Molecular detection of disease-causing agent infecting Malvastrum coromandelianum L. in Bahawalpur District Punjab Pakistan

Abstract

Weeds are common ancestors of modern crops. They are critical source of genes for resistance to diseases, pests and stresses such as drought and extreme environmental conditions. The wild relatives led to improve resistance to wheat curl mite, late blight in potato and to grassy stunt disease in rice. Agricultural pathogens are infecting economically important cash crops and weeds as well. Malvastrum coromandelianum is highly invasive weed specie of family Malvaceae. It is distributed all over the world in all climatic condition of tropical, sub-tropical and temperate region. The Malvaceae family is economically important as cotton (Gossipium hirsutem) belongs to it. M. coromandelianum has ethnobotanical importance and is extensively applied in the treatment of different diseases in south Punjab of Pakistan. It has been observed that there is a specific disease that affects the leaves of M. coromandelianum. In this study, we investigated the disease-causing agents (viruses and bacteria) at molecular level. Molecular investigation includes DNA isolation of unknown pathogens, verification through agarose gel electrophoresis, for identification of bacterial pathogens, 16s RNA primers were applied, and for viral pathogen using specific primers and RCA (rolling circle amplification) product as template. PCR was carried out for the amplification of full-length genomes. Manifestation of 1.4 kb bands showed the presence of the alpha and beta satellite of begomoviruse. Two types of begomoviruses, Malvestrum yellow vain younnan virus (MaYVYV) and Malvastrum yellow vain virus (MaYVV) was confirmed in this weed. The intermediate host Bemisia tabaci is the most common for the begomovirus transmission in crops and weeds. Intercrops and trap-crops techniques decrease the rate of whitefly population. Cultural methods, use of chemicals and biocontrol are useful practices to eliminate whitefly from field.