The "cagaita tree" (Eugenia dysenterica) is a plant found widespread in the Brazilian Cerrado. Its fruit is used for popular consumption and for industrial purposes. This study opens a new perspective for the generation of population genetic data and parameters estimates for devising sound collection and conservation procedures for Eugenia dysenterica. A battery of 356 primer pairs developed for Eucalyptus spp. was tested on the "cagaita tree". Only 10 primer pairs were found to be transferable between the two species. Using a polyacrilamide gel, an average of 10.4 alleles per locus was detected, in a sample of 116 individuals from 10 natural "cagaita tree" populations. Seven polymorphic loci allowed estimation of genetic parameters, including expected average heterozygosity H e = 0,442, among population diversity, R ST = 0,268 and gene flow Nm = 0,680. Results indicated a potential of SSR locus transferability developed for Eucalyptus to other species of different genera, such as in the case of the "cagaita tree". The high genetic diversity among populations detected with SSR markers indicated that these markers are highly sensitive to detect population structure. Estimated Nm values and the existence of private alleles indicated reduced gene flow and consequently possible damage to the metapopulation structure.

Resumo -O objetivo deste trabalho foi avaliar a influência da interação de genótipos com ambientes (GxA) na produtividade de grãos de um conjunto de linhagens de soja (Glycine max L.). Foram utilizados dados de 11 experimentos (ambientes) realizados no Estado de Goiás. Em cada experimento foram avaliados 18 genótipos, sendo quatro cultivares comerciais como testemunhas. O método de análise da interação foi o procedimento AMMI (modelo de efeitos principais aditivos e interação multiplicativa). O padrão significativo das interações GxA foi captado apenas pelo primeiro eixo principal AMMI, o qual explicou 36% da soma de quadrados GxA original, sugerindo contaminação da matriz de interações clássica por ruídos que prejudicam a qualidade das predições de respostas fenotípicas obtidas pelos métodos tradicionais. Quanto à estabilidade de comportamento, a maioria das linhagens experimentais destacou-se (com menores interações com ambientes) em relação às cultivares testemunhas. Estas, no entanto, foram relativamente mais produtivas, sobretudo a cultivar Conquista. Entre as novas linhagens, os genótipos L-16, L-13 e L-14 mostraram ser os mais promissores para fins de recomendação como cultivares.Termos para indexação: Glycine max, progênie, interação genótipo-ambiente, adaptação, biplot. Application of AMMI analysis in the assessment of yield stability in soybeanAbstract -The objective of this work was to evaluate the influence of the genotype environment (GE) interaction on the grain yield of a soybean (Glycine max L.) lines group. Yield data from 11 trials (environments) conducted in the State of Goiás, Brazil were used. In each trial 18 genotypes were tested, from which four were commercial cultivars as checks. The statistical method was the AMMI analysis (additive main effect and multiplicative interaction analysis). A significant GE interaction pattern was captured only for the first principal AMMI axis, which explained 36% of the original square sum of the GE interaction, suggesting contamination of the classic GE interaction matrix by noise arising from unpredictable factors, assuring that AMMI analysis provides a better prediction of phenotypic responses than traditional methodologies. About yield stability, most experimental lines outstands (with low GE interaction) over checks. However, the checks, mainly the cultivar Conquista, showed higher yield averages. Among the experimental lines, the genotypes L-16, L-13 and L-14 appeared to be the most promising for cultivars recommendation.Index terms: Glycine max, progeny, genotype environment interaction, adaptation, biplot.(1) Aceito para publicação em 17 de dezembro de 2002. IntroduçãoAs interações de genótipos com ambientes (GxA) trazem aos melhoristas dificuldades na identificação de genótipos superiores, seja por ocasião da seleção, seja no momento da recomendação de cultivares. A presença dessas interações indica que o comportamento relativo dos genótipos nos testes depende, fundamentalmente, das condições ambientais a que estão submetidos. Desta forma, a res...

-This study was carried out to assess the genetic variability of ten "cagaita" tree (Eugenia dysenterica) populations in Southeastern Goiás. Fifty-four randomly amplified polymorphic DNA (RAPD) loci were used to characterize the population genetic variability, using the analysis of molecular variance (AMOVA). A φ ST value of 0.2703 was obtained, showing that 27.03% and 72.97% of the genetic variability is present among and within populations, respectively. The Pearson correlation coefficient (r) among the genetic distances matrix (1 -Jaccard similarity index) and the geographic distances were estimated, and a strong positive correlation was detected. Results suggest that these populations are differentiating through a stochastic process, with restricted and geographic distribution dependent gene flow.Index terms: Myrtaceae, Cerrado, tropical species, genetic diversity. Estrutura genética e fluxo gênico em populações naturais de cagaitaResumo -Este trabalho teve por objetivo o estudo da variabilidade genética em 10 populações de cagaiteiras (Eugenia dysenterica), da região Sudeste do Estado de Goiás. Foram identificados 54 locos marcadores RAPD, para a caracterização da variabilidade genética, avaliada por meio da análise da variância molecular (AMOVA). Foi verificado que 27,03% da variabilidade genética está entre populações, e 72,97% dentro de populações, índices obtidos a partir do valor de φ ST igual a 0,2703. Foi estimado o coeficiente de correlação de Pearson (r) entre a matriz de distâncias genéticas (1 -índice de similaridade de Jaccard) e de distâncias geográficas, tendo sido encontrada forte correlação positiva. Os resultados sugerem que essas populações estão se diferenciando por um processo estocástico havendo fluxo restrito dependente da distribuição geográfica.Termos para indexação: Myrtaceae, Cerrado, espécies tropicais, diversidade genética, Eugenia dysenterica.

Key message This review provides a comprehensive atlas of QTLs, genes, and alleles conferring resistance to 28 important diseases in all major soybean production regions in the world. Abstract Breeding disease-resistant soybean [Glycine max (L.) Merr.] varieties is a common goal for soybean breeding programs to ensure the sustainability and growth of soybean production worldwide. However, due to global climate change, soybean breeders are facing strong challenges to defeat diseases. Marker-assisted selection and genomic selection have been demonstrated to be successful methods in quickly integrating vertical resistance or horizontal resistance into improved soybean varieties, where vertical resistance refers to R genes and major effect QTLs, and horizontal resistance is a combination of major and minor effect genes or QTLs. This review summarized more than 800 resistant loci/alleles and their tightly linked markers for 28 soybean diseases worldwide, caused by nematodes, oomycetes, fungi, bacteria, and viruses. The major breakthroughs in the discovery of disease resistance gene atlas of soybean were also emphasized which include: (1) identification and characterization of vertical resistance genes reside rhg1 and Rhg4 for soybean cyst nematode, and exploration of the underlying regulation mechanisms through copy number variation and (2) map-based cloning and characterization of Rps11 conferring resistance to 80% isolates of Phytophthora sojae across the USA. In this review, we also highlight the validated QTLs in overlapping genomic regions from at least two studies and applied a consistent naming nomenclature for these QTLs. Our review provides a comprehensive summary of important resistant genes/QTLs and can be used as a toolbox for soybean improvement. Finally, the summarized genetic knowledge sheds light on future directions of accelerated soybean breeding and translational genomics studies.

-The objectives of this work were to investigate the genetic variation in 79 soybean (Glycine max) accessions from different regions of the world, to cluster the accessions based on their similarity, and to test the correlation between the two types of markers used. Simple sequence repeat markers present in genomic (SSR) and in expressed regions (EST-SSR) were used. Thirty SSR primer-pairs were selected (20 genomic and 10 EST-SSR) based on their distribution on the 20 genetic linkage groups of soybean, on their trinucleotide repetition unit and on their polymorphism information content. All analyzed loci were polymorphic, and 259 alleles were found. The number of alleles per locus varied from 2-21, with an average of 8.63. The accessions exhibit a significant number of rare alleles, with genotypes 19, 35, 63 and 65 carrying the greater number of exclusive alleles. Accessions 75 and 79 were the most similar and accessions 31 and 35, and 40 and 78, were the most divergent ones. A low correlation between SSR and EST-SSR data was observed, thus genomic and expressed microsatellite markers are required for an appropriate analysis of genetic diversity in soybean. The genetic diversity observed was high and allowed the formation of five groups and several subgroups. A moderate relationship between genetic divergence and geographic origin of accessions was observed.Index terms: Glycine max, molecular marker, plant breeding, plant germplasm, polymorphism information content. Termos para indexação: Glycine max, marcadores moleculares, melhoramento de plantas, germoplasma vegetal, conteúdo de informação polimórfica. Diversidade genética em germoplasma de soja identificada por marcadores SSR e EST-SSR