The characteristics of petal epidermal conical cells affect the quality of the signals perceived by various pollinators. This study aimed to identify variations in micromorphological characteristics of flower petals and their relationship to melittophily, ornithophily and chiropterophily pollination systems. The petals of 11 species were analysed using scanning electron microscopy and optical microscopy and the micromorphological traits were described, measured and compared using Tukey's test, PCA and cluster analysis. Unlike chiropterophily, all melittophilous and some ornithophilous species possessed adaxial epidermal conical cells. Cluster grouping separated chiropterophilous flowers from melittophilous and ornithophilous. PCA analysis showed that the two morphometric profile of conical cells was the attribute that most strongly influenced the grouping of species. When considering the data set of the three pollination systems, melittophilous and ornithophilous plants were more similar to each other than they were to chriopterophilous species. The distance between conical cell apices is an important parameter in interactions with pollinators. This study facilitated recognition of smoothing pollinator resource access through petal micromorphological characteristics. Further research regarding the biometry of micromorphological traits related to pollination is required.

O objetivo deste trabalho foi avaliar a germinação e a organogênese in vitro em Gongora quinquenervis em dois meios nutritivos, Knudson "C" e Murashige & Skoog, com três concentrações de BAP (0,0, 0,5 e 1,0 mg L-1). Os protocormos cultivados no meio Knudson "C" necrosaram. A maioria dos embriões cultivados em meio Murashige & Skoog tendeu a diferenciar-se em calos. Estes calos apresentaram alto potencial morfogenético, regenerando grande número de plantas via organogênese indireta, sobretudo no material proveniente do tratamento desprovido de BAP. Foram formadas 41 plantas pela rota normal de germinação, contrastando com 715 plantas regeneradas via organogênese indireta.

Woody plant resprouting has received considerable attention in the last two decades as human disturbances continue to encroach on terrestrial ecosystems globally. We examined the regeneration mechanisms of a Caatinga dry forest in the context of slash-and-burn agriculture and resprouting ability of the local flora. We excavated two old fields (from 32) experiencing early forest regeneration dominated by the tree Pityrocarpa moniliformis (Fabaceae) to map clonal propagation and, in parallel, submitted 260 seedlings from 13 woody plant species to experimental clipping. What seemed to be ‘seedlings’ popping up around P. moniliformis stumps and remaining adults actually were condensed sets of root suckers connected via complex networks of long, ramified shallow horizontal roots without taproots. We mapped respectively 39 and 783 connected root suckers, which summed 96 m and 910 m in root length. Regarding the seedlings, 33% resprouted across nine species with resprouting rates varying between 5–100%. Seedling height before clipping positively influenced resprouting vigour. Our preliminary results suggest that the Caatinga dry forest supports a relatively high proportion of resprouting species, some of them able to clonally propagate and playing an ecosystem-level role by responding to early forest regeneration and high abundance/biomass across both regenerating and old-growth forests.

RESUMO: Quatro genótipos de milho (Zea mays L.), Jatinã C3 anão, BR-201, V-190 e LW-1, foram avaliados quanto à tolerância ao estresse salino (0, 50 e 100 mM NaCl) em condições hidropônicas. As plantas submetidas a 100 mM de NaCl durante 29 dias apresentaram uma redução na produção de matéria seca superior a 50%, e uma redução na área foliar superior a 75%, quando comparadas ao tratamento controle (0 mM NaCl). Dentre os quatro genótipos estudados, a linha pura LW-1 apresentou produção de matéria seca e área foliar inferiores aos demais. O aumento dos níveis de sal na solução resultou em uma diminuição da taxa de crescimento da parte aérea e da raiz, de todos os genótipos. O sistema radicular apresentou os maiores teores de sódio e também os maiores decréscimos na taxa de crescimento relativo, evidenciando o efeito negativo da acumulação deste cátion. O número e o tamanho dos estômatos não sofreram alterações em conseqüência do estresse salino. Palavras-chave: salinidade, tolerância, taxa de crescimento, área foliar RESPONSE OF MAIZE GENOTYPES TO SALINE STRESS IN HYDROPONIC CONDITIONSABSTRACT: Four maize (Zea mays L.) genotypes, Jatinã C3 anão, BR-201, V-190 and LW-1, grown under hidroponic conditions, were evaluated for their tolerance to saline stress imposed by three salt levels (0, 50 and 100 mM NaCl). Plants submitted to 100 mM NaCl for 29 days had 50% lower dry matter production and 75% reduced leaf area, as compared to the control (0 mM NaCl) plants. Among the four genotypes studied, LW-1, a pure line, produced the least dry matter and leaf area. The increase salt levels in solution decreased the growth rate of both shoot and root in all genotypes. Roots had the largest sodium concentration and also showed the largest decrease in the relative growth rate, demonstrading the negative effect of sodium accumulation. The number and size of the stomata were not affected by saline stress.

Amburana cearensis (Allemao) A.C. Smith is a widely used legume by the population due to its medicinal properties. This species establish symbiosis with the arbuscular mycorrhizal fungi (AMF) that can increase the production of secondary metabolites, a fact which has not been clarified for this plant. Therefore, the aim of this study was to examine the contribution of the AMF in the production increase of foliar bioactive compounds in A. cearensis seedlings. The experiment which under-goes protected roofing was carried out using four inoculation treatments: non-inoculated control treatment, inoculated with Gigaspora albida, inoculated with Claroideoglomus etunicatum and inoculated with Acaulospora longula. After 160 days, the following was examined: dry matter of the aerial part, chlorophylls a, b and total, soluble carbohydrates, total proteins, total phenols, total flavonoids and total tannins. A. cearensis seedlings inoculate with C. etunicatum accumulated more dry matter of the aerial part (78.38%), total chlorophylls (24.28%) and chlorophylls b (53.63%), total phenols (47.82%), total flavonoids (32.28%) and total tannins (61.58%) in relation to the control treatment. Mycorrhizal technology using the C. etunicatum fungus is an alternative to increase the levels of foliar bioactive compounds in A. cearensis seedlings.Key words: Caatinga, phenolic compounds, arbuscular mycorrhizal fungi (AMF). INTRODUCTIONArbuscular mycorrhizal fungi (AMF) are inhabitants of the soil and belong to the Phylum Glomeromycota (Schubler et al., 2001). Such organisms are obligatory symbionts because they complete their life-cycle only in the presence of a host plant (Souza et al., 2008). After the fungus has established on the root, the AMF absorb (Smith and Read, 2008).Various studies relate the benefits of mycorrhizal association with legumes and point out the increased vegetable growth and optimized production of primary (Manoharan et al., 2010) and secondary metabolites (Silva et al., 2014a;Nisha and Rajeshkumar, 2010;Kapoor et al., 2004).The increase in the production of secondary compounds in plants associated with AMF may be due to the increased nutritional supply (Toussaint et al., 2007), hormonal changes, enzymatic activation (Zhang et al., 2013) and increased activity of plastidial and mitochondrial pathways (Lohse et al., 2005), however, the effects seem to be somatory and multifactorial (Toussaint et al., 2007).The Caatinga is a biome that is rich in leguminous species with medicinal properties that are widely used by the local population as phytotherapeutic drugs (Agra et al., 2007(Agra et al., , 2008. Amburana cearensis is found among the medicinal plants of the Caatinga, a legume that is used by the local population. Parts of this plant, such as the stem, the seeds and bark are used in the production of pastilles, syrups and teas for the treatment of various diseases due to their antioxidant , antiinflammatory (Leal et al., 2008), antifungal (Santos et al., 2009), antibacterial (Figueiredo et al., 2013 and antineopl...