Growth Of Sugarcane Plants Research Articles

Exploitation of new endophytic bacteria and their ability to promote sugarcane growth and nitrogen nutrition.

Few studies have evaluated endophytic bacteria in relation to plant growth promotion, nitrogen uptake and biological control. The aim of this study was to molecularly and physiologically characterize thirteen endophytic bacteria strains, evaluate their biological control properties and their ability to promote plant growth and plant N nutrition. All the strains produced indole acetic acid and promoted increase of plant biomass, N accumulative amount and N-use efficiency index. None of the strains carries the nifH gene. Four strains stimulated plant nitrate reductase activity, four solubilized phosphate, nine produced siderophores and none produced HCN. Seven strains inhibited Bipolaris sacchari growth and one was antagonistic to Ceratocystis paradoxa. The pathogens were inhibited by the production of diffusible and volatile metabolites by the bacterial strains. Moreover, this is the first study to demonstrate the effect of Delftia acidovorans on sugarcane plant growth, nitrogen metabolism improvement and antagonism to B. sacchari. The most efficient strains in promoting plant growth and exhibiting antagonistic activities towards fungal pathogens were Herbaspirillum frinsingense (IAC-BECa-152) and three Pantoea dispersa strains (IAC-BECa-128, IAC-BECa-129, and IAC-BECa-132). These bacteria show potential to be used as inoculants for sustainable agricultural management, mainly at the seedling production phase.

Nitrogen fertilizer effect in production, nutrient accumulation and nitrogen efficiency use of second ratoon sugarcane harvested without straw burning

Sugarcane harvest after straw burning implies rapid mineralization of biomass and greenhouse gas emissions. In this context, maintenance of sugarcane straw on the soil is as a new strategy to circumvent the harmful environmental effects, but imposes a new dynamic regarding nitrogen in the soil-plant system. This study sought to evaluate the effect of nitrogen fertilization on biomass production and nutrient accumulation in leaf (senescent and young) and stalks of sugarcane plant from the second sugarcane ratoon, variety SP 83-2847, harvested mechanically in 2007 after six years without straw burning for six years. This study adopted a randomized block design with five nitrogen doses application (0, 60, 120, 180 and 240 kg ha-1) in the form of ammonium nitrate and four replications. Nitrogen fertilization promoted an increase in leaf (senescent and young) and stalk production of the sugarcane plants. However, excess nitrogen decreased accumulation of macro and micronutrients and nitrogen use efficiency by sugarcane due to dilution effect. Although straw deposition on the soil surface of the sugarcane field had occurred for six years, but mineralization of organic matter from the straw did not provide sufficient nitrogen for the growth of sugarcane plants in control treatments, requiring nitrogen application via fertilization. There is a need to adopt new nitrogen fertilization strategies in order to increase nitrogen use efficiency for greater production of sugarcane.

Selection and evaluation of reference genes for RT-qPCR expression studies on Burkholderia tropica strain Ppe8, a sugarcane-associated diazotrophic bacterium grown with different carbon sources or sugarcane juice.

Among the members of the genus Burkholderia, Burkholderia tropica has the ability to fix nitrogen and promote sugarcane plant growth as well as act as a biological control agent. There is little information about how this bacterium metabolizes carbohydrates as well as those carbon sources found in the sugarcane juice that accumulates in stems during plant growth. Reverse transcription quantitative PCR (RT-qPCR) can be used to evaluate changes in gene expression during bacterial growth on different carbon sources. Here we tested the expression of six reference genes, lpxC, gyrB, recA, rpoA, rpoB, and rpoD, when cells were grown with glucose, fructose, sucrose, mannitol, aconitic acid, and sugarcane juice as carbon sources. The lpxC, gyrB, and recA were selected as the most stable reference genes based on geNorm and NormFinder software analyses. Validation of these three reference genes during strain Ppe8 growth on the same carbon sources showed that genes involved in glycogen biosynthesis (glgA, glgB, glgC) and trehalose biosynthesis (treY and treZ) were highly expressed when Ppe8 was grown in aconitic acid relative to other carbon sources, while otsA expression (trehalose biosynthesis) was reduced with all carbon sources. In addition, the expression level of the ORF_6066 (gluconolactonase) gene was reduced on sugarcane juice. The results confirmed the stability of the three selected reference genes (lpxC, gyrB, and recA) during the RT-qPCR and also their robustness by evaluating the relative expression of genes involved in glycogen and trehalose biosynthesis when strain Ppe8 was grown on different carbon sources and sugarcane juice.

Weed management options for sugarcane-vegetable intercropping systems in north-western India

Sugarcane is an important crop in north-western India but due to its long duration annual economic returns tend to be lower than the dominant rice-wheat system. Intercropping of short duration crops in sugarcane could improve profitability and make it more attractive for growers. Sugarcane planted in the autumn season is more suitable for intercropping, as low temperature during winter slows down the growth of sugarcane plants. Therefore, suitability of short duration winter vegetables for intercropping in autumn planted sugarcane and the efficacy of herbicides for weed control in these intercropping systems was investigated over two years. Four cropping systems (sole sugarcane, sugarcane-cabbage, sugarcane-peas and sugarcane-garlic) and six weed control treatments were investigated during 2010–11 and 2011–12. Intercropping of sugarcane with peas, cabbage and garlic produced cane yield (75.3–88.3 t ha−1) similar to sole sugarcane (76.1–86.0 t ha−1) and intercrop yields of 6.28–6.57 t ha−1 for garlic, 7.45–7.88 t ha−1 for peas and 15.3–15.8 t ha−1 for cabbage. The intercropping of these vegetables in sugarcane increased the net monetary returns by 1.74–2.66 fold as compared to sole sugarcane (USD 1648 ha−1). Sugarcane-garlic intercrop had the highest net monetary returns of USD 4384 ha−1 and the highest benefit cost ratio of 2.45; net returns from intercropping of sugarcane with peas and cabbage varied from USD 2873–3094 ha−1. Pre-emergence application of oxyfluorfen 0.234 kg ha−1 and pendimethalin 0.75 kg ha−1 provided similar level of weed control to hand-weeding, and increased the yield of cabbage, peas and garlic than the weedy check. The use of herbicides increased the net returns by USD 229–725 ha−1 as compared to the weedy check.

Glyphosate Effects on Sugarcane Metabolism and Growth

Glyphosate is the most widely used herbicide in the world. In sugarcane, it is used as a herbicide when applied at its field rate, but it is also used as ripener when applied as low doses. However, the effects of glyphosate on plant metabolism and sugarcane growth are not fully understood. This study aimed to evaluate the metabolic changes and the effects on sugarcane plant growth caused by the application of different doses of glyphosate. Sugarcane plants were grown in a greenhouse and subjected to glyphosate applications at doses of 7.2; 18; 36; 72; 180; 360 and 720 g a.e. ha-1. Plants grown without an herbicide application were used as a control. Plants from each treatment were collected at 2, 7, 14, and 21 days after treatment (DAT) application to quantify the levels of shikimic acid, quinic acid, shikimate-3-phosphate, glyphosate, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), phenylalanine, tyrosine, and tryptophan. Visual evaluations of plant intoxication were performed at the same time as the collection of plants, and the quantification of their shoot dry biomass was performed at 21 DAT. At doses of glyphosate greater than 72 g a.e. ha-1, increases in the levels of shikimic acid, quinic acid, and shikimate-3-phosphate occurred and AMPA was detected in the plants. Initially, glyphosate caused increases in the plant levels of phenylalanine and tyrosine at doses of 72 and 180 g a.e. ha-1, although a decrease in the levels of aromatic amino acids subsequently occurred at and above the doses of 72 or 180 g a.e. ha-1. The doses ranging from 7.2 to 36 g a.e. ha-1 promoted an increase in plant shoot biomass, and doses greater than 72 g a.e. ha-1 caused significant reductions in dry mass.

Plant-parasitic nematodes in sugarcane fields in Kitadaito Island (Okinawa), Japan, as a potential sugarcane growth inhibitor

Sugarcane is the main industrial crop in Kitadaito Island (Okinawa), Japan, and the objective of this study was to estimate potential damage to sugarcane by plant-parasitic nematodes (PPN). We selected 15 sugarcane fields with the same cultivar and cropping type in Kitadaito Island. Various kinds of PPN were found in all the fields and the proportion of PPN to the total nematode number was ca 50%, which is relatively high compared to other Japanese upland fields. Lesion (Pratylenchus sp.), stunt (Tylenchorhynchus sp.) and spiral (Helicotylenchus sp.) nematodes were detected at mean densities of 48, 22 and 6 (20 g soil)−1, respectively, from all the fields, and lance (Hoplolaimus sp.) and ring nematodes from half of the fields. The results suggested that sugarcane fields in Kitadaito Island were ubiquitously infested with a variety of PPN with a relatively high abundance. One of the fields was studied further to examine the potential relationship between PPN and sugarcane plant growth. Since no nematicide is registered for sugarcane fields in Japan, an appropriate agrochemical was selected by testing its efficacy against PPN before evaluating the relationship between a PPN community and sugarcane growth. The results of a 10-week pot experiment for sugarcane growth showed that the number of PPN decreased by applying a nematicide fosthiazate, and that sugarcane seedling biomass was significantly greater by 34-63% in soils with applied nematicide than in non-applied control soils, suggesting that PPN may suppress sugarcane growth in Kitadaito Island.

Effect of Trash Addition to the Soil on Microbial Communities and Physico-Chemical Properties of Soils and Growth of Sugarcane Plants

Sugarcane trash addition to the soils was found to alter the structure of microbial communities in soil and increased the number of microbial colonies. The total number of bacterial, fungal and actinomycetes colonies was found to be increased by 2.38, 1.80 and 2.74 folds, respectively, in trash added soil as compared to the conventional one. Further, the addition of trash in soils increased its organic matter and available nutrients, improve the moisture and enhanced the pH, which led to improve physico-chemical properties of soil. Moreover, the trash addition promoted the growth of sugarcane plants, leading to 8.41 and 1.53 t per hectare increase in cane and sucrose yield, respectively. Therefore, the addition of trash to the sugarcane fields improved physico-chemical properties of soil by increasing moisture, organic matter and nutrient content and promoting microbial growth and activities which led to a significant increase in sugarcane production and economic benefits.

Isolation and Characterization of Phosphate-Solubilizing Bacteria from Rhizosphere Soil

ABSTRACTDifferent strains of phosphate-solubilizing bacteria (PSB) were isolated from the rhizosphere of different plants of Lahore District, Pakistan. The objective of the study was to explore the capabilities of PSB and evaluate their efficiency to enhance growth of sugarcane plants under greenhouse condition. The purified isolates were identified as Proteous vulgaris, Klebsiella pneumoniae, Enterobacter aerogenes, Burkholederi acepacia, Citrobacter freundii, Acinetobacter lwoffii, and Pseudomonas fluorescens, and the identification was based on the characteristic morphological and biochemical behavior. The efficiency of different PSB isolates for phosphate solubilization was evaluated from the zones they formed on agar plates of Pickovaskaya growth medium (PVK) by solubilizing the tricalcium phosphate of the medium. The efficiency of purified PSB was evaluated from pot experiments of two different genetically modified sugarcane varieties (SCMV resistant CAMB-I and CAMB-II) under greenhouse condition for their positive role in plant growth promotion. All the six PSB enhanced the growth rate significantly over that in the non-inoculated control. A significant increase in plant height, number of leaves, root length and dry matter contents was recorded and E. aerogenes and C. freundii were found significantly superior over the rest of the isolates for all the tested parameters. The efficiency gradient of different isolates for CAMB-I and CAMB-II varieties was recorded as C. freundii> K. pneumoniae> E. aerogenes> B. capacia> A. lwoffi> P. vulgaris and E. aerogenes> C. freundii> A. lwoffi> B. capacia> P. vulgaris, respectively. The results of this greenhouse evaluation are encouraging and need to be confirmed under field condition in combination with organic and chemical fertilizers.

Effect of exogenous application of ascorbic acid on antioxidant enzyme activities, proline contents, and growth parameters of Saccharum spp. hybrid cv. HSF-240 under salt stress

The present study was undertaken to examine the effects of exogenous application of ascorbic acid (AA) through different modes on growth and associated biochemical parameters in Saccharum spp. hybrid cv. HSF-240, under salt stress. In a pot experiment, AA was applied through irrigation or foliar-spray at the concentrations of 0.1, 0.5, and 1 mM with or without 100 mM NaCl concentration. Vegetative growth measurements, antioxidant enzyme activities (POD and SOD), and protein and proline contents of plants were recorded to study the effects of these treatments. The presence of salt reduced the growth of sugarcane plants. The AA application not only mitigated the inhibitory effects of salt stress but also induced a stimulatory effect on all the studied growth parameters. The activities of antioxidant enzymes (POD and SOD) as well as proline contents of plants were increased, although the protein contents were decreased after AA application. The exogenous application of AA through either way significantly alleviated the adverse effects of salinity on growth and biochemical parameters of sugarcane plants. However, in this study, the AA application through irrigation proved to be a better option in mitigating the adverse effects of salinity.

Omissão de macronutrientes na nutrição e no crescimento da cana-de-açúcar cultivada em solução nutritiva

Nutrients deficiency may limit the nutrition, growth and production of sugarcane. In this context, the objective of this work was to evaluate the growth, dry matter production, nutrient content and nutrients accumulation in sugarcane plants grown in nutritious solution, submitted to macronutrients omission, and to describe the visual symptoms of such omission. The experiment was carried out at the School of Agrarian and Veterinarian Sciences - Jaboticabal Campus, São Paulo, Brazil, with seven treatments (complete and with the omission of N, P, K, Ca, Mg and S), arranged in a completely randomized design, with three replications. Eleven weeks after the transplant to the nutrient solutions, the tiller number the fully developed leaves number, the height, the tillers diameter, the plant dry matter and the shoot and root macronutrient content of sugarcane were evaluated. N and P were the nutrients that limited the growth of sugarcane plants the most, with reductions of 91 and 57 %, respectively. However, regarding the root growth, the omission of N and Ca resulted in the greatest limitations, reducing the root growth in 83 and 48 %, respectively.

Assessing the in vitro zinc solubilization potential and improving sugarcane growth by inoculating Gluconacetobacter diazotrophicus

Gluconacetobacter diazotrophicus is an endophytic diazotroph of sugarcane that has been reported to possess various plant growth-promoting characteristics. We have assessed the zinc (Zn) solubilization potential of G. diazotrophicus isolates under in vitro conditions (plate and broth assay) with different Zn compounds (ZnO, ZnCO3, and ZnSO4) and by the improvement of sugarcane growth following inoculation. The soluble Zn present in the culture broth by inductively coupled plasma–optical emission spectrophotometry. All five isolates solubilized the tested Zn compounds, although there were variations in the solubilization potentials, and effectively solubilized ZnO over ZnCO3 or ZnSO4. The solubilization might be due to the production of acids, since the pH of the culture broth shifted during the solubilization of Zn compounds. The nitrogenase activity of the G. diazotrophicus isolates ranged between 80.3 and 125.3 C2H4 h-1 vial-1 (ethylene), which was much more efficient than the nitrogenase activity in micropropagated plants. The GaD-1 isolate was found to be the most efficient isolate in terms of Zn compound solubilization and promotion of sugarcane plant growth when compared to other isolates. The application of G. diazotrophicus isolates with efficient nitrogenase activity in sugarcane production systems may possibly result in the reduction of chemical N fertilizer usage and the cost of sugarcane production; there may also be a considerable increase in production of sugarcane.

SULFUR APPLICATION EFFECTS ON SOIL PROPERTIES IN A CALCAREOUS SOIL AND ON SUGARCANE GROWTH AND YIELD

High pH soils limit availability of pH sensitive nutrients including phosphorus (P), even though abundant levels are present. Application of such nutrients to the soil is ineffective because they quickly get tied up in unavailable forms. Elemental sulfur (S) application in a narrow band to lower root zone pH and increase nutrient availability to the crop is a possible economically feasible solution. A four year field study was conducted in which S was applied to sugarcane (Saccharum spp.) at rates up to 1120 kg S ha−1 each of the 1st three years in a band using different application methods. Sulfur application effects on soil pH were gradual, causing only a slight reduction in the application zone after one year; but was long lasting, resulting in continuing substantial declines in soil pH in an adjacent zone four years after the first S application. Soil available P, sulfate (SO4)-S, and salinity levels increased with increasing S applied. Sugarcane plant growth, as indicated by leaf area index during the grand growth period responded to moderate S application levels. Sugarcane yields increased linearly in the plant crop, but showed quadratic responses to S applications in the 1st through 3rd ratoon crops. Initial soil available P levels prior to the first treatment application were at the critical level considered adequate for crop requirements, yet growth and yield increases in response to S application suggest that the critical available soil P levels for sugarcane may be higher than previously established. Sulfur application at rates beyond those necessary to produce maximum yields resulted in salinity problems which probably reduced yields. The ‘stool splitter’ application method, which slices the plant stool using a coulter and places the fertilizer directly in the middle of the furrow caused crop damage and stand loss which persisted for the remainder of the sugarcane crops. Based on the results of this study, a single application of elemental S at up to 1120 kg S ha−1 directly below the seed cane at planting is recommend for sugarcane on a calcareous soil, with no additional applications in later crops.

N, P K absorption and utilization in sugarcane under different substrates of fertilizer resources

关键词: 甘蔗 / 糖蜜酒精废液 / 农艺性状 / 氮 / 磷 / 钾

Dinâmica de nutrientes em tecidos foliares de cana-de-açúcar após aplicação de herbicidas

Avaliaram-se, neste trabalho, os efeitos dos herbicidas ametryn, 2,4-D, trifloxysulfuron-sodium e da mistura ametryn+trifloxysulfuron-sodium na nutrição mineral e no crescimento da cana-de-açúcar. Para isso, utilizou-se o delineamento inteiramente casualizado no esquema de parcelas subdivididas, com quatro repetições. Os efeitos dos herbicidas foram avaliados nas parcelas, e o efeito do tempo, expresso em dias após aplicação dos herbicidas (DAA), considerando as diversas amostragens nas subparcelas. Os herbicidas foram aplicados em pós-emergência, quando as plantas de cana-de-açúcar se apresentavam com três a quatro folhas. As características avaliadas foram: a altura e massa seca da parte aérea, o número de folhas, o número de perfilhos e as concentrações de macro e micronutrientes nos tecidos foliares das plantas. As concentrações de N, P e Mg nos tecidos foliares não foram afetadas pelo uso dos herbicidas, independentemente da época de avaliação (15, 30, 45 e 60 DAA). Ao longo do tempo após a aplicação, constatou-se acréscimo da taxa de acúmulo (coeficiente beta0) dos nutrientes catiônicos Ca, Mg e K em plantas expostas ao ametryn+trifloxysulfuron-sodium. Quando da aplicação do 2,4-D, verificou-se redução na taxa de acúmulo de S e alteração na dinâmica dos nutrientes Mg, Ca e K, comparado à testemunha sem herbicida. Os herbicidas provocaram redução na concentração de Fe nessa cultura aos 15 DAA, na seguinte ordem: ametryn+trifloxysulfuron-sodium > ametryn > trifloxysulfuron-sodium > 2,4-D. Em relação às plantas de cana-de-açúcar não tratadas com herbicida (testemunha), o herbicida trifloxysulfuron-sodium provocou acréscimo de 22,10% no acúmulo de massa seca da sua parte aérea aos 60 DAA. O número de perfilhos observados em plantas tratadas com trifloxysulfuron-sodium foi o dobro do encontrado com ametryn, demonstrando efeito negativo deste herbicida nessa característica. Evidenciaram-se neste trabalho os efeitos dos herbicidas na concentração dos nutrientes e o crescimento das plantas de cana-de-açúcar.

Cloning of three members of acc synthase gene family in sugarcane

To clone the members of ACC synthase gene family in sugarcane, two degenerate oligonucleotide primers were designed, coding for two conservative acid regons in ACC synthase protein family. PCR amplification was performed on sugarcane DNA template, which produced three fragments that were 1041 bp (Sc-ACS1), 1345bp (Sc-ACS2) and 1707bp (Sc-ACS3), respectively. Analyses by using the program of BLAST on NCBI GenBank database showed that the polypeptide sequences of their coding regions highly matched with the family of ACC synthase genes from grass plants, the identity of their nucleotide sequence reached 88% to 98%. The nucleotide sequence of both Sc-ACS1 and Sc-ACS3 in opposite directons shared a homology of 98% but they were less similar to Sc-ACS2 (49%). Alignment and phylogenetic analyses of the amino acid sequence deduced from these fragments and sequences of ACC synthase from other plants in the GenBank. According to the ACC synthase protein family, the intron was excluding and the three sequences coded 326,242 and 310 amino acids, respectively, which spanned 67%, 50% and 64.6%, respectively, of the putative whole sequence in length. The putative amino acid sequence of both Sc-ACS1 and Sc-ACS3 shared significant identity to other ACC synthases (53–96%) and they were more similar to the sequences in grass plant species (80% with Zea mays Zm-ACS6, 75% withAsparagus officinaland andPhyllostachs edulis, and 73% withOryza sativa OS-ACS1) than to Sc-ACS2 (45–49%). The amino acid sequence of both Sc-ACS1 and Sc-ACS3 in opposite directions shared a homology of 96%. Based on the Northern analysis of the three ACC synthase gene members isolated it was concluded that accumulation of Sc-ACS1 RNA increased moderately in the sugarcane leaves treated with dark-growing condition, ethrel, IAA, LiCl and cold-stress, but not expressed while treated with BA and light- growing condition. The Sc-ACS2 was only expressed in the ethrel treatment, whereas Sc-ACS3 did not express in any treatment. The present study provided a new evidence of ethylene regulation in sugarcane at molecular level, as part of the regulation mechanism of ethylene to the growth of sugarcane plants.

Oxidative stress response and glutathione linked enzymes in relation to growth of sugarcane plants exposed to hexavalent chromium

Effect of hexavalent chromium (Cr6+) was seen onSaccharum species hybrid (cv. CoSe 92423) grown for 27 days in sand culture supplemented with 30,60 and 90 ppm of chromium. The inhibitory response of Cr6+ on shoot and root growth was concentration dependent. The stimulation in germination per cent was observed at 30 ppm which did not sustain at higher concentrations. Despite reduction in growth, dry matter production increased substantially with increase in Cr concentration after 27 days exposure to Cr6+. Significant increase in lipid peroxidation and tissue concentration of H2O2 occurred in plants exposed to 30, 60 and 90 ppm Cr6+. Effect of Cr6+ on Glutathione reductase (GSSG-R) and ascorbate peroxidase (APX) activity in roots and leaves was differential. Glutamyl cysteine synthetase activity increased up to 60 ppm treatment but it decreased slightly at 90 ppm, nevertheless, it remained higher than the control. The results suggested that Cr6+ induced depression in plant growth of sugarcane to be a function of increased cellular accumulation of Cr, despite increase in the activities of some of the antioxidative enzymes. One positive effect was observed in the form of increased germination per cent of the sugarcane buds at 30 ppm, possibly due to increased antioxidative enzyme activities and operation of glutathione-ascorbate cycle to scavenge H2O2.