Forty isolates of endophytic bacteria isolated from banana tree roots were assessed as to their capacity to solubilize phosphate in a solid culture medium supplemented with different inorganic and ...one organic source of phosphorus. The amount of phosphorus (P) in each liquid medium was quantified, and an indirect assessment of acid phosphatase activity was performed. All assays had a fully randomized design, with three repetitions. Approximately 67.5% of the 40 isolates assessed in solid medium solubilized phosphorus from tricalcium phosphate and 7.5% of the isolates solubilized phosphorus from soy lecithin; no isolates exhibited P solubilization capacity in medium supplemented with iron phosphate. Acid phosphatase activity was detected in 65% of the isolates; Aneurinibacillus sp. and Lysinibacillus sp. isolates presented with the best solubilization indexes. All of the assessed isolates exhibited a capacity to reduce the potential of hydrogen in liquid medium supplemented with tricalcium phosphate. Isolate EB. 78 (Bacillus sp.) exhibited P solubilization capacity in solid media when Ca3(PO4)2 and soy lecithin were used as P sources; this isolate significantly reduced the pH of the liquid medium and exhibited acid phosphatase activity. The results of the present study highlight isolates that exhibit variations in their capacity to solubilize P. These isolates should be used in future tests to assess their field performance.
Adenium obesum
(Forssk.) Roem. & Schult. is an important plant for the floriculture sector. Detailed information on floral structures is scarce and important for breeding programs, especially ...considering the great phenotypic variability. The objective of this study was to describe the floral events, morphology and anatomy of three
A. obesum
(Forssk.) Roem. & Schult. accessions (ICA-rt, ICA-wd and ICA-ps) relating these traits to the ornamental value and to species propagation. The accessions bloomed throughout most of the evaluation period, and their flowers opened during the morning. The time elapsed from initiation until the opening of the bud ( ≈ 32 days), as well as the floral longevity ( ≈ 27 days), was longest for ICA-rt accession. The morphological and anatomical analysis detected phenotypic diversity in
A. obesum
(Forssk.) Roem. & Schult. Variations in the reproductive organs, levels and types of male sterility, as well as a reduced female fertility, were reported. Hercogamy and functional dioecy were registered. The high floricultural potential of ICA-rt accession was identified, in view of its morphological, morphometric and floral longevity features. These results may inspire several new studies on
A. obesum
(Forssk.) Roem. & Schult. in the fields of applied genetics and plant breeding.
Abstract Adenium obesum belongs to the Apocynaceae family and is characterized as a succulent shrub with a multitude of botanical and morphological features of ornamental interest. The aim of this ...study was to evaluate the genetic dissimilarity of 28 accessions of A. obesum using morphological descriptors and multivariate techniques with the aim of pre-selecting the genotypes with the greatest ornamental potential. The distribution of the number of flowers throughout the year showed two flowering peaks in January and September. Twenty-one petal pigmentation patterns were identified, and 50% of the accessions had double-petal arrangement. The Gower’s algorithm and the UPGMA-generated dissimilarity matrix indicated the formation of three groups. While Tocher’s clustering method separated the accessions into eight groups showing greater ability to distinguish the evaluated genotypes. In conclusion, the multivariate analyses applied were effective in accessing the genetic diversity among the 28 accessions evaluated. The accessions ICA001, ICA005, ICA006, ICA018, ICA019, and ICA027 were preselected to compose the germplasm collection due to their high ornamental potential.
Resumo Adenium obesum, conhecida popularmente como rosa-do-deserto, pertence à família Apocynaceae e caracteriza-se por ser um arbusto suculento, com uma infinidade de aspectos botânicos e morfológicos de interesse ornamental. Objetivou-se no presente estudo avaliar a dissimilaridade genética de 28 acessos de A. obesum por meio de descritores morfológicos e técnicas multivariadas com objetivo de pré-selecionar os genótipos com maior potencial ornamental. A distribuição do número de flores durante os meses do ano demonstrou dois picos de florescimento em janeiro e em setembro. Vinte e um padrões de pigmentação petalar foram identificados e 50% dos acessos apresentaram 10 pétalas por flor (arranjo petalar duplo). Considerando os dados mistos, o algoritmo de Gower juntamente com a matriz de dissimilaridade gerada pelo método UPGMA indicou a formação de três grupos. O agrupamento de Tocher separou os acessos em oito grupos. Conclui-se as análises multivariadas aplicadas foram eficazes em acessar a diversidade genética entre os 28 acessos avaliados. Os acessos ICA001, ICA005, ICA006, ICA018, ICA019 e ICA027 foram pré-selecionados para comporem a coleção de germoplasma por apresentarem alto potencial ornamental.
•ISSR detected medium to high variability in the evaluated full-sib families of J. curcas.•UPGMA dendrogram grouped all the accessions into four clusters.•The 108 full-sib accessions of the Jatropha ...curcas showed a mean distance of 61%.•Most of the genetic variations existed within families and family 1 is the most divergent.
The aim of this study was to evaluate the genetic diversity between and within of six full-sib families of Jatropha through ISSR molecular markers. Six genitors were selected based on oil and seed potentiality. A set of 20 ISSR markers was used. The genetic distances were estimated based on Jaccard similarity coefficient and the descriptive statistics of populations for estimation of genetic parameters were also performed. A total of 177 polymorphic bands were obtained. The polymorphism within full-sib families ranged from 22 to 51.6% for families 2 and 5, respectively. The similarity analysis between families presented an average distance of 61%. The effective number of alleles varied from 0.56 to 1.86. The lowest value for Nei’s gene diversity index was 0.34 and the largest was 0.46 and the Shannon information index ranged from 0.51 to 0.65. The genetic variability analysis, by ISSR molecular markers showed low genetic dissimilarity within of full-sib families of Jatropha. However, the evaluation between the full-sib families demonstrated that the accessions belonging to family 1 are the most divergent, and should be considered in future artificial hybridations strategies.
The aim of this work was to evaluate the effect of 40 endophytic bacteria isolates on the control of
in ‘Prata-Anã’ banana seedlings. Two experiments were carried out in a completely randomized ...design with eight replicates. In each trial, 20 bacteria isolates and control were evaluated. Bacterial suspensions were applied to substrates during the acclimatization of seedlings at 15 and 30 days. On the 31st day, seedlings were transplanted into pots and soil was infested with
egg suspension at 8 days. After 90 days, the following variables were evaluated: number of galls, egg masses, eggs per root, reproduction factor (RF), second-stage juveniles, and shoot dry matter. The results of nematological variables were submitted to Principal Components Analysis. In trial I, the variables that most contributed to data variability were as follows: number of eggs and RF. In trial II, RF had greater influence. Of the 40 isolates evaluated, 39 reduced RF, and of the 20 isolates evaluated in the first trial, all reduced the number of eggs per root.
EB26,
EB25, and
sp. EB37 isolates stood out in the control of nematodes, with RF reduction above 80%.
A total of 40 endophytic bacterial isolates obtained from banana tree roots were characterized for their biotechnological potential for promoting banana tree growth. All isolates had at least one ...positive feature. Twenty isolates were likely diazotrophs and formed pellicles in nitrogen-free culture medium, and 67% of these isolates belonged to the genus
Bacillus
sp. The isolates EB-04, EB-169, EB-64, and EB-144 had N fixation abilities as measured by the Kjeldahl method and by an acetylene reduction activity assay. Among the 40 isolates, 37.5% were capable of solubilizing inorganic phosphate and the isolates EB-47 and EB-64 showed the highest solubilization capacity. The isolate EB-53 (
Lysinibacillus
sp.) had a high solubilization index, whereas 73% of the isolates had low solubilization indices. The synthesis of indole-3-acetic acid (IAA) in the presence of L-tryptophan was detected in 40% of the isolates. The isolate EB-40 (
Bacillus
sp.) produced the highest amount of IAA (47.88 μg/ml) in medium supplemented with L-tryptophan and was able to synthesize IAA in the absence of L-tryptophan. The isolates EB-126 (
Bacillus subtilis
) and EB-47 (
Bacillus
sp.) were able to simultaneously fix nitrogen, solubilize phosphate and produce IAA
in vitro
. The results of this study demonstrated that the isolates analyzed here had diverse abilities and all have the potential to be used as growth-promoting microbial inoculants for banana trees.
The banana tree is associated with different species of endophytic bacteria that can stimulate plant growth. However, further studies are needed to better understand the relationships between this ...group of bacteria and the host plant. The objective of this study was to investigate the localization of the EB-40 (Bacillus sp.) through anatomical and ultrastructural analyses in micropropagated banana plantlets. The results demonstrated the effective colonization of the EB-40 isolate in the intercellular and intracellular spaces, as well as in the rhizosphere region. The wall of endophytic bacteria contains calcium and nitrogen. The EB-40 isolate was also observed to associate with the plasma membrane and cell wall. These results further our understanding of the mechanisms involved in the colonization of plant cells by endophytic bacteria in micropropagated banana plantlets.
ABSTRACT Increased planting density, different types of thinning management, and the use of beneficial microorganisms have been adopted as strategic tools in the effort to increase crop yields in a ...sustainable manner. This investigation evaluated the growth and production of ‘Prata Anã Gorutuba’ banana ( Musa spp., AAB) under different plant densities during two production cycles in the semiarid region of Minas Gerais, Brazil. Micropropagated plantlets were also inoculated with endophytic bacteria and cultivated as part of two mat management strategies. Planting density varied between 1,680 and 3,920 plant ha–1. During the experiment, water was less than optimal because of rationing due to drought in the region. Under field conditions, there was no difference between bacterially inoculated and non-inoculated plants. The dense planting system increased the crop cycle. The highest-density planting treatment (3,920 plant ha–1) resulted in the highest yield in the first cycle, but no net income was observed. However, the high-density planting treatments resulted in the highest yields and gross incomes in the second production cycle. Management with thinning of plants up to 10-months-old and thinning up to harvest associated with high planting density increased the length of the production cycles. Although the water restriction experienced in the first and second crop cycles, the vegetative and productive traits of ‘Prata Anã Gorutuba’ banana did not compromise the objectives of this study.
The present research aimed to evaluate the effect of applying gibberellic acid (GA3) with hand (HP) or natural pollination (NP) on fruit set and the fruit quality of ‘Red’ and ‘Lessard Thai’ sugar ...apple and ‘Gefner’ atemoya fruits.This study was performed in an experimental orchard located in Homestead, Florida, USA. The experimental design included randomized blocks, with eight treatments, four replicates and four plants per plot. Treatments included: (1) HP; (2) HP + 10 mg L-1 GA3; (3) HP + 100 mg L-1 GA3; (4) HP + 1,000 mg L-1 GA3; (5) NP; (6) NP + 10 mg L-1 GA3; (7) NP + 100 mg L-1 GA3 and (8) NP + 1,000 mg L-1 GA3. The HP plus 1,000 mg L-1 GA3 promoted fruit setting above 90% over the 14 weeks for all genotypes evaluated. Significant increments for length and total fruit weight were observed. ‘Red’ sugar apple and atemoya had a reduced number of seeds per fruit. The NP plus GA3 (1,000 mg L-1) was effective in producing high quality seedless ‘Gefner’ atemoya fruits. This investigationdemonstratedthat GA3 plus hand pollination produced high quality sugar apple and atemoya seeded fruits and in association with natural pollination promoted seedless ‘Gefner’atemoya fruits.
RESUMO: O presente trabalho teve como objetivo avaliar o efeito da aplicação de ácido giberélico (GA3) associado com e sem polinização artificial, no pegamento e na qualidade de frutos das pinheiras ‘Red’ e ‘Lessard Thai’ e da atemoieira‘Gefner’. O experimento foi realizado em pomar localizado em Homestead, EUA. O delineamento experimental foi em blocos casualizados, com oito tratamentos, quatro repetições e quatro plantas por parcela. Os tratamentos utilizados neste experimento foram: 1) Polinização Artificial (PA); 2) PA + 10 mg L-1 GA3; 3) PA + 100 mg L-1 GA3; 4) PA + 1000 mg L-1 GA3; 5) Polinização natural (PN); 6) PN + 10 mg L-1 GA3; 7) PN + 100 mg L-1 GA3; e 8) PN + 1000 mg L-1 GA3. A PA combinada com a concentração de 1000 mg L-1 de GA3 promoveu o estabelecimento de frutos acima de 90% durante as 14 semanas de avaliação para todos os genótipos avaliados. Incrementos significativos para o comprimento e peso dos frutos também foram observados a variedade de pinha “Red” e a atemoia, em que apresentaram redução no número total de sementes.A PN em associação com GA3 (1000 mg L-1) foi eficaz na produção de frutos sem sementes de alta qualidade em atemóia ‘Gefner. Estes dados mostram que o GA3, combinado com a polinização manual, produziu frutos com semente de alta qualidade e, em associação com a polinização natural, promoveu frutos sem sementes em atemóia ‘Gefner’.
PDF
