3 research outputs found
BactĂ©rias endofĂticas promotoras de crescimento de plantas em mudas de pupunheira
The objective of this work was to isolate endophytic bacteria from peach palm (Bactris gasipaes var. gasipaes) plants and to evaluate the effects of their inoculation on the plant seedlings. Bacteria were isolated from the leaves and roots of the seedlings and from the meristems of peach palm plants in vitro. The isolates were characterized phenotypically and, then, 15 of them, representing different phenotypic groups, were selected and identified by partial sequencing of the 16S rRNA gene. Afterward, these isolates and two commercial strains of Azospirillum brasilense (Ab-V5 and Ab-V6) were inoculated in the peach palm seedlings. After 76 days, the seedlings were evaluated for plant development. The following six genera were identified based on the sequencing: Pseudomonas, Enterobacter, Rhizobium, Stenotrophomonas, Klebsiella, and Erwinia. Out of the 15 inoculated isolates, 9 had a positive effect on the root dry mass of palm peach, with CNPF 77 (Enterobacter sp.), CNPF 100 (Rhizobium sp.), and CNP 179 and CNPF 277 (Stenotrophomonas sp.) standing out. Peach palm seedlings harbor endophytic bacteria which are able to increase root dry matter.O objetivo deste trabalho foi isolar bactĂ©rias endofĂticas de pupunheira (Bactris gasipaes var. gasipaes) e avaliar os efeitos da inoculação delas em mudas da planta. As bactĂ©rias foram isoladas de folhas e raĂzes das mudas e de meristemas de pupunheira in vitro. Os isolados foram caracterizados fenotipicamente, e, depois, 15 deles, representando grupos fenotĂpicos distintos, foram selecionados e identificados por meio do sequenciamento parcial do gene 16S rRNA. Em seguida, esses isolados e duas estirpes comerciais de Azospirillum brasilense (Ab-V5 e Ab-V6) foram inoculados em plântulas de pupunheira. ApĂłs 76 dias, as mudas foram avaliadas quanto ao desenvolvimento vegetal. Foram identificados os seis seguintes gĂŞneros com base no sequenciamento: Pseudomonas, Enterobacter, Rhizobium, Stenotrophomonas, Klebsiella e Erwinia. Dos 15 isolados inoculados, 9 tiveram efeito positivo sobre a massa de matĂ©ria seca de raĂzes, com destaque para CNPF 77 (Enterobacter sp.), CNPF 100 (Rhizobium sp.), e CNP 179 e CNPF 277 (Stenotrophomonas sp.). Mudas de pupunheira abrigam bactĂ©rias endofĂticas capazes de aumentar a matĂ©ria seca das raĂzes
Resgate vegetativo e propagação de cedro‑australiano por estaquia
The objective of this work was to evaluate vegetative rescue methods for the production of cuttings (clearcutting, full annealing, and half‑annealing) of red cedar (Toona ciliata var. australis) mature trees. The number of produced shoots was evaluated at 60, 120 and 180 days, as well as the correlation between stem mean diameter at breast height (DBH) and the number of sprouts. From the resulting sprouts of each method, cuttings were produced and subjected to cutting and removal of leaflets, and then received the application of indolbutyric acid (IBA) (0 and 6,000 mg L‑1). Evaluations were made for the influence of the following factors on plant survival and rooting: rescue method, collection time, number of leaflets of cuttings, and matrix tree, in the presence and absence of IBA. There was no correlation between the DBH of trees and the number of produced shoots. Clearcutting at 120 days provided the highest increase of shoots (15.31). Cuttings obtained from half‑annealing had higher survival (57.8%) and rooting (55.5%) rates. Cuttings with two pairs of preserved leaflets and treated with 6,000 mg L‑1 IBA showed higher rates of survival (65.5%) and rooting (56.7%). There was wide variation in survival and rooting capacity among matrix trees. The vegetative rescue and propagation by cuttings have potential for clonal multiplication of Australian red cedar mature trees.O objetivo deste trabalho foi avaliar mĂ©todos de resgate vegetativo para a produção de estacas (corte raso, anelamento total e semianelamento) de árvores adultas de cedro-australiano (Toona ciliata var. australis). Avaliou-se o nĂşmero de brotos produzidos aos 60, 120 e 180 dias, bem como a correlação entre o diâmetro mĂ©dio do tronco Ă altura do peito (DAP) e o nĂşmero de brotos. Com as brotações resultantes de cada mĂ©todo, produziram-se estacas que foram submetidas Ă retirada e ao corte de folĂolos, e entĂŁo receberam a aplicação de ácido indolbutĂrico (AIB) (0 e 6.000 mg L‑1). Avaliou-se a influĂŞncia dos fatores mĂ©todo de resgate, tempo de coleta, nĂşmero de folĂolos das estacas e planta matriz, em presença e ausĂŞncia de AIB, na sobrevivĂŞncia e no enraizamento das estacas. NĂŁo houve correlação entre o DAP das árvores e o nĂşmero de brotações. O corte raso aos 120 dias proporcionou a maior produção de brotos (15,31). Estacas obtidas do semianelamento apresentaram maior sobrevivĂŞncia (57,8%) e enraizamento (55,5%). Estacas com dois pares de folĂolos inteiros e tratadas com 6.000 mg L‑1 de AIB apresentaram maior sobrevivĂŞncia (65,5%) e enraizamento (56,7%). Houve grande variação na sobrevivĂŞncia e no enraizamento entre plantas matrizes. O resgate vegetativo e a estaquia apresentam potencial para multiplicação clonal de árvores adultas de cedro‑australiano
EPICORMIC SHOOTS INDUCTION AND ROOTING CUTTINGS OF Calophyllum brasiliense
Calophyllum brasiliense is present in a wide natural distribution range in Brazil and its monopodial growth, with a rectilinear stem and a moderately dense timber has attracted the attention from the logging industry in recent decades. In the meantime, the lack of efficient rescue and vegetative propagation methods of adult plants has been a narrowing condition for the selection of superior genotypes in breeding programs of the species. Therefore, we evaluate epicormic shoots induction methods and the rooting cuttings of 14 year-old Calophyllum brasiliense trees. From this scope, three methods of epicormic shoots induction were evaluated: coppicing, girdling and partial girdling. We evaluate the number of produced sprouts and the percentage of sprouted trees at 06, 12 and 15 months’ after the experiment installation. Results have indicated the feasibility of Calophyllum brasiliense vegetative rescue by cuttings method using epicormic shoots induced by coppicing and girdling. In contrast, partial girdling was not effective in epicormic shoots emission. Concerning adventitious roots, the sprouting technique had no influence in the rooting of cuttings, showing variation among the different stock plants