Abstract Asian soybean rust (Phakopsora pachyrhizi – ASR) is one of the major diseases that occur in soybean and causes great damage to commercial crops. Therefore, the goal of this work was to investigate the relationship between biochemical and photosyntetic parameters in soybean with ASR. Two experiments were performed in a randomized complete block with three treatments (water, Tween 20, and methyl jasmonate). The evaluated traits were: severity, chlorophyll pools, concentration of phenolic compounds content, enzyme activity, and photosyntetic parameters. Based on Pearson correlation, correlation network and path analysis it was verified that the severity had high correlation with almost all traits evaluated meanwhile photosynthesis is weakly related with almost all traits. Therefore, the occurrence of ASR affects directly the traits related to enzymatic activity and phenolic compounds content in soybean plants inoculated with ASR. The management of ASR is important to keep in normal levels the rates of photosynthesis carried out by the plant, and thus not affect the yield. Besides that, understanding the biochemical mechanisms and ecophysiological responses that occur during the soybean-P. pachyrhizi interaction has a great importance for breeding programs, as it will help for obtaining resistant cultivars or efficient methods in fungus control.

Abstract Yarrow (Achillea millefolium L., Asteraceae) is an important medicinal plant used worldwide for its medicinal properties such as the analgesic, antioxidant and anti-inflammatory ones. The aim of this study was to evaluate the growth and production of photosynthetic pigments and of volatile constituents of Achillea millefolium L. under different irrigation depths. The treatments were the application of 55, 110, 220, 440 and 880 mm of water for a period of 110 days. Data were submitted to polynomial regression analysis at 5% probability, while the volatile constituents were analyzed by standard deviation. Different irrigation depths provided quadratic growth responses being the highest dry matter production at the depth of 440 mm. The contents of chlorophyll a, b, total and carotenoids were higher at the lower depth tested (55 mm). The major volatile compounds identified were sabinene, 1,8-cineol, borneol and β-caryophyllene. Increased water availability reduced the complexity of the volatile fraction of essential oil. Thus, it is recommended that the species be cultivated at 440 mm irrigation depth to have a higher production of dry matter and lower variation in the volatile profile of the essential oil.

ABSTRACT Piper hispidinervum C. DC. is popularly known as long-pepper and it owns a commercial value due to the essential oil it produces. Long-pepper oil is rich in safrole and eugenoln components that have insecticidal, fungicidal and bactericidal activity. It has been establish that to medicinal plants light influences not only growth but also essential oil production. The growth, the content of photosynthetic pigments and the essential oil production of Piper hispidinervum at greenhouses with different light conditions was evaluated. The treatments were characterized by cultivation of plants for 180 days under different light conditions, produced by shading greenhouses with 50% and 30% of natural incident irradiance, two colored shading nets red (RN) and blue (BN) both blocking 50% of the incident radiation and one treatment at full-sun (0% of shade). The results showed that the treatments of 50% shade and RN and BN were the ones which stimulated the greater growth. Blue and red light also had the best production of photosynthetic pigments. Essential oil yielded more under full sun therefore this is the most indicated condition to produce seedlings for the chemical and pharmaceutical industry.

O guaco (Mikania glomerata Sprengel) é espécie de uso medicinal conhecida pela atividade broncodilatadora. Muitos estudos têm evidenciado mudanças nas características anatômicas e fisiológicas de plantas medicinais sob influência de condições de radiação. Neste trabalho analisou-se a influência de fotoperíodos (8; 12; 16 e 20 h) na anatomia foliar, nos teores de clorofila e condutância estomática em três regiões da planta. Após 90 dias de tratamento, plantas adultas e com diferentes tamanhos influenciados pelos fotoperíodos foram submetidas às avaliações anatômicas e fisiológicas. Os teores de clorofila foram maiores nos fotoperíodos de 8 e 12 h nas regiões superior e mediana da planta e menores no fotoperíodo de 8 h na região basal. A condutância e densidade estomática apresentaram relação inversa ao aumento do fotoperíodo, sendo significativamente decrescente do ápice para a base da planta. Houve aumento da espessura da epiderme adaxial nas regiões mediana e basal da planta até o fotoperíodo de 16 h. Nestas regiões houve aumento progressivo do parênquima esponjoso até o fotoperíodo de 20 h. Verificou-se modificações no tamanho e organização dos feixes vasculares influenciadas pelos fotoperíodos.

Guaco (Mikania glomerata Sprengel) is a medicinal species known because of its bronchi-dilating activity. Many studies have indicated changes in anatomical and physiological characteristics of medicinal plants when submitted to different conditions of light. The effect of photoperiods (8; 12; 16 and 20 h) on leaf anatomy, content of chlorophyll and stomatal conductance in distinct regions of guaco plants were analyzed. Adult plants of different sizes influenced by distinct photoperiods were submitted to anatomical and physiological analyses. 90 days after starting photoperiod treatments the chlorophyll content was higher in plants submitted to photoperiods of 8 and 12 hours in the superior and intermediary regions of plant, decreasing at 8 h of photoperiod treatment in the basal region of the plants. The conductance and stomatal density presented inverse relation to increase of photoperiod, decreasing from apical to basal regions of the plants. The thickness of the superior epidermis increased in the intermediary and basal regions of the plants submitted to a photoperiod up to 16 h. These regions presented a progressive increase of the lacunose parenchyma thickness under a photoperiod up to 20 h. The size and organization of the vascular bundles were influenced by the photoperiods.

O murici-pequeno (Byrsonima intermedia A. Juss.), espécie medicinal do Cerrado, apresenta dificuldade de propagação sexuada decorrente da baixa taxa de germinação e emergência lenta das plântulas em campo. Objetivou-se com o presente trabalho estudar aspectos da germinação in vitro de murici-pequeno mediante avaliação do efeito dos meios de cultura MS e WPM e diferentes concentrações de BAP. Frutos maduros foram coletados de populações naturais, dos quais sementes e embriões foram excisados e utilizados como explante. Pelos resultados, infere-se que os meios de cultura mais eficientes para a germinação in vitro de sementes e embriões são o MS e WPM 50%, sem sacarose, apresentando 60% e 100% de germinação, respectivamente. Observou-se também que não se faz necessária a adição de BAP na germinação in vitro de embriões.

The murici-pequeno (Byrsonima intermedia A. Juss.) is a medicinal plant of cerrado that presents difficulties of sexual propagation due to a low rate of seed germination and plant emergency in the field. The objective of this work was study aspects of the in vitro germination of murici-pequeno evaluating the effects of MS and WPM culture media and different concentrations of BAP. Mature fruits were collected from native plants and their seeds and embryos excised and used as explants. The results indicated that the most effective culture media used for the in vitro seed and embryo germination were MS and WPM 50%, both with no sucrose, presenting 60 and 100% germination, respectively. The use of BAP is not required for in vitro embryo germination.