Major Virus Diseases of Groundnut in India and Their Management

Abstract

Several virus diseases of groundnut have been reported in India based on symptoms, host range, and biological properties. Among those, peanut bud necrosis virus (PBNV), tobacco streak virus (TSV), peanut mottle virus (PeMoV), and Indian peanut clump virus (IPCV) are the economically important viruses of groundnut in India. Peanut bud necrosis virus belongs to the genus Tospovirus, transmitted effectively by Thrips palmi. PBND alone may cause 30–90 % yield losses. Necrosis of the terminal buds occurs which is a characteristic symptom of PBNV. Extensive field screening of the several genotypes, released varieties, and wild species at the hot spots has revealed the field tolerance of some of those genotypes. Peanut stem necrosis disease (PSND) is caused by the TSV of the genus Ilarvirus of the family Bromoviridae. Necrotic lesions on terminal leaflets, complete stem necrosis, and often total necrosis of entire plant are the characteristic symptoms of this disease. The PSND spreads mainly through the weed of crop species. A desired level of resistance of TSV has not yet been found in cultivated varieties of groundnut. The peanut clump disease of groundnut in India is caused by the IPCV of the genus Pecluvirus, family Virgaviridae. Symptoms are severe stunting of the plant appeared first on newly emerged leaves of two- to three-week-old seedlings. The host range of IPCV includes many monocot and dicot crop plants and weed species tested. IPCV was reported to be transmitted by the obligate fungal parasite (Polymyxa graminis) which is soilborne. Germplasm accessions, viz., NCAc 17099, NCAc 17133 (RF), and NCAc 17536, have been reported resistant to IPCV. Peanut mottle virus disease has been reported to occur on rabi/summer groundnut mainly in Andhra Pradesh, Maharashtra, and Gujarat. Newly formed leaves show mild mottling and vein clearing, whereas older leaves show upward curling and interveinal depression with dark green islands. The peanut mottle virus (PeMoV) occurs in nature on several important legume crops. Aphids are efficient vectors of PeMoV. Several lines of Arachis species like A. glabrata are reported to be resistant to this disease. Peanut stripe virus (PStV) is of quarantine significance to India and is almost eradicated from India. Since in most of the viral diseases sources with desired levels of genetic resistance could not be identified so far, transgenic approaches to engineer resistance to viruses by expressing the glycoproteins of tospoviruses in transgenic plants to block virus acquisition by thrips, by expressing truncated or modified forms of movement protein(s) of heterologous viruses, or by expressing virus-specific antibody genes may be adopted to tackle the viral diseases in groundnut.