Selection for resistance to black pod disease and yield gains prediction by use of selected cocoa varieties in Cameroon

2003 ◽  
Vol 1 (2-3) ◽  
pp. 157-160 ◽  
Author(s):  
S. Nyasse ◽  
I. B. Efombagn Mousseni ◽  
A. B. Eskes
Keyword(s):  
Disease Resistance ◽  
Genome Mapping ◽  
Basic Knowledge ◽  
Screening Tests ◽  
Resistance Quantitative Trait Locus ◽  
Early Screening ◽  
Cocoa Production ◽  
Black Pod ◽  
Trait Locus ◽  
Growing Conditions

Research on resistance to black pod caused by Phytophthora megakarya has been carried out in Cameroon for 40 years. It has yielded a significant database which is currently being exploited for the modelling of disease resistance levels of the major clones selected as candidate parents for the creation of new resistant and consequently more productive cocoa varieties. These outputs are expected to meet the increasing need of producers for improved planting material to extend cultivation into emerging cocoa-growing areas or to renew old cocoa production basins. These outputs have been made possible through an international collaborative effort and, more recently, within the scope of regional or international initiatives sponsored by CFC/ICCO/IPGRI and by CAOBISCO. New selection approaches and methodologies, such as rapid field assessment and early screening tests, have been promoted, along with the use of molecular tools for genome mapping and disease resistance quantitative trait locus (QTL) identification. Promising material has been introduced, evaluated in the laboratory and on-farm, and compared to the local cocoa germplasm. The basic knowledge developed from this local database has enabled the definition of an empirical disease resistance sorting and subsequently a prediction of the yield gains expected from the use of different cocoa clones and possible combinations (progenies) available on-station and in farmers' stands in different agro-ecological growing conditions; or which have to be created following strategies in the new breeding programme.

scholarly journals A Model-Based Meta-Analysis of Willingness to Participate in Cancer Screening

2021 ◽  
Vol 18 (5) ◽  
pp. 2580
Author(s):  
Guangchao Charles Feng ◽  
Zhiliang Lin ◽  
Wanhua Ou ◽  
Xianglin Su ◽  
Qing Yan
Keyword(s):  
Structural Equation ◽  
Meta Analysis ◽  
Health Belief ◽  
Screening Tests ◽  
Equation Modeling ◽  
Willingness To Participate ◽  
Early Screening ◽  
The Public ◽  
Screening Programs ◽  
Belief Model

Although early screening tests are beneficial for the detection and treatment of cancers, many people have failed to participate in screening tests. The present study aims to explore the theoretical underpinning of low participation in screening programs using the method of meta-analytic structural equation modeling. It was found that the health belief model is the most adopted theoretical framework. Moreover, the intended uptake of screening was positively predicted only by cues to action, health literacy, and perceived susceptibility. As a result, a health intention model, including the three significant variables, is proposed. The practical implications of the findings are that health communication campaigns should focus on enlightening and engaging the public through all necessary means to raise awareness and transfer knowledge in relation to screening procedures as well as cancers per se.

Developmental morphology and anatomy of the reproductive structures in sunflower (Helianthus annuus): a unified temporal scale

Botany ◽  
2015 ◽  
Vol 93 (5) ◽  
pp. 307-316 ◽  
Author(s):  
L.I. Lindström ◽  
L.F. Hernández
Keyword(s):  
Disease Resistance ◽  
Helianthus Annuus ◽  
Oil Content ◽  
Genetic Selection ◽  
Reproductive Development ◽  
Developmental Morphology ◽  
Male And Female ◽  
Reproductive Structures ◽  
Selection For ◽  
Growing Conditions

In sunflower (Helianthus annuus L.), there has been an intense genetic selection for achenes with agronomic value, such as greater mass, oil content, and disease resistance. However, the information regarding the anatomical events that control their growth and maturation is surprisingly scarce. The aim of the present work was to study sunflower male and female sporogenesis and gametogenesis, as well as cell division and enlargement and tissue differentiation in the ovary and the embryo, linking the timing of these events to two frequently used phenological scales and a thermal time scale. In addition, we propose an ontogenetic scale that integrates the results of the present work to that of previous studies on sunflower reproductive development. The unified scales presented here provide a framework for others to investigate the relationships uncovered in this study in different genetic backgrounds and under different growing conditions.

scholarly journals Enviromic assembly increases accuracy and reduces costs of the genomic prediction for yield plasticity

2021 ◽  
Author(s):  
Germano MF Costa-Neto ◽  
Jose M F Crossa ◽  
Roberto F Fritsche-Neto
Keyword(s):  
Phenotypic Variation ◽  
Field Trials ◽  
Proof Of Concept ◽  
Tropical Maize ◽  
Early Screening ◽  
Environmental Similarity ◽  
Genetic And Environmental Factors ◽  
Growing Conditions ◽  
Algorithm Scheme

Quantitative genetics states that phenotypic variation is a consequence of genetic and environmental factors and their subsequent interaction. Here, we present an enviromic assembly approach, which includes the use of ecophysiology knowledge in shaping environmental relatedness into whole-genome predictions (GP) for plant breeding (referred to as E-GP). We propose that the quality of an environment is defined by the core of environmental typologies (envirotype) and their frequencies, which describe different zones of plant adaptation. From that, we derive markers of environmental similarity cost-effectively. Combined with the traditional genomic sources (e.g., additive and dominance effects), this approach may better represent the putative phenotypic variation across diverse growing conditions (i.e., phenotypic plasticity). Additionally, we couple a genetic algorithm scheme to design optimized multi-environment field trials (MET), combining enviromic assembly and genomic kinships to provide in-silico realizations of the future genotype-environment combinations that must be phenotyped in the field. As a proof-of-concept, we highlight E-GP applications: (1) managing the lack of phenotypic information in training accurate GP models across diverse environments and (2) guiding an early screening for yield plasticity using optimized phenotyping efforts. Our approach was tested using two non-conventional cross-validation schemes to better visualize the benefits of enviromic assembly in sparse experimental networks. Results on tropical maize show that E-GP outperforms benchmark GP in all scenarios and cases tested. We show that for training accurate GP models, the genotype-environment combinations' representativeness is more critical than the MET size. Furthermore, we discuss theoretical backgrounds underlying how the intrinsic envirotype-phenotype covariances within the phenotypic records of (MET) can impact the accuracy of GP and limits the potentialities of predictive breeding approaches. The E-GP is an efficient approach to better use environmental databases to deliver climate-smart solutions, reduce field costs, and anticipate future scenarios.

scholarly journals Set theoretic approach to the concept of net sensitivity and net specificity in screening test results

2018 ◽  
Vol 5 (5) ◽  
pp. 1690 ◽  
Author(s):  
Bansi Badan Mukhopadhyay ◽  
Himadri Bhattacharjya
Keyword(s):  
Sensitivity And Specificity ◽  
Set Theory ◽  
Screening Test ◽  
Basic Knowledge ◽  
Screening Tests ◽  
Theoretic Approach ◽  
Test Results

Net sensitivity and net specificity have been reviewed from set theoretic approach. With a basic knowledge of set theory one can estimate the net sensitivity and specificity in an easy way in both sequential and simultaneous screening tests. Union, intersection and complementary operations of set theory have been adopted to find out the solutions. 

scholarly journals Efficacy of screening methods used in breeding for black pod disease resistance varieties in cocoa

2010 ◽  
Vol 17 (4) ◽  
Author(s):  
D Nyadanu ◽  
MK Assuah ◽  
B Adomako ◽  
YP Asiama ◽  
IY Opoku ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Screening Methods ◽  
Black Pod ◽  
Black Pod Disease

Early Screening Tests: Some Uses and Abuses

1979 ◽  
Vol 12 (1) ◽  
pp. 56-60 ◽  
Author(s):  
Paul Satz ◽  
Jack M. Fletcher
Keyword(s):  
Screening Tests ◽  
Early Screening
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