Background and Objective: The L-tyrosine is one of the important natural amino acids used in promoting growth and productivity of various crops and used to build hormones. Salicylic acid (SA), is naturally produced compound with several promotive effects in plants. This study aimed to evaluate the physiological role of L-tyrosine and salicylic acid on growth, some biochemical aspects, yield and nutritional values of the peanut seeds under sandy soil conditions. Materials and Methods: During 2018 and 2019 summer seasons, 2 field trials were conducted at the Research and production Station of NRC, El-Nubaria Province, El-Beheira Governorate, Egypt. To study the physiological role of tyrosine and salicylic acid foliar treatment on vegetative growth (60 days after sowing, DAS), photosynthetic pigments in fresh leaves. Total carbohydrates, IAA (Indole acetic acid), flavonoids, β-carotene, lycopene, total phenol and enzyme activities (PAL and TAL) were determined in plant shoots. Moreover, yield and its components (Number of branches/plant, straw yield/plant, pod yield/plant, biological yield/plant, number of pods/plant, number of seeds/pod and seed yield/plant as well as seed quality (oil yield) and fatty acids of peanut grown under sandy soil conditions were recorded. Results: Results showed that, external treatment of L-tyrosine (50, 100 and 150 mg L1) and salicylic acid (100, 200 and 300 mg L1) increased significantly growth criteria and photosynthetic pigments, total carbohydrate, IAA and phenolic contents in shoots. In addition, yield and its components significantly increased with all treatments. The highest increases in seed yield (t ha1) and oil yield (t ha1) were recorded 14.45 and 144.93%, respectively when 100 mg L1 tyrosine was applied. Moreover, all treatments caused significant increases in carbohydrate, oil, antioxidants compounds as flavonoids, β-carotene and lycopene contents, antioxidant activity and unsaturated fatty acids as compared with untreated control plants of the yielded peanut seeds. Conclusion: The L-tyrosine and salicylic acid has a regulatory role on growth, some biochemical aspects, yield quantity and quality as well as improve fatty acid composition of the yielded oil. The L-tyrosine with 100 mg L1 was the best treatment on enhancing growth and productivity of peanut plant.
Bakry Ahmed Bakry, Mervat Shamoon Sadak and Amany A. Abd El-Monem, 2020. Physiological Aspects of Tyrosine and Salicylic Acid on Morphological, Yield and Biochemical Constituents of Peanut Plants. Pakistan Journal of Biological Sciences, 23: 375-384.