The investigation and comparison of growth and stress parameters under boron stress when different nitrogen sources and some nutrient were added on plants(red lentil and barley)

In this study, the effects of different nitrogen sources on lentil and barley plants, which were exposed to 5 and 10 mM boron stress previously, were studied. After ten-day germination, the lentil (Native) and arpa (Tokak157/37,) were incubated 16-hour lighted and 8-hour darkened per day for 7-day growth cycle under the conditions of boron stress via different nitrogen sources (10 mM nitrogen in NH4 Cl, KNO3, Urea). As consequence of changes in nitrogen sources of the plants, The effect of boron toxicity on the activities of SOD, GPX and LOX was the similar in the two species but the levels of CAT and APX activities were different in both species under 5 and 10 mM boron stress (p<0,01). SOD, GPX and LOX activies increased in the roots and shoots of boron treated plants as compared with the controls (p<0,01). The concentrations of MDA, H2O2, and proline showed increases (p<0,05). There were determined decreases in the relative growth rate (%), and photosynthetic pigments related to boron stress, (p<0,05) and (p<0,01) respectively. The changes in the lentil were obtained much more than those in the barley. In addition, the changes in the groups in which NH4+ was used as nitrogen source were obtained at lowest levels.The effects of Ca addition on the certain parameters were examined via changing the nitrogen sources of the lentil and barley plants,. Addition of Ca led to changes in ascorbat peroxidase and catalase activities in shoots and roots of the boron-stressed lentil and barley plants, were obtained higher than the control groups (p<0,05), while superoxide dismutase and guasikol peroxidase showed lower activities. The concentrations of MDA, H2O2, and proline showed decreases (p<0,05). There were determined increases in the relative growth rate (%), and photosyntehic pigments related to calcium concentrations, (p<0,05) for both of them. The changes in the lentil were obtained much more than those in the barley. In aspect of nitrogen sources the highest changes were obtained at the groups in which NO3- was used as a nitrogen source.As a conclusion, the fertilizers which contain NH4+, or Ca added NO3- as a nitrogen source should be used in the boron stressed farmlands.