Use as indicator species

Some assays were done using sinigrin (Sarsyntex brand) and with the chloroform-soluble fraction obtained from campestris, at the same concentration (0.013 g per Petri dish), using as indicator species Hordeum vulgare, Lolium multiflorum, Rapheinus sativus, and oleracea var. italics. 

Aside from the primary research objective, several other criteria should be considered carefully in selecting and designing a bioassay. These include sensitivity, specificity, response time, reproducibility, plant material, cost, labor, equipment, and space requirements. The bioassay should be highly sensitive to the allelochemical(s) in question. Sensitivity and selectivity are dependent on the plant species and plant material being used as the indicator and on the efficacy of the allelochemical studied. In practice, several plant species should be used as indicator species, some of which are highly sensitive to the test compound(s) and some of which appear to be more resistant. Reproducibility is another key factor. 

Biological indicator species such as fresh water sponges, clams, mussels, insect larvae that sorb water-borne pollutants are difficult to assess over time periods of years. The lanthanides may be used as indicator species utilizing the adventitious roots of stream-side trees [204-206]. The ability of tree roots to sorb both chelated and non-chelated lanthanides from water indicate that aquatic roots accumulate, concentrate and retain lanthanides to such an extent that the roots can be used as indicators of aquatic pollution, and that lanthanides can be studied as analogues of toxic elements and compounds. 

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