Cotton leaf curl disease (CLCuD), caused by monopartite begomoviruses and its satellite molecules, is one of the serious constrains in cultivation of cotton in India. In the present study, five CLCuD-begomovirus and its associated satellite molecules were characterized based on rolling circle amplification and sequencing of complete genome. Sequence analysis showed 82-99 % nucleotide identity among them. The phylogenetic analysis and nt identity matrix determined that of the five CLCuD-begomovirus isolates, three IARI-34, IARI-42 and IARI-50 were members of Cotton leaf curl Multan virus (CLCuMuV)-Rajasthan isolates, designated as CLCuMuV-Rajasthan-34 and two, IARI-30 and IARI-45 of Cotton leaf curl Kokhran virus (CLCuKoV)-Burewala isolates, designated as CLCuKoV-Burewala-45. The present CLCuMuVRajasthan-34 is recombinant isolate showing recombination events in IR, C1 and C4 regions of its genome with high probality (P = 9.9 9 10 -10 -3.2 9 10 -6 ). Same species of betasatellite (1371 nt) molecules obtained from both the present isolates was related with cotton leaf curl Multan betasatellite by 89-97 % nt identity. Three alphasatellites (1366-1396 nt) related to Cotton leaf curl Burewala alphasatellite and Gossypium darwinii symptomless alphasatellite by 86 % nt identity were also obtained. This is the first report of appearance of CLCuKoV-Burewala isolate and CLCuD associated alphasatellites in New Delhi. The present study demonstrated that CLCuD in New Delhi is caused by three kinds of variants, two are strains of CLCuMuV and one of CLCuKoV, either by single or mixed infection along with beta-and alphasatellite molecues.

Citrus tristeza virus (CTV, genus ) is one of the most serious pathogens responsible for huge loss of citrus trees worldwide. Four Indian CTV isolates, Kat1 (/Central India), D1 (/North India), B5 (/South India) and G28 (/Northeast India) collected from different regions of India were characterized based on sequencing of 3' half genome (~ 8.4 kb) comprising 10 open reading frames (ORFs2-11) and 3' UTR and the sequences were submitted to NCBI database as Acc. No KJ914662, HQ912022, HQ912023 and KJ914661, respectively. The present and previously reported Indian isolates Kpg3 and B165 were analyzed and compared with other Asian and international CTV isolates. The Indian CTV isolates had 92-99% nt identities among them. The phylogenetic analysis generated overall ten genogroups/lineages. Of them, all the Asian isolates fell into seven genogroups, whereas the Indian isolates into four. Indian isolates Kat1, D1 and Kpg3 grouped together, termed "Kpg3Gr", along with Florida severe isolate T3. The Indian isolates B5, and G28 were found to be two distinct and separate lineages, indicating that these isolates are two new CTV entities. Based on phylogenetic analysis, Kpg3Gr was identified as "Indian VT" subtype which is distinct from the Asian and the Western VT subtype within diversified VT genotype. The recombination detecting-program, RDP4 detected Indian isolates Kat1, B5, B165 and G28 as recombinants, where G28 as strong recombinant. The present study determined the occurrence of at least four CTV genotypes, B5 (distinct), B165 (T68 type) G28 (distinct) and Kpg3Gr in citrus growing regions of India.

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Groundnut (Arachis hypogaea L.) is a member of sub-family, Papilionaceae of the family Leguminosae. Groundnut is also known as peanut, mungphalli, china badam and wonder badam. Arachis hypogaea mainly two type Virginia (spreading) and Spanish (bunch). The Virginia group does not produce flowers on the central branch, only on the lateral branches. The seeds show some dormancy and the crop is relatively late maturing (130-170 days). Collar rot (Aspergillus niger Van Tiegham) of groundnut caused by Aspergillus niger has become severe and wide spread in many districts of Rajasthan state resulting in huge economic losses. An experiment was conducted during kharif seasons of 2018 to 2019 to find out some resistance sources against collar rot disease of groundnut in sick plot condition at Agricultural Research Station, Bikaner. Evaluation of forty genotypes /varieties of groundnut were revealed that none of the entries was found free or resistance from the disease. However, five genotypes /varieties were found moderately resistant (< 20%) against collar rot disease. These were Girnor-3, HNG-69, TG-37, ICMS-6 and ICMS-28. Twenty-five genotypes/varieties were found tolerant (20-40%) against collar rot disease.

A survey was made to study cotton leaf curl disease (CLCuD) incidence in cotton growing areas of Haryana, Punjab and Rajasthan in Northwest (NW) India during the years of 2013 and 2014. The present study revealed higher overall CLCuD incidence of 77.5% with higher overall boll number reduction (BNR) of 36.9% in 2013 compared to incidence of 49.6% with 7.6% BNR in 2014 in Haryana. In Rajasthan the disease incidence of 55.9% and 21.6% BNR in 2013 when compared to 10.8% of incidence and 2.9% BNR in 2014 was recorded. The overall CLCuD incidence and BNR in cotton growing areas of Punjab were more or less similar for both the years of 2013 and 2014, where disease incidence of 54.1% with BNR 14.6% in 2013 and disease incidence 57.8% with BNR of 15.9% in 2014 was recorded. All the 11 Bt-cotton hybrids from the farmer’s fields of Sri Ganganagar and Sirsa districts surveyed were highly susceptible to CLCuD in both the years; showing 100% disease incidence with BNR of 32.3-82.3% in 2013 and 49.2-100% with BNR of 8.7-17.4% in 2014. Infectivity study through whitefly (Bemisia tabaci) and polymerase chain reaction (PCR) of ORF V1 (CP gene) determined that CLCuD in NW India is caused by whitefly transmitted CLCuD-begomoviruses. Sequence analysis of CP gene indicated that at least three CLCuD-begomoviruses variants appeared in this cotton growing region. The increased CLCuD incidence with huge yield loss and occurrence of CLCuD-begomovirus variants reported in the present is an alarming situation for the profitable cultivation of cotton in north India.