Genomic selection in Coffea canephora.

Coffee is one of the most heavily globally traded commodities and its production is based on Coffea arabica and Coffea canephora and Brazil being the world's largest coffee producer. It is believed that all this production will be affected due to climatic changes, with low flower viability, fruit development, yield and beverage quality. An alternative to assist in obtaining coffee plants more adapted to future climatic conditions would be genomic selection (GS). The implementation of these programs requires a lot of genetic markers, which are more readily discovered now after the reference genome of C. canephora became available. Another important factor is the high genetic variability of C. canephora, due to its level of allogamy, being of great importance for breeding programs of coffee

Genetic progress, adaptability and stability of maize cultivars for value of cultivation and use trials.

Made available in DSpace on 2019-05-31T00:36:54Z (GMT). No. of bitstreams: 1 Geneticprogress.pdf: 820188 bytes, checksum: 6533c2a586ba13682c1a1deea64517a8 (MD5) Previous issue date: 2019bitstream/item/197962/1/Genetic-progress.pd

QTL Mapping of Combining Ability and Heterosis of Agronomic Traits in Rice Backcross Recombinant Inbred Lines and Hybrid Crosses

BACKGROUND: Combining ability effects are very effective genetic parameters in deciding the next phase of breeding programs. Although some breeding strategies on the basis of evaluating combining ability have been utilized extensively in hybrid breeding, little is known about the genetic basis of combining ability. Combining ability is a complex trait that is controlled by polygenes. With the advent and development of molecular markers, it is feasible to evaluate the genetic bases of combining ability and heterosis of elite rice hybrids through QTL analysis. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we first developed a QTL-mapping method for dissecting combining ability and heterosis of agronomic traits. With three testcross populations and a BCRIL population in rice, biometric and QTL analyses were conducted for ten agronomic traits. The significance of general combining ability and special combining ability for most of the traits indicated the importance of both additive and non-additive effects on expression levels. A large number of additive effect QTLs associated with performance per se of BCRIL and general combining ability, and dominant effect QTLs associated with special combining ability and heterosis were identified for the ten traits. CONCLUSIONS/SIGNIFICANCE: The combining ability of agronomic traits could be analyzed by the QTL mapping method. The characteristics revealed by the QTLs for combining ability of agronomic traits were similar with those by multitudinous QTLs for agronomic traits with performance per se of BCRIL. Several QTLs (1-6 in this study) were identified for each trait for combining ability. It demonstrated that some of the QTLs were pleiotropic or linked tightly with each other. The identification of QTLs responsible for combining ability and heterosis in the present study provides valuable information for dissecting genetic basis of combining ability

Cost-Effectiveness of Preventing Loss to Follow-up in HIV Treatment Programs: A Côte d'Ivoire Appraisal

Based on data from West Africa, Elena Losina and colleagues predict that interventions to reduce dropout rates from HIV treatment programs (such as eliminating copayments) will be cost-effective

Estudo de associação genômica ampla para importantes características agronômicas em Coffea canephora.

RESUMO: O Estudo de Associação Genômica Ampla (Genome-Wide Association Studies ? GWAS) surgiu com o intuito de capturar o efeito de genes na determinação de determinada característica fenotípica. Para isso, os indivíduos selecionados são genotipados em escala genômica e fenotipados para as características de interesse e então, a partir de análises estatísticas entre os polimorfismos de DNA e a variação no fenótipo, os genes que controlam essas características podem ser identificados. Por se tratar de uma espécie perene e de ciclo longo, os programas de melhoramento genético convencional do cafeeiro são demorados (vários anos) e de custo elevado. A geração de cultivares superiores via melhoramento genético ainda lida com o desafio de agregar simultaneamente diversas características quantitativas de relevância agronômica, assim como a qualidade de bebida. Neste contexto, na tentativa de identificar genes/regiões genômicas associadas à características agronômicas importantes, 1.319 indivíduos da Embrapa Cerrados foram genotipados e fenotipados, e posteriormente, realizou-se um estudo de GWAS com os softwares TASSEL e rrBLUP. Um número diferente de marcadores associados foi identificado com as duas estratégias utilizadas. Foram identificados marcadores tanto em regiões intergênicas como em regiões gênicas, sendo que, nesta última, os marcadores estavam presentes em genes já caracterizados e descritos na literatura para outras espécies como estando relacionados às características agronômicas aqui analisadas.Título em inglês: Genome-wide association studies for important agronomic traits in Coffea canephora