International Journal of Medicinal Plants and Alternative Medicine Vol. 2(1), pp. 001-004, July 2013 ISSN 2327-560X ©2013 Academe Research Journals

Full Length Research Paper

Analysis of medicinal weeds associated with phytoplasma by morphological characters

Namita Singh* and P. P. Upadhyaya

Department of Botany, D.D.U. Gorakhpur University, Gorakhpur- 273009 (U.P.), India.

*Corresponding author. E-mail: namitasinghphd123@gmail.com.

Accepted 22 October, 2013

Abstract

Phytoplasmas have been documented in more than 100 weeds plant species, including dicots and monocots. The wide host range of phytoplasmas is an important parameter for the epidemiology of its diseases. Overlapping plant hosts and vectors also give ample opportunities for them to interact and exchange genetic information. Some of them share host plants, though genetic exchange might also occur between these mollicutes. Phytoplasmas have been detected in most organs of infected plants, where they colonize the sieve tubes of the phloem. Infestations of floral tissue by them have been observed, but it is believed that seed transmission is generally not possible because the sieve tubes lack a direct connection to the seed. However, they can still occur in the seed. Suspected phytoplasma symptoms were observed in some weeds such as Datura stramonium L., Achyranthes aspera L., Ranunculus scleratus L. and Ageratum conyzoides L., found in Gorakhpur and its adjoining areas in Eastern U.P. India. The aim of this work is to predict phytoplasma infected plant and differentiate it from other causal organism like: bacteria, virus, fungi, etc. Phytoplasma are plant pathogenic mollicutes, originating from bacteria, which cause severe loss of diversity of many plants, but we selected some medicinal plants which are used in a direct way as a form of leaf, stem, flower, etc. These weeds are highly affected by phytoplasma, thereby making them lose their diversity; however, these weeds are present in moderate amount in this region. The major symptoms considered are witches’ brooms, little and yellow leaf, phyllody disease, little leaf necrosis and witches’ brooms, and abnormal proliferation of twinges, which at some point in time cause the death of complete plants. All weeds plants are confirmed on the basis of nested PCR and Phylogenetic analysis. These weeds are highly used medicinally in direct and indirect ways. These are severally affected by phytoplasma infection. Identification of the diagnosis of phytoplasma remains a challenge because of its rapid lethal course and lack of consistency to particular clinical signs and symptoms. Moreover, many difficulties occur because its concentration in host plants highly fluctuates over all seasons. These plants are firstly identified on the basis of peculiar symptoms of phytoplasma, after which they are confirmed by electron microscopy, and a particular group of phytoplasma is then identified by PCR, gene sequencing, and blast analysis.

Key words: Phytoplasma, dicots, monocots, phloem.