Bioassay radicle growth

Principle Phytotoxic effects of the aqueous leachate of an allelopathic plant can be tested in vitro bioassays. Test or target plants are placed in contact with 0.5 % aqueous leachate from the allelopathic plant. Germination and radicle growth can be monitored during time-course experiments (i.e. after 24,48 and 72 h of treatment), but in this chapter we will include only the results obtained after 72 h of treatment. 

Compounds 58 and 59 showed phytotoxic effects when tested against seedlings of A. hypochondriacus using a Petri dish bioassay. Compounds 58 [IC50 = 6.57 xM] and 59 [IC50 = 3.86 xM] inhibited radicle growth of this species with a similar potency to 2,2—dichlorophenoxyacetic acid [2,4-D IC50 = 18 xM], which was used as a positive control. 

Bioassay of solid medium Bioassay of liquid medium Microbial Growth rating Germination Radicle length isolate Cucu Bygr Cress Cucu Bygr Cress Bygr Cress ... 

Bioassays are performed under sterile conditions in a laminar flow hood. Tomato seeds are previously washed and disinfected with 1% sodium hypochlorite. Seeds are germinated in the Petri dishes containing the S. deppei aqueous leachate. For control, seeds are germinated in 1% agar. Twelve seeds are placed on each Petri dish and kept in the dark at 27°C in a growth chamber. For enzyme activities, 40-50 Petri dishes are used per treatment. Primary roots (radicles) are excised after 72 h, frozen in liquid nitrogen and kept at -70 °C until use. For root growth response, experiments... 

Effect on the Growth of Mungbeans and Lettuce in a 72-H Bioassay. Partially purified saponins at concentrations of 1, 10, 100, and 1,000 ppm were dissolved in distilled water, adjusted to pH 7.0 0.1, and used in bioassays for 72 h. After that time, the lengths of mungbean and lettuce seedlings were measured in millimeters and compared to those grown in distilled water. Results of the complete study are reported in documents filed in the Oklahoma State University Library. Some typical results are presented for mungbean radicles in Fig. 12a, b, c and for lettuce radicals in Fig. 13a, b, c however, most of the results are not shown in this... 

Fig. 12a, b, c. The effects of partially purified saponins extracted from the (a) leaves, (b) stems, and (c) roots of mungbean at 2, 4, 7, and 10 weeks of growth on the growth of mungbean radicle at 72-h bioassay. Bars having different letters are significantly different, P = 0.05, ANOVA, with Duncan s Multiple-Range Test. 

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