SCREENING SOME MEDICINAL PLANTS AGAINST MOROCCAN WATERMELON MOSAIC VIRUS (MWMV)

SCREENING SOME MEDICINAL PLANTS AGAINST MOROCCAN WATERMELON MOSAIC VIRUS (MWMV)

ABSTRACT

The antiviral properties of plant leaves extract of four species, were studied. The extract were tested for antiviral effects on the host plant (Cocumba) against Moroccan watermelon mosaic virus. Results demonstrated that two plants (Phyllanthus amerus and Mirabiles jalapa) presented inhibitory effects against the virus. While Ficus exaspirata and Citrus spp were unable to suppress the virus. In Africa, Moroccan watermelon mosaic virus continues to be a significant issue with cucubite cultivation.

CHAPTER ONE

INTRODUCTION

1.1 Background of the Study 

In several nations worldwide, plant viruses are the cause of significant economic losses. A virus is an infection agent that can only multiply within a host’s living cells, is too small to be seen under a light microscope, and usually consists of nuclei and molecules covered in a protein coat. Holmes (1939). Direct transmission of viruses can happen when a damaged plant comes into contact with a healthy one.

This can happen naturally, like when an animal feeds on the plant, or during agricultural operations, like when tools or hands cause damage. The majority of plant-infecting viruses are spread by insects;

some of them stick to the mouth regions and can infect a host in a matter of seconds or minutes. Martinus, 1898. This work focusses on mechanical inoculation rather than insect transmission.

1.2 Techniques used to manage plant viruses

For over a century, researchers have been studying plant viruses and virus illnesses, and controlling them has received a lot of attention. This has proven challenging to accomplish, though, as there are currently no proven methods for treating virus-infected plants. Although they can be effective, chemotherapy, thermotherapy, and meristem-tip culture cannot be applied widely.

Brook (1964). Preventing, delaying, or reducing the impact of viral infection has been the primary strategy. To accomplish these goals, a variety of strategies have been employed, including phyto-sanitation. (Involving quarantine measures, crop hygiene use of virus-free plant materials and eradication) changes in crop practices, use of pesticide for control of vectors, mild strain protection and the employment of resistant or tolerant varieties. (Sarkar, 1995).

In order to create virus-free plants of vegetatively-propagated crops for future propagation, some viruses can be removed from infected plants using heat, meristem-tip therapy, or chemicals (Faccioli and Marami, 1998).

It delays infection until a crop reaches a stage where it is affected, keeps plants from getting infected, and lessens the impacts of infection. (Mink and others, 1998).

1.2.1 Ricinus Sp (Castor oil plant) has being recognised as a member of the sponge family, Euphobiaceae. The seed from Ricinus sp plant contain in excess of 45% oil.

There are several uses for the aforementioned oil. It is utilised in the production of soap, transparent paper, printing ink, varnishes, linolilium, plasticiser, high-speed engines, and aeroplanes. It is also utilised for illumination and medical applications.

Gram-positive bacteria are susceptible to its antibacterial properties (Nuttall & Labuda, 2008). 1.2.2 Mirabilis Jalapa. (The four 0’clock plant) has being classed as a member of the Nyctaginaleae family the species mirabilis Jalapa is a regularly grown decorative plant and is available in a range of colours.

The leaves of Mirabilis Jalapa can be consumed cooked, while the blossom is used to colour cuisine. It’s emergency food. It is used for dye manufacture for cakes and jellies.

It is also employed in the manufacturing of cosmetics. It contains antiviral protein (MAP), which has been shown to have antiproliferative effects on tumour cells, an inhibitory effect on call-free protein synthesis, and an abortificant action in pregnant mice. (Wong and others, 2014).

1.2.3 Phyllanthus amerus: a member of the Euphorbiaceae family, Phyllanthus is also known as the stone buster. According to Nicole (1998), Phyllanthus plant extract has been used to treat malaria, kill bacteria, and expel stones. 1.2.4 Adansonia Digitata: A member of the Malvaceae family.

The scorching, arid savannahs of Sub-Saharan Africa are home to this species. Common names include dead-rat tree, monkey bread tree, cream of taster tree, baobab, and others. The leaves can be dried and used to soups and sauces, or they can be consumed fresh as a cooked vegetable.

Seedlings’ roots and branches are also consumed. In times of famine in West Africa, the roots are boiled and consumed. In the past, the packing and paper industries brought the bark of a digitata to Europe for use as medicine, fodder for cattle, shelter for the dead and living, and functional food for the health of rural people. Cortex Cael Cedra is the name given. It was used to lower fever instead of quinine (Jardin, 1968).

Acalypha Indica is a member of the Euphorbialeae family. It is a common herb with oval leaves that can grow up to 75 cm tall. The cooked leaves are consumed as a vegetable. Because it is thought to revitalise the body, this plant is highly valued in traditional medicine.

It is beneficial for pulmonary tuberculosis, ashma, pneumonia, and bronchitis. Additionally, it exhibits strong antifungal and antibacterial properties against plant and human pathogens. Burkill (1974).

1.3 Plant as an antiviral material reservoir

Northern Nigerian plants that have long been used in traditional veterinary and human medicine have had their hypotoxility and antiviral activities examined. At dose rates ranging from 100 to 400 microg/100 microl, the majority of extracts exhibit efficacy against several viruses. Mehesh (2000).

Lawsonia Inermis is a medium-sized, evergreen shrub that belongs to the Hythraccere family. In the oriental world, it is commonly referred to as Hemma or mehindi. This herb has a long folklore history of being used to heal malignant ulcers, jaundice, and convulsions.

Numerous bioactive molecules, including isophumpagin, hipeol, 30-norlupan -3-01-20-one betuhennan, betuhennamic acid, and nstigmasterol, have been found in the leaves and roots of henna plants, according to phytochemical investigations.

According to Keyvan (2008), plant extract has been shown to have analgesic, antibacterial, antioxidant, wound-healing, anti-inflammatory, and antipyretic properties.

1.4 Watermelon Morocan Mosaic virus : the moroceam water melon mosaic virus (MWMV), has been proven to be a distinct members of the polyvirus group.

By analysing tryptic peptide profiles using high performance liquid chromatography, the link between the W strain of papaya ricknspoot virus and other polyviruses and the morocean water melon mosaic virus was investigated (Cockerhem, 1970).

The profolus demonstrated that the low protein sequence of MWMV differed greatly from those of the other poly-viruses. McKern (1993).