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The evaluation of accessions in a germplasm bank is essential for determining the potential parents in conservation programs, especially for native trees. This study aimed to determine the genetic diversity among 68 Amburana cearensis genotypes from different locations in the state of Pernambuco, Brazil. Their genetic patterns were evaluated by Inter Simple Sequence Repeat (ISSR) molecular markers and genetic divergence was evaluated through multivariate analyses using different clustering methods. The optimization method used (Tocher) was in agreement with all the hierarchical models used, in which clustering of the genotypes occurred similarly, specifically for the accession BB116, which is an important genetic material to be preserved and studied. Among the various hierarchical methods applied, the Average Linkage method exhibited higher discrimination power, allowing identification of a larger number of divergent groups, thus implying wide genetic diversity among A. cearensis accessions.

Increasing corn grain production without devastating new forest areas is a viable alternative to controlling deforestation. However, increasing plant density in the area may alter plant morphophysiological and productive traits. The objective of this study was to characterize relationships between physiological, morphological and yield traits of corn plants, as well as the cause, effect and relationship of the traits on grain yield. The experiment was carried out in randomized complete block design with four replications. The corn hybrids (2B655PW, AG7088PRO3 and P4285YHR) were grown with row spacing of 40 cm, 60 cm, 80 cm, 95 cm. The evaluated traits physiological were: net photosynthesis (PN), stomatal conductance (Gs), intercellular concentration of CO2 (Ci), leaf transpiration (E), water use efficiency (WUE) and carboxylation efficiency (CE). The morphological were: plant height (PH) and ear insertion height (EIH), stem diameter (SD), and leaf area (LA) and the productive traits were the total number of ear per hectare (NE), number of grains per ear (NGE), grain mass per ear (GME), 100 grain weight (100GW) and grain yield (GY). The characteristics of maize hybrids cultivated in environment with reduced spacing (40cm, 60cm, 80cm, 95cm) of the 2016/2017 crop were investigated through the multicollinearity path analysis. The physiological, morphological and productive traits are considered sources of variation of cause and effect of corn yield in reduced spaced. This traits are essential for observations in maize breeding programs to obtain high yielding varieties in reduced spacing. In conclusion, the physiological (PN, CE, WUE, Ci, Gs), morphological (EIH, SD, LA) and productive (NE, GME) traits provide gains in maize grain yield via indirect selection when the crop is subjected to 40 cm row spacing.

As espécies de pimenta do gênero Capsicum têm sido cultivadas por vários séculos, encontrando-se frutos pungentes ou doces, dependendo da presença de um grupo de alcalóides, denominado capsaicinóide. Dentre as cinco espécies cultivadas, Capsicum chinense é uma das mais empregadas, sendo nativa da região amazônica. Essa espécie é caracterizada por apresentar tamanhos, formas e massa dos frutos bastante variados, por conter diferentes concentrações de capsaicinóides, além de serem ricos nas vitaminas A e C. Embora seja destacada a importância dessas plantas condimentares e medicinais, investigações sobre a variabilidade genética e potencial para futuros programas de melhoramento, ainda são incipientes. Sendo assim, o presente trabalho teve como objetivos estudar a variabilidade genética de acessos pungentes e com frutos doces por meio de marcadores isoenzimáticos e RAPD. Um total de 10 acessos de Capsicum chinense foram cultivados, sendo metade deles pungentes, em bandejas contendo substrato comercial em condições de casa de vegetação, tendo sido coletado um “pool” de tecido foliar para as análises de marcadores isoenzimáticos e RAPD. Os resultados das análises de marcadores isoenzimáticos e RAPD evidenciaram a ocorrência de variabilidade genética, e a análise de divergência pelos métodos do UPGMA e de Tocher propiciou a formação de dois grupos, com um deles composto por três subgrupos. A maior divergência genética foi observada entre os acessos P2 (BGH4289-44) e P8 (BGH4223-39), enquanto que os mais similares foram os acessos P1 (BGH1716-17) e P6 (BGH1716-16). A análise da divergência genética evidencia que o cruzamento de P2 (BGH4289-44) com os demais acessos estudados pode propiciar resultados promissores na obtenção de segregantes superiores no melhoramento para caracteres de frutos.

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