A preliminary study on heavy metal monitoring in soil and guar (Cyamopsis tetragonoloba) biomass amended with sewage sludge.

Applying sewage sludge in agricultural soils is an interesting source of organic matter. This study aimed to monitor concentrations of heavy elements in soil and guar plants, which can pose a risk to the health of humans and animals if they enter the food chain through the soil-plant system. The experiment revealed that applying sludge increased the amount of organic matter, total nitrogen, potassium, and phosphorus in the soil. Additionally, the concentration of heavy metals such as Pb, Co, Cr, Ni, Cu, and Zn in all treatments remained below the permissible limits for soil. The highest plant height and plant dry weight were recorded in the sludge and sludge + fertilizer treatments. The dry weight of the guar varied from 629 g m-1 in the control treatment to 1050 g m-1 in the sludge + fertilizer plots. The use of sludge increased the accumulation of heavy metals in the above-ground parts of the guar plant compared to the control. However, the level of heavy metal remained within the normal range and below the toxic concentration. Our results also showed that the application of sludge along with fertilizer improved the quality of the guar forage by increasing the levels of crude protein, digestible dry matter and water-soluble carbohydrates. Overall, the results indicated that using sludge as organic fertilizer can improve soil properties, reduce the use of inorganic fertilizers, and decrease the harmful effects of heavy metals on the environment and health in the research area.

Genetic differentiation between bitter and sweet asafetida plants using ISSR markers.

Bitter (Ferula pseudalliacea) and sweet (Ferula assa-foetida) asafetida (Apiaceae family) are well-known economic and medicinal herbs owing to their gum. This study investigates genetic differentiation of F. pseudalliacea and F. assa-foetida using ISSR markers, to determine the effective primer and to assess the possibility of separating sweet and bitter plant populations from each other. Results showed that among 22 primers, eight markers reproduced obvious DNA patterns and revealed 234 scorable DNA bands. ISSR-16 and ISSR-55 primers had better performance than other primers according to the number of bands, PIC and Marker Index. Bitter population showed polymorphic loci (224), percentage of polymorphic loci (95.73%) and observed number of alleles (1.96 ± 0.2), while sweet populations showed the amount of these parameters as 218, 93.16% and 1.93 ± 0.25, respectively. Estimated Gst of sweet population was 0.09 and Gst of bitter population was 0.06. Comparing gene flow in bitter and sweet populations showed a lower level of gene flow between sweet populations (Nm = 4.93) compared to bitter ones (Nm = 7.89). Within group genetic similarity of sweet asafetida population was higher than between group variation of bitter and sweet populations. The highest similarity was observed between bitter populations (0.95). The highest genetic dissimilarity was also estimated between bitter and sweet populations (0.08). Cluster analysis grouped four studied populations into 13 clusters using Jaccard's similarity coefficient and UPGMA method. Principal coordinate analysis showed that 61.02% of total variance was explained using three components and it could completely separate populations as well as cluster analysis. These grouping correspond nearly with geographical distribution. Analysis of molecular variance showed that genetic variation within populations (87%) was more than among populations (13%). The results indicated that ISSR marker is suitable to investigate genetic diversity of asafetida populations and could separate populations of the same genera with similar germplasm.