Estudios citogenéticos en el complejo poliploide Zephyranthes mesochloa (Amaryllidaceae)

Background and aims: Zephyranthes mesochloa, is a bulbous species with white flowers that inhabits the subtropical region of South America and presents different chromosome numbers. The aim of this work is to carry out the chromosome analysis of Z. mesochloa from northern Argentina, to contribute to the cytogenetic knowledge of the genus. M&M: Ploidy levels and somatic chromosome numbers were determined in individuals from 8 populations in northern Argentina using conventional staining. In addition, meiotic preparations with acetic carmine were performed on individuals from one population. Results: Seventy-five percent of the populations were diploid, with 2n = 2x = 12 and presented a karyotypic formula of 4m + 4sm + 4st. In two of the diploid populations, individuals with 2n = 13 were observed, with the presence of an additional metacentric chromosome, possibly a B chromosome. Microsporogenesis analysis, in diakinesis and metaphase I, of aneuploid cytotype (2n = 13), showed six bivalents and one univalent in all pollen mother cells (PMCs) analyzed. The remaining populations (25%) were tetraploids with 2n = 4x = 24 and karyotypic formula 8m + 8sm + 8st. Geographically, the distribution of cytotypes in Z. mesochloa is discontinuous. Conclusions: The duplicate karyotype formula in tetraploids regarding its con-specific diploids may indicate the origin of an autopolyploid cytotype. The available data allows us to consider the group of cytotypes as part of a polyploid complex with a basic number of x = 6.Introducción y objetivos: Zephyranthes mesochloa es una especie bulbosa de flores blancas que habita en la región subtropical del sur de Sudamérica y registra distintos números cromosómicos. El objetivo del presente trabajo es analizar cromosómicamente individuos de la especie Z. mesochloa del norte de Argentina, con el objeto de contribuir al conocimiento citogenético del género.  M&M: El nivel de ploidía y el número cromosómico somático se determinó en individuos procedentes de 8 poblaciones del norte de Argentina a partir de tinción convencional. Además, se realizaron preparaciones meióticas con carmín acético en individuos de una de las poblaciones.  Resultados: El 75% de las poblaciones resultaron diploides, con 2n = 2x = 12 y fórmula cariotípica 4m + 4sm + 4st. En dos de las poblaciones diploides se observaron individuos con 2n = 13, con presencia de un cromosoma metacéntrico adicional, que posiblemente se trate de un cromosoma B. El análisis de la microsporogénesis, en diacinesis y metafase I, del citotipo aneuploide (2n = 13), mostró 6 bivalentes y 1 univalente en todas las células madre del polen (CMP) analizadas. Las poblaciones restantes (25%), resultaron tetraploides con 2n = 4x = 24 y fórmula cariotípica 8m + 8sm + 8st. Geográficamente, la distribución de los citotipos de Z. mesochloa es discontinua. Conclusiones: La fórmula cariotípica duplicada en los tetraploides con respecto a los diploides conespecíficos indicarían un origen autopoliploide de este citotipo. El conjunto de datos disponibles permite considerar al conjunto de citotipos como un complejo poliploide con número básico x = 6

Estudios citogenéticos en el complejo poliploide Zephyranthes mesochloa (Amaryllidaceae)

Introducción y objetivos: Zephyranthes mesochloa es una especie bulbosa de flores blancas que habita en la región subtropical del sur de Sudamérica y registra distintos números cromosómicos. El objetivo del presente trabajo es analizar cromosómicamente individuos de la especie Z. mesochloa del norte de Argentina, con el objeto de contribuir al conocimiento citogenético del género.  M&M: El nivel de ploidía y el número cromosómico somático se determinó en individuos procedentes de 8 poblaciones del norte de Argentina a partir de tinción convencional. Además, se realizaron preparaciones meióticas con carmín acético en individuos de una de las poblaciones.  Resultados: El 75% de las poblaciones resultaron diploides, con 2n = 2x = 12 y fórmula cariotípica 4m + 4sm + 4st. En dos de las poblaciones diploides se observaron individuos con 2n = 13, con presencia de un cromosoma metacéntrico adicional, que posiblemente se trate de un cromosoma B. El análisis de la microsporogénesis, en diacinesis y metafase I, del citotipo aneuploide (2n = 13), mostró 6 bivalentes y 1 univalente en todas las células madre del polen (CMP) analizadas. Las poblaciones restantes (25%), resultaron tetraploides con 2n = 4x = 24 y fórmula cariotípica 8m + 8sm + 8st. Geográficamente, la distribución de los citotipos de Z. mesochloa es discontinua. Conclusiones: La fórmula cariotípica duplicada en los tetraploides con respecto a los diploides conespecíficos indicarían un origen autopoliploide de este citotipo. El conjunto de datos disponibles permite considerar al conjunto de citotipos como un complejo poliploide con número básico x = 6

The effect of 5-aminolevulinic-acid (ALA) on the development of Saintpaulia ionantha

In recent work the effect of 5-aminolevulinic-acid (ALA) agent (commercial name Pentakeep-V) was examined on the chlorophyllcontent, growth and development of Saintpaulia ionantha. The newly re-rooted potted plants were irrigated or sprayed with 0.3‰ or 0.5‰Pentakeep-V solution, and plus 30% long lasting fertilizer was added to half of the all treatments. Control plants were sprayed with tap water.Best result were obtained on the field of flowering. All the treatments promoted chlorophyll-content in the leaves especially spraying with0.3‰concentration. Plants treated with Pentakeep-V in both concentrations and independently from the spraying or irrigation flowered morethan two weeks earlier than control and those that got plus 30% fertilizer. Besides in the case of some treatments the diameter of leaf rosette,the number and surface size of leaves grew comparing to the control. The longlasting fertilizer had positive effect on the fresh weight but noneof treatments had effect on the dry weight

The effect of 5-aminolevulinic-acid (ALA) on the development of Saintpaulia ionantha

In recent work the effect of 5-aminolevulinic-acid (ALA) agent (commercial name Pentakeep-V) was examined on the chlorophyll content, growth and development of Saintpaulia ionantha. The newly re-rooted potted plants were irrigated or sprayed with 0.3‰ or 0.5‰ Pentakeep-V solution, and plus 30% long lasting fertilizer was added to half of the all treatments. Control plants were sprayed with tap water. Best result were obtained on the field of flowering. All the treatments promoted chlorophyll-content in the leaves especially spraying with 0.3‰concentration. Plants treated with Pentakeep-V in both concentrations and independently from the spraying or irrigation flowered more than two weeks earlier than control and those that got plus 30% fertilizer. Besides in the case of some treatments the diameter of leaf rosette, the number and surface size of leaves grew comparing to the control. The longlasting fertilizer had positive effect on the fresh weight but none of treatments had effect on the dry weight

Comportamiento reproductivo de poblaciones sudamericanas de Paspalum Malacophyllum.

Edições dos trabalhos apresentados na XXXVII Jornadas Argentinas de Botánica, Tucumán (Argentina), 2019

Interspecific hybrids between Paspalum plicatulum and P. oteroi: a key tool for forage breeding.

ABSTRACT Grama-tio-pedro (Paspalum oteroi Swallen) is a rare stoloniferous grass of the Plicatula group of Paspalum, well adapted to continuous grazing in areas subject to seasonal flooding in the Pantanal region, in central western Brazil. The species is a facultative apomictic (asexual reproduction by seed) tetraploid, sporadically cultivated on Pantanal farms, propagated either by cuttings or seed. Due to its potential for extensive cultivation and forage quality, Grama-tio-pedro appears as a candidate for genetic improvement within the Plicatula group through plant breeding. We used a colchicine-induced sexual autotetraploid genotype of P. plicatulum Michx. to obtain interspecific hybrids using the apomictic species, P. oteroi, as pollen donor. The very similar meiotic chromosome behavior observed in both parents, with main quadrivalent and bivalent associations, suggested that P. oteroi is a natural autotetraploid. The hybrids showed less irregular meiotic behavior with fewer quadrivalents and more bivalents than either parent. Fertility among interspecific hybrids varied from complete sterility in some of them to seed productions in others that were approximately twice as much as for either parent. The great variability of seed set performance may well be a drastic genetic consequence of joining two homologous chromosome sets of P. plicatulum together with two homologous sets of P. oteroi that, in turn, have some homeology between them. Most hybrids reproduce by sexual means, thus, they could be used as female parents in backcrosses and in crosses with other species of the Plicatula group for interspecific gene transferring in breeding programs

International Survey

No abstract available

Improver International Survey

In recent years, the concept of resilience started to dominate strategic, operational as well as political domains of modern societies. Living in highly interconnected environment, where layers of infrastructures, people and economic interests interact creating both opportunities and vulnerabilities, different countries around the world turned towards resilience practices to reduce vulnerability of their critical infrastructures and societies. However, how can one implement resilience concepts without a comprehensive understanding of the concept itself? Focusing on the concept and practice of critical infrastructure resilience, this report provides a comprehensive overview of the existing scientific literature regarding the concept of resilience in general. It discusses the development of the concept of resilience and its application in societal, economic, ecological, organisational and critical infrastructure domains. The report provides an extensive discussion on the definition of resilience concepts, as well as information on scientific endeavours to implement and measure concepts of resilience. The report also contains detailed information on the definitions and implementation of the concepts of resilience in different continents, namely Europe, Africa, Asia, Oceania, North America and South America. Focusing on the concept of critical infrastructure resilience, it provides an overview of the existing official concepts of resilience, implementation tools, and general practices aimed at increasing organisational, societal, economic and technical resilience in different countries. To collect all the information, the IMPROVER consortium performed an extensive literature review on the use of resilience concepts. We also held a workshop with the associate partners, and conducted a set of personal interviews with critical infrastructure operators and resilience experts around the Europe. While conducting a number of case studies in different continents, we analysed existing region and state-level documents, and reports