The most dynamic and global environmental issue to date is climate change. The consequences of greenhouse effect and climate change from rising temperatures, frequent droughts, irregular rainfall, etc. are already evident. Insects and plants are affected by climate change and extreme weather events and the direct impact of anthropogenic climate change has been reported on every continent, in every ocean and in most major taxonomic groups. In the modern period, as a result of natural cycles and anthropogenic activities and their effects on the global climate, plants are typically susceptible to new environmental factors, i.e. higher levels solar radiation, rise in temperatures, greenhouse effect and changes in rainfall patterns over the seasons. Increased temperatures, CO2 and rapid changes in rainfall patterns can dramatically alter the biochemistry of plants and thus plant defence responses. This can have important implications in insect fertility, feeding rates, survival, population size, and dispersal. The relationships between plants and insects are thus changed with significant consequences for food security and natural ecosystems. Similarly, mismatches between plants and insect pollinators are caused by the acceleration of plant phenology by warming. Human nutrition which depends on insect pollination can be affected with reduction in plant reproduction and fitness. Thus, understanding abiotic stress reactions in plants and insects is relevant and challenging in agriculture. In the preparation and implementation of effective strategies for future insect pest management programmes, the impact of climate change on crop production, mediated by changes in the populations of extreme insect pests should be carefully considered.

A total of 50 Fusarium isolates were collected from major pigeonpea growing states of India and studied for cultural and morphological characters. Among 50 isolates, a total of 30 isolates were selected based on their cultural and morphological characters and studied for pathogenic variability on eight pigeonpea (ICP8858, ICP 8859, ICP 8862, BDN-2, ICP 9174 ICP 8863, ICP 2376 and BAHAR) differential genotypes. Among eight genotypes, the four genotypes namely ICP8858, ICP 8859, ICP 8862, BDN-2 reacted differentially to isolates and not much consistent in their pathogenicity, however two genotypes ICP 9174 and ICP 8863 exhibited resistant reactions and two genotypes ICP 2376 and BAHAR exhibited consistent susceptibility to wilt disease and could differentiate the 30 Fusarium isolates into six pathogenic variants (0, 1, 2, 3, 4 and 5). Among 6 variants, maximum distribution of Fusarium variants was noticed in Bihar and Telangana (4 variants in each state) followed by Andhra Pradesh, Karnataka Uttar Pradesh and, Maharashtra (2 variants) and one variant each in New Delhi and Jharkhand states. The ITS-rDNA sequencing 23 Fusarium isolates of revealed that Fusarium udum (65.21) was the dominant species causing pigeonpea wilt in India followed by Fusarium solani (21.7) and Fusarium equiseti (13.04). The results of present study were notable in terms of Fusarium variants, which might be used to deploy location specific wilt resistant cultivars for improved disease management tactics. This study will also aid in the development of broad- based pigeonpea wilt resistant varieties to supress potential epidemics.

No abstract

Nicotine is a highly addictive alkaloid and a neurostimulator found in tobacco that causes addiction in humans and makes tobacco a high-demand commercial product. It is popularly used for recreational purposes and is a harmful substance (Oral LD50 value for rat is 50 mg/kg) and causes addiction. The metabolites of nicotine such as the Tobacco-specific Nitrosamines (TSNAs) are hazardous substances whose metabolites are highly electrophilic and form DNA adducts, which will initiate the process of carcinogenesis. TSNAs are formed during curing, storage and fermentation due to the nitrosation of nicotine and other tobacco alkaloids. TSNAs are used as biomarkers for cancer risk assessment in humans exposed to tobacco and its products. To determine the occasional formation of TSNAs in tobacco-feeding insects, 5th instar larvae of Spodoptera litura and their faeces were analyzed for the presence of N′-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) along with the stored tobacco leaves (PT-76) using an Agilent 6470B LC–MS/MS system following ISO/DIS 19290:2015 protocol. The larvae are extracted in a buffered acetonitrile–water extraction and the amount of TSNAs are quantified in multiple reaction monitoring (MRM) mode. 20 $$\upmu$$ μ l of each extracted and cleaned up sample was injected into the LC–MS/MS system for quantification. The Limit of Detection (LOD) and Limit of Quantification (LOQ) were 0.001 mg/kg and 0.005 mg/kg for all the tested nitrosamines. NNN was found to be 0.361 mg/kg, 0.340 mg/kg, and 5.66 mg/kg in insect whole-body samples, faeces, and tobacco leaves, respectively. NNK was found to be 0.060 mg/kg, 0.035 mg/kg and 0.93 mg/kg in insect whole body samples, faeces and tobacco leaves, respectively. However, NNAL was not detected in both the insect’s whole body and faeces. Recoveries ranged between 95 and 98% for all compounds when spiked at LOD and LOQ. The presence of TSNAs is a biomarker for cancer risk and their presence in insects would point to cancer risk assessment in tobacco feeding insects and any possible TSNA-detoxifying pathways in insects that might prevent mutagenesis caused these compounds.