ABSTRACT
Prosopis juliflora (Mimosoideae) is a fast growing and drought resistant tree of semi-arid region of India where fluoride (F) toxicity is a common problem. In the present investigations this species was fluoride tested to check their capacity as bioindicator plant and its efficiency to accumulate. To achieve this aim, P. juliflora seedlings grown in hydroponic culture containing different concentrations of F were analyzed for germination percentage together with some biochemical parameters viz, antioxidant enzyme activities, total chlorophyll and accumulation of F in different plant parts. After 15 days of treatment, root growth (r = -0.928, p<0.01), shoot growth (r = -0.976, p<0.01), vigor index (r = -0.984, p<0.01) were in decreasing trend with increasing concentration of NaF. Both catalase (3.2 folds) and peroxidase (2.7 folds) enzymes activity increased with increase in F concentration. Plant accumulated larger portion of the F in the roots (1024.63 µg g-1 d.wt.) followed by shoot (492.30 µg g-1 d.wt.). As P. juliflora did not show any morphological changes (marginal and tip chlorosis of leaf portions, necrosis and together these features are referred to as leaf “tip-burn”) therefore, this species may be used as suitable bioindicator species for potentially F affected areas. Further, higher accumulation of F in roots indicates that P. juliflora is a suitable species for the removal of F in phytoremediation purposes.
ABSTRACT
Syzygium cumini Linn. (Myrtaceae) is a medicinal tree (Jamun) used worldwide in treatment of diabetes. However, no molecular data is available on genetic polymorphism and its relationship, if any with fluoride pollution. In the present study, the genetic variability of two populations of S. cumini growing in fluoride rich soils and normal soils located in Rajasthan and Haryana regions of India, respectively was determined using random amplified polymorphic DNA (RAPD) markers. Different measures of diversity in Rajasthan populations: Shannon’s index of phenotypic diversity (I) = 0.440; Nei’s genetic diversity (h) = 0.292; effective number of alleles per locus (Ne) = 1.497; total species diversity (Hsp) = 0.307 and within population diversity (Hpop) = 0.158 showed high diversity in comparison to Haryana populations. Thus, it seems that Rajasthan population responds with increased genetic variation resulting possibly from new mutation that affect allele frequencies as a consequence of adaptation to contaminated environment. This may imply that the increased diversity levels may act as a buffer to combat fluoride stress. Cluster analysis and principal component analysis (PCA) results showed mixing between the populations.