Desenvolvimento de mudas de guanandi (Calophyllum brasiliens Cambess.) sob diferentes condições de sombreamento

Guanandi is a tree species greatly valued for its wood and widely used in mixed reforestation programs in degraded riparian forests. We aimed to evaluate the relationship between the initial development of the species saplings and shading levels, by analyzing variations in the concentration of chlorophylls (a/b), carotenoids, and foliar nitrogen, as well as biomass accumulation. Treatments with intermediary shading (30% and 50%) resulted in increased height and increased stem secondary growth. The lowest foliar nitrogen content was found in saplings grown under 70% shading. Saplings grown under 50% shading showed lower levels of chlorophyll a than of chlorophyll b, and consequently a lower chlorophyll a/b ratio than plants subjected to the other treatments. Overall, the best vegetative performance was observed in saplings grown under 30% and 50% shading. The full-sun growth condition is not recommended for the initial development of guanandi saplings.Guanandi é uma espécie arbórea muito utilizada na obtenção de madeira e em programas de reflorestamentos mistos de matas ciliares degradadas. Objetivou-se caracterizar o desenvolvimento de mudas sob diferentes níveis de sombreamento, pleno sol, 30%, 50% e 70%, avaliando-se características físicas e químicas das plantas. Tratamentos com sombreamento intermediário (30% e 50%) foram os que exibiram as plantas com maior altura e crescimento secundário de caule. Menor teor de nitrogênio foliar foi encontrado em mudas a 70% de sombreamento. Já as mudas crescidas em 50% de sombreamento mostraram menores valores de clorofila a do que de clorofila b, com menor relação clorofila a/b. O melhor desempenho vegetativo das mudas foi obtido sob 30% e 50% de sombreamento, sendo a condição de pleno sol não recomendada para a formação de mudas da espécie

Morphological and Physiological Germination Aspects of Anadenanthera colubrina (Vell.) Brenan

Anadenanthera colubrina is a species native to Brazil, from the Fabaceae family and has potential for use in the timber industry, in the reforestation of degraded areas, besides having medicinal properties. Its propagation is mainly by seeds, but basic subsidies regarding the requirements for optimal germination conditions are still lacking. Aiming to contribute to the expansion of its cultivation, rational use and conservation, the objective of this study was to investigate the morphology and anatomy of fruits and seeds, as well as the responses to factors as thermal regimes and substrates in seed germination. The 1000-seed weight and seeds per fruit were determined. To characterize the seed tissues, histochemical test with Sudan III and Lugol was used. The temperatures analyzed in the germination test were 15-25 C; 25 C; 20-30 C and 30 C. Different substrates for germination (paper rolls, paper sheet such as germitest, commercial substrate and sand) were also analyzed in the presence of light at 30 C. The average number of seeds per fruit is 10 and the 1000-seed weight is 118 g. Germination is fast and high over a wide temperature range; however, the temperature of 25 C contributes to a substantial increase in the percentage of abnormal seedlings and dead seeds, both in the absence and presence of light. A. colubrina seeds are indifferent to light and the highest vigor was verified at 30 C. Sand and commercial substrates are efficient in initial seedling development