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The introgression of genetic material from one species to another through wide hybridization and repeated back-crossing, plays an important role in genetic modification and enriching the cultivated gene-pool with novel genetic variations. Okra ( [(L.) Moench)] is a popular vegetable crop with high dietary fibre and protein, rich in essential amino acids, lysine and tryptophan. The wild genepool has many desirable traits like ornamental value, short internodal length, more number of productive branches, extended bearing, perennation tendency, reduced fruit length (more consumer preferred trait), high mucilage content (medicinal value), abiotic stress tolerances such as drought, high temperature and biotic stress resistances such as okra Yellow Vein Mosaic Virus (YVMV) and Enation Leaf Curl Virus (ELCV) diseases. The repeated use of elite breeding lines led to narrowing of the genetic base of the okra crop, one of the major factors attributed to breakdown of resistance/ tolerance to biotic stresses. YVMV and ELCV are the two major diseases, causing significant yield loss in okra. Hence, wide hybridization was attempted to transfer tolerance genes from wild species to the cultivated genepool to widen the genetic base. The screening of germplasm of wild species at hotspots led to the identification of tolerant species ( , , , and ), which were further used in a wide-hybridization programme to generate interspecific hybrids with the cultivated okra. Presence of pre- and post-zygotic barriers to interspecific geneflow, differences in ploidy levels and genotype specific variations in chromosome numbers led to varying degrees of sterility in F plants of interspecific crosses. This was overcome by doubling the chromosome number of interspecific hybrids by applying Colchicine at the seedling stage. The 113 cross derivatives generated comprising amphidiploids in the F generation (30), F (14), one each in F and F generations, back cross generation in BC F (03), BC F (25), and BC2F3 (02), crosses between amphidiploids (27), multi-cross combinations (07) and inter-specific cross (between × subsp. ) selfed derivatives at F generation (03) were characterized in the present study. Besides they were advanced through selfing and backcrossing. The amphidiploids were found to possess many desirable genes with a considerable magnitude of linkage drag. Majority of the wide cross derivatives had an intermediate fruit morphology and dominance of wild characters ., hispid fruits, stem, leaves, tough fruit fibre, vigorous perennial growth habit and prolonged flowering and fruiting. The fruit morphology of three BC progenies exhibited a high morphological resemblance to the cultivated okra, confirming successful transfer of useful genes to the cultivated okra genepool. The detailed morphological characteristics of the various combinations of amphidiploids and the genetic enhancement of the genepool achieved in this process is reported here.

Late blight ( Phytophthora infestans ), characterized by small water-soaked areas that rapidly enlarge to form purple-brown, oily appearing blotches, is the most destructive fungal disease that continues to stymie worldwide tomato production. Severe outbreaks have been recorded in tomato-growing areas throughout the world in recent years, and the vast majority of commercial tomato cultivars are extremely vulnerable to the late blight infection. The aim of this study was to screen the wild tomato  Solanum habrochaites accessions LA1223, LA1353, LA1718, LA1777, LA2156, LA2167, and LA2556 under natural disease pressure conditions to find a possible source of resistance to late blight and also characterized these accessions for various morphological characters. Three S. habrochaites accessions (LA1777, LA2167, and LA2556) were resistant and superior to the susceptible check. With a PDI of 22.29, LA 1777 was shown to have the highest resistance, and as such, it may be used as a donor for late blight resistant tomato pre-breeding programmes in the near future. The success of high crossability (percentage) of some hybrid combinations using LA1777 as a male parent, such as LA3846 × LA1777 (77.77), LA2377 × LA1777 (62.50), and LA3317 × LA1777 (60.00), is encouraging for the development of pre-breeding genetic stocks as well as for the discovery of novel alleles in wild tomato populations. The morphological characterization of seven wild tomato accessions mainly confirms the guidelines of the International Plant Genetic Resources Institute. These accessions and their interspecific crosses showed wide variability in phenotypic and reproductive characters for plant height, flower color, exserted stigma, leaf margin, flowering time, fruit set, and other economic traits that will facilitate breeders in the development of superior tomato cultivars and F 1 hybrids resistant to biotic stresses, as well as differentiate these S. habrochaites accessions for their potential use in genetic enhancement of cultivated tomatoes.

Tomato leaf curl virus (ToLCV) is the most destructive disease of tomato causing fruit yield losses of up to 90–100%. The tomato cultivars are highly susceptible to ToLCV. There are six resistance genes; Ty-1 , Ty-2 , Ty-3 , Ty-4 , ty-5 and Ty-6 which are being practically utilized in resistance breeding. Ty-3 and Ty-4 showed highly stable resistance to ToLCV but searching for new genes is a key interest in long-term breeding programmes. In the present experiment, eight Solanum chilense accessions along with three cultivars or advance breeding lines were screened under field conditions prevailing high disease pressure to find new sources of resistance. All accessions of S. chilense were resistant to ToLCV. Ty-1 , Ty-1 / Ty-3 linked five each of sequence-based markers (WU_M17, WUR_M25, WU_M27, WU_M29 and WU_M31) and five SCAR markers (P6-25-F2/P6-25-R5, FLUW-25 F, UF_TY3-P19, Ualty3a and Ualty3b) were validated with all accessions for identification of novel alleles. Ualty3b marker amplified Ty-1 and Ty-3 amplicons only in LA2879, LA1930, LA1969, LA2748 and LA2773 and no amplicons were observed in LA1938, LA2759 and LA1958. This suggests that Ty-1 / Ty-3 genes that possibly exist in these accessions need to be explored in the breeding program. Marker P6-25-F2 amplified Ty-3 specific 630 bp amplicons in LA2879, LA1930, LA1969 and LA2773. The marker P6-25-F2 also amplified 450 bp amplicons of allele-specific Ty-3a in LA1938, LA2879, LA1969 and LA2748. Both Ty-3 and Ty-3a alleles were amplified in LA2879 and LA1969. The marker and field screening results showed that accessions LA1938, LA2879, LA1969 and LA2748 carry novel alleles resistant to ToLCV and are the potential sources for introgression of ToLCV resistant genes into commercial tomato cultivars.

Morinda (Rubiaceae) is considerably recognized for its multiple uses viz . food, medicine, dyes, firewood, tools, oil, bio-sorbent etc. The molecular characterization of such an important plant would be very useful for its multifarious enhanced utilization. In the present study, 31 Morinda genotypes belonging to two different species Morinda citrifolia L. and Morinda tomentosa B. Heyne exRoth collected from different regions of India were investigated using inter simple sequence repeat (ISSR) markers. Fifteen ISSR primers generated 176 bands with an average of 11.7 bands per primer, of which (90.34%) were polymorphic. The percentage of polymorphic bands, mean Nei’s gene diversity and mean Shannon’s information index in M. tomentosa and M. citrifolia was [(69.89%, 30.68%); (0.21 ± 0.19, 0.12 ± 0.20) and (0.32 ± 0.27 0.17 ± 0.28)] respectively, revealing higher polymorphism and genetic diversity in M. tomentosa compared to M. citrifolia . These diversity rich genotypes of M. tomentosa can be evaluated for nutraceutical, nutritional and other nonfood purposes to identify trait specific genotypes for its enhanced utilization. ISSR markers based Structure, and UPGMA cluster analysis placed the M. tomentosa and M. citrifolia genotypes into well-defined separate clusters. Further, distinct ecotypes within a particular species could also be inferred. Priority regions identified can be earmarked for exploration and collecting substantial number of genotypes for ex-situ conservation. In-situ conservation of Morinda genotypes in hotspots to preserve the diversity in their natural habitats vis-à-vis evolution and increased adaptation of newer diversity with respect to changing environment was also emphasized.

The introgression of genetic material from one species to another through wide hybridization and repeated back-crossing, plays an important role in genetic modification and enriching the cultivated gene-pool with novel genetic variations. Okra (Abelmoschus esculentus [(L.) Moench)] is a popular vegetable crop with high dietary fibre and protein, rich in essential amino acids, lysine and tryptophan. The wild Abelmoschus genepool has many desirable traits like ornamental value, short internodal length, more number of productive branches, extended bearing, perennation tendency, reduced fruit length (more consumer preferred trait), high mucilage content (medicinal value), abiotic stress tolerances such as drought, high temperature and biotic stress resistances such as okra Yellow Vein Mosaic Virus (YVMV) and Enation Leaf Curl Virus (ELCV) diseases. The repeated use of elite breeding lines led to narrowing of the genetic base of the okra crop, one of the major factors attributed to breakdown of resistance/ tolerance to biotic stresses. YVMV and ELCV are the two major diseases, causing significant yield loss in okra. Hence, wide hybridization was attempted to transfer tolerance genes from wild species to the cultivated genepool to widen the genetic base.IntroductionThe introgression of genetic material from one species to another through wide hybridization and repeated back-crossing, plays an important role in genetic modification and enriching the cultivated gene-pool with novel genetic variations. Okra (Abelmoschus esculentus [(L.) Moench)] is a popular vegetable crop with high dietary fibre and protein, rich in essential amino acids, lysine and tryptophan. The wild Abelmoschus genepool has many desirable traits like ornamental value, short internodal length, more number of productive branches, extended bearing, perennation tendency, reduced fruit length (more consumer preferred trait), high mucilage content (medicinal value), abiotic stress tolerances such as drought, high temperature and biotic stress resistances such as okra Yellow Vein Mosaic Virus (YVMV) and Enation Leaf Curl Virus (ELCV) diseases. The repeated use of elite breeding lines led to narrowing of the genetic base of the okra crop, one of the major factors attributed to breakdown of resistance/ tolerance to biotic stresses. YVMV and ELCV are the two major diseases, causing significant yield loss in okra. Hence, wide hybridization was attempted to transfer tolerance genes from wild species to the cultivated genepool to widen the genetic base.The screening of germplasm of wild Abelmoschus species at hotspots led to the identification of tolerant species (Abelmoschus pungens var. mizoramensis, A. enbeepeegeearensis, A. caillei, A. tetraphyllus and A. angulosus var. grandiflorus), which were further used in a wide-hybridization programme to generate interspecific hybrids with the cultivated okra. Presence of pre- and post-zygotic barriers to interspecific geneflow, differences in ploidy levels and genotype specific variations in chromosome numbers led to varying degrees of sterility in F1 plants of interspecific crosses. This was overcome by doubling the chromosome number of interspecific hybrids by applying Colchicine at the seedling stage. The 113 cross derivatives generated comprising amphidiploids in the F1 generation (30), F3 (14), one each in F2 and F4 generations, back cross generation in BC1F2 (03), BC1F3 (25), and BC2F3 (02), crosses between amphidiploids (27), multi-cross combinations (07) and inter-specific cross (between A. sagittifolius × A. moschatus subsp. moschatus) selfed derivatives at F8 generation (03) were characterized in the present study. Besides they were advanced through selfing and backcrossing.Material and methodsThe screening of germplasm of wild Abelmoschus species at hotspots led to the identification of tolerant species (Abelmoschus pungens var. mizoramensis, A. enbeepeegeearensis, A. caillei, A. tetraphyllus and A. angulosus var. grandiflorus), which were further used in a wide-hybridization programme to generate interspecific hybrids with the cultivated okra. Presence of pre- and post-zygotic barriers to interspecific geneflow, differences in ploidy levels and genotype specific variations in chromosome numbers led to varying degrees of sterility in F1 plants of interspecific crosses. This was overcome by doubling the chromosome number of interspecific hybrids by applying Colchicine at the seedling stage. The 113 cross derivatives generated comprising amphidiploids in the F1 generation (30), F3 (14), one each in F2 and F4 generations, back cross generation in BC1F2 (03), BC1F3 (25), and BC2F3 (02), crosses between amphidiploids (27), multi-cross combinations (07) and inter-specific cross (between A. sagittifolius × A. moschatus subsp. moschatus) selfed derivatives at F8 generation (03) were characterized in the present study. Besides they were advanced through selfing and backcrossing.The amphidiploids were found to possess many desirable genes with a considerable magnitude of linkage drag. Majority of the wide cross derivatives had an intermediate fruit morphology and dominance of wild characters viz., hispid fruits, stem, leaves, tough fruit fibre, vigorous perennial growth habit and prolonged flowering and fruiting. The fruit morphology of three BC progenies exhibited a high morphological resemblance to the cultivated okra, confirming successful transfer of useful genes to the cultivated okra genepool. The detailed morphological characteristics of the various combinations of Abelmoschus amphidiploids and the genetic enhancement of the genepool achieved in this process is reported here.Results and DiscussionThe amphidiploids were found to possess many desirable genes with a considerable magnitude of linkage drag. Majority of the wide cross derivatives had an intermediate fruit morphology and dominance of wild characters viz., hispid fruits, stem, leaves, tough fruit fibre, vigorous perennial growth habit and prolonged flowering and fruiting. The fruit morphology of three BC progenies exhibited a high morphological resemblance to the cultivated okra, confirming successful transfer of useful genes to the cultivated okra genepool. The detailed morphological characteristics of the various combinations of Abelmoschus amphidiploids and the genetic enhancement of the genepool achieved in this process is reported here.

The Omicron variant of SARS-CoV-2 is capable of infecting unvaccinated, vaccinated and previously-infected individuals due to its ability to evade neutralization by antibodies. With multiple sub-lineages of Omicron emerging in the last 12 months, there is inadequate information on the quantitative antibody response generated upon natural infection with Omicron variant and whether these antibodies offer cross-protection against other sub-lineages of Omicron variant. In this study, we characterized the growth kinetics of Kappa, Delta and Omicron variants of SARS-CoV-2 in Calu-3 cells. Relatively higher amounts infectious virus titers, cytopathic effect and disruption of epithelial barrier functions was observed with Delta variant whereas infection with Omicron sub-lineages led to a more robust induction of interferon pathway, lower level of virus replication and mild effect on epithelial barrier. The replication kinetics of BA.1, BA.2 and BA.2.75 sub-lineages of the Omicron variant were comparable in cell culture and natural infection in a subset of individuals led to a significant increase in binding and neutralizing antibodies to the Delta variant and all the three sub-lineages of Omicron but the level of neutralizing antibodies were lowest against the BA.2.75 variant. Finally, we show that Cu 2+ , Zn 2+ and Fe 2+ salts inhibited in vitro RdRp activity but only Cu 2+ and Fe 2+ inhibited both the Delta and Omicron variants in cell culture. Thus, our results suggest that high levels of interferons induced upon infection with Omicron variant may counter virus replication and spread. Waning neutralizing antibody titers rendered subjects susceptible to infection by Omicron variants and natural Omicron infection elicits neutralizing antibodies that can cross-react with other sub-lineages of Omicron and other variants of concern.

IntroductionTuberculosis (TB) continues to be one of the deadliest infectious diseases over the centuries, killing more people worldwide than any other single infectious disease. There is an urgent need for additional strategies which can expedite efforts to combat TB including a preventive vaccine. In this endeavour, we have developed a protocol for a multisite, double-blind, placebo-controlled clinical trial in India that aims to evaluate the efficacy and safety of two TB vaccines; namely, VPM1002 and Immuvac (M.w) (Mycobacterium Indicus Pranii) (MIP) among healthy household contacts (HHCs) of sputum smear-positive pulmonary TB (PTB) patients.Methods and analysisIn the three-arm randomised double-blind placebo-controlled trial study protocol, a total of 12 000 HHCs (aged 6−99 years) of sputum smear-positive PTB patients will be randomised to receive either of the two vaccine candidates VPM1002 and MIP or placebo. The primary efficacy endpoint is the prevention of microbiologically confirmed TB. Secondary endpoints will include (1) prevention against Latent TB infection, (2) incidence of adverse events and serious adverse events in study participants, (3) efficacy of vaccine in prevention of PTB/extra PTB in different age groups (6–18 years, 19–35 years, 36–60 years and above 60 years) and (4) immunogenicity of VPM1002 and MIP at month 2 and month 6 after first vaccination in terms of flow cytometric analysis of M.Tb specific CD4+ and CD8+ T cells secreting cytokines and Luminex assays for the presence of different cytokines in the sera and supernatants of peripheral blood mononuclear cells cultures stimulated with whole cell lysates of M.Tb and subsequently similar analysis for the cases who develop TB postvaccination during the follow-up period.Ethics and disseminationEthics committees’ approvals have been granted by the Institutional Human Ethics Committees of all participating centres in this study and the names of the ethics committees and approvals are as follows: (1) National Institute for Research in Tuberculosis (NIRT)-Chennai (including subsites): ECR/135/Inst/TN/2013/RR-19, Approval No. 390/NIRT-Institutional Ethics Committee (IEC)/2018 dated 5 December 2018 (NIRT-Madurai-ECR/1365/Inst/TN/2020; approval dated 8 June 2020; NIRT, Vellore: ECR/1215/Inst/TN/2019; approval dated 26 September 2020); (2) All India Institute of Medical Sciences (AIIMS), Delhi (including subsites)-Institute Ethics Committee, ECR/547/Inst/DL/2014/RR-17 ECR/538/Inst/DL/2014/RR-20; approval No.IEC-385/06-07-2018, approval OP-28/05.04.2019 and SFH- ECR/593/Inst/DL/2014/RR-20 IEC/VMMC/SJH/project/2019-05/25 ; 23 May 2019; (3) National Institute of Tuberculosis and Respiratory Diseases (NITRD), Delhi: ECR/315/Inst/DL/2013/RR-19; approval IEC-No-NITRD/EC/2019/9004; 8 January 2019; (4) Pune-National AIDS Research Institute (NARI) and subsite-ECR/23/Inst/MH/2013/RR-19; IEC-NARI/EC/approval/2018/196; 29 May 2018; (5) Regional Medical Research Centre-Bhubaneshwar-ECR/911/Inst/OR-2017/RR-21; approval, dated 25 April 2018; Subsites- AIIMS, Bhubaneshwar ECR/534/Inst/OD/2014/RR-17 and 20 approval No. T/EMF/Pulm. Med/19/01 dated 13 May 2019; SCB, Cuttack No. No.ECR/84/Inst/OR/2013/RR-20; approval no.186 dated 7 February 2020; (6) NTI-Bengaluru: Ethics Committee-No-ECR/1819/Inst/KA/2019; approval No NTI-IEC/1.2019/principal investigator, dated 31 January 2019; (7) BMMRC, Hyderabad- ECR/450/Inst/AP/2013/RR-16 approval No. 779/BMMRC/2018/IEC, dated 11 June 2018 (Subsite Share India- Mediciti Ethics Committee-ECR/283/Inst/AP/2013/RR-20; Approval no. EC/11/VII/2K20(1) dated 11 July 2020) and (8) SJMC-Bengaluru: ECR/238/Inst/KA/2013/RR-19; approval IEC/1/491/2020; 7 August 2020.The trial findings will be published in accordance with the Consolidated Standards of Reporting Trials guidance. The results of this clinical trial will be presented at scientific conferences and disseminated through publications in peer-reviewed journals, conference presentations and shared with Ministry of Health and Family Welfare, policy-makers and other stakeholders.Trial registration numberCTRI/2019/01/017026.