Detection of target spot and bacterial spot diseases in tomato using UAV-based and benchtop-based hyperspectral imaging techniques

Early and accurate diagnosis is a critical first step in mitigating losses caused by plant diseases. An incorrect diagnosis can lead to improper management decisions, such as selection of the wrong chemical application that could potentially result in further reduced crop health and yield. In tomato, initial disease symptoms may be similar even if caused by different pathogens, for example early lesions of target spot (TS) caused by the fungus Corynespora cassicola and bacterial spot (BS) caused by Xanthomonas perforans. In this study, hyperspectral imaging (380–1020 nm) was utilized in laboratory and field (collected by an unmanned aerial vehicle; UAV) settings to detect both diseases. Tomato leaves were classified into four categories: healthy, asymptomatic, early and late disease development stages. Thirty-five spectral vegetation indices (VIs) were calculated to select an optimum set of indices for disease detection and identification. Two classification methods were utilized: (i) multilayer perceptron neural network (MLP), and (ii) stepwise discriminant analysis (STDA). Best wavebands selection was considered in blue (408–420 nm), red (630–650 nm) and red edge (730–750 nm). The most significant VIs that could distinguish between healthy leaves and diseased leaves were the photochemical reflectance index (PRI) for both diseases, the normalized difference vegetation index (NDVI850) for BS in all stages, and the triangular vegetation index (TVI), NDVI850 and chlorophyll index green (Chl green) for TS asymptomatic, TS early and TS late disease stage respectively. The MLP classification method had an accuracy of 99%, for both BS and TS, under field (UAV-based) and laboratory conditions.

     

Synthesis and quantitative structure-activity relationships of oxanilates as chemical hybridizing agents for wheat (Triticum aestivum L.)

Chemical hybridizing agents (CHAs) can facilitate two-line breeding in heterosis programs of crops. Twenty-seven oxanilates having different aromatic substitutions were synthesized and screened as CHAs on two genotypes of wheat, PBW 343 and HD 2733, during two Rabi (winter) seasons, 2000-01 and 2001-02. The oxanilates prepared by thermal condensation of anilines with diethyl oxalate or by acylation with ethoxycarbonyl methanoyl chloride were sprayed at 1000 and 1500 ppm at the premeiotic stage of wheat, when the length of the emerging spike of the first node was 7-8 mm. Pollen sterility and spikelet sterility were measured in each treatment. Ethyl oxanilates 5, 6, and 25,containing 4-F, 4-Br, and 4-CF(3) aromatic substituents, respectively, induced greater than 98% spikelet sterility, the desired level, at 1500 ppm. Quantitative structure-activity relationship analysis revealed a direct relationship between F(p) and molecular mass but an inverse relationship between MR, E(S), and R in influencing the bioactivity. Several F(1) hybrids were developed using 5, and at least one showed heterosis.     

The response of microbial composition and enzyme activities to hydrological gradients in a riparian wetland

Journal of Soils and Sediments - Hydrological condition is one of the important factors impacting microbial structure in riparian wetlands. However, how these microbial communities respond to...     

Changes in colostrum of Murrah buffaloes after calving

Colostrum samples were collected from 8 Murrah buffaloes on days 1, 2, 3, 4 and 5 after calving. Levels of IgG averaged 54.0 mg/ml at calving, then decreased significantly (P < 0.01). IgA and IgM on day 1 were 3.22 mg/ml and 5.22 mg/ml, respectively; both decreased during the first five days after calving. Values of IgA and IgM were higher than those reported in cows. SCC values, which were high at calving (500 000 per ml), reduced significantly (P < 0.01) on day 2, then decreased slightly until day 5 (180 000 per ml). At calving, macrophages were the most prominent cells in buffalo colostrum, followed by lymphocytes and neutrophils. Phagocytic activity was 23% at calving and reduced significantly (P < 0.01) to 14% on day 5. Phagocytic index was highest in the first colostrum, and then decreased non-significantly.     

Effect of aromatase inhibitors on the ovarian development of stunted yearlings of rohu (Labeo rohita): a preliminary study

In India, many of the fish farmers stock 1-year-old stunted fishes (stunted yearlings) of Indian major carps (IMC) for enhancing fish production through compensatory growth, but many of them observed problems of early maturation in these fishes. Application of aromatase inhibitors for deceleration of ovarian maturation is one of the probable solutions to mitigate this issue. In the present study, a synthetic aromatase inhibitor letrozole [25 (L₂₅) and 50 (L₅₀) mg kg^?1 feed] and a plant-derived aromatase inhibitor, grape seed extract [100 (G₁₀₀) and 200 (G₂₀₀) mg kg^?1 feed], were fed to stunted yearlings of rohu (Labeo rohita) for 45 days well before the onset of breeding season. Maturation indices such as gonadosomatic index (GSI) and serum oestradiol (E) levels indicated a dose-dependent inhibition of ovarian development in the aromatase-inhibitor-treated fish. Higher dose of letrozole (GSI, 15.12 ± 0.18; E, 3.19 ± 0.42) and grape seed extract (GSI, 16.90 ± 0.40; E, 3.60 ± 0.75) were found to be more effective since control fish showed further advancement in maturation (GSI, 21.20 ± 1.10; E, 7.33 ± 0.74) during the peak breeding season (15th June). Histological observations also confirmed the results revealing a delayed initiation of ovarian development in the case of higher doses of letrozole and grape seed extracts. These results indicate the possible use of aromatase inhibitors in arresting the early maturation process in IMC.     

Identification of Minimum Data Set Under Balanced Fertilization for Sustainable Rice Production and Maintaining Soil Quality in Alluvial Soils of Eastern India

The scarcity of non-renewable fertilizers resources and the consequences of climate change can dramatically influence the food security of future generation. Introduction of high yielding varieties, intensive cropping sequence and increasing demand of food grains day-by-day, application of recommended dose of fertilizers could not fulfill our targets due to outdated fertilizers recommendations are yet in practice. It not only alters soil quality, nutrient balance, microbial and enzymatic ecology but also affected productivity and sustainability of rice in Gangetic alluvial soils of India. The effect of fertilizers application based on “fertilizing the soil versus fertilizing the crop” which insure real balance between the applied and available soil nutrient is urgently needed. Hence, the present study was conducted during three consecutive crop seasons (2010, 2011, and 2012) to assess the effect of imbalance and balance fertilization based on initial soil test values and targeted yields, and to determine the effect of farmyard manure (FYM) when superimposed with balanced fertilizers on identification of minimum data set for the development soil quality, nutrient acquisition, and grain yield of rice. The six fertilizer treatments were laid out in a randomized block design with three replications. The treatments were: T₁-control (no fertilization), T₂-farmyard manure @ 5 t ha^?1, T₃-farmers practice (60:30:30 kg N:P₂O₅:K₂O ha^?1), T₄-precise application of mineral fertilizers based on initial soil test values (77:24:46 kg N:P₂O₅:K₂O ha^?1) for targeted grain yield of 4.0 t ha^?1, T₅-precise application of mineral fertilizers based on initial soil test values (74:23:43 kg N:P₂O₅:K₂O ha^?1) plus FYM (5 t ha^?1) for targeted grain yield of 4.0 t ha^?1 and T₆-precise application of mineral fertilizers based on initial soil test values (135:34:65 kg N:P₂O₅:K₂O ha^?1) for targeted rice grain yield of 5.0 t ha^?1. Result revealed that the targeted rice grain yield of 4.0 and 5.0 t ha^?1 was achieved in T₄ and T₆ treatments with 1.59% (4.06 t ha^?1) and –3.40% (4.83 t ha^?1) deviations, respectively. T₄, T_5, and T₆ significantly increased crop growth, nutrient uptake, available P (P_a) and K (K_a) and augmented rice grain yield by 10.6, 20.2 and 31.6%, respectively, over T₃. Microbial biomass carbon, soil respiration and enzymatic activity were enhanced significantly in T₅ as compared to T₆. Highest soil quality index was found in T₅ (0.95) followed by T₆ (0.90) and, lowest was in T₁ (0.63). The contribution of minimum data set (MDS) toward the SQI was in the descending order of ALP (30.6%) > SOC (21.5%) > K_a (11.3%) > PSM (9.68%) > N_a (8.51%). Overall, rice yield and soil quality was improved by using balance fertilization based on fertilizing the crop Vs fertilizing the soil in alluvial soils of India.     

RNA elimination machinery targeting meiotic mRNAs promotes facultative heterochromatin formation

Facultative heterochromatin that changes during cellular differentiation coordinates regulated gene expression, but its assembly is poorly understood. Here, we describe facultative heterochromatin islands in fission yeast and show that their formation at meiotic genes requires factors that eliminate meiotic messenger RNAs (mRNAs) during vegetative growth. Blocking production of meiotic mRNA or loss of RNA elimination factors, including Mmi1 and Red1 proteins, abolishes heterochromatin islands. RNA elimination machinery is enriched at meiotic loci and interacts with Clr4/SUV39h, a methyltransferase involved in heterochromatin assembly. Heterochromatin islands disassemble in response to nutritional signals that induce sexual differentiation. This process involves the antisilencing factor Epe1, the loss of which causes dramatic increase in heterochromatic loci. Our analyses uncover unexpected regulatory roles for mRNA-processing factors that assemble dynamic heterochromatin to modulate gene expression.     

In vitro antimicrobial activity of equine platelet lysate and mesenchymal stromal cells against common clinical pathogens

Septic arthritis is considered a medical emergency. Disease following bacterial colonization can lead to significant morbidity and mortality and requires costly treatment. Antimicrobial properties of regenerative therapies, including mesenchymal stromal cells and platelet products, have been researched extensively in human medicine. Although fewer studies have been conducted in veterinary species, they have shown promising results. The purpose of this study was to evaluate bacterial suppression by equine platelet lysate (EPL) and adipose-derived mesenchymal stromal cells (ASCs) in vitro. We hypothesized that both products would significantly inhibit the growth of Staphylococcus aureus and Escherichia coli. Pooled blood from 10 horses was used for production of EPL. Mesenchymal stromal cells were isolated from adipose tissue harvested from the gluteal region of 3 horses. The study evaluated 3 treatment groups: 10 × EPL, 1.6 million ASCs, and a control, using an incomplete unbalanced block design with repeated measurements. Optical density readings and colony-forming units/mL were calculated at 0, 3, 6, 9, 12, 18, and 24 hours. Decreased bacterial growth was seen at multiple time points for the S. aureus-ASC and S. aureus-EPL treatments, supporting our hypothesis. Increased bacterial growth was noticed in the E. coli-EPL group, with no difference in the E. coli-ASC treatment, which opposed our hypothesis. A clear conclusion of antimicrobial effects of EPL and ASCs cannot be made from this in vitro study. Although it appears that ASCs have a significant effect on decreasing the growth of S. aureus, further studies are needed to explore these effects, particularly in Gram-positive bacteria.