Induce of Plant Growth Regulators with and without Bio-fertilizer for Enhances the Adverse Effect of Salinity on Germination, Growth and Photosynthetic Pigments

This study aimed to explain the induce of plant growth regulators (ascorbic acid - AsA & salicylic acid - SA) in the presence or absence of bio-fertilizer (Acadian extract –ACE) for alleviated the effect of salinity stress on two cultivars of lettuce (Lactuca sativa, L. cv. Paris & cv. Royal). The lettuce seeds for four cultivars (cv. Paris Island Cos (cv. Paris) S1, cv. Royal S2, cv. Nader S3 & cv. Marvilli S4) soaked in PGRs (AsA, SA & GSH – 0.5 mM) and Acadian extract (ACE - 1%) for 12 hours in the dark at 4°C, for test of lettuce seeds viability (germination rate %). Germination both cultivars (cv. Paris S1 & cv. Royal S2) in trays of cork contains 218 eye for 14 days, transplanted the seedlings plant to plastic containers each pot containing one plant was irrigated with using NaCl salinity concentrations (0.00, 50; 100; 150 mM) 1st group alternative with distilled water and 2nd group alternating with ACE (1%), until harvest after 84 days. The results of germination indicated that the PGRs (AsA & SA) with both cultivars (cv. Paris S1 & cv. Royal S2) gives best results more the other PGRs (GSH) & bio-fertilizer (ACE) for the other cultivars. The data explained that the leaf number and leaf area, fresh and dry weights for shoot decreased significantly with increasing salinity concentrations compared with control, whereas the growth increased significantly more in cv. Royal S2 than in cv. Paris S1, particularly with AsA in the absence of bio-fertilizer (-ACE) more than SA compared with control. Whilst, the shoot succulence increased significantly with salinity concentrations more with AsA than SA especially in the absence of bio-fertilizer (-ACE) compared with control. However, the shoot dry matter content % decreased for both cultivars with increasing NaCl salinity concentrations especially with AsA more than SA in the absence (-ACE) compared with control. The evident recorded a significantly increased the photosynthetic pigments (Chl. a, Chl. b, carotenoids and total pigments) of leaves lettuce plant for both cultivars (cv. Paris & cv. Royal) with increasing NaCl salinity, also the photosynthetic pigments increasing more in cv. Royal S2 than in cv. Paris S1 especially with AsA more than SA in the absence (-ACE) under saline or non-saline conditions compared with the control. The data provide strong support to the hypothesis that exogenous application of AsA individually reduces the harmful effects of salinity and increases resistance to salinity in lettuce plant for both cultivars.