Bio-chemical changes in tomato (Lycopersicon esculentum Mill) at different levels of salinity stresses

Introduction

Tomato (Lycopersicon esculentum) is one of the most important vegetable crops cultivated all over the world for its fleshy fruits. It belongs to the family Solanaceae. The cultivated tomatoes originated as wild forms in the Peru-Ecuador-Bolivia area of South America .Earlier, tomatoes were thought to be poisonous and long before it was considered fit to eat, and it was grown only as an ornamental garden plant. Today, it is recognized as one of the important commercial and dietary vegetable crops (Bauer et al., 2004) [3] . Importantly, calcium chloride is involved in the regulatory mechanisms that plants activate to adjust to adverse environmental conditions of salt (Zehra et al., 2012) [11] . Calcium chloride has been shown to ameliorate the adverse effects of stress on many plants (Xu et al., 2013) [10] . Calcium appears to play a central role in many defense mechanisms that are induced by stress and Ca 2+ signaling is required for the acquisition of stress tolerance or resistance (Cousson, 2009) [4] . Importantly, calcium chloride is involved in the regulatory mechanisms that plants activate to adjust to adverse environmental conditions of salt (Zehra et al., 2012) [11] . Calcium chloride has been shown to ameliorate the adverse effects of stress on many plants (Xu et al., 2013) [10] . Calcium appears to play a central role in many defense mechanisms that are induced by stress and Ca2+signaling is required for the acquisition of stress tolerance or resistance (Cousson, 2009) [4] . Calcium chloride plays an active role on growth and photosynthetic pigments of tomato under salinity stress conditions (Ahlam and Babu 2015) [2] . Calcium chloride not only alleviates stress effects in potted ornamentals salvia splendens and Ageratum houstonianum but also improves all the growth and yield parameters under stress condition (Agata et al., 2016) [1]

Materials and Methods

The present investigation was carried out at Department of Biological Science, Sam Higginbottom Institute of Agriculture, Technology and Sciences, Pryagraj Uttar Pradesh. India.

with 80% acetone made the volume to 10 ml with 80% acetone, centrifuged at 800 ppm for 5 minute. The supernatant was read under 663, 645 nanometer. The readings were fed in the following formula and results were determined under spectrophotometer. Amount of chlorophyll a, b and total chlorophyll are calculate as fallow -Chlorophyll a (mg/g) = 12.9 × A (663 nm) -2.69 × A (645 nm) Chlorophyll b (mg/g) = 41.50 × A (645 nm) -5.10 × A (663 nm)

Lycopene

Extraction was performed according to (Fish et al. 2002) [5] . Samples were first chopped and homogenized in a laboratory homogenizer. Approximately 0.3-0.6 g samples were weighed and 5 mL of 0.05% (w/v) BHT in acetone, 5 mL of ethanol and J10 mL of hexane were added. The absorbance of the hexane layer (upper layer) was measured at absorbance 503 nm spectrophotometry using theredetermined extinction coefficients (Perkins et al., 2004) [5] .

Carotenoids

Carotenoid was estimated according to method. The leaves were collected for the carotenoid content estimation. Fresh leaves weighing of 0.5 gm was taken and homogenized in 10 ml of acetone (80% acetone) and centrifuged at 3000rpm at 10 min. The absorbance was recorded at 470 nm. It was calculated by using formula:

Total Soluble Solids

The percentage of total soluble solids of the fruit was determined with the help of Portable Hand Refracto meter. The sample of juice for this purpose was taken from the strained juice. The observed value of T.S.S. was recorded from the scale of the instrument (0-32 range).

Results and Discussion

The maximum chlorophyll a content was recorded (Table-1 and fig. 1) in tomato leaves at T 6 -CaCl 2 2400 ppm (2.40 mg/g) followed by T 5 -CaCl 2 1800 ppm (1.81 mg/g), T 4 -CaCl 2 1200 ppm (1.68 mg/g), T 9 -NaCl 100 ppm + CaCl 2 2400 ppm (1.58 mg/g), T 8 -NaCl 100 ppm + CaCl 2 1800 ppm (1.43 mg/g), T 7 -NaCl 100 ppm + CaCl 2 1200 ppm (1.38 mg/g), T 12 -NaCl 200 ppm + CaCl 2 2400 ppm (1.34 mg/g), T 11 -NaCl 200 ppm + CaCl 2 1800 ppm (1.29 mg/g), T 14 -NaCl 300 ppm + CaCl 2 1800 ppm (1.27 mg/g), T 10 -NaCl 200 ppm + CaCl 2 1200 ppm, T 13 -NaCl 300 ppm + CaCl 2 1200 ppm (1.22 mg/g), T 1 -NaCl 100 ppm (1.20 mg/g), T 2 -NaCl 200 ppm and T 15 T NaCl 300 ppm + CaCl 2 2400 ppm (1.13 mg/g) respectively as compared to T 0 -(1.55 mg/g) control. The minimum chlorophyll a content was recorded in treatment T 3 -NaCl 300 ppm (0.97 mg/g). Individually Calcium is known to play a special role in tolerance under salinity .Calcium with magnesium increasing the chlorophyll contents, membrane stability under stress conditions. The same report was reported by (Pan et al., 1995; Sagi, 2005) [6,7] . The maximum chlorophyll a content was recorded (Table-1 and fig. 2) in tomato leaves at T 6 -CaCl 2 2400 ppm (1.080 mg/g) followed by T 5 -CaCl 2 1800 ppm (0.975 mg/g), T 4 -CaCl 2 1200 ppm (0.950 mg/g), T 9 -NaCl 100 ppm + CaCl 2 2400 ppm (0.855 mg/g), T 8 -NaCl 100 ppm + CaCl 2 1800 ppm (0.795 mg/g), T 7 -NaCl 100 ppm + CaCl 2 1200 ppm (0.770 mg/g), T 12 -NaCl 200 ppm + CaCl 2 2400 ppm (0.765 mg/g), T 11 -NaCl 200 ppm + CaCl 2 1800 ppm (0.735 mg/g), T 14 -NaCl 300 ppm + CaCl 2 1800 ppm, T 13 -NaCl 300 ppm + CaCl 2 1200 ppm (0.720 mg/g), T 10 -NaCl 200 ppm + CaCl 2 1200 ppm (0.710 mg/g), T 1 -NaCl 100 ppm (0.580 mg/g), T 2 -NaCl 200 ppm (0.525 mg/g), and T 15 T NaCl 300 ppm + CaCl 2 2400 ppm (0.685 mg/g) respectively as compared to T 0 -(0.900 mg/g) control. The minimum chlorophyll a content was recorded in treatment T 3 -NaCl 300 ppm (0.465 mg/g). The phenomena is same as reported in chlorophyll a and the similar results was reported by (Pan et al., 1995; Sagi, 2005) [6, 7] .

The maximum lycopene content was recorded (Table-1 and fig. 3) in tomato leaves at T 6 -CaCl 2 2400 ppm (3.13 mg/g) followed by T 4 -CaCl 2 1200 ppm (3.08 mg/g), T 13 -NaCl 300 ppm + CaCl 2 1200 ppm (2.96 mg/g), T 7 -NaCl 100 ppm + CaCl 2 1200 ppm, T 2 -NaCl 200 ppm (2.94 mg/g), T 5 -CaCl 2 1800 ppm (2.92 mg/g), T 11 -NaCl 200 ppm + CaCl 2 1800 ppm (2.91 mg/g), T 15 T NaCl 300 ppm + CaCl 2 2400 ppm (2.80 mg/g), T 9 -NaCl 100 ppm + CaCl 2 2400 ppm, T 10 -NaCl 200 ppm + CaCl 2 1200 ppm (2.77 mg/g), T 12 -NaCl 200 ppm + CaCl 2 2400 ppm (2.75 mg/g), T 1 -NaCl 100 ppm (2.58 mg/g), T 14 -NaCl 300 ppm + CaCl 2 1800 ppm (2.53 mg/g) and T 8 -NaCl 100 ppm + CaCl 2 1800 ppm (2.44 mg/g) respectively as compared to T 0 -(2.31 mg/g) control. The minimum lycopene content was recorded in treatment T 3 -NaCl 300 ppm (2.17 mg/g). As already mentioned that the application of CaCl 2 was found better to improve the carotenoid and lycopene, index of tomato fruits under stress conditions. The same report was reported by (Subiah and Perumal, 1990) [8] .

The maximum lycopene content was recorded (Table-1 and fig. 4) in tomato leaves at T 6 -CaCl 2 2400 ppm (4.40 mg/g) followed by T 4 -CaCl 2 1200 ppm (4.36 mg/g), T 13 -NaCl 300 ppm + CaCl 2 1200 ppm (4.23 mg/g), T 2 -NaCl 200 ppm (4.21 mg/g), T 7 -NaCl 100 ppm + CaCl 2 1200 ppm, T 11 -NaCl 200 ppm + CaCl 2 1800 ppm (4.16 mg/g), T 5 -CaCl 2 1800 ppm (4.12 mg/g), T 10 -NaCl 200 ppm + CaCl 2 1200 ppm (4.02 mg/g), T 14 -NaCl 300 ppm + CaCl 2 1800 ppm (3.99 mg/g), T 9 -NaCl 100 ppm + CaCl 2 2400 ppm (3.96 mg/g), T 12 -NaCl 200 ppm + CaCl 2 2400 ppm (3.93 mg/g), T 15 T NaCl 300 ppm + CaCl 2 2400 ppm (3.92 mg/g), T 1 -NaCl 100 ppm (3.69 mg/g), and T 8 -NaCl 100 ppm + CaCl 2 1800 ppm (3.48 mg/g) respectively as compared to T 0 -(3.31 mg/g) control. The minimum lycopene content was recorded in treatment T 3 -NaCl 300 ppm (3.11 mg/g). The application of CaCl 2 was found to be better to improve carotenoid and lycopene,index of tomato fruits under stress conditions. The similar report was reported by (Subiah and Perumal, 1990) [8] . (22.78 0 Brix) Effect of NaCl and CaCl2 salinity on the Total soluble Solids ( 0 Brix) of tomato fruits The maximum Total soluble Solids ( 0 Brix) was recorded (Table-1 and fig. 4) in tomato leaves at T 6 -CaCl 2 2400 ppm (22.96 0 Brix) followed by T 5 -CaCl 2 1800 ppm (20.44 0 Brix), T 4 -CaCl 2 1200 ppm (20.24 0 Brix), T 9 -NaCl 100 ppm + CaCl 2 2400 ppm (17.81 0 Brix), T 8 -NaCl 100 ppm + CaCl 2 1800 ppm (17.62 0 Brix), T 7 -NaCl 100 ppm + CaCl 2 1200 ppm (17.17 0 Brix), T 12 -NaCl 200 ppm + CaCl 2 2400 ppm (17.20 0 Brix), T 11 -NaCl 200 ppm + CaCl 2 1800 ppm (16.73 0 Brix), T 14 -NaCl 300 ppm + CaCl 2 1800 ppm (16.62 0 Brix), T 10 -NaCl 200 ppm + CaCl 2 1200 ppm (16.57 0 Brix), T 13 -NaCl 300 ppm + CaCl 2 1200 ppm (16.40 0 Brix), T 1 -NaCl 100 ppm (16.33 0 Brix), T 2 -NaCl 200 ppm (16.08 0 Brix) and T 15 T NaCl 300 ppm + CaCl 2 2400 ppm (16.06 0 Brix) respectively as compared to T 0 -(19.06 0 Brix) control. The minimum Total soluble Solids ( 0 Brix) was recorded in treatment T 3 -NaCl 300 ppm (15.22 0 Brix). The application of CaCl 2 was found better to increase the total soluble solids even in presence of stress conditions in tomato crop. The similar report was seen by (Yaseen et al., 2006) [9] . From the present study it was concluded that T 6 (CaCl 2 2400 ppm) was the most effective followed by T 5 -(CaCl 2 1800 ppm). Amongst all the treatments T 3 -(NaCl 300 ppm) showed most deleterious effect on different parameters of tomato .It was clear from the study that calcium chloride could be used to mitigate the stress of sodium chloride on tomato.

References

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