Genetic diversity in Corchorus olitorius L. revealed by morphophysiological and molecular analyses.

Assessment of genetic diversity has an efficient role in plant breeding and improvement programs. There is a limit number of investigations dealing with the evaluation of genetic diversity in Jew's mallow (Corchorus olitorius L.), despite its valuable importance as a leafy vegetable and a delicious dish rich in vitamins and antioxidants. Therefore, in this study, 18 landraces of Jew's mallow-collected from different locations in Egypt-were used for genetic diversity assessment based on morphophysiological and molecular evaluations. A high degree of variability was found among the evaluated landraces at both levels, indicating the appropriateness of such collection to be involved in breeding approaches. Some morphophysiological traits offered a high level of diversity and effectively discriminated the landraces. Thus, they are recommended to be used in successive morphological evaluation studies. On the other hand, molecular evaluation using the random amplified polymorphic DNA (RAPD) and the sequence related amplified polymorphism (SRAP) efficiently supported the morphological results by exposing a clear genetic relationship among the landraces. In addition, the principal coordinate analysis based on combined data of RAPD and SRAP divided the landraces into two main groups, reflecting their relationship molecularly. The first group included nine landraces related to Upper Egypt and the second gathered three landraces from Delta, while the other six landraces were distinctly distributed around these two groups. The two groups may have two distinct ancestors in addition to the different ancestors of the scattered landraces. Findings of this study are valuable and could assist in Jew's mallow breeding programs.

Variations in growth behavior, yield and DNA stability of two vegetable crops cultivated in radioactive spiked soils.

Radioactive pollution comes on the top of pollution types that affect human life directly through damaging the human genome or indirectly via his food web. The current study focused on the evaluation of radiation effects of Assiut Thermal Power Plant (ATPP) ashes on two crop plants, potato and squash, in terms of morphological and molecular levels. More particularly, the specific activity concentrations were measured in Bq/kg, of the 238U (226Ra) and 232Th series, and 40K-isotope for the untreated soil sample (control) and ATPP ash sample (represents the radioactive source with 100% concentration). Different concentrations of ATPP ash (0, 2, 4, 6 and 8%) were mixed with soil sample to study the effect of radioactively contaminated soil on potato and squash plants. The results of the present investigation revealed that the morphological characteristics of both potato and squash plants were changed, which reflected a steep regression in the values of all vegetative growth and yield traits. The alterations of the characteristic values were directly proportional to the radioactive ash concentration in the soil. In the same context, the molecular evaluation using PCR-based markers, e.g., ISSR and SCoT helps in understanding and explaining experimental observations at morphological level. ISSR/SCoT bands confirmed the toxicity and mutagenicity of radioactive ash samples at their present dose on both potato and squash plants. The present findings clearly explained the morphometric and genetic abnormalities in two of the main consumed crops by a human. Thus, the green area around the ATPP may disappear in the future due to increasing the pollution in terms of the radioactive component that directly attached to plants or indirectly by mixing with soil.