Effects of Molybdenum on growth of fennel (Foeniculum vulgare Mill.) plant and absorption of Zn under Zn stress

Using the method of solution culture, the effects of different concentrations 0.05, 0.1, 0.2, 0.5 mg/L ofMo on fennel plant growth, physiological and biochemical indexes, Zn accumulation were studied after treatment with10 mg/L Zn in Hoagland爷s formula. The results showed that the height of fennel plant had a decreased trend with theincrease of Mo concentration. With the increase of Mo concentration, fresh weight (FW) and dry weight (DW) ofaboveground, belowground firstly increased then decreased. Root/shoot ratio had no significant difference among thetreatments. Contents of chlorophyll a (Chl.a), chlorophyll b (Chl.b), chlorophyll a+b (Chl.a+b) and carotenoid firstlydecreased then increased with the increase of Mo concentrations. Contents of soluble sugar in Mo treatmentsdecreased, while content of soluble protein increased. Content of malondialdehyde (MDA) firstly decreased thenincreased, and it was significantly lower in 0.1 mg/L Mo treatment than that in the control. Contents of Proline (Pro)had the contrary trend as MDA. Activity of POD was significantly higher in all Mo treatments than that in the control,while activity of SOD had the contrary trend as POD. Content of N had no difference among the treatments, andcontents of P and K in 0.1 mg/L Mo treatment was thelowest among the treatments, and it was significantlylower than that in the control. With the increase of Moconcentration, contents of Zn of above ground andunderground in fennel plant firstly decreased thenincreased, and content of Zn in root was more than thatin shoot. Content of Zn of above ground was significantly lower in 0.1 mg/L Mo treatment than that in the control. Content of Zn of underground in 0.5 mg/L Mo treatment was significantly higher than that in all other treatments. It indicated that increasing the Moconcentration under Zn treatment could inhibit fennel plant growth while improve biomass significantly.Furthermore, a certain Mo concentration could reduce Zn accumulation of aboveground, while improve Znaccumulation of underground.