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The intensity of rice false smut disease in selected states of northwest and south India was studied. In northern Indian states as a whole, disease incidence (percentage of false smut-infected tillers) varied from 2% to 75%. In the state of Haryana, maximum infection was recorded on hybrids like PA 6444 and PA 6129 while in Punjab state, 10-20% disease incidence was recorded in popular inbred rice varieties like PR 114, PA 116 and PAU 201. In the southern state of Tamil Nadu, the disease incidence varied from 5% to 85%. A heavy incidence of the disease was noticed in variety BPT 5204 and due to this, the air above the infected field gave a black smoky appearance from a distance as a result of release of spore mass in the atmosphere. In severe cases the number of infected grains reached even more than 100 per panicle. The pathogen Ustilaginoidea virens was isolated in potato dextrose agar medium and was characterized by both pathogenicity test and molecular analysis. Under glasshouse conditions, when a conidial suspension of the pathogen was injected during boot leaf stage of the rice variety TN1, typical smut balls were observed. The identity of the pathogen was further confirmed through polymerase chain reaction (PCR) analysis using U. virens-specific internal transcribed spacer (ITS) primers. The primer pair US 1-5/US3-3 and US2-5/US4-3 amplified 380 bp and 232 bp product, respectively, which are typical for the U. virens fungus.

Drought is a serious threat to the farming community, biasing the crop productivity in arid and semi-arid regions of the world. Drought adversely affects seed germination, plant growth, and development via non-normal physiological processes. Plants generally acclimatize to drought stress through various tolerance mechanisms, but the changes in global climate and modern agricultural systems have further worsened the crop productivity. In order to increase the production and productivity, several strategies such as the breeding of tolerant varieties and exogenous application of growth regulators, osmoprotectants, and plant mineral nutrients are followed to mitigate the effects of drought stress. Nevertheless, the complex nature of drought stress makes these strategies ineffective in benefiting the farming community. Seed priming is an alternative, low-cost, and feasible technique, which can improve drought stress tolerance through enhanced and advanced seed germination. Primed seeds can retain the memory of previous stress and enable protection against oxidative stress through earlier activation of the cellular defense mechanism, reduced imbibition time, upsurge of germination promoters, and osmotic regulation. However, a better understanding of the metabolic events during the priming treatment is needed to use this technology in a more efficient way. Interestingly, the review highlights the morphological, physiological, biochemical, and molecular responses of seed priming for enhancing the drought tolerance in crop plants. Furthermore, the challenges and opportunities associated with various priming methods are also addressed side-by-side to enable the use of this simple and cost-efficient technique in a more efficient manner.

Mungbean yellow mosaic virus (MYMV) disease is one of the most vicious diseases of green gram and has been renowned in India for more than five decades. It is caused by a group of geminiviruses belonging to the genus, begomovirus of the family, Geminiviridae. They are transmitted through whitefly in a persistent manner. The economic losses due to this virus account up to 85% in green gram which is spreading faster towards newer areas. The escalating economic importance of MYMV has resulted in the call for accurate detection and identification procedures that inspire rigorous research efforts focussing on the biology, diversity and epidemiology of the virus, so that viable management strategies could be designed. Breeding for resistance or tolerance appears to be the best approach to control this disease. However, the commercially offered genotypes are only partially resistant. Therefore, the hunt for newer sources of disease resistance needs to be intensified. This review updates all the accessible information on MYMV and outlines the areas in which advance research is indispensable.

One DNA A (KA30) and five different DNA B components (KA21, KA22, KA27, KA28 and KA34) of a geminivirus, Mungbean yellow mosaic virus-Vigna (MYMV-Vig) were cloned from a pooled sample of field-infected Vigna mungo plants from Vamban, South India. MYMV-Vig DNA A (KA30) and one of the DNA B components (KA27) exhibited 97% and 95% sequence identities, respectively, to those of MYMV reported from Thailand. However, the DNA B components KA21, KA22, KA28 and KA34 exhibited only 71 to 72% sequence identity to MYMV DNA B. Co-existence of multiple DNA B components in field-infected V. mungo was proved by Southern and PCR analyses. Each of the five DNA B components was infective together with the DNA A upon agroinoculation. Agroinoculation with mixed cultures of Agrobacterium with partial dimers of DNA A and all five DNA Bs proved that all five DNA B components can co-infect a single V. mungo plant.