Identification of new sources of salt tolerance is particularly important to develop crop varieties suitable for saline soils. We evaluated 129 Pakistani and 58 exotic wheat landraces/cultivars grown in Hoagland's hydroponic nutrient solution, under control (tap water equivalent to 10 mM salt) and salt stress (200 mM NaCl) conditions. Forty-four genotypes were also tested under 250 mM NaCl stress. High heritability and positive correlations suggested that number of tillers per plant, root length, root fresh and dry weights, and shoot fresh and dry weights are associated with salt tolerance and could be used as selection criteria. SSR markers revealed high genetic variation in the wheat genotypes. Twelve SSR markers (cfd 1, cfd 9, cfd 18, cfd 46, cfd 49, cfd 183, wmc 11, wmc 17, wmc 18, wmc 154, wmc 432, and wmc 503) were found to be associated with salt tolerance because they were amplified in tolerant genotypes only. Five markers, cfd 9, cfd 18, cfd 183, wmc 96, and wmc 405, were identified as most suitable to evaluate salt tolerance because they were associated with four or more salt tolerance traits studied. Cultivars Pasban 90, accessions 10790, 10828, 10823, and 4098805 from Pakistan and Sakha-92 from Egypt performed best at both stress levels.

The genetic variation and relationships among 277 individual plants from 10 wheat genotypes were evaluated using RAPD markers. A total of 190 DNA fragments was generated by 25 random primers, with an average of 7.6 easily detectable fragments per primer. Of these, 84 fragments (44.64%) were polymorphic among the 10 genotypes. Several RAPD marker bands showed unique patterns of mean frequency that differed among the wheat germplasm groups. Within-population genetic variation ranged from 83% to 93% of the total. The greatest similarity was observed between Marghila-99 and Marvee-2000, whereas the local variety 8670-3 showed the lowest similarity with the exotic types. RAPD analysis can be used for the characterization and grouping of wheat genotypes. These results will be helpful in future wheat breeding programs.

Wheat pollen, which is characterized by its short lifespan, exhibits rapid germination after anthesis. The preservation of wheat pollen is contingent upon environmental factors including temperature, relative humidity, light, and wind. The aim is to explicate the process for efficiently storing wheat pollen, particularly with regard to breeding. The short longevity of wheat pollen grains renders it impractical to conduct tests for pollen viability and in vitro germination on a large scale. Herein, the impact of storage temperatures and duration was assessed on pollen viability and in vitro germination in order to optimize storage conditions for preserving pollen viability. Pollen grains from 50 diverse spring wheat genotypes, each with three replicates, were harvested and stored at temperatures of 22 °C, −20 °C, and 4 °C. Subsequently, pollen viability and in vitro germination rates were determined after storage for 1, 3, and 6 days. The results revealed that storage temperatures, durations, genotypes, and their interactions had a statistically significant impact on both pollen viability and in vitro germination. Notably, when pollen was kept at 22 °C, almost all genotypes exhibited a loss of pollen viability and in vitro germination after 1, 3, and 6 days of storage. Likewise, storage at −20 °C failed to extend pollen germination. However, at a storage temperature of 4 °C, the pollen of 36 wheat genotypes exhibited a range of 6–14% for in vitro pollen germination and even remained viable for 6 days. The ANOVA revealed a substantial variation in grain number per spike between wheat genotypes, thereby highlighting the significant influence of genetic variations on grain yield. Moreover, a slight positive association between the viability of wheat pollen and the number of grains was found in the current study, suggesting that a variety of factors affect the number of grains produced. Simple linear regression analysis further revealed a significant negative correlation between pollen viability, in vitro germination, and storage time and temperature. In conclusion, our findings underscore that 4 °C is the optimal temperature for preserving pollen viability and in vitro pollen germination in spring wheat for up to 6 days. The results of the present study suggests that the pollen viability of wheat is dependent on genotype, storage temperature, and storage duration. Thus, the 36 wheat genotypes identified during the present work could be efficiently maintained at 4 °C for short-term storage (6 days) and could be further used for genetic and breeding purposes.

Application of different fertilizers to check the efficiency of expression of Bt (Bacillus thuringiensis) gene in one of the leading commercialized crops (cotton) against Lepidopteran species is of great concern. The expression of Cry protein level can be controlled by the improvement of nutrients levels. Therefore, the myth of response of Cry toxin to different combinations of NP fertilizers was explored in three Bt cotton cultivars. Combinations include three levels of nitrogen and three levels of phosphorus fertilizers. Immunostrips and Cry gene(s) specific primer based PCR (Polymerase Chain Reaction) analysis were used for the presence of Bt gene that unveiled the presence of Cry1Ac gene only. Further, the ELISA (enzyme-linked immunosorbent assay) kit was used to quantify the expression of Cry1Ac protein. Under various NP fertilizers rates, the level of toxin protein exhibited highly significant differences. The highest toxin level mean was found to be 2.3740 and 2.1732 µg/g under the treatment of N150P75 kg ha-1 combination while the lowest toxin level mean was found to be 0.9158 and 0.7641 µg/g at the N50P25 kg ha-1 level at 80 and 120 DAS (Days After Sowing), respectively. It was concluded from the research that the usage of NP fertilizers has a positive relation with the expression of Cry1Ac toxin in Bt cotton. We recommend using the N150P50 kg ha-1 level as the most economical and practicable fertilizer instead of the standard dose N100P50 kg ha-1 to get the desired level of Cry1Ac level for long lasting plant resistance (<1.5). The revised dose of fertilizer may help farmers to avoid the cross-resistance development in contradiction of insect pests.