•Elicitors application increased markedly all leaf anatomical characteristics.•Elicitors application improved ultrastructural characters compared with control plant.•1000mg/l Silicon could be ...suggested for controlling grapevine downy mildew disease.•1000mg/l Silicon increased plant growth, yield and quality.
Many elicitors (silicon, chitosan, bion or fungicide) were investigated on grapevines grown under natural infestation to evaluate their capacity on inducing defense from downy mildew disease and enhancing growth, yield, berries quality as well as some physiological and anatomical characteristics of Roumy Ahmar grapevines.
Foliar application of any elicitors used, in special, silicon was significantly increased yield per vine, cluster weight, 100 berry weight, soluble solids%, total anthocyanin and total phenols while reducing the total acidity% in berries as well as increasing leaf area and potassium percentage in leaves and antioxidant enzyme activities comparing with control. Chitosan application was significantly superior than using other elicitors in increasing shoot length, nitrogen and phosphorous percentage, photosynthetic pigment, ascorbic acid, proline and phenolic compounds in the leaves, and decreased hydrogen peroxide and lipid peroxidation leading to improved membrane permeability. All tested elicitors, in special, Si reduced downy mildew disease severity as compared with untreated control vines. Also, the chloroplast exhibited different degrees of malformation and lysis. The mitochondria were highly vacuolated and the nucleus was misshapen in infested vines.
It could be suggested that spraying Roumy Ahmar grapevine with 1000mg/l silicon four times controlled downy mildew disease in grapevine as well as improving its growth, yield and quality.
Abstract Pearl millet ( Cenchrus americanus ) is the sixth most significant cereal crop cultivated on 30 million ha and a staple diet for 90 million poor people across the globe. Besides abiotic ...stresses several biotic stresses have been limiting production of pearl millet in the semi-arid and arid regions. Although, the Quantitative Trait Loci (QTLs) associated with key diseases like blast, rust and downy mildew resistance and nutritional content has been reported, the use of these QTLs is limited in breeding programs. To identify highly stable consensus genomic regions, we conducted Meta-QTL analysis using 191 QTLs reported in 12 independent studies over the last two decades. As a result, we report 34 Meta-QTLs regions on a consensus genetic map comprising of 692 markers and spanning 2070.7 cM. The confidence interval of Meta-QTLs was reduced by 3.63 folds (0.18–7.49 cM), in contrast to projected QTLs interval of 1.11–60.63 cM. Further, a total of 1198 genes were identified in 34 Meta-QTL regions. Among 34 Meta-QTL regions, Meta-QTL1.1 is found to be region of significant importance as it harbours genes for enhanced biotic stress tolerance, plant growth and development as well as genes related with enhanced seed development. Meta-QTL2.4 has highest number of genes with a significant role in disease resistance which contains basic leucine zipper domain, zinc family, leucine rich repeat regions. Meta-QTL3.1 has ABC transporter like activity coupled with the ATPase activity which has a role in Fe and Zn uptake in leaves and root tissues. These Meta-QTL regions can be used in genomics-assisted breeding for enhancing the blast, rust downy mildew resistance as well as yield and nutritional traits.
Grape diseases are major factors causing severe diminution in its fruit development. Unfavorable climatic conditions are one of the principal dangers for grape disease development. Downy Mildew, ...Powdery Mildew, Anthracnose, Stem borer, Black Rot, Leaf Blight are widespread grape leaf vermin and diseases, which cause stern monetary losses to the grape industry. Devices ready to quantify the climate conditions in real-time for disease onset are hence crucial to perform timely diagnosis and precise detection of grape leaf diseases. This will ensure the healthy growth of grape plants, further controlling the spread of diseases. This paper discusses the requirements for building a consistent grape disease detection framework that would encourage headways in agribusiness. The primary aim of this work is to adapt an Internet of Things (IoT) based approach to predict the occurrence of Downey and Powdery Mildew grape diseases at an early stage. The sensor values received are transmitted to the Central Server with the help of the IoT device NodeMCU. At the server side, an analysis is made based on weather conditions. Further notification to the farmer is sent if weather properties are conducive for disease onset. The exclusivity of the system lies in using a rain gauge sensor along with the temperature sensor to predict the occurrence of grape diseases. This system realizes an overall accuracy of 94.4% for Downey Mildew and 96% for Powdery Mildew. Experimental results suggest the projected model can proficiently recognize Downey and Powdery Mildew grape diseases.
•Grape diseases are major concern in agriculture to minimize the loss of production.•Unfavorable conditions become the reason for grape disease development.•Major Grape diseases are Downey, Powdery Mildew.•IoT Approach can better help to prevent disease occurrence at much early stage.
In the present study, thirteen SSRs (Simple Sequence Repeats) were employed for screening the level of similarity between sunflower parental lines and progeny obtained in final stages of selection. ...Another aim of the study was to compare the success of making isogenic lines through selection. Line P (donor line) was used as a donor of downy mildew gene Pl6 and backcrossed with four commercial inbred lines (A, B, C and D) susceptible to downy mildew. HAP3, a DNA-specific primer, was used to test the success of transfer of Pl6 gene from the donor line to the progeny lines in the F6 and F7 generations. It was found that all progeny lines were resistant to downy mildew. Results obtained by using thirteen primers showed that progeny lines were similar to their respective recipient parent, but further studies have to be conducted using a larger number of primers and a larger number of genotypes.
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