Comparative transcriptome analysis of Ts(Resistant genotype)and Ma(Susceptible genotype)marigold(Tagetes erecta L.)leaves in response to Alternaria tagetica

Marigold black spot caused by Alternaria tagetica is a major disease that can decrease marigold production by 40%,resulting in serious economic losses.In this study,we identified many genes responsive to A.tagetica in the resistant and susceptible marigold genotypes.Analyses of differentially expressed genes,expression trends,and a weighted gene co-expression network revealed a series of hub genes with key roles in different A.tagetica infection stages.Additionally,1216 unigenes encoding transcription factors from eight families were differentially expressed between Ts and Ma.Moreover,R genes fromvarious families(e.g.,N,NL,RLP,and TNL)were differentially expressed in the twomarigold genotypes before and after the inoculation with A.tagetica.Pathway diagrams were used to visualize the leaf transcriptional changes in the two marigold genotypes infected by A.tagetica to clarify the effects of A.tagetica on the expression patterns of genes involved in phosphatidylinositol signaling,plant–pathogen interactions,and plant hormone signal transduction.We identified candidate genes related to disease resistance and generated valuable resources for analyzing the candidate gene functions related to black spot resistance in marigold.The study data may be useful for the molecular marker-assisted screening and breeding of marigold lines with increased disease resistance.

Termiticidal and Biochemical Activity of Combinatorial Essential Oil Ingredients of Tagetes erecta on Indian White Termite Odontotermes obesus

In present investigation, various bio-molecular parameters i.e. glycogen, protein, amino acid, DNA, RNA and lipid, were determined for evaluation of anti-termite efficacy of Tagetes erecta essential oil based combinatorial formulations against Indian white termite Odontotermes obesus. For this purpose, 40% and 80% of 24 hrs of LD50 values of various formulations were provided for treatment of termite workers. Observations were taken at 4 hrs time interval up to 16 hrs to know inhibitory activity of these combinatorial mixtures on termite species Odontotermes obesus. Significant (p > 0.05) alterations were observed in the level above mentioned bio-molecules when termites were treated with different combinatorial essential oils ingredients of Citrus maxima. Combinatorial mixtures of Tagetes erecta essential oils have shown synergistic activity against termites. This study will provide an overall sustainable way to termite control in crop field, gardens and houses. It also suggests use of essential oils as better alternative of synthetic termiticides as these are safer for environmental and human health.

Toxicity of Tagetes erecta Essential Oil Based Combinatorial Formulations on Various Metabolic Enzymes in Indian White Termite Odontotermes obesus

Plant essential oils and their constituents have proven to be very effective against insects, especially termites. They are the best alternative to synthetic pesticides that are harmless to the environment and human health. In the present study, different enzymes, namely alkaline phosphatase, acid phosphatase, glutamate-oxaloacetate transaminase, glutamate-pyruvate transaminase and acetylcholinesterase, were evaluated in Indian termite Odontotermes obesus in a combination preparation based on Tagetes erecta essential oil. For the study of anti-termite effects against worker termites were treated topically with 40% and 80% of the 24-hour LD50 values of various combination formulations. Subsequent bioassays at 40% and 80% of LD50 of combinatorial preparations S-AST-A, S-AST-B, and S-AST-C resulted in a significant (p > 0.05) decrease in glutamate-oxaloacetate transaminase. After 16 hours of treatment, they were 87.92%, 80.17%, 89.30%, 79.17%, 81.92% and 73.17% respectively. In vivo exposures of 40% and 80% of the LD50 of the combination formulation caused a highly significant (p > 0.05) reduction (p > 0.05) of all test enzymes tested compared to controls. The effects of different oil formulations exhibited time- and dose-dependent responses, resulting in physiological changes in the concentrations of various enzymes. The combined mixture of Tagetes erecta essential oils has significantly better anti-termite ability compared to inorganic insecticides. Findings from this study will help support termite control in fields, gardens and homes in a sustainable way, without the downsides of insecticide resistance and pollution. These could potentially be used to produce commercial formulations for use against pests.

Induction of Tetraploid Male Sterile Tagetes erecta by Colchicine Treatment and Its Application for Interspecific Hybridization

Tagetes erecta is an annual multifunctional plant which can be cultivated under a broad range of climatic conditions. Polyploidization and interspecific hybridization are applied to facilitate breeding cultivars of T. erecta with improved ornamental qualities. Colchicine treatment to the germinating seeds was proved to be a useful tool for chromosome doubling of the male sterile two-type line ‘M525AB', with the resulting frequency of polyploid seedlings ranging from 88.89%(following 0.05% w/v colchicine applied for a 3–6 h exposure period) to a maximum of100.00%(following 0.1% for 3–6 h, or 0.2% for 3 h). Morphological observation, stomatal size and density analysis, flow cytometric analysis and chromosome counting were conducted to identify the tetraploid plants. Distinctive morphological changes were observed in a notable proportion of polyploid plants. The colchicine-treated polyploid T. erecta plants showed dwarfed and more robust growth, thicker, larger and greener leaves, larger inflorescences and florets. The mutant plants identified through morphological observation all aligned as polyploid plants, thus morphological observation could be an effective method for the detection of polyploidy. The polyploid plants had significant larger stomata size over the abaxial leaf surface, whereas the density of stomata distribution was remarkably reduced. The survival rate of tetraploid cuttings(i.e. 38%)was greatly reduced compared to that of diploid plants. The fertility of tetraploid plants was also decreased, as shown by cross-pollination yields.Interspecific hybridizations between colchicine-induced tetraploid plants of a male sterile T. erecta line and the naturally tetraploid fully fertile Tagetes patula species resulted in hybrid progeny. Most of these hybrids displayed the dwarfed growth stature and compact, larger-flower morphology which is the typical ideotype of herbaceous flowers. Thus, polyploidization may be employed effectively as a means to facilitate interspecific hybridization, thereby contributing significantly to the improvement of quantitative traits of Tagetes spp.

Chromatographic Analysis of Thiophenes in Calli and Suspension Cultures of Tagets spp.

The thiophene isomer fractions were investigated by TLC （thin layer chromatography） and GLC （gas liquid chromatography）. The TLC analysis revealed that, 5-（4-acetoxy-l-butynyl）-2,2-bithenyl （BBTOAc, Rf 0.78 I）; 5-（3-buten-l-ynyl）-2,2-bithineyl （BBT, Rf 0.39 II） and 2,2,5,2-oc-terthienyl （∝-T, Rf 0.32 III） were detected in extracts of leaf, stem and root calli or suspension cultures of Tagetes erecta and T. patula as well as leaf cell culture of T. patula which treated with DL-tryptophan under light or dark conditions. The GLC quantitative analysis of thiophenes in subjected revealed that the percentage distribution of the major thiophenes in all the analysed samples were determined as follows： BBT II 〉 ∝ -TllI 〉 BBTOAc I. Another thiophene was determined in relatively small amounts and found to be 5-（3-penten-l-ynyl）-2,2-bithienyl （PBT IV）. Other thiophenes were quantitated in trace amounts with unidentified or unknown chemical structure from the investigated extracts.

The Effect of Nitrogen and Phosphorus Ratios and Electrical Conductivity on Plant Growth

Environmental concerns surround the use of plant growth retardants (PGRs) for plant height control, and non-chemical alternatives to PGRs can be labor intensive and expensive. Macronutrient modification is a little-studied, yet potentially effective method of controlling plant height. A number of studies have suggested that phosphorus (P) limitation may restrict plant height. Anecdotal evidence also suggests that using nitrate (NO3-), rather than ammonium (NH4+), as the principal nitrogen (N) source may help control plant height. The primary objective of this study was to evaluate different ratios of NO3-/ NH4+, NO3-/P and NH4+/P as well as electrical conductivity (EC) on plant height and growth. This was tested in a hydroponic system using marigolds, sunflowers and tomatoes. Initially, different ratios were tested at an EC of 1.2 dS·m-1, followed by using the same ratios at four ECs (0.6, 1.2, 2.2 and 4.0 dS·m-1) as a second objective. Although ratios did, at times, limit plant height, responses were season and species dependent, suggesting that modifications in plant nutrition, at the ratios used in this study, may not effectively control plant height in hydroponic systems. More consistent, yet species specific, height control was achieved by increasing EC level.

陇东万寿菊适宜移栽期分析

利用甘肃省陇东地区共15县(区)的国家气象站1990—2021年观测资料及各县所辖的乡镇区域气象站观测数据,结合2017年陇东地区引进万寿菊(Tagets erecta L)种植后的农业栽培和产量资料,筛选气温稳定通过10、15℃初日为指标,基于GIS地理信息系统的栅格化处理,确定陇东地区万寿菊最适移栽期。结果表明,陇东地区万寿菊适宜移栽期各地有较大差异,自4月下旬开始,至5月下旬末结束,各地移栽时间早晚相差约30 d,主要由当地日平均气温稳定通过15℃的日期决定,地势平坦、热量条件较好的中南部区域移栽期偏早;海拔较高、气候寒凉的西部和北部山区及东部平原区,万寿菊适宜移栽期偏迟;全陇东地区万寿菊适宜移栽期主要集中在5月上、中旬。

Evaluating the effectiveness of marine actinobacterial extract and its mediated titanium dioxide nanoparticles in the degradation of azo dyes

Aim of the present study was to synthesize titanium dioxide nanoparticles （YiO2 NPs） from marine actinobacteria and to develop an eco-friendly azo-dye degradation method. A total of five actinobacterial isolates were isolated from Chennai marine sediments, Tamilnadu, India and analyzed for the synthesis of TiO2 NPs using titanium hydroxide. Among these, the isolate PSV 3 showed positive results for the synthesis of TiO2 NPs, which was confirmed by UV analysis. Further characterization of the synthesized TiO2 NPs was done using XRD, AFM and FI＇-IR analysis. Actinobacterial crude extract and synthesized TiO2 NPs was found efficient in degrading azo dye such as Acid Red 79 （AR-79） and Acid Red 80 （AR-80）. Degradation percentage was found to be 81% for AR-79, 83% for AR-80 using actinobacterial crude extract and 84% for AR-79, 85% for AR-80 using TiO2 NPs. Immobilized actinobacterial ceils showed 88% for AR-79 and 81% for AR- 80, dye degrading capacity. Degraded components were characterized by FT-IR and GC-MS analysis. The phytotoxicity test with 500 μg/mL of untreated dye showed remarkable phenotypic as well as cellular damage to Tagetes erecta plant. Comparatively no such damage was observed on plants by degraded dye components. In biotoxicity assay, treated dyes showed less toxic effect as compared to the untreated dyes.