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Plant-derived insecticides have been focused for biorational pest management because these are relatively quickly biodegradable, cost-effective, less persistent and exhibit low mammalian toxicity than synthetic pesticides. This study assessed the toxicity potential of seven local plant species (i.e. parthenium Parthenium hysterophorus L., eucalyptus Eucalyptus camaldulensis Dehnh., milkweed Calotropis gigantean (L.) Dryand., bakain Melia azedarach L., neem Azadirachta indica A. Juss., tobacco Nicotiana tabacum L. and thorn apple Datura stramonium L.) against wheat aphid (Schizaphis graminum Rondani) under laboratory and field conditions. Using foliar spray method, toxicity bioassay was conducted with three different concentrations (i.e. 250, 500 and 1000 ppm) of methanolic plant extracts under controlled laboratory conditions, while three different concentrations (25, 50 and 75 g/L) of each botanical extract was tested in the field trial. Results showed a significant mortality and suppression of S. graminum individuals at 72 h after treatment in the laboratory and at 10th day post-treatment in the field. In laboratory bioassay, maximum aphid mortality was caused by the extracts of D. stramonium (92%), A. indica (84%), N. tabacum (78%) and M. azedarach (70%) at 72 h post-treatment at their highest concentration (1000 ppm). Results of field trial showed significant aphid mortality by D. stramonium (78%), A. indica (72%), N. tabacum (68%) and M. azedarach (62%) extracts noted for their highest concentration (75 g/L) at 10th day after treatment. Based on overall results of the study, the extracts of D. stramonium, A. indica, N. tabacum and M. azedarach are recommended to be considered for biorational management of S. graminum. [ABSTRACT FROM AUTHOR]

Since the 19th century to date, the fungal pathogens have been involved in causing devastating diseases in plants. All types of fungal pathogens have been observed in important agricultural crops that lead to significant pre and postharvest losses. The application of synthetic fungicide against the fungal plant pathogens (FPP) is a traditional management practice but at the same time these fungicides kill other beneficial microbes, insects, animal, and humans and are harmful to environment. The antagonistic microorganism such as bacteria are being used as an alternate strategy to control the FPP. These antagonistic species are cost-effective and eco-friendly in nature. These biocontrol bacteria have a broad mechanism against fungal pathogens present in the phyllosphere and rhizosphere of the plant. The antagonistic bacteria have different strategies against the FPP, by producing siderophore, biofilm, volatile organic compounds (VOCs), through parasitism, antibiosis, competition for limited resources and induce systemic resistance (ISR) in the host plant by activating the immune systems. The commercial bio-products synthesized by the major bacterial species Pseudomonas syringae, Burkholderia cepacia, Streptomyces griseoviridis, Pseudomonas fluorescens and Bacillus subtilis are used to control Fusarium, Pythium, Rhizoctonia, Penicillium, Alternaria, and Geotrichum. The commercial bio-formulations of bacteria act as both antifungal and plant growth regulators. The Plant growth-promoting rhizobacteria (PGPR) played a significant role in improving plant health by nitrogen-fixing, phosphorus solubilization, phytohormones production, minimizing soil metal contamination, and by ACC deaminase antifungal activities. Different articles are available on the specific antifungal activity of bacteria in plant diseases. Therefore, this review article has summarized the information on biocontrol activity of bacteria against the FPP and the role of PGPR in plant growth promotion. This review also provided a complete picture of scattered information regarding antifungal activities of bacteria and the role of PGPR. [ABSTRACT FROM AUTHOR]

Cucumber mosaic virus (CMV) is a destructive and menace to a wide range of plant species including eggplant crop worldwide. This study was carried out to define the current status of CMV infecting eggplant crop in Pothwar region of Pakistan and characterization of CMV eggplant isolates as well as to recognize the sources of resistance in eggplant genotypes. A total of 660 leaf samples with the virus and virus-like symptoms were collected from different sites of Pothwar region and subjected to CMV specific DAS-ELISA using monoclonal antibodies. ELISA results indicated that approximately 56% of samples were positive for CMV infection and the disease incidence was highest (62.50%) in Jhelum district followed by Rawalpindi (58.33%), Chakwal (58.33%) and Attock (55.55%) districts with the lowest disease incidence (46.15%) was recorded in Islamabad district. Two ELISA positive samples from each district were further confirmed by RT-PCR and subsequently sequenced based on their coat protein cistron. All isolates were identical to each other so the nucleotide sequence of one eggplant isolate (CMV-Pak) was deposited in GenBank with accession number MH119063. BLAST and phylogenetic analysis revealed that CMV-Pak eggplant isolate shared 90-94% nucleotide and 80-100% amino acid similarities with other isolates available in GenBank. Moreover, 10 eggplant genotypes were tested against CMV-Pak eggplant isolate, ELISA results categorized three genotypes (Singh Nath 666, Neelum, and Brinjal Jamak) as moderately resistant, two genotypes (Round Black, and Global Brinjal PPL) as susceptible and rest of the five genotypes (Bemissal, Brinjal Shilpa, Short Purple, Brinjal PPL, and Namyal Ratchburi) as moderately susceptible. Therefore, the three moderately resistant genotypes could be recommended to farmers for farming and plant breeders for developing new eggplant resistant genotypes to CMV. To the best of our knowledge, this study is the first time provided evidence that CMV infects eggplant in Pakistan. [ABSTRACT FROM AUTHOR]

First report of cucurbit aphid borne yellows virus (CABYV) infecting melon in Pakistan Keywords: RNA virus; CABYV; Coat protein; Melon EN RNA virus CABYV Coat protein Melon 563 564 2 05/29/20 20200501 NES 200501 Melon ( I Cucumis melo i L.) is one of the most important crops in Pakistan and ranked as 4th largest produced with an annual production of 0.54 M tonnes over an area of 0.037 M hectares (GOP [1]). The presence of this potentially destructive virus on melon could be a serious threat to this important crop, and therefore further studies are needed to monitor CABYV disease impact on cucurbits across the country. [Extracted from the article]