Leaf crinkle disease in urdbean (Vigna mungo L. Hepper): An overview on causal agent, vector and host

Abstract

Urdbean leaf crinkle disease (ULCD) is an economically significant widespread and devastating disease resulting in extreme crinkling, puckering and rugosity of leaves inflicting heavy yield losses annually in major urdbean-producing countries of the world. This disease is caused by urdbean leaf crinkle virus (ULCV). Urdbean (Vigna mungo L. Hepper) is relatively more susceptible than other pulses to leaf crinkle disease. Urdbean is an important and useful crop cultivated in various parts of South-East Asia and well adapted for cultivation under semi-arid and subtropical conditions. Aphids, insects and whiteflies have been reported as vectors of the disease. The virus is also transmitted through sap inoculation, grafting and seed. The loss in seed yield in ULCD-affected urdbean crop ranges from 35 to 81%, which is dependent upon type of genotype location and infection time. The diseased material and favourable climatic conditions contribute for the widespread viral disease. Anatomical and biochemical changes take place in the affected diseased plants. Genetic variations have been reported in the germplasm screening which suggest continuous screening of available varieties and new germplasm to search for new traits (new genes) and identify new sources of disease resistance. There are very few reports on breeding programmes for the development and release of varieties tolerant to ULCD. Mostly random amplified polymorphic DNA (RAPD) as well as inter-simple sequence repeat (ISSR) molecular markers have been utilized for fingerprinting of blackgram, and a few reports are there on sequence-tagged micro-satellite site (STMS) markers. There are so many RNA viruses which have also developed strategies to counteract silencing process by encoding suppressor proteins that create hindrances in the process. But, in the case of ULCV, there is no report available indicating which defence pathway is operating for its resistance in the plants and whether same silencing suppression strategy is also followed by this virus causing leaf crinkle disease in urdbean. The antiviral principles (AVP) present in leaf extracts of several plants are known to inhibit infection by many viruses. Many chemicals have been reported as inhibitors of virus replication in plants. Raising the barrier crops also offers an effective solution to control the spread of virus.

Inheritance of Urdbean Leaf Crinkle Virus Disease in Blackgram [Vigna mungo (L.) Hepper]

“…Blackgram or Urdbean [Vigna mungo (L.) Hepper] is an important food legume crop of Indian sub-continent. It is a self-pollinated crop rich in protein (24%) in addition to lysine and phosphoric acid but are deficient in sulphur containing amino acids (Gautam et al, 2016). The center of origin is India where blackgram has been cultivated from ancient times.…”

RAPD assisted selection of black gram (Vigna mungo L. Hepper) towards the development of multiple disease resistant germplasm

“…UCLV is another virus which is ubiquitous in all commercially viable Vigna genus including V. mungo, and affects the crop in all stages especially in early stage which devastates total seed yield. In time, leaves become leathery and crinkled and lose the ability to perform normal physiological functions (Gautam et al 2016). …”

Silicon and Nitrate Differentially Modulate the Symbiotic Performances of Healthy and Virus-Infected Bradyrhizobium-nodulated Cowpea (Vigna unguiculata), Yardlong Bean (V. unguiculata subsp. sesquipedalis) and Mung Bean (V. radiata)

“…Vigna species, in general, are highly susceptible to many viruses as described in recent publications [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. Amid Vigna infecting virus, the Cowpea chlorotic mottle virus (family Bromoviridae , genus Bromovirus )/(CCMV) and the Cowpea mild mottle virus (Order Tymovirales, family Betaflexiviridae , genus Carlavirus )/(CMMV) have emerged in the past two decades as an important threat to legume crops globally [ 16 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 ].…”