So far in this course we have dealt entirely with the evolution of characters that are controlled by simple Mendelian inheritance at a single locus. There are notes on the course website about gametic disequilibrium and how allele frequencies change at two loci simultaneously, but we didn’t discuss them. In every example we’ve considered we’ve imagined that we could understand something about evolution by examining the evolution of a single gene. That’s the domain of classical population genetics. For the next few weeks we’re going to be exploring a field that’s actually older than classical population genetics, although the approach we’ll be taking to it involves the use of population genetic machinery. If you know a little about the history of evolutionary biology, you may know that after the rediscovery of Mendel’s work in 1900 there was a heated debate between the “biometricians” (e.g., Galton and Pearson) and the “Mendelians” (e.g., de Vries, Correns, Bateson, and Morgan). Biometricians asserted that the really important variation in evolution didn’t follow Mendelian rules. Height, weight, skin color, and similar traits seemed to

Human biochemical genetics

In mammals, cadmium is widely considered as a non-genotoxic carcinogen acting through a methylation-dependent epigenetic mechanism. Here, the effects of Cd treatment on the DNA methylation patten are examined together with its effect on chromatin reconfiguration in Posidonia oceanica. DNA methylation level and pattern were analysed in actively growing organs, under short- (6 h) and long- (2 d or 4 d) term and low (10 mM) and high (50 mM) doses of Cd, through a Methylation-Sensitive Amplification Polymorphism technique and an immunocytological approach, respectively. The expression of one member of the CHROMOMETHYLASE (CMT) family, a DNA methyltransferase, was also assessed by qRT-PCR. Nuclear chromatin ultrastructure was investigated by transmission electron microscopy. Cd treatment induced a DNA hypermethylation, as well as an up-regulation of CMT, indicating that de novo methylation did indeed occur. Moreover, a high dose of Cd led to a progressive heterochromatinization of interphase nuclei and apoptotic figures were also observed after long-term treatment. The data demonstrate that Cd perturbs the DNA methylation status through the involvement of a specific methyltransferase. Such changes are linked to nuclear chromatin reconfiguration likely to establish a new balance of expressed/repressed chromatin. Overall, the data show an epigenetic basis to the mechanism underlying Cd toxicity in plants.

/pdf/in-posidonia-oceanica-cadmium-induces-changes-in-dna-3cu7uj83mr.pdf

In Posidonia oceanica cadmium induces changes in DNA methylation and chromatin patterning

After oil, coffee is the most valuable traded commodity worldwide. In this review we highlighted some aspects of coffee growth and development in addition to focusing our attention on recent advances on the (eco)physiology of production in both Coffea arabica and C. canephora, which together account for 99% of the world coffee bean production. This review is organized into sections dealing with (i) climatic factors and environmental requirements, (ii) root and shoot growth, (iii) blossoming synchronisation, fruiting and cup quality, (iv) competition between vegetative and reproductive growth and branch die-back, (v) photosynthesis and crop yield, (vi) physiological components of crop yield, (vii) shading and agroforestry systems, and (viii) high-density plantings.

/pdf/ecophysiology-of-coffee-growth-and-production-1r0hiua9fh.pdf

Ecophysiology of coffee growth and production

Coffee quality, in the present context of overproduction worldwide, has to be considered as a main selection criterion for coffee improvement. After a definition of quality, and an overview of the non genetic factors affecting its variation, this review focuses on the genetic factors involved in the control of coffee quality variation. Regarding the complexity of this trait, the different types of quality are first presented. Then, the great variation within and between coffee species is underlined, mainly for biochemical compounds related to quality (caffeine, sugars, chlorogenic acids, lipids). The ways for breeding quality traits for cultivated species, Coffea arabica and Coffea canephora are discussed, with specific challenges for each species. For C. arabica, maintaining a good quality in F 1 intraspecific hybrids, introgressed lines from Timor hybrid, and grafted varieties are the main challenges. For C. canephora, the improvement is mainly based on intraspecific and interspecific hybrids, using the whole genetic variability available within this species. An improvement is obtained for bean size, with significant genetic gains in current breeding programmes. The content in biochemical compounds related to cup quality is another way to improve Robusta quality. Finally, ongoing programmes towards the understanding of the molecular determinism of coffee quality, particularly using coffee ESTs, are presented.

/pdf/genetics-of-coffee-quality-2l16s2kty5.pdf

Genetics of coffee quality

Effects of long-term soil drought on photosynthesis and carbohydrate metabolism in mature robusta coffee (Coffea canephora Pierre var. kouillou) leaves

The objective of this study was to select and to multiply clones of Conilon coffee (Coffea canephora Pierre ex Froehner) to obtain clonal varieties with improved yield and quality. Two hundred and sixty seven mother plants were selected based on coffee grain yield, rust (Hemilea vastatrix) resistance, brown blight (Colletotrichum sp.) resistance, plant architecture, plant vigor, fruit size and time to fruit maturity. The selected clones were evaluated in four field experiments conducted on a Dark Yellow Latosol (Oxisol) at Instituto Capixaba de Pesquisa, Assistencia Tecnica e Extensao Rural (INCAPER), in Marilândia, ES, Brazil. Coffee trees were planted in rows 3.5 m apart with 1.5 m between plants in the rows. A randomized block design with four replications and six plants per plot was used. The selected clones, EMCAPA 8111, EMCAPA 8121, and EMCAPA 8131, early, medium and late maturity, respectively, were released for the State of Espirito Santo, Brazil. The productivity varied from 58 to 60 bags of 60 kg and was 33% greater than the control variety.

http://www.scielo.br/pdf/pab/v36n5/5549.pdf

Variedades clonais de café Conilon para o Estado do Espírito Santo

O objetivo deste trabalho foi avaliar a produtividade e obter as estimativas de parâmetros geneticos e nao geneticos de 40 materiais geneticos do programa de melhoramento genetico de cafe Conilon do Incaper, no Estado do Espirito Santo. Foram analisados dados de dois experimentos, nos municipios de Marilândia e Sooretama, ES, nas safras de 1996, 1997, 1998, 1999, 2000, 2001 e 2002, em que se avaliaram 16 caracteristicas. Realizou-se, inicialmente, a analise de variância individual, por local em cada ano, com base na media de parcelas, em blocos ao acaso. Posteriormente foi feita a analise de variância conjunta. Os genotipos apresentaram grande variabilidade genetica para a maioria das caracteristicas avaliadas. Os elevados coeficientes de determinacao genotipico e coeficientes de variacao geneticos, associados as altas produtividades e a variabilidade genetica indicam a possibilidade de obtencao de exitos em programas de melhoramento genetico para diferentes caracteristicas avaliadas nos dois municipios.

/pdf/parametros-geneticos-em-cafe-conilon-2936xgdasz.pdf

Parâmetros genéticos em café Conilon

O objetivo deste trabalho foi avaliar a divergencia genetica entre 32 clones de cafe conilon ( Coffea canephora Pierre ex Frohener) componentes de tres variedades clonais melhoradas, com vistas a identificacao dos mais dissimilares, para o estabelecimento de programas de cruzamentos dirigidos. A divergencia genetica foi avaliada por procedimentos multivariados: distância generalizada de Mahalanobis, metodo de agrupamento de otimizacao de Tocher e tecnica de variaveis canonicas. Sete caracteres foram avaliados em experimento conduzido em Marilândia, ES. Os genotipos ES 92, ES 25 e ES 22 sao os mais divergentes, sendo os dois ultimos os mais indicados para cruzamento com os demais, tendo em vista aliarem divergencia genetica a um bom desempenho produtivo.

/pdf/divergencia-genetica-em-cafe-conilon-2i785m1053.pdf

Divergência genética em café conilon

Conilon Vitória Incaper 8142 is a Coffea canephora var. kouillou clone type cultivar developed by Incaper, composed by clustering 13 superior clones. It presents a mean productivity of 70.4 bags of 60 kg ha, broad environmental adaptation and production stability, drought tolerance, uniformity of fruit maturation, and moderate rust resistance.

'Conilon Vitoria - Incaper 8142': improved Coffea canephora var. kouillou clone cultivar for the State of Espirito Santo

O objetivo deste trabalho foi analisar a producao de 50 clones de cafe 'Conilon' (Coffea canephora), por meio da analise de medidas repetidas, para identifica-los e agrupa-los para a formacao de variedades mais produtivas e, simultaneamente, modelar possiveis oscilacoes da producao ao longo do tempo. A influencia de ciclos produtivos foi considerada, tendo-se modelado as correlacoes existentes entre anos subsequentes, de forma eficiente, por meio da metodologia de analise de medidas repetidas, para avaliar producoes dos materiais geneticos em cinco safras (1997 a 2001), o que possibilitou captar oscilacoes anuais na producao, ao longo do ciclo produtivo de C. canephora, relacionadas as maiores producoes no terceiro e quarto anos. Alem disso, a analise de grupo classificou os 50 materiais avaliados em apenas 10 grupos, de acordo com o padrao de oscilacao da producao identificado pelo modelo de regressao adotado.

/pdf/analise-de-medidas-repetidas-na-avaliacao-de-clones-de-cafe-2qg3xeqwcw.pdf

Romário Gava Ferrão

Papers

Variedades clonais de café Conilon para o Estado do Espírito Santo

Parâmetros genéticos em café Conilon

Divergência genética em café conilon

'Conilon Vitoria - Incaper 8142': improved Coffea canephora var. kouillou clone cultivar for the State of Espirito Santo

Análise de medidas repetidas na avaliação de clones de café 'Conilon'