Globally, abiotic stresses, such as temperature (heat or cold), water (drought and flooding), and salinity, cause significant losses in crop production and have adverse effects on plant growth and development. A variety of DNA-based molecular markers, such as SSRs, RFLPs, AFLPs, SNPs, etc., have been used to screen germplasms for stress tolerance and the QTL mapping of stress-related genes. Such molecular-marker-assisted selection strategies can quicken the development of tolerant/resistant cultivars to withstand abiotic stresses. Oilseeds such as rapeseed, mustard, peanuts, soybeans, sunflower, safflower, sesame, flaxseed, and castor are the most important source of edible oil worldwide. Although oilseed crops are known for their capacity to withstand abiotic challenges, there is a significant difference between actual and potential yields due to the adaptation and tolerance to severe abiotic pressures. This review summarizes the applications of molecular markers to date to achieve abiotic stress tolerance in major oilseed crops. The molecular markers that have been reported for genetic diversity studies and the mapping and tagging of genes/QTLs for drought, heavy metal stress, salinity, flooding, cold and heat stress, and their application in the MAS are presented.

Field pea is one of the important short-duration cool season pulse crops which contributes significantly towards food and nutritional security. Two heat-susceptible (HS) and two heat-tolerant (HT) genotypes were selected from the previous study for further characterization. A significant variation was observed for morpho-physiological traits studied. Principal component analysis explained that first two principal components, i.e., PC1 and PC2 showed 76.5% of the total variance in optimal condition, whereas 91.2% of the total variance was covered by the first two PCs in heat stress environment. The seed yield per plant determined significant and positive association with superoxide dismutase and number of seeds per pod under optimal conditions, whereas under heat stress condition, it was positively associated with number of effective pods per plant, biological yield per plant, proline, pod length, number of seeds per pod, superoxide dismutase, and peroxidase. The significant reduction was noticed in the susceptible genotypes, whereas tolerant genotypes showed stable and non-significant reduction in chlorophyll content. Further, minimum cell damage and higher hydrogen peroxide production was noticed in the susceptible genotypes. In addition, the biochemical characterization of HS and HT genotypes revealed that the higher expression of peroxidase, superoxide dismutase, and catalase modulates the tolerant responses in HT genotypes. These genotypes were further used in developing heat-tolerant field pea genotypes.

Waterlogging represents a substantial agricultural concern, inducing harmful impacts on crop development and productivity. In the present study, 142 diverse sesame genotypes were examined during the early vegetative phase to assess their response under waterlogging conditions. Based on the severity of symptoms observed, 2 genotypes were classified as highly tolerant, 66 as moderately tolerant, 69 as susceptible, and 5 as highly susceptible. Subsequent investigation focused on four genotypes, i.e., two highly tolerant (JLT-8 and GP-70) and two highly susceptible (R-III-F6 and EC-335003). These genotypes were subjected to incremental stress periods (0 h, 24 h, 48 h, 72 h, and 96 h) to elucidate the biochemical basis of tolerance mechanisms. Each experiment was conducted as a randomized split-plot design with three replications, and the statistical significance of the treatment differences was determined using the one-way analysis of variance (ANOVA) followed by the Fisher least significant difference (LSD) test at p ≤ 0.05. The influence of waterlogging stress on morphological growth was detrimental for both tolerant and susceptible genotypes, with more severe consequences observed in the latter. Although adventitious roots were observed in both sets of genotypes above flooding levels, the tolerant genotypes exhibited a more rapid and vigorous development of these roots after 48 h of stress exposure. Tolerant genotypes displayed higher tolerance coefficients compared to susceptible genotypes. Furthermore, tolerant genotypes maintained elevated antioxidant potential, thereby minimizing oxidative stress. Conversely, susceptible genotypes exhibited higher accumulation of hydrogen peroxide (H₂O₂) and malondialdehyde content. Photosynthetic efficiency was reduced in all genotypes after 24 h of stress treatment, with a particularly drastic reduction in susceptible genotypes compared to their tolerant counterparts. Tolerant genotypes exhibited significantly higher activities of anaerobic metabolism enzymes, enabling prolonged survival under waterlogging conditions. Increase in proline content was observed in all the genotypes indicating the cellular osmotic balance adjustments in response to stress exposure. Consequently, the robust antioxidant potential and efficient anaerobic metabolism observed in the tolerant genotypes served as key mechanisms enabling their resilience to short-term waterlogging exposure. These findings underscore the promising potential of specific sesame genotypes in enhancing crop resilience against waterlogging stress, offering valuable insights for agricultural practices and breeding programs.

Finger millet blast caused by Pyricularia grisea hinders crop’s growth and is a serious threat to economic yield. It can lead to massive yield losses i.e. up to 80%, which is a cause of major concern. In this study, we evaluated 200 accessions of finger millet at Banda University of Agriculture & Technology in Banda, India, under natural conditions to determine their resistance against leaf, neck, & finger blast diseases. Nine accessions displayed strong resistance against all forms of blast. The genetic variability analysis revealed high phenotypic & genotypic coefficients of variation. This was especially true for seed yield, plant height, & days to flowering. Most traits had heritability estimates exceeding 80%. Such results indicate a significant potential for effective selection in breeding programs. Leaf blast ratings had a significant but weaker correlation to both neck blast (r = 0.31) and finger blast (r = 0.31) whereas neck and finger blast ratings were very highly correlated and significant (r = 0.97). All types of blast had negative correlation with various agronomic traits studied. Furthermore, DNA fingerprinting of resistant genotypes with SSR markers displayed 10 polymorphic markers with an average of 2.6 alleles per locus. This points to the genetic diversity present within the germplasm. In summary, these findings provide vital insights for breeding initiatives focused on enhancing blast resistance in finger millet. Such efforts are crucial for maintaining the sustainability of this important crop for global food security.

The movements of the lateral leaflets of the Indian telegraph plant Desmodium gyrans (L. F.) DC, have earlier been studied in detail with regards to the effects of chemicals, DC currents, and static magnetic fields. In the present paper we have discussed the oscillation of the lateral leaflets under the influence of white light of various light levels (0-75 micromol x m(-2) x s(-1)), produced by an array of LEDs (light emitting diodes). LEDs were used in contrast to fluorescense tubes as in earlier studies in order to minimize changes of wavelength when light intensity was decreased or increased. Furthermore, care was taken to ensure that the temperature in the experimental chamber was constant. When the oscillations were first monitored in bright light, the oscillations were found to be very rapid and with decreasing light intensity the oscillations slowed down. For light levels lower than about 20 micromol x m(-2) x s(-1) the period of the oscillation of the lateral leaflets was almost constant (or even decreased slightly towards complete darkness). We also show that the oscillations could completely stop under prolonged darkness (for longer than about 6 h) and that such halted oscillations could be restarted in most of the leaflets when he light was turned back on. Such stopping of the oscillation of the lateral leaflets in prolonged darkness suggests that these short period oscillations of the lateral leaflets could have a daily component and in natural environment these oscillations could serve the purpose of optimising the amount of light falling on the leaflets or/and facilitating transpiration of water through stomata. Such a finding could have an implication for the answer to the long standing question of adaptive significance of short period oscillation of the Indian telegraph plant Desmodium gyrans (L. F.) DC.

Eight field pea parental lines and their twenty-eight F₁s resulting from diallel design (excluding reciprocal) were analyzed for their combining ability and heterosis for yield and associated traits. ANOVA revealed significant variation among parents and among hybrids for days to 50% flowering, plant height, total number of pods, effective pods, seeds per pod, 100-seed weight, biological yield and seed yield; pod length also revealed significant differences among hybrids, suggesting the occurrence of considerable variability for studied traits. Crosses P-1541-16 × P-92-97-11 and P-1541-16 × P-1297-97 displayed significant heterosis over better-parent and control varieties for seed yield and associated traits. Combining ability analysis showedthat SCAvariance was considerably higher than corresponding GCAvariance for all traits. Genotype Aman and P-1297-97 were identified as good general combiners for seed yield, while cross P-1541-16 × P-1297-97, Aman × EC-564817, P-1541-16 × P-92-97-11 and P-1297-97 × P-92-97-11 were identified as specific cross-combiners for most of the studied traits. Consequently, these crosses might be exploited in future breeding programs to find desired segregants. PCA explained 81.68% and 83.34% variability in parents and crosses, respectively, for yield component. Furthermore, trait association between GCA effects and SCA effects demonstrates that biological yield, total number of pods, and effective pods exhibit additive gene action, but 100-seed weight exhibits non-additive gene action.