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Resumo -O objetivo deste trabalho foi verificar possíveis divergências entre os resultados obtidos nas avaliações da adaptabilidade de 27 genótipos de milho (Zea mays L.), e na estratificação de 22 ambientes no Estado do Paraná, por meio de técnicas baseadas na análise de fatores e regressão bissegmentada. As estratificações ambientais foram feitas por meio do método tradicional e por análise de fatores, aliada ao porcentual da porção simples da interação GxA (PS%). As análises de adaptabilidade foram realizadas por meio de regressão bissegmentada e análise de fatores. Pela análise de regressão bissegmentada, os genótipos estudados apresentaram alta performance produtiva; no entanto, não foi constatado o genótipo considerado como ideal. A adaptabilidade dos genótipos, analisada por meio de plotagens gráficas, apresentou respostas diferenciadas quando comparada à regressão bissegmentada. A análise de fatores mostrou-se eficiente nos processos de estratificação ambiental e adaptabilidade dos genótipos de milho.Termos para indexação: Zea mays, interação genótipo x ambiente, estabilidade. Factor analysis and bissegmented regression for studies about environmental stratification and maize adaptabilityAbstract -The objective of this work was to verify possible divergences among results obtained on adaptability evaluations of 27 maize genotypes (Zea mays L.), and on stratification of 22 environments on Paraná State, Brazil, through techniques of factor analysis and bissegmented regression. The environmental stratifications were made through the traditional methodology and by factor analysis, allied to the percentage of the simple portion of GxE interaction (PS%). Adaptability analyses were carried out through bissegmented regression and factor analysis. By the analysis of bissegmented regression, studied genotypes had presented high productive performance; however, it was not evidenced the genotype considered as ideal. The adaptability of the genotypes, analyzed through graphs, presented different answers when compared to bissegmented regression. Factor analysis was efficient in the processes of environment stratification and adaptability of maize genotypes.Index terms: Zea mays, genotype x environment interaction, stability. IntroduçãoNos programas de melhoramento genético das diversas espécies, inclusive o milho (Zea mays L.), a interação genótipo x ambiente (GxA) dificulta a seleção e indicação de cultivares, em razão da inconsistência de performance dos genótipos em ambientes distintos.A interação GxA pode ser dividida em duas partes. Uma de natureza simples, quando não ocorre alteração das posições relativas dos genótipos avaliados, dentro de um conjunto de ambientes, tomados dois a dois. A outra, chamada de complexa, ocorre quando a correlação entre o desempenho dos genótipos ao longo dos ambientes em estudo é baixa, o que faz com que a posição relativa dos genótipos seja alterada em virtude das diferentes respostas às variações ambientais (Robertson, 1959).Para que as indicações de genótipos sejam mais seguras, ...

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A newly emerged disease, the Pyricularia blast caused by Pyricularia grisea, is commonly observed on wheat and black oats, since its discovery in 1985. Within a few years the disease spread to other species of Gramineae, but white oat cultivars remained resistant and were the only ones among cultivated cereals resistant to this disease. In 2012, one commercial field of white oat cultivar IAC 7 was found severely attacked by Pyricularia blast in Assis, in the state of São Paulo. The objective of the present investigation was to find out whether other white oat cultivars are also susceptible to the new P. grisea isolate from cv. IAC 7 and to determine the pathogenic variability, if any, among P. grisea isolates from black oats. Thirty-three white oat cultivars, along with some cultivars of black oat, barley, wheat, triticale, and rye were evaluated against the IAC 7 isolate. Results of disease severity analysis indicated that four white oat cultivars were resistant, seven were moderately resistant and the remaining were susceptible or highly susceptible. Five wheat cultivars were also resistant. Pathogenic variation among P. grisea isolates from black oats was observed.

-Soybean is cultivated in the wide range of environments of Paraná State. Selection for genotypes of high and predictable yields with wide adaptability are main targets of the breeding programs for this region. The adaptability and stability of 30 soybean cultivars of three different maturity groups (early, semi-early and medium maturity) with a focus on grain yield were evaluated in the