Effect of different concentrations of pyridoxine on physiological indices of Brassica rapa varieties

Role of vitamin B6 (pyridoxal HCL) is well known in different enzymatic reactions, cellular processes and in oxidative stress responses. Pathway for the natural synthesis of pyridoxal has been identified by several workers. A total of 24 genes, actively involved in the synthesis of vitamin B6 were identified from Arabidopsis thaliana (14 genes) and Brassica rapa (10 genes). Field experiment was conducted on B. rapa varieties (white and purple cap) to study the effect of three different levels of pyridoxine (25, 50 and 75 ppm) for 15 days during March. Growth indices were recorded on 15th day after sowing for control, test-I (25 ppm), test-II (50ppm) and test-III (75ppm). The germination time of seeds was reduced by two days for test-III in comparison to control. Similarly, growth indices like total fresh material (TFM), total dry material (TDM), root and shoot length, chlorophyll contents, carotenoids, indole acetic acid and anthocyanin pigments were also calculated for both B. rapa varieties. Apart from anthocyanin, all the recorded parameters shows significant increase for test-III (75 ppm) followed by test-I (25 ppm), test-II (50ppm) and control group respectively. Similarly, chlorophyll b contents for purple cap Brassica shows an uneven pattern, i.e. initially decreased with pyridoxine of 25 ppm in comparison to control and then increased with 50 ppm and 75 ppm treatments. The results of the current study expose the positive effect of pyridoxine in enhancing growth indices of B. rapa which will in turn leads to increase in yield of this important cash crop.