Transcriptome analysis of female and male flower buds of Idesia polycarpa Maxim. var. vestita Diels

Background: Idesia polycarpa Maxim. var. vestita Diels, a dioecious plant, is widely used for biodiesel due to the high oil content of its fruits. However, it is hard to distinguish its sex in the seedling stage, which makes breeding and production problematic as only the female tree can produce fruits, and the mechanisms underlying sex determination and differentiation remain unknown due to the lack of available genomic and transcriptomic information. To begin addressing this issue, we performed the transcriptome analysis of its female and male flower. Results: 28,668,977 and 22,227,992 clean reads were obtained from the female and male cDNA libraries, respectively. After quality checks and de novo assembly, a total of 84,213 unigenes with an average length of 1179 bp were generated and 65,972 unigenes (78.34%) could be matched in at least one of the NR, NT, Swiss-Prot, COG, KEGG and GO databases. Functional annotation of the unigenes uncovered diverse biological functions and processes, including reproduction and developmental process, which may play roles in sex determination and differentiation. The Kyoto Encyclopedia of Genes and Genomes pathway analysis showed many unigenes annotated as metabolic pathways, biosynthesis of secondary metabolites pathways, plant­ pathogen interaction, and plant hormone signal transduction. Moreover, 29,953 simple sequence repeats were identified using the microsatellite software. Conclusion: This work provides the first detailed transcriptome analysis of female and male flower of I. polycarpa and lays foundations for future studies on the molecular mechanisms underlying flower bud development of I. polycarpa.

Estaquia caulinar de guaçatonga (Casearia sylvestris Swartz) nas quatro estações do ano, com aplicação de diferentes concentrações de AIB / Stem cuttings of "guaçatonga" (Casearia sylvestris Swartz) in the four seasons of the year with the use of different IBA concentrations

Casearia sylvestris Swartz (Salicaceae) ou guaçatonga é uma árvore nativa do México, da América Central, e da América do Sul, com grande importância ecológica, farmacológica, e comercial. No entanto, como a maioria das espécies nativas de interesse medicinal no Brasil, a guaçatonga não é cultivada comercialmente, sendo obtida por extrativismo. O presente trabalho foi conduzido com o objetivo de testar um protocolo de propagação vegetativa de guaçatonga por meio da estaquia, visando identificar qual a melhor estação do ano para o enraizamento de estacas e avaliar o efeito da utilização do regulador vegetal ácido indolbutírico (AIB). No outono, inverno e primavera de 2007, e no verão de 2008, estacas caulinares semilenhosas de 12-14 cm de comprimento e com duas folhas foram preparadas e tratadas com AIB (0, 1000, 2000 e 3000 mg L-1), em solução alcoólica, através da imersão rápida por 10 segundos da base das estacas, e foram plantadas em tubetes contendo substrato Plantmax HT® em casa-de-vegetação sob nebulização intermitente. O delineamento experimental utilizado foi o inteiramente casualizado, com 4 repetições, 4 tratamentos, e 16 estacas por parcela. Todos os experimentos foram avaliados após 90 dias, sendo que para dois deles (primavera 2007 e verão 2008) prolongou-se o tempo de permanência em casa-de-vegetação para melhor desenvolvimento das raízes. Foram avaliados os parâmetros: porcentagem de estacas enraizadas, porcentagem de estacas vivas (com calos e sem raízes, sem calos e sem raízes), porcentagem de folhas retidas, porcentagem de estacas mortas, número de raízes, comprimento das três maiores raízes (cm), e média da massa seca das raízes (mg). Não ocorreu enraizamento nas estacas retiradas no outono e no inverno. Com as estacas retiradas na primavera obteve-se 39,1% de enraizamento. Estacas coletadas no verão não responderam como o esperado, apresentando, após 240 dias, 6,3% de enraizamento no tratamento com 3000 mg L-1 de AIB. O AIB até 3000 mg L-1 não estimulou o enraizamento de estacas de guaçatonga e a melhor estação do ano para a estaquia é a primavera.

Casearia sylvestris Swartz (Salicaceae), or "guaçatonga", is a tree native to Mexico and Central and South America, with great ecological, pharmacological and commercial relevance. Similarly to most native species of medicinal interest in Brazil, "guaçatonga" is not commercially cultivated and is obtained by means of extraction. The aim of this study was to test a protocol for the vegetative propagation of "guaçatonga" by means of stem cutting, identifying the best season for stem rooting and assessing the effect of using the growth regulator indolebutyric acid (IBA). In the fall, winter and spring 2007 and summer 2008, semi-hardwood cuttings with 12-14 cm length and two leaves were prepared and treated with IBA (0, 1000, 2000 and 3000 mg L-1), in alcohol solution, by rapidly immersing for 10 seconds the base of cuttings and planting them in tubes containing Plantmax HT® in greenhouse under intermittent nebulization. Experimental design was completely randomized with 4 replicates, 4 treatments and 16 cuttings per plot. All experiments were evaluated after 90 days, and for two of them the time of maintenance in greenhouse was prolonged in order to improve root development. The following parameters were evaluated: percentage of rooted cuttings, percentage of live cuttings (with callus and without roots, without callus and without roots), percentage of retained leaves, percentage of dead cuttings, number of roots, length of the largest roots (cm) and mean dry mass of roots (mg). There was no rooting on cuttings collected during the fall and the winter. For cuttings collected in the spring, 39.1% rooting was obtained. Cuttings collected in the summer did not show the expected results, presenting after 240 days 6.3% rooting when treated with 3000 mg L-1 IBA. Up to 3000 mg L-1, IBA did not stimulate the rooting of "guaçatonga" cuttings and the best season for cutting is spring.