Nilton César Mantovani

RESGATE VEGETATIVO POR ALPORQUIA DE GENÓTIPOS ADULTOS DE URUCUM (Bixa orellana L.)

This study aimed to evaluate the usefulness of an air layering technique for vegetative rescue of annatto ( Bixa orellana L.) genotypes and obtainment of propagules for vegetative propagation. Ten 12 year-old annatto stock plants, whose genotypes are derived from artificial crossing between “Hairy-green capsule” X “Smooth-red capsule” were used in this study. Air layering adventitious roots were induced in branches (1-2 cm diameter) using as substrate a mixture of vermiculite and moss. The effects of (1) the type of girdling (total or partial), 1 cm in length, (2) IBA (indole-3-butyric acid at 0 and 4.92 mM) solution in paper filter and (3) the covering with either transparent or dark plastic films and tencel were evaluated. The technique of air layering provided rooted branches for the 10 genotypes evaluated, with efficiency ranging from 20 to 100%, and a genotype effect was observed on rooting frequency. Under greenhouse conditions, the survival of layers derived from totally girdled stems treated with IBA and protected with transparent plastic was 100%. Established layers provided vigorous branching from which shoot apexes or nodal segment explants were obtained for in vitro establishment and propagation of this species.

AVALIAÇÃO DE GENÓTIPOS DE URUCUM ( Bixa orellana L.) POR MEIO DA CARACTERIZAÇÃO MORFOLÓGICA DE FRUTOS, PRODUTIVIDADE DE SEMENTES E TEOR DE BIXINA

Bixa orellana L. (urucum) e considerada uma fonte importante de corantes naturais para as industrias alimenticia, farmaceutica e textil, sendo o Brasil um dos maiores produtores e exportadores do corante extraido das sementes desta planta. O objetivo deste trabalho foi a caracterizacao morfologica de frutos, a avaliacao da produtividade de sementes e do teor do carotenoide bixina presente nas sementes recem- colhidas e armazenadas por periodos de 30, 60, 90 e 120 dias, realizada em 10 genotipos de urucum, a fim de fornecer subsidios para a selecao de genotipos superiores para estas caracteristicas. Houve variacao em todas as caracteristicas avaliadas entre os 10 genotipos. Os frutos, de todos os genotipos, sao recobertos por cerdas ou pelos, apresentam coloracao avermelhada, verde, amarela ou vermelha e duas formas basicas, oval ou lanceolada. Os frutos apresentaram comprimentos medios que variaram entre 3,1 a 4,8 cm e larguras entre 2,4 a 3,1 cm. O numero medio de sementes por fruto variou de 41,5 a 50,6. A massa de 100 sementes variou de 1,1 a 2,24 g. Houve significativa diferenca na concentracao de bixina entre os genotipos, sendo possivel identificar genotipos com altos niveis deste carotenoide (5,05 %), superior aos ja relatados por outros estudos. O teor de bixina decresceu com o aumento no periodo de armazenamento das sementes.

In vitro shoot induction and multiplication from nodal segments of adult Ginkgo biloba plants

The in vitro performance of herbaceous and woody nodal segments from adult plants and the effect of hydrolyzed casein (HC 500 mg L-1), kinetin (KIN; 6-furfurylaminopurine 0.46 and 4.65 µM) and activated charcoal (AC 1.5 g L-1) were evaluated upon new shoots induction and development, and to establish a system of in vitro propagation from adult plants of Ginkgo biloba. Woody nodal segments did not produce axillary shoots and presented 100% of bacterial and fungal contamination in culture. However, nodal segments from herbaceous shoots were successfully disinfected and displayed high in vitro morphogenic capacity. The HC was essential for the axillary shoots induction and further multiplication, stimulating shoot formation in 85% of the cultured nodal segments and multiple shoots induction in 35% of them at establishment stage. During the multiplication stage, 66.6% of propagules formed new shoots and 33.3% of them formed multiple shoots when cultured with HC. The KIN and AC inhibited the organogenic process in ginkgo. Two distinct patterns of sprouts development were observed in vitro, similar to what occurs in vivo: 1) short shoots with crowded internodes and expansion of only a few leaves and slow growth; 2) long shoots with separated nodes and marked apical growth. This is the first report of multiple shoots in vitro formation in nodal segments obtained from adult plants of Ginkgo biloba.