Effect of mycorrhizal inoculations on physiological traits and bioactive compounds of tomato under water scarcity in field conditions

Abstract

Mycorrhizal inoculations were investigated to reveal their effects on the growth and productivity of processing tomato grown under field conditions. Plants inoculated at sowing (M1), sowing + transplanting (M2) and non-inoculated plants (M0) were grown under regularly irrigated (RI), deficit irrigated (DI), and non-irrigated (I0) conditions. In dry years, under non-irrigated conditions (M2) treatment significantly decreased the canopy temperature, improved the photosynthetic efficiency expressed by chlorophyll fluorescence (Fv/Fm) and the fruit setting, significantly increased the total carotenoids and lycopene concentration of fruits but increased the ratio of green yield. Using deficit irrigation, (M2) plants produced more and larger weighed red fruits than (M1) plants but the β carotene, lutein and lycopene concentration of fruits, except for the vitamin C, decreased. Under severe drought conditions the mycorrhizal inoculations positively influenced the all carotenoids and lycopene concentration of fruits (r = 0.8150, r = 0.7837), but their impact was negative under deficit irrigation. Under water deficiency (I0, DI) the mycorrhizal symbiosis increased the marketable yield and resulted in a 33% increase in green yield and an 18 % increase in the total carotenoids content in dry years but the unmarketable yield decreased. Under water deficiency (M2) treatment produce more marketable yield resulting in 9.8% higher total carotenoids in the tomato fruits than (M1) treatment under field conditions.