scholarly journals Optimization of Pollen Germination in Tectona grandis (Teak) for Breeding Programs

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 908
Author(s):  
Ana Hine ◽  
Alejandra Rojas ◽  
Lorenzo Suarez ◽  
Olman Murillo ◽  
Mario Espinoza
Keyword(s):  
Latin American ◽  
Pollen Viability ◽  
Tree Improvement ◽  
Quality Analysis ◽  
High Price ◽  
Breeding Programs ◽  
Pollen Quality ◽  
Latin American Region ◽  
Improvement Programs ◽  
Operational Activities

Teak has become one of the most widely planted species in tropical regions of the world, given its high price for its timber in international markets. This has motivated the development of tree improvement programs in the Latin American region and in the tropical world in general. The latest advances have achieved clonal forestry at an operational scale. Recently, important efforts are being made to advance towards the next breeding generation, since knowledge about floral biology and pollen management have become important issues. A breeding program is being developed through the Tree Improvement Cooperative GENFORES—a vinculation model between the academy and forestry companies that was initiated in Costa Rica and now involves six Latin American countries. In order to advance into the next breeding generations, building capacities in topics such as pollen banks requires pollen quality, thus enabling the exchange of pollen among cooperative members. Pollen fertility studies are of considerable value in breeding programs, in order to determine pollen viability and germination in collections of genotypes, before going into mating operational activities. In this study, we optimized pollen quality analysis protocols in terms of the viability and germination of fresh teak pollen. Results of this research show that 90% viability and 28% germination can be achieved in fresh pollen grains, both inside and outside the anther, previously dehydrated in silica gel for 2 to 4 h (40% and 33% humidity, respectively). Brewbacker and Kwack (BK) medium at 10% of its salts + 10% sucrose and at a pH of 7 must be used as the germination medium. It is possible to evaluate teak pollen quality using the parameters defined in this study, which will in turn allow pollen management and purification, providing an opportunity for carrying out controlled crosses at an operational scale as part of teak breeding programs.

scholarly journals The status and potential of using controlled parentage in operational reforestation in New Brunswick

1998 ◽  
Vol 74 (2) ◽  
pp. 190-194 ◽  
Author(s):  
G. W. Adams ◽  
K. J. Tosh
Keyword(s):  
New Brunswick ◽  
Black Spruce ◽  
Seed Orchard ◽  
Tree Improvement ◽  
Breeding Programs ◽  
Future Challenges ◽  
The Status ◽  
Vegetative Multiplication ◽  
Improvement Programs ◽  
Initial Research

Tree improvement programs began in New Brunswick in the 1970s, and, by the early 1990s, most of the seed used in reforestation was from seed orchards. Initial research such as fertilizer trials and other flower induction methods focussed on increasing seed orchard yields. Trials have also been established to investigate parental contribution to seed orchard production. As the New Brunswick Tree Improvement Council breeding programs advance into the second generation, two new approaches have been developed to capture genetic gain more efficiently. The use of controlled breeding followed by vegetative multiplication of black spruce has been adopted operationally by J.D. Irving, Limited, and a jack pine meadow orchard has been established by the New Brunswick Department of Natural Resources and Energy. This paper presents an overview of these programs and the future challenges of using controlled parentage in operational reforestation stock production.

Genetically based differences in susceptibility of white spruce to the spruce bud moth

1991 ◽  
Vol 21 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Dan Quiring ◽  
Jean Turgeon ◽  
Dale Simpson ◽  
Allan Smith
Keyword(s):  
Plant Traits ◽  
White Spruce ◽  
Seed Orchard ◽  
Tree Improvement ◽  
Breeding Programs ◽  
Seedling Seed Orchard ◽  
Sib Families ◽  
Improvement Programs ◽  
Selection For ◽  
One Year

The susceptibility of white spruce, Piceaglauca (Moench) Voss, leaders to damage by the spruce bud moth, Zeirapheracanadensis Mut. & Free., was assessed for 72 half-sib families at four half-sib family test sites and in one seedling seed orchard in New Brunswick. Trees of intermediate height (1.5–3.75 m) were the most damaged, and damage in one year was positively correlated to damage in the next. During 2 consecutive years, half-sib family explained only 1% of the variation in damage when all four test sites were analysed together. However, half-sib family explained between 2.9 and 7.9% of the variation in damage at individual sites. At the four test sites, mean growth reductions of trees in the two most susceptible families were estimated to be approximately 30% higher than those of trees in the two least susceptible families. When all 72 families were ranked with respect to height, trees in the most susceptible and least susceptible families were ranked very poorly and highly, respectively. This suggested that trees in more susceptible families were smaller because of damage by the spruce bud moth. However, this pattern was observed at all sites, including one where bud moth damage was negligible. Thus even in the absence of damage by the spruce bud moth, trees in these least susceptible families had a greater growth rate, in terms of height, than trees in the most susceptible families. This indicates that selection for plant traits reducing susceptibility to bud moth may be compatible with breeding programs attempting to improve height growth. Implications of these results for tree improvement programs are discussed.

scholarly journals Determining conditions for best pollen quality of red-purple tree tomato (Solanum betaceum Cav.) germplasm

Bionatura ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 2222-2227
Author(s):  
Andrea Sotomayor ◽  
Jorge Merino ◽  
William Viera
Keyword(s):  
Pollen Viability ◽  
Breeding Programs ◽  
Pollen Quality ◽  
Local Cultivar ◽  
Two Temperatures ◽  
Storage Times ◽  
Days After Anthesis ◽  
Solanum Betaceum ◽  
Tree Tomato

The germination and viability of pollen are characteristics required for fecundation when individuals of different or the same species are crossed. For this reason, assessing these parameters in selected individuals to be used in breeding programs will increase the chances for the obtainment of new progeny. In this study, pollen from different accessions of the red-purple tree tomato (Solanum betaceum Cav.) was used: local cultivar (Morado Puntón), two commercial varieties (Large Red and Oratia Red) and six segregants [(Solanum unilobum x Solanum betaceum) x Solanum betaceum]. Three types of flowers were taken (A-day of anthesis, B-one day after anthesis, and C-two days after anthesis). The pollen was conserved in two temperatures (4° and 22° C) and four storage times (0, 5, 10, 20 days). The percentage of germination and pollen viability of the selected individuals were evaluated. It was observed that the commercial materials showed higher germination percentages than the segregants in flower A and B at a temperature of 4 ° C at all storage times, except for the segregants GT7P47 and GT7P48 at the same temperature on day 0. In addition, high percentages of viability were obtained both in flowers A and B, at both temperatures and at all storage times. However, the immediate use of pollen after it is collected is recommended because better germination is achieved. This study is helpful to improve breeding procedures in the initial stages of directed crosses.

Reagan and Thatcher's Special Relationship

2015 ◽  
Author(s):  
Sally-Ann Treharne
Keyword(s):  
Latin American ◽  
Special Relationship ◽  
Pivotal Moments ◽  
Political Relationships ◽  
Latin American Region ◽  
The Us ◽  
Anglo American ◽  
Elite Interviews ◽  
Personal Diplomacy ◽  
The Cold War

Reagan and Thatcher’s Special Relationship offers a unique insight into one of the most controversial political relationships in recent history. An insightful and original study, it provides a new regionally focused approach to the study of Anglo-American relations. The Falklands War, the US invasion of Grenada, the Anglo-Guatemalan dispute over Belize and the US involvement in Nicaragua are vividly reconstructed as Latin American crises that threatened to overwhelm a renewal in US-UK relations in the 1980s. Reagan and Thatcher’s efforts to normalise relations, both during and after the crises, reveal a mutual desire to strengthen Anglo-American ties and to safeguard individual foreign policy objectives whilst cultivating a close personal and political bond that was to last well beyond their terms in office. This ground-breaking reappraisal analyses pivotal moments in their shared history by drawing on the extensive analysis of recently declassified documents while elite interviews reveal candid recollections by key protagonists providing an alternative vantage point from which to assess the contentious ‘Special Relationship’. Sally-Ann Treharne offers a compelling look into the role personal diplomacy played in overcoming obstacles to Anglo-American relations emanating from the turbulent Latin American region in the final years of the Cold War.

scholarly journals Inequalities in access to safe drinking water in Peruvian households according to city size: an analysis from 2008 to 2018

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Akram Hernández-Vasquéz ◽  
Carlos Rojas-Roque ◽  
Denise Marques Sales ◽  
Marilina Santero ◽  
Guido Bendezu-Quispe ◽  
...  
Keyword(s):  
Drinking Water ◽  
Latin American ◽  
Socioeconomic Inequalities ◽  
City Size ◽  
Infrastructure Development ◽  
Safe Drinking Water ◽  
Small Cities ◽  
Cross Sectional ◽  
Percentage Points ◽  
Latin American Region

Abstract Background Peru is one of the countries with the lowest percentage of population with access to safe drinking water in the Latin American region. This study aimed to describe and estimate, according to city size, socioeconomic inequalities in access to safe drinking water in Peruvian households from 2008 to 2018. Methods Secondary analysis of cross-sectional data using data from the 2008–2018 ENAHO survey. Access to safe drinking water, determined based on the presence of chlorinated water supplied by the public network, as well as socioeconomic variables were analyzed. A trend analysis from 2008 to 2018, and comparisons between 2008 versus 2018 were performed to understand and describe changes in access to safe drinking water, according to city size. Concentration curves and Erreygers concentration index (ECI) were estimated to measure inequalities in access to safe drinking water. Results In 2008, 47% of Peruvian households had access to safe drinking water, increasing to 52% by 2018 (p for trend < 0.001). For small cities, access to safe drinking water did not show changes between 2018 and 2008 (difference in proportions − 0.2 percentage points, p = 0.741); however, there was an increase in access to safe drinking water in medium (difference in proportions 3.3 percentage points, p < 0.001) and large cities (difference in proportions 12.8 percentage points, p < 0.001). The poorest households showed a decreasing trend in access to safe drinking water, while the wealthiest households showed an increasing trend. In small cities, socioeconomic inequalities showed an increase between 2008 and 2018 (ECI 0.045 and 0.140, p < 0.001), while in larger cities, socioeconomic inequality reduced in the same period (ECI: 0.087 and 0.018, p = 0.036). Conclusions We report a widening gap in the access to safe drinking water between the wealthiest and the poorest households over the study period. Progress in access to safe drinking water has not been equally distributed throughout the Peruvian population. Promoting and supporting effective implementation of policies and strategies to safe drinking water, including equity-oriented infrastructure development and resource allocation for most vulnerable settings, including emerging small cities, is a priority.

scholarly journals The Influence of Government Effectiveness and Corruption on the High Levels of Homicide in Latin America

2021 ◽  
Vol 10 (5) ◽  
pp. 172
Author(s):  
Spencer P. Chainey ◽  
Gonzalo Croci ◽  
Laura Juliana Rodriguez Forero
Keyword(s):  
Economic Development ◽  
Latin America ◽  
Latin American ◽  
International Variation ◽  
Government Effectiveness ◽  
Latin American Region ◽  
Socio Economic Development ◽  
Structural Variables ◽  
The Relationship ◽  
Latin America Region

Most research that has examined the international variation in homicide levels has focused on structural variables, with the suggestion that socio-economic development operates as a cure for violence. In Latin America, development has occurred, but high homicide levels remain, suggesting the involvement of other influencing factors. We posit that government effectiveness and corruption control may contribute to explaining the variation in homicide levels, and in particular in the Latin America region. Our results show that social and economic structural variables are useful but are not conclusive in explaining the variation in homicide levels and that the relationship between homicide, government effectiveness, and corruption control was significant and highly pronounced for countries in the Latin American region. The findings highlight the importance of supporting institutions in improving their effectiveness in Latin America so that reductions in homicide (and improvements in citizen security in general) can be achieved.

scholarly journals ICH Guideline for Biopharmaceutics Classification System-Based Biowaiver (M9): Toward Harmonization in Latin American Countries

Pharmaceutics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 363
Author(s):  
Claudia Miranda ◽  
Alexis Aceituno ◽  
Mirna Fernández ◽  
Gustavo Mendes ◽  
Yanina Rodríguez ◽  
...  
Keyword(s):  
Latin American ◽  
Classification System ◽  
Biopharmaceutics Classification System ◽  
In Vitro Dissolution ◽  
Ich Guidelines ◽  
Latin American Region ◽  
Regulatory Guidelines ◽  
Biopharmaceutics Classification

The biopharmaceutical classification system (BCS) is a very important tool to replace the traditional in vivo bioequivalence studies with in vitro dissolution assays during multisource product development. This paper compares the most recent harmonized guideline for biowaivers based on the biopharmaceutics classification system and the BCS regulatory guidelines in Latin America and analyzes the current BCS regulatory requirements and the perspective of the harmonization in the region to develop safe and effective multisource products. Differences and similarities between the official and publicly available BCS guidelines of several Latin American regulatory authorities and the new ICH harmonization guideline were identified and compared. Only Chile, Brazil, Colombia, and Argentina have a more comprehensive BCS guideline, which includes solubility, permeability, and dissolution requirements. Although their regulatory documents have many similarities with the ICH guidelines, there are still major differences in their interpretation and application. This situation is an obstacle to the successful development of safe and effective multisource products in the Latin American region, not only to improve their access to patients at a reasonable cost, but also to develop BCS biowaiver studies that fulfill the quality standards of regulators in developed and emerging markets.

Breeding for improved growth and juvenile corewood stiffness in slash pine

2007 ◽  
Vol 37 (10) ◽  
pp. 1886-1893 ◽  
Author(s):  
Xiaobo Li ◽  
Dudley A. Huber ◽  
Gregory L. Powell ◽  
Timothy L. White ◽  
Gary F. Peter
Keyword(s):  
Genetic Correlation ◽  
Growth Traits ◽  
Low Cost ◽  
Genetic Correlations ◽  
Volume Growth ◽  
Pinus Elliottii ◽  
Tree Improvement ◽  
Slash Pine ◽  
Narrow Sense Heritability ◽  
Improvement Programs

The importance of integrating measures of juvenile corewood mechanical properties, modulus of elasticity in particular, with growth and disease resistance in tree improvement programs has increased. We investigated the utility of in-tree velocity stiffness measurements to estimate the genetic control of corewood stiffness and to select for trees with superior growth and stiffness in a progeny trial of 139 families of slash pine, Pinus elliottii Engelm. grown on six sites. Narrow-sense heritability estimates across all six sites for in-tree acoustic velocity stiffness at 8 years (0.42) were higher than observed for height (0.36) and diameter at breast height (DBH) (0.28) at 5 years. The overall type B genetic correlation across sites for velocity stiffness was 0.68, comparable to those found for DBH and volume growth, indicating that family rankings were moderately repeatable across all sites for these traits. No significant genetic correlations were observed between velocity stiffness, DBH, and volume growth. In contrast, a significant, but small, favorable genetic correlation was found between height and velocity stiffness. Twenty percent of the families had positive breeding values for both velocity stiffness and growth. The low cost, high heritability and nearly independent segregation of the genes involved with in-tree velocity stiffness and growth traits indicate that acoustic methods can be integrated into tree improvement programs to breed for improved corewood stiffness along with growth in slash pine.

Payment for Ecosystem Services policies in Peru: assessing the social and ecological dimensions of water services in the upper Santa River basin 

2021 ◽  
Author(s):  
Rosa María Dextre ◽  
María Luisa Eschenhagen ◽  
Mirtha Camacho ◽  
Sally Rangecroft ◽  
Laurence Couldrick ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
River Basin ◽  
Latin American ◽  
Social Systems ◽  
Water Services ◽  
Payment For Ecosystem Services ◽  
Metabolic Pattern ◽  
Design And Implementation ◽  
The Social ◽  
Latin American Region

&lt;p&gt;Increasing pressures on ecosystems in the Latin American region as well as the adoption of multilateral conservation commitments have led to the implementation of instruments that are economic in nature but oriented towards the recovery, conservation, and functioning of ecosystems. The increasing adoption of schemes such as payment for ecosystem services (PES) has emerged as multilateral strategies to address water security problems in the mountain regions of Per&amp;#250;. However, their design and implementation can face many barriers when the policy is translated into practice in a local context. Socio-economic processes and hydro-climatic factors are affecting the capacity of the ecosystems of the glaciated Cordillera Blanca (Peruvian Andes) to provide water services, in terms of both, quality and quantity, to the main users of the Santa River basin. This study thus aims to analyze how the hydro-social relations affect, and are affected by, the introduction of water-related PES in the Quillcay sub-basin, one of the most populated sub-basin along the Santa River basin. The water metabolism approach was used to characterize water as a service produced by ecological systems (water as an ecological fund) and co-produced by social systems (water as a social flow). For this purpose, a classification of the different social and ecological uses and meanings of water was used, as well as the role of the different actors involved.&amp;#160;&lt;/p&gt;&lt;p&gt;Based on the combination of primary data, both from an urban citizens survey (Huaraz) and semi-structured interviews with different actors, and from secondary sources, we present evidence that the metabolic pattern of water in the upper Santa basin is impacted not only by the glacial meltwater and rainwater regime but also by political, economic and cultural power relations over water. Thus, the implementation of a PES policy in the upper Santa basin affects and is affected by, ecological and social dimensions of water. In the ecological dimension, glacial retreat makes the design of a water-related PES more complex. In the social dimension, some socio-political processes, such as the lack of experience and the limited technical and financial capacity of public water management institutions to carry out these processes, as well as the lack of political will of regional and local authorities to promote them, are affecting the way these PES schemes are implemented. Along with these institutional bottlenecks, local socio-cultural processes related to a lack of interest in participating and demanding to participate in these decision-making processes could result in the design of a mechanism in which not all stakeholders benefit equally. This raises the need to recognize the multi-dimensional nature of water in the design and implementation of policies, and the importance of identifying processes and barriers which affect the success of these policies.&lt;/p&gt;

Who uses Transport Network Companies?: Characterization of Demand and its Relationship with Public Transit in Medellín

2021 ◽  
Author(s):  
Felipe Bedoya-Maya ◽  
Lynn Scholl ◽  
Orlando Sabogal-Cardona ◽  
Daniel Oviedo
Keyword(s):  
Latin American ◽  
Public Transit ◽  
Descriptive Analysis ◽  
Discrete Choice Models ◽  
Transport Network ◽  
Gender Effects ◽  
Transport Systems ◽  
Factors Affecting ◽  
On Demand ◽  
Latin American Region

Transport Network Companies (TNCs) have become a popular alternative for mobility due to their ability to provide on-demand flexible mobility services. By offering smartphone-based, ride-hailing services capable of satisfying specific travel needs, these modes have transformed urban mobility worldwide. However, to-date, few studies have examined the impacts in the Latin American context. This analysis is a critical first step in developing policies to promote efficient and sustainable transport systems in the Latin-American region. This research examines the factors affecting the adoption of on-demand ride services in Medellín, Colombia. It also explores whether these are substituting or competing with public transit. First, it provides a descriptive analysis in which we relate the usage of platform-based services with neighborhood characteristics, socioeconomic information of individuals and families, and trip-level details. Next, factors contributing to the election of platform-based services modeled using discrete choice models. The results show that wealthy and highly educated families with low vehicle availability are more likely to use TNCs compared to other groups in Medellín. Evidence also points at gender effects, with being female significantly increasing the probability of using a TNC service. Finally, we observe both transit complementary and substitution patterns of use, depending on the context and by whom the service is requested.

Sign in / Sign up

Export Citation Format

Share Document