect the shoot, but far less is understood about how they modify root development and root system architecture (RSA). RSA is the distribution of roots in space and over time. RSA reflects host resource allocation into below-ground organs and patterns of host resource foraging underpinning its resource acquisition capacity. Recent studies have revealed a more comprehensive relationship between hosts and symbionts: the latter can affect host resource acquisition for phosphate and iron, and the symbiont's production of plant growth regulators can enhance host resource flux and abundance. We review the current understanding of the effects of rhizobia-legume symbioses on legume root systems. We focus on resource acquisition and allocation within the host to conceptualize the effect of symbioses on RSA, and highlight opportunities for new directions of research.

Test de desarrollo motor aplicados en Chile entre el período 2014-2018: una revisión sistemática / Motor development tests applied in Chile between the period 2014-2018: a systematic review

El desarrollo motor es un proceso continuo y multidimensional del ciclo vital del ser humano. Para el profesor de educación física se hace esencial buscar instrumentos que permitan medir el desarrollo motor para una intervención intencionada que permita alcanzar un desarrollo apropiado a la edad de cada estudiante. El objetivo de este estudio es identificar los test de desarrollo motor aplicados en Chile entre 2014-2018. Se realizó una revisión sistemática de artículos científicos que aplicaron test de desarrollo motor, entre los años 2014-2018. La búsqueda de artículos se realizó en las bases de datos "Ebsco", "Dialnet" y "Scielo". Las palabras claves en la búsqueda fueron, desarrollo motor y test desarrollo motor, en los idiomas español, inglés y portugués. Se obtuvo un total de 9 artículos que cumplieron los criterios de inclusión. Los resultados mostraron que se han utilizado 4 test de desarrollo motor en el periodo declarado. En conclusión, el test más utilizado en Chile es el TGMD-2 el cual es ampliamente recomendado y validado en el contexto chileno; y cuyo propósito se basa en la identificación de los niveles de ejecución (bajo o superior) del desarrollo motor grueso en los niños según la edad cronológica

Motor development is a continuous and multidimensional process of the human being life cycle. For the physical education teacher it is essential to look for instruments that allow measuring the motor development for an intentional intervention that allows achieving an appropriate development at the age of each student. The objective of this study is to identify the motor development test applied in Chile between 2014-2018. A systematic review of scientific articles that applied motor development tests was carried out between 2014-2018. The search for articles was carried out in the "Ebsco", "Dialnet" and "Scielo" databases. The keywords in the search were; motor development and motor development test, in the Spanish, English and Portuguese languages. Nine articles were obtained that met the inclusion criteria. The results showed that four motor development tests have been used in the declared period. In conclusion, the most used test in Chile is TGMD-2 which is widely recommended and validated in the Chilean context; and whose purpose is based on the identification of the performance levels (lower or higher) of gross motor development in children according to chronological age

Methyl jasmonate treatment induces changes in fruit ripening by modifying the expression of several ripening genes in Fragaria chiloensis fruit.

To investigate the role of jasmonates (JAs) in the ripening of Fragaria chiloensis fruit, two concentrations of methyl jasmonate (MeJA, 10 and 100 µM) were evaluated at 2, 5 and 9 d using an in vitro ripening system. Fruit quality parameters; the contents of anthocyanin, lignin and cell wall polymers; and the transcriptional profiles of several ripening-related genes were analyzed. MeJA accelerated fruit ripening by means of a transitory increase in the soluble solid content/titratable acidity ratio, anthocyanin accumulation and an increase in softening at day 5. The expression of several phenylpropanoid-related genes, primarily those associated with anthocyanin biosynthesis, was increased under MeJA treatment, which correlated with an increased accumulation of anthocyanin. MeJA also altered the expression profiles of some cell wall-modifying genes, namely, EG1 and XTH1, and these changes correlated with a transient reduction in the firmness of MeJA-treated fruits. MeJA-responsive elements were observed in the promoter region of the EG1 gene. MeJA also increased the expression of LOX, AOS and OPR3, genes involved in the biosynthesis of JAs, and these changes correlated with the transient activation of fruit ripening observed. Conversely, the expression of ethylene and lignin biosynthesis genes (ACS, ACO, CAD and POD27) increased in MeJA-treated fruits at day 9. The present findings suggest that JAs promote the ripening of non-climacteric fruits through their involvement in anthocyanin accumulation, cell wall modification and the biosynthesis of ethylene and JAs.