ABSTRACT
<p><b>OBJECTIVE</b>The effects of different nitrogen forms on the growth and photosynthetic characteristics of Prunella vulgaris were observed.</p><p><b>METHOD</b>Water culture experiments were carried out to observe the effects of NH4+: NO3- ratios(100:0, 75: 25, 50:50, 25:75, 0:100 in mmol x L(-1)) on the growth and photosynthetic characteristics of P. vulgaris.</p><p><b>RESULT</b>The leaf area, fresh biomass and P(n) of these cultivars increased with the increasing of NH4(+) -N: NO3(-) -N ratios, and they were found to be the highest in 25: 75 NH4(+) -N: NO3)-) -N. However, they decreased with the increasing NH4(+) -N: NO3(-) -N ratio further. P. vulgaris had a minimum leaf area, biomass, chlorophyll content and P(n) in pure ammonium group. The biggest chlorophyll and carotenoid contents were found in the ratios of NH4(+) -N to NO3(-) -N of 50: 50.</p><p><b>CONCLUSION</b>The results indicated that properly increasing nitrate proportion could promote the growth and photosynthesis of P. vulgaris.</p>