Rate and forms of Mineral Nutrition CAN Influence Dry Matter Accumulation and Saponin Content of Puncture Vine (Tribulus Terrestris L.)

ABSTRACT

Effect of mineral nutrition (soil or foliar supply of nutrients) on the growth, dry matter and saponin content of the shoot biomass of Bulgarian variety puncture vine (Tribulus terrestris L.) grown on soil as pot experiment in green house were studied. Soil fertilization rate of 100mgN/kg or 90P/kg of dry soil, oppositely to the results obtained from the foliar fed plants (0.3 % solution of liquid fertilizer Agroleaf^R (Scotts Co, USA) with formulation N₁₂P₅₂K₅, increased shoot total N and P without significant change of dry matter. Changes of total reducing sugars, amino acids, phenolics and flavonoids and activity of leaf photosynthetic apparatus (chlorophyll (Chl) a, b and carotenoids content and parameters of chlorophyll a prompt fluorescence) were found to relate to the variation of individual saponin content analysed by HPLC technique. Soil fertilized plants in contrast to the foliar fed plants showed more protodioscin, prototribestan and dioscin than control but contained less of flavonoid glycoside rutin.

Keywords:

• puncturevine (Tribulus terrestris L.)
• mineral nutrition
• saponins
• growth