One hundred and sixty two genotypes of different Lens species were screened for salinity tolerance in hydroponics at 40, 80 and 120 mM sodium chloride (NaCl) for 30 d. The germination, seedling growth, biomass accumulation, seedling survivability, salinity scores, root and shoot anatomy, sodium ion (Na+), chloride ion (Cl-) and potassium ion (K+) concentrations, proline and antioxidant activities were measured to evaluate the performance of all the genotypes. The results were compared in respect of physiological (Na+, K+ and Cl-) and seed yield components obtained from field trials for salinity stress conducted during two years. Expression of salt tolerance in hydroponics was found to be reliable indicator for similarity in salt tolerance between genotypes and was evident in saline soil based comparisons. Impressive genotypic variation for salinity tolerance was observed among the genotypes screened under hydroponic and saline field conditions. Plant concentrations of Na+ and Cl- at 120 mM NaCl were found significantly correlated with germination, root and shoot length, fresh and dry weight of roots and shoots, seedling survivability, salinity scores and K+ under controlled conditions and ranked the genotypes along with their seed yield in the field. Root and shoot anatomy of tolerant line (PDL-1) and wild accession (ILWL-137) showed restricted uptake of Na+ and Cl- due to thick layer of their epidermis and endodermis as compared to sensitive cultigen (L-4076). All the genotypes were scanned using SSR markers for genetic diversity, which generated high polymorphism. On the basis of cluster analysis and population structure the contrasting genotypes were grouped into different classes. These markers may further be tested to explore their potential in marker-assisted selection.

Aluminium (Al) stress was imposed on 285 lentil genotypes at seedling stage under hydroponics to study its effects on morpho-physiological traits where resistant cultigens and wilds showed minimum reduction in root and shoot length and maximum root re-growth (RRG) after staining. Molecular assortment based on 46 simple sequence repeat (SSR) markers clustered the genotypes into 11 groups, where wilds were separated from the cultigens. Genetic diversity and polymorphism information content (PIC) varied between 0.148–0.775 and 0.140–0.739, respectively. Breeding lines which were found to be most resistant (L-7903, L-4602); sensitive cultivars (BM-4, L-4147) and wilds ILWL-185 (resistant), ILWL-436 (sensitive) were grouped into different clusters. These genotypes were also separated on the basis of population structure and Jaccard’s similarity index and analysed to study Al resistance mechanism through determination of different attributes like localization of Al and callose, lipid peroxidation, secretion of organic acids and production of antioxidant enzymes. In contrast to sensitive genotypes, in resistant ones most of the Al was localized in the epidermal cells, where its movement to apoplastic region was restricted due to release of citrate and malate. Under acidic field conditions, resistant genotypes produced maximum seed yield/plant as compared to sensitive genotypes at two different locations i.e. Imphal, Manipur, India and Basar, Arunanchal Pradesh, India during 2012–13, 2013–14 and 2014–15. These findings suggest that Al stress adaptation in lentil is through exclusion mechanism and hybridization between the contrasting genotypes from distinct clusters can help in development of resistant varieties.

Screening for drought tolerance is severely handicapped by the lack of a simple and reliable phenotyping technique. The objective of this study was to develop a new screening technique based on seedling survivability, drought tolerance score, root and shoot length, and fresh and dry weight of roots and shoots of lentil plants exposed to drought under hydroponic conditions. Its effectiveness was compared with two soil culture techniques. The hydroponic technique involved removing 15‐day‐old seedlings of 80 genotypes from the nutrient solution and exposing them to air for 5 h daily for 6 days. Three genotypes received from ICARDA, ‘ILL‐10700’, ‘ILL‐10823’ and ‘FLIP‐96‐51’, showed maximum seedling survivability and minimum reduction in the growth parameters with a drought score of 0.0–0.2 indicating higher tolerance to drought stress, while Indian genotypes ‘JL‐3’, ‘E‐153’ and ‘VL‐507’ showed no seedling survivability and maximum reduction in growth parameters with a drought score of 4.0 indicating low drought tolerance. The results suggest that this new phenotyping technique is effective, rapid and easy for screening a large number of genotypes.

Heat stress is one of the most severe abiotic stresses affecting yield of agricultural crops. Its effects can be minimized through development of heat‐tolerant genotypes. In this study, the populations were developed through crossing heat‐stress‐sensitive (‘JL‐3’ and E‐153) and tolerant (PDL‐1 and PDL‐2) lentil (Lens culinaris Medik.) genotypes for studying the genetics and molecular mapping of heat tolerance. The parents, F1, F2, F3, and backcross populations were exposed to heat stress at seedling (35/33°C) and reproductive (35/20°C) stages under hydroponic assay. The F1s were found tolerant, indicating dominance of heat tolerance based on seedling survival and pod set per plant. The segregation ratios obtained for heat tolerance in the F2, F3, and backcross populations were 3:1, 1:2:1, and 1:1 based on seedling survival and pod set per plant. This suggested the presence of a single dominant gene for seedling survival and pod set related to heat tolerance in PDL‐1 and PDL‐2. This matched with one major quantitative trait locus (QTL) in each trait (i.e., seedling survival and pod set per plant). Out of 495 simple sequence repeat markers used in this study, 13 distinguished the parental lines. However, tolerant and sensitive bulks could be distinguished by seven markers, which were used for genotyping the F2 mapping population. The QTL analysis using data for genotyping and phenotyping identified two major QTLs, qHt_ss and qHt_ps, with 12.1 and 9.23% phenotypic variance explained for seedling survival and pod set, respectively. These QTLs would provide further opportunities to dissect candidate genes and development of molecular markers for improving lentil cultivars with heat tolerance.

An understanding of the inheritance of aluminium (Al) tolerance is important to breed for Al-tolerant genotypes of chickpea (Cicer arietinum L.). Therefore, a study was undertaken to infer genes governing Al tolerance in chickpea. Tolerant lines ÔICC14880Õ and ÔIPC92-39Õ were crossed with sensitive lines ÔIPCK96-3Õ and ÔIPC99-4Õ. Parental, F 1 , F 2 , F 3 and backcross generations were evaluated in a nutrient solution containing 20 ppm Al for haematoxylin staining and root re-growth and classified for tolerance by staining of root tips and root re-growth. The F 1 hybrids responded similarly to the tolerant parents indicating dominance of Al tolerance over sensitivity. Segregation for tolerance vs. sensitivity in F 2 fitted well with the 3 : 1 ratio expected for a single gene. The backcross and F 3 data confirmed the presence of single dominant gene common in tolerant parents. Experimental findings showed that Al tolerance is a monogenic dominant trait that can be easily transferred to high yielding lines through a backcross breeding.

The success of drought tolerance breeding programs can be enhanced through molecular assortment of germplasm. This study was designed to characterize molecular diversity within and between Lens species with different adaptations to drought stress conditions using SSR markers. Drought stress was applied at seedling stage to study the effects on morpho-physiological traits under controlled condition, where tolerant cultivars and wilds showed 12.8–27.6% and 9.5–23.2% reduction in seed yield per plant respectively. When juxtaposed to field conditions, the tolerant cultivars (PDL-1 and PDL-2) and wild (ILWL-314 and ILWL-436) accessions showed 10.5–26.5% and 7.5%–15.6% reduction in seed yield per plant, respectively under rain-fed conditions. The reductions in seed yield in the two tolerant cultivars and wilds under severe drought condition were 48–49% and 30.5–45.3% respectively. A set of 258 alleles were identified among 278 genotypes using 35 SSR markers. Genetic diversity and polymorphism information contents varied between 0.321–0.854 and 0.299–0.836, with mean value of 0.682 and 0.643, respectively. All the genotypes were clustered into 11 groups based on SSR markers. Tolerant genotypes were grouped in cluster 6 while sensitive ones were mainly grouped into cluster 7. Wild accessions were separated from cultivars on the basis of both population structure and cluster analysis. Cluster analysis has further grouped the wild accessions on the basis of species and sub-species into 5 clusters. Physiological and morphological characters under drought stress were significantly (P = 0.05) different among microsatellite clusters. These findings suggest that drought adaptation is variable among wild and cultivated genotypes. Also, genotypes from contrasting clusters can be selected for hybridization which could help in evolution of better segregants for improving drought tolerance in lentil.

With 5 figures and 5 tables Abstract Aluminium (Al) tolerance of 60 genotypes was evaluated using the growth response and haematoxylin staining methods. Major traits used to evaluate Al tolerance were score of root staining, root regrowth after staining, root and shoot length, dry weight of roots and shoots, and pods/plant. Significant variability was noted for tolerance to Al toxicity among the lentil genotypes for all traits except score of root staining. Score of haematoxylin root staining did not show any correlation with growth response method. However, root regrowth after staining showed significant correlation with root and shoot length, dry weight of roots and shoots, and pods/plant. In a further long‐term experiment, the Al tolerance of three tolerant (‘L‐7903’, ‘L‐4602’ and ‘ILL‐6002’) and two sensitive (‘L‐4147’ and ‘BARI Massor‐4’) lines was assessed at the adult stage to evaluate the consistency of Al tolerance. This study also showed that Al tolerance of lentil does not vary with plant growth stage, so selection for increased Al tolerance can be carried out at the seedling growth stage.

With the emergence of second wave of COVID-19 infection globally, particularly in India in March–April 2021, protection by massive vaccination drive has become the need of the hour. Vaccines have been proved to reduce the risk of developing severe illness and are emerging as vital tools in the battle against COVID-19. As per the GLOBOCAN database, nearly 19.3 million new cancer cases have been reported in 2020 globally, which posed a significant challenge to health care providers to protect such large number of ‘vulnerable’ patients from COVID-19. Nevertheless, a considerable degree of doubt, hesitancy and misconceptions are noted regarding the administration of vaccines particularly during active immuno-suppressant treatment. This review article highlights the added vulnerability of cancer patients to the COVID-19 infection and has explored the immunological challenges associated with malignancy, anticancer treatment and COVID-19 vaccination. Supplementary Information The online version contains supplementary material available at 10.1007/s12032-021-01540-8.