Research Article | | Peer-Reviewed

Influence of Different Rates of Salinity on Flowering, Yield and Fruit Nutritional Value of Three Okra [Abelmoschus esculentus (L.) Moench] Cultivars in far North Region of Cameroon

Published in Plant (Volume 12, Issue 3)
Received: 30 April 2024     Accepted: 27 May 2024     Published: 20 September 2024
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Abstract

Context: Salinity is in coastal, arid and semi-arid regions a major constraint in the productivity and agricultural development around the world. Objectifs: The objective of this study is to evaluate the effect of salinity on the growth, the nutritional value of the fruits of three okra (Abelmoschus esculentus L.) cultivars including two local (Javia and Parkwa) and a hybrid variety (Hire). Methodology: This is how four solutions of different NaCl concentrations from 0, 60, 120 to 240 mM were used to water okra plants at the four-leaves stage and this for two months in completely randomized device with four repetitions. Results: The results have differneces and similarities between the three varities during saline treatments. Salinity causes a decrease in growth, performance yield (from 0 to 240 mM NaCl to 28%, 23.6% and 22% in Parkwa, Hire, Javia cultivars respectively), mineral elements, antioxidants components and accumulation of Na content (to 45% in Parkwa, 23% in Hire and 18.4% in Javia from 0 to 240 mM NaCl) and flowering period (from 0 to 240 mM NaCl to 27.5%, 23.1% et 21.9% in Parkwa, Hire, Javia respectively). The reductions generated by salt have been less strong in Javia and Hire cultivars while the reductions were stronger at Parkwa cultivar. In addition, NaCl, at high concentrations, advantage of osmoticum accumulation involved in the osmotic ajustement mechanisms and would also serve as osmoprotector. Accumulation of osmolytes is salinity tolerance index that explains the maintenance of good water status in okra. Conclusion: Cultivars Javia and Hire were the most salt tolerant while the Parkwa was the most sensitive. The good behaviour of Javia and Hire varieties in the face of salinity can be considered for their use to better enhance the sahelian and coastal areas.

Published in Plant (Volume 12, Issue 3)
DOI 10.11648/j.plant.20241203.13
Page(s) 66-75
Creative Commons

This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.

Copyright

Copyright © The Author(s), 2024. Published by Science Publishing Group

Keywords

Growth, Nutritional Value, Okra, Salinity, Tolerance

1. Introduction
Okra is a vegetable-fruit containing many nutrients (calcium, iron, proteins and vitamins) that are food supplements. It is grown in tropical and subtropical regions of the world and has great importance as well as social and economic. Indeed the okra is used in the kitchen as condiment or as binder in sauces (fruit and leaves), in medecine (roots) in crafts or industry (fiber of stem) . The okra’s culture remains facing the problems of climate change, the degradation of natural resources especially the ground, diseases and pests (natural enemies), but also to that of varietal selection that does not allow to make available to producers of the performance varieties. In several tropical countries, okra faces multiple constraints that negatively affect its production with salinity and low availability of mineral elements in the soil.
In Cameroon, the okra is increasingly cultivated in coastal and sahelian region where salinity of ground and irrigation water is a reality.
Salin stress is known for its adverse effects on growth and development of the plant at all stages of development . Plant production in saline areas depends largely on the success of germination, lifting, planting and the efficiency of the reproduction phase . Salinity causes a significant change in the concentration of certain osmo-regulatory molecules in plants and those of the bioactive compounds of the fruits of some vegetable thus leading to a modification of their nutritional quality . Thus salt stress reduces the size of fruits, the productivity and increases the flowering time, the rate of total soluble solids (organic acids, sugar, amino acids) . Salt stress also influences vitamin and lycopene content, which has involvement of plant physiology . Soil salinity affects plants through osmotic effects, ion-specific effects, and oxidative stress . The effect of salinity stress in plants is mediated at least in part by an enhanced generation of active oxygen species, especially in chloroplasts and mitochondria which cause lipid peroxidation and membrane injury, protein degradation and enzyme inactivation. Plants have developed a complex antioxidant system which mitigates and repairs the damage initiated by reactive oxygen species, toward enzyme synthesis to protect the cellular and subcellular systems from the cytotoxic effects of these active oxy-free radicals.
If many physical factors affect the production of okra, including salinity and poverty in fertilizer elements, it is therefore necessary to conduct investigations to assess the impact of soil salinity on the production and fruit quality of okra hence the interest of this study. This article analyzes the effects of different levels of salinity on growth, performance and nutritional value of fruit of three okra cultivars in Far noth region in Cameroon. The purpose of this study is also to identify the most tolerant okra cultivars with saline stress that can give satisfactory yields in salt areas.
2. Materials and Methods
2.1. Site Description
The study was conducted from 22 March 2023 to 12 August 2023 at Palar harde, in the Maroua city, Department of Diamare, Region of Far nord of Cameroun (latitude: 10°36’37, 57’’N, longitude: 14°17’34, 41’’ E). The climate is tropical of a hot sudano-sahelian type, average annual rainfall is estimated at 700 mm. The rainy season lasts about 3 to 4 months from June to September. The temperatures range from 25°C à 30°C in rainy season and culminate at 45°C in the dry season. The soil of the experimental site is mainly the sandy-clay type. In these periods of heaplers, it is a consequitus of precipitation related to an important evaporation thus promoting the accumulation of salt in the soil .
2.2. Plant Material and Experimental Device
Plant material was consisting of three okra cultivars of which two local cultivars from the department of Mayo Sava: Javia (its fruit is pyramidal, long and green color) and Parkwa (fruit is pyramidal, medium size and dark green color) and a hybride variety call Hire (characterized by a short shot) purchased from AGRISEP of Maroua. These three cultivars of okra were chosen for their socio-economic importance and the nutritional value of their fruit. The seeds were surface sterilized with 3% sodium hypochlorite for 20 min and washed four times with deionized water. The seeds were planted in cavity trays in the greenhouse of Maroua-Palar, Cameroon and transplanted when seedlings reached 10 cm in height into the prepared polythene bags containing
The plants were watered immediately after transplanting to avoid drought stress. Before initiating treatments plants were irrigated with normal tap water using a hand sprinkler to full saturation for two weeks in order to improve root development . After which 500 ml of water was applied to each pot and this was able to wet the soil to full saturation. All plants were fertilized daily with a modified nutrient solution (in g L-1): 150 g Ca(NO3)2, 70 g KNO3, 15 g Fe-EDTA, 0.14 g KH2PO4, 1.60 g K2SO4, 11 g MgSO4, 2.5 g CaSO4, 1.18 g MnSO4, 0.16 g ZnSO4, 3.10 g H3BO4, 0.17 g CuSO4 and 0.08 g MoO3 . The pH of the nutrient solution was adjusted to 7.0 by adding HNO3 0.1 mM. Plants were watered with deionized water every morning. The amendment in each case was applied 5 WAS with organic fertilization rates each of compost and 150 kg h-1 of NPK (10 – 18 – 18).
2.3. Soil Moisture Content Determination, Irrigation Water and Analysis
Soil samples were collected from representative spots on the experimental site from where soil was collected for potting using soil auger to a depth of 20 cm, the samples were made into a sample. A sub-sample was taken, air-dried, crushed and sieved with 2-mm mesh sieve after which physical and chemical analyses were carried out (Table 1). The following chemical analyses were done on the soil and tap water (Tables 1 and 2). Organic carbon (C), was determined by the wet oxidation procedure and total Nitrogen (N) by micro-Kjeldahl digestion method. Magnesium (Mg) was extracted using the Mehlich 3 method and determined by auto ANALYSER 5Technicon 2). The total and available soil phosphorus (P) were determined by the method of . Soil was measured potentionmetrically in 1:2.5 soil: water mixture. Calcium (Ca), potassium (K) and sodium (Na) were determined by aflame photometer (JENWAY) as described by . Ca2+, Mg2+, Na+, K+, HCO3-, SO42-, NO3-, Cl- content in water tap was determined by using colorimetric amperometric titration method (Table 2). Electric conductivity and pH were determined by conductometer.
Table 1. Physical and chemical characteristics of soil used.

Physio-chemical properties

Quantity

Clay %

38.98 ± 2.59

Sand%

67.04 ± 2.77

Total carbon %

0.77 ± 0.09

Total nitrogen %

0.33 ± 0.23

Ratio C/N

3.67 ± 1.06

Phosphorus (%)

0,28 ± 0.09

Potassium (meq 100g-1)

2.23 ± 1.03

Sodium (meq 100g-1)

1.14 ± 0.57

Calcium (meq 100g-1)

11.19 ± 1.85

Magnésium (meq 100g-1)

2.65 ± 1.01

pH

5.89 ± 1.02

EC (dS/m)

3.15 ± 1.49

Table 2. Chemical characteristics of irrigation water.

Chemical characteristics

Irrigation Water

Ca2+ (mg g-1)

Mg2+ (mg g-1)

K+ (mg g-1)

HCO3- (mg g-1)

Na+ (mg g-1)

SO42- (mg g-1)

Cl- (mg g-1)

pH

CE (dS m-1)

Tap water

238.2

118.3

25.4

63.1

441.4

515.9

26.8

7.34

2.11

2.4. Plant Measurements
Seedlings were harvested 16 WAS by carefully removing and washing the soil particles from the roots, after which the plants parts were separated into shoots and roots . The tissues (fruit) were dried for 24 h at 105˚C . The dry samples were weighted. Plant samples were harvested after 4 months culture and under 10 weeks of salt stress, plant were collected to determine plant height, flowering, number of fruit per plant, number of seed per fruit, fruit fresh weight, longer of fruit, width of fruit, fruit yield (measuring fresh weight of fruits from 10 plants per plot at 50 % flowering and 50 % maturity) in okra.
The relative water content (RWC) in fruit was recorded according to the formula as follows: RWC = (FFW - FDW)/ (TW - FDW) × 100, where FFW is fresh weight, FDW is dry weight, and TW is turgid weight .
2.5. Organics Compounds in Fruit
For measurement of total soluble sugar (TSS), a modified phenolsulfuric assay was used . Subsamples (100 mg) of dry fruit were placed in 50 mL centrifuge tubes. 20 mL of extracting solution (glacial acetic acid: methanol: water, 1:4:15 (v/v/v)) was added to the ground tissue and homogenized for 15 sec at 16000 rpm. The homogenate was centrifuged for 10 mn and the supernatant was decanted to a 125 ml Erlenmeyer flask. The residue was resuspended in 20 mL of extracting solution and centrifuged another 5 min. The supernatant was decanted, combined with the original extract, and made up to 100 mL with water. One mL of 5% (v/v) phenol solution and 5 mL of concentrated H2SO4 were added to 1 mL aliquots of SS (reconstituted with 1 mL water). The mixture was shaken, cooled to room temperature, and absorbance recorded at 490 nm wavelength with spectrophotometer (Pharmaspec UV-1700 model). The amount of TSS present in the extract was calculated using standard curve prepared from graded concentration of glucose.
Soluble protein content (SP) was determined by method. Briefly, appropriate volume (from 0 - 100 µl) of sample was aliquoted into a tube and the total volume was adjusted to 100 µl with distilled water. A 1 ml of Bradford working solution was added to each sample well. Then the mixture was thoroughly mixed by vortex mixer. After left for 2 min, the absorbance was read at 595 nm. The standard curve was established by replacing the sample portions in the tubes with proper serial dilutions of bovine serum albumin.
Fiber content (FC) analysis have been realised by the method of .
2.6. Fruit Antioxidant Components
For estimation of ascorbic acid content (ASA), 1 g of frozen fruit tissues was homogenised in 5 mL of ice-cold 6% m-phosphoric acid (pH 2.8) containing 1 mM EDTA . The homogenate was centrifuged at 20,000 × g for 15 min at 4˚C. The supernatant was filtered through a 30-µm syringe filter, and 50 µL of the filtrate was analyzed using an HPLC system (PerkinElmer series 200 LC and UV/VIS detector 200 LC, USA) equipped with a 5-µm column (Spheri-5 RP-18; 220 × 4.6 mm; Brownlee) and UV detection at 245 nm with 1.0 mL/min water (pH: 2.2) as the mobile phase, run isocratically .
Beta-carotene (BC) was extracted by grinding fruit tissues in a solution of 100% acetone containing CaCO3 (Jung, 2004) The extracts were centrifuged at 16,000 × g for 10 min, and 20 µL of the resulting supernatants were used for HPLC analysis, as described by using the previously mentioned HPLC system. Solvent A (acetonitrile, methanol, Tris-HCl buffer 0.1 M, pH 8.0, 72:8:3) was run isocratically from 0 to 4 min followed by a 2.5 min linear gradient to 100% solvent B (methanol, hexane, 4:1) at a flow rate of 2 mL/min. The detector was set at 440 nm for the integration of peak areas after calibration with the external standard.
2.7. Fruit Minerals Contents
K, Ca, Na, Mg and P contents in the fruit tissue of the plants were evaluated in dry, ground, and digested samples in a CEM microwave oven . P was determined by colorimetry; potassium by flame photometry; magnesium, sodium and calcium by atomic absorption spectrometry . Iron content was determined by method reported in . Fruit of okra was dry ashed at 450˚C for 2 hours and digested on heat cave with 10 ml HNO3 1 M. The solution was filtrated and adjusted at 100 ml with HNO3 at 1/100 and analyzed with an atomic absorption spectrophotometer (Rayleigh, WFX-100).
2.8. Experimental Design and Statistical Analysis
The experiment was conducted as a factorial completely randomized design with four NaCl treatments and three cultivars in four replications. Data are presented in term of mean (±standard deviation). All data were statistically analysed using Statistica (version 9, Tulsa, OK, USA) and first subjected to analyses of variance (ANOVA). Statistical differences between treatment means were established using the Fisher LSD test at p < 0.05.
3. Results and Discussion
3.1. Effects of NaCl on Growth, FRWC and Yield Characteristics
The growth parameters, yield and fruit relative water decreased significantly with increasing NaCl salinity concentrations (Table 3); whereas, the period of flowering increased more in the presence of NaCl application. For Javia cultivar, PH, NF, NS, LF, WF, FFW, FY, FRWC decreased to 29.3%, 28.8%, 20.5%, 27.7%, 45.3%, 28.3%, 22% and 9.6%, and FLO increased to 21.9% from control (0 mM) to 240 mM respectively. For Hire cultivar, PH, NF, NS, LF, WF, FFW, FY, FRWC decreased to 33.7%, 43.5%, 19.8%, 31.4%, 50.5%, 39.7%, 23.6% and 9.8%, and FLO increased to 23.1% from control to 240 mM respectively. For Parkwa cultivar, PH, NF, NS, LF, WF, FFW, FY, FRWC decreased to 34.7%, 46.8%, 24%, 31.9%, 57.5%, 42.3%, 28% and 10.8%, and FLO increased to 27.5% from control to 240 mM respectively.
This results were agreed with who observed that the fresh weight in four tomato cultivars decreased with salt stress. found relative water content (RWC) decreased progressively with increasing of NaCl concentration in the leaves; reported that salinity reduces plant productivity first by reducing plant growth during the phase of osmotic stress and subsequently by inducing leaf senescence during the phase of toxicity when excessive salt is accumulated in transpiring leaves. Increasing NaCl concentration tended to reduce the absorption of water leading to a drop in water content, the inhibitory effect of NaCl on growth parameters could be attributed to the osmotic effect of NaCl. The changes in water status under NaCl stress may cause a reduction in meristem activity as well as cell elongation .
3.2. Effects of NaCl on Osmolytes Compounds
The TSS, FC and SP in okra plant increased significantly with NaCl concentration compared to control as shown in Figure 1C, 1D and 1E. The highest values of TSS (30.74 mg g-1 for Javia, 36.22 mg g-1 for Hire and 36.19 mg g-1 for Parkwa), FC (32 mg g-1 for Javia, 36.31 mg g-1 for Hire and 30.62 mg g-1 for Parkwa) and SP (28.78 mg g-1 for Javia, 31.64 mg g-1 for Hire and 34.73 mg g-1 for Parkwa) were recorded with 240 mM NaCl. This accumulation varied from 0 to 240 mM NaCl for TSS (76.6% for Javia, 98.4% for Hire and 118.9% for Parkwa), for FC (40.2% for Javia, 47.9% for Hire and 41.6% for Parkwa) and SP (76.9% for Javia, 88.9% for Hire and 125.8% for Parkwa).
This study showed that increase of NaCl salinity caused high accumulation of fiber content, soluble protein and sugar . The increment of fiber contents in okra with NaCl could be contributed to human diet in the communities of saline prone area compared to non-saline area. The substantial increase in soluble sugars and proteins may be due to the activation of photosynthetic machinery, as a result of the stimulatory effects of the used plant growth bio stimulators on photosynthetic process. Soluble sugars and proteins play an important role of accelerating the cellular metabolism and maintaining homeostasis in the plant when it is under risk .
3.3. Effects of NaCl on Fruit Antioxidant Components
There was a significant reduction in the ASA and BC with the increase in the salinity levels from the control condition (Figure 1A and 1B). The highest ascorbic acid and beta-carotene content were observed in the control treatment for Javia (163.24 and 1.86 µg·g-1 respectively) followed by Hire (161.29 and 1.81 µg·g-1 respectively) and Parkwa (160.52 and 1.79 µg·g-1 respectively). The lowest values of ASA and BC were obtained in 240 mM NaCl for Javia (109.34 and 1.09 µg·g-1 respectively) followed by Hire (98.76 and 0.84 µg·g-1 respectively) and Parkwa (91.57 and 0.82 µg·g-1 respectively).
In the present study, salinity decreased β-carotene and Ascorbic acid content of all okra cultivars. Ascorbic acid helps in absorption of dietary iron by keeping it in the reduced form . It is an important component of several fruits (tomato, pepper, and strawberry) that reacts with singlet oxygen and other free radicals and suppresses peroxidation . showed that the β-carotene content decrease with increasing salinity levels in mung beans.
3.4. Effects of NaCl on Fruit Minerals Contents
The effect of saline treatment Na, K, Ca, Mg, P and Iron concentrations varies according to the three cultivars (Table 4). Salinity stress caused an increase in Na content in the three varieties studied. On the other hand, K, Ca, Mg, P and Iron concentrations decrease significantly in the fruits of all cultivars of okra. The highest K+, Ca++, Mg++, P and Iron content were obseved at 0 mM NaCl (1.34 mg g-1, 762.49, 356.24, 318.64 and 2.95 µg g-1) for Javia, (1.32 mg g-1, 766.11, 335.35, 316.29 and 2.65 µg g-1) for Hire and (1.36 mg g-1, 758.54, 358.17, 312.65 and 2.78 µg g-1) for Parkwa. And the lowest content were obtained at 240 mM (0.74 mg g-1, 582.52, 231.26, 209.34 and 1.74 µg g-1) for Javia, (0.78 mg g-1, 405.43, 196.53, 194.55 and 1.47 µg g-1) for Hire and (0.61 mg g-1, 402.74, 199.12, 167.12 and 1.23 µg g-1) for Parkwa. From 0 to 240 mM NaCl, the Na+ content increased to 18.4, 23 and 45% for Javia, Hire and Parkwa respectively.
Depending the growing salt doses, the sensitive cultivar Parkwa has higher Na+ content and the low P, K, Mg and Fe content; while the most tolerant cultivar Javia, has lowest Na+ content, which indicates that it is « excluder » type. It develops mechanisms to limit Na+ accumulation in its tissues . In saline condition, plants absorb of significant amounts of Na+ and of Cl-, but the transport and accumulation of these elements often seek to depend on degree of tolerance of species considered . Toxic effects of ions mainly Na+ and Cl-, nutritional imbalance caused by reduced nutrient (P, K, Ca, Mg, Fe) uptake and/ortransport to the shoot .
Table 3. Effects of salinity rates on plant growth, fruit relative water content and yield characters of three okra cultivars (16 WAS).

Growth and yield parameters

Cultivars

Treatment (mM NaCl)

PH (cm)

FLO (days)

NF per plant

NS per fruit

FFW (g)

LF (cm)

WF (g)

FY (t ha-1)

FRWC (% )

Hire

0

31.56±1.13j

56.71±2.31f

11.86±1.26m

60.95±3.12e

6.85±1.11m

6.02±0.92n

2.06±0.78o

25.84±1.09k

89.94±3.53a

60

28.95±1.02j

59.53±2.42f

9.91±2.33n

57.52±3.66f

6.15±1.21m

5.73±0.84n

1.79±0.59o

23.95±1.06k

87.32±4.07a

120

25.67±1.13k

63.45±1.52e

7.88±2.12n

52.73±3.17g

5.01±0.88m

5.04±1.07n

1.36±1.01o

21.22±0.84k

84.10±3.55b

240

20.93±1.09k

69.83±2.01d

6.72±3.01n

48.91±2.83h

4.13±0.92n

4.13±1.09o

1.02±1.08o

19.73±0.79l

81.13±4.01b

Parkwa

0

33.51±1.23j

53.91±1.88g

13.26±2.51m

55.95±3.28f

6.15±1.23m

9.57±0.92n

1.67±1.23o

25.22±1.22k

86.55±3.03a

60

30.27±1.06j

57.27±1.73f

11.07±2.25m

51.76±2.55g

5.26±1.02m

8.25±1.11n

1.31±0.95o

23.31±1.05k

83.25±3.27b

120

25.68±1.16k

62.68±2.86b

9.13±2.46n

47.29±2.43h

4.22±0.73n

7.79±0.86n

0.92±1.04p

21.53±0.94k

80.28±2.66b

240

21.89±1.14k

68.76±1.93d

7.05±1.98n

42.54±3.01i

3.55±1.24n

6.52±1.03n

0.71±0.86p

18.18±1.31l

77.17±2.45c

Javia

0

29.96±1.07j

50.55±2.32g

14.43±1.17m

53.87±3.15g

8.12±2.17m

11.51±0.88m

1.61±0.84o

27.85±1.11j

85.16±2.27a

60

27.82±2.12j

53.45±2.83g

13.15±2.88m

50.63±3.14g

7.55±1.15m

11.02±1.12m

1.30±0.92o

26.94±1.12k

83.52±2.19b

120

25.63±1.07k

57.34±2.71f

11.73±3.22m

46.74±2.43h

6.81±1.18m

10.24±0.97m

1.08±0.76o

24.19±0.95k

79.64±2.38c

240

21.19±2.13k

61.62±1.65e

10.27±3.02lm

42.83±3.52i

5.82±1.01m

8.32±0.77n

0.88±1.03p

21.71±1.03k

76.95±3.01c

Two way ANOVA results

Salt stress (S)

*

*

*

*

*

*

*

*

*

Cultivar (C)

NS

NS

NS

*

NS

NS

NS

NS

*

Interaction C x SS

*

*

**

*

*

*

*

*

*

Values shown are means (n=5) ± SD; within columns, means followed by different letter are significantly different (p < 0.05). **, * significant at 1 and 5% probability levels, respectively, NS not significant
Figure 1. Effects of salinity rates (60, 120 and 240 mM NaCl) on fruit osmolytes and antioxidant components of three okra cultivars (16 WAS). Ascorbic acid (A), Beta carotene (B), Total soluble sugar (C) Soluble protein (D) and Fiber content (E). Bars are means (n=5) ± SD. Means followed by different letter are significantly different (p < 0.05).
Table 4. Effects of salinity rates on fruit mineral components of three Okra cultivars (16 WAS).

Fruit mineral components

Cultivars

Treatment (mM NaCl)

Ca (µg g-1)

P (µg g-1)

K (mg g-1)

Mg (µg g-1)

Iron (µg g-1)

Na (µg g-1)

Hire

0

766.11±3.02a

316.29±1.33g

1.32±2.01m

355.35±2.33f

2.65±0.55m

59.33±2.22k

60

694.90±3.14b

283.14±1.51g

1.05±2.22m

320.54±2.45f

2.37±0.62m

63.12±2.14k

120

579.12±3.05c

240.72±2.02h

0.83±3.07n

242.26±2.81g

2.01±0.74m

67.50±2.44j

240

405.43±3.07e

194.55±1.83i

0.68±2.12n

196.53±2.24h

1.47±0.88m

72.94±1.79i

Parkwa

0

758.54±3.11a

312.65±1.72g

1.36±2.11m

358.17±1.84f

2.78±0.85m

57.55±2.12l

60

589.81±3.43c

259.22±1.73g

1.02±2.06m

301.79±2.21g

2.32±0.47m

65.95±1.99j

120

456.36±2.96d

202.46±1.75h

0.78±2.64n

273.65±1.92g

1.93±0.91m

72.16±1.77j

240

402.74±2.88e

167.12±0.97i

0.61±2.53n

199.12±1.89h

1.23±0.94m

83.47±3.14i

Javia

0

762.49±3.16a

318.64±1.99g

1.34±3.19m

356.24±1.93f

2.95±0.83m

58.61±3.11l

60

701.83±3.22b

288.25±1.07g

1.09±3.27m

314.18±2.11f

2.61±0.78m

62.83±2.93k

120

660.18±3.18b

241.43±2.05h

0.85±2.04n

288.54±2.05g

2.23±1.02m

65.92±3.07j

240

582.52±3.06c

209.34±1.76i

0.74±2.77n

231.26±2.57h

1.74±1.09m

69.37±2.19i

Two way ANOVA results

Salt stress (SS)

**

*

*

*

*

*

Cultivars (PP)

NS

NS

NS

NS

NS

NS

Interaction PP x SS

*

*

*

*

*

*

Values shown are means (n=5) ± SD; within columns, means followed by different letter are significantly different (p < 0.05). **, * significant at 1 and 5% probability levels, respectively, NS not significant
4. Conclusion
This study found that salinity provoked a decrease in growth parameters, antioxidants compound (ascorbic acid, beta-carotene), mineral elements (P, K, Mg, Fe, Ca), yield and accumulation of osmoprotectors (proteins and solubles sugar), fiber content, period of flowering and Na content of all okra cultivars studied with difference of comportment between the cultivars and the level of NaCl. Of the three cultivars tested, Javia and Hire are the most resistants, while Parkwa is the most sensitive. Complementary studies are needed to determine physiological and molecular mechanisms involved in the behavior of cultivars. At this stage of the work, varieties Javia and Hire may be advised to producers of areas affected by salinity.
Abbreviations

ASA

Ascorbic Acid

BC

Beta Carotene

Ca

Calcium

DAP

Days After Planting

DAS

Days After Sowing

FC

Fiber Content

FLO

Flowering

FFW

Fruit Fresh Weight

FRWC

Fruit Relative Water Content

FY

Fruit Yield

LF

Longer of Fruit

Mg

Magnesium

N

Nitrogen

NF

Number of Fruit per Plant

C

Organic Carbon

PH

Plant Height

P

Phosphorus

K

Potassium

Na

Sodium

SP

Soluble Protein

S

Sulfate

TSS

Total Soluble Sugar

WAS

Week after Sowing

WF

Width of Fruit

Acknowledgments
We appreciate all who helped us to carry out this study.
Author Contributions
Mathias Julien Hand: Conceptualization, Data curation, Formal Analysis, Funding acquisition, Investigation, Methodology, Project administration, Resources, Software, Supervision, Validation, Visualization, Writing – original draft, Writing – review & editing
Kingsley Mbi Tabi: Formal Analysis, Methodology, Resources, Visualization
Salomon Ousman: Conceptualization, Data curation, Methodology, Resources, Writing – original draft
Chimène Fanta Abib: Formal Analysis, Resources, Visualization
Bogno Oumarou: Data curation, Investigation, Methodology
Victor Désiré Taffouo: Project administration, Resources, Supervision, Validation, Visualization
Emmanuel Youmbi: Project administration, Supervision, Validation, Visualization
Conflicts of Interest
The authors declare no conflicts of interest.
Appendix
Table A1. Effects of salinity rates on osmolytes and antioxidant content of three okra cultivars (16 WAS). Effects of salinity rates on osmolytes and antioxidant content of three okra cultivars (16 WAS). Effects of salinity rates on osmolytes and antioxidant content of three okra cultivars (16 WAS).

Osmolytes, antioxidant components

Cultivars

Treatment (mM NaCl)

FC (mg g-1)

ASA (µg g-1)

BC (µg g-1)

TSS (mg g-1)

SP (mg g-1)

Hire

0

24.55±0.93g

161.29±3.22a

1.81±1.19i

18.26±0.88h

16.75±0.97h

60

27.77±1.01f

141.80±3.71b

1.49±1.21i

23.48±0.79g

20.92±0.89g

120

31.36±1.04e

117.32±3.62c

1.12±1.03i

28.82±0.92f

25.53±0.68f

240

36.31±1.07e

98.76±2.52b

0.84±1.09j

36.22±1.12e

31.64±0.61e

Parkwa

0

21.63±0.92g

160.52±2.88a

1.79±0.85i

16.53±0.98h

15.38±0.74h

60

23.57±0.88g

127.66±3.77c

1.38±1.02i

21.74±0.73g

20.10±0.77g

120

26.70±0.91f

98.85±3.33d

0.97±1.01j

28.68±0.85f

26.91±1.01f

240

30.62±0.89e

91.57±2.64d

0.82±0.88j

36.19±1.14e

34.73±1.08e

Javia

0

22.94±0.76g

163.24±3.71a

1.86±1.11i

17.41±1.17h

16.24±1.17h

60

24.26±1.22g

140.43±2.81b

1.61±1.03i

21.26±0.87g

19.69±0.83h

120

27.53±1.09f

120.47±3.13c

1.39±0.68i

26.87±0.91f

23.55±0.95g

240

32.17±1.12e

109.34±2.87d

1.09±1.01i

30.74±1.03e

28.73±0.87f

Two way ANOVA results

Salt stress (SS)

**

*

*

**

**

Cultivars (C)

NS

NS

NS

NS

NS

Interaction C x SS

*

*

*

*

*

Values shown are means (n=5) ± SD; within columns, means followed by different letter are significantly different (p < 0.05).
**, * significant at 1 and 5% probability levels, respectively, NS not significant
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    Hand, M. J., Abib, C. F., Ousman, S., Tabi, K. M., Oumarou, B., et al. (2024). Influence of Different Rates of Salinity on Flowering, Yield and Fruit Nutritional Value of Three Okra [Abelmoschus esculentus (L.) Moench] Cultivars in far North Region of Cameroon. Plant, 12(3), 66-75. https://doi.org/10.11648/j.plant.20241203.13

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    Hand, M. J.; Abib, C. F.; Ousman, S.; Tabi, K. M.; Oumarou, B., et al. Influence of Different Rates of Salinity on Flowering, Yield and Fruit Nutritional Value of Three Okra [Abelmoschus esculentus (L.) Moench] Cultivars in far North Region of Cameroon. Plant. 2024, 12(3), 66-75. doi: 10.11648/j.plant.20241203.13

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    Hand MJ, Abib CF, Ousman S, Tabi KM, Oumarou B, et al. Influence of Different Rates of Salinity on Flowering, Yield and Fruit Nutritional Value of Three Okra [Abelmoschus esculentus (L.) Moench] Cultivars in far North Region of Cameroon. Plant. 2024;12(3):66-75. doi: 10.11648/j.plant.20241203.13

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  • @article{10.11648/j.plant.20241203.13,
      author = {Mathias Julien Hand and Chimène Fanta Abib and Salomon Ousman and Kingsley Mbi Tabi and Bogno Oumarou and Victor Désiré Taffouo and Emmanuel Youmbi},
      title = {Influence of Different Rates of Salinity on Flowering, Yield and Fruit Nutritional Value of Three Okra [Abelmoschus esculentus (L.) Moench] Cultivars in far North Region of Cameroon
    },
      journal = {Plant},
      volume = {12},
      number = {3},
      pages = {66-75},
      doi = {10.11648/j.plant.20241203.13},
      url = {https://doi.org/10.11648/j.plant.20241203.13},
      eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.plant.20241203.13},
      abstract = {Context: Salinity is in coastal, arid and semi-arid regions a major constraint in the productivity and agricultural development around the world. Objectifs: The objective of this study is to evaluate the effect of salinity on the growth, the nutritional value of the fruits of three okra (Abelmoschus esculentus L.) cultivars including two local (Javia and Parkwa) and a hybrid variety (Hire). Methodology: This is how four solutions of different NaCl concentrations from 0, 60, 120 to 240 mM were used to water okra plants at the four-leaves stage and this for two months in completely randomized device with four repetitions. Results: The results have differneces and similarities between the three varities during saline treatments. Salinity causes a decrease in growth, performance yield (from 0 to 240 mM NaCl to 28%, 23.6% and 22% in Parkwa, Hire, Javia cultivars respectively), mineral elements, antioxidants components and accumulation of Na content (to 45% in Parkwa, 23% in Hire and 18.4% in Javia from 0 to 240 mM NaCl) and flowering period (from 0 to 240 mM NaCl to 27.5%, 23.1% et 21.9% in Parkwa, Hire, Javia respectively). The reductions generated by salt have been less strong in Javia and Hire cultivars while the reductions were stronger at Parkwa cultivar. In addition, NaCl, at high concentrations, advantage of osmoticum accumulation involved in the osmotic ajustement mechanisms and would also serve as osmoprotector. Accumulation of osmolytes is salinity tolerance index that explains the maintenance of good water status in okra. Conclusion: Cultivars Javia and Hire were the most salt tolerant while the Parkwa was the most sensitive. The good behaviour of Javia and Hire varieties in the face of salinity can be considered for their use to better enhance the sahelian and coastal areas.
    },
     year = {2024}
    }
    

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  • TY  - JOUR
    T1  - Influence of Different Rates of Salinity on Flowering, Yield and Fruit Nutritional Value of Three Okra [Abelmoschus esculentus (L.) Moench] Cultivars in far North Region of Cameroon
    
    AU  - Mathias Julien Hand
    AU  - Chimène Fanta Abib
    AU  - Salomon Ousman
    AU  - Kingsley Mbi Tabi
    AU  - Bogno Oumarou
    AU  - Victor Désiré Taffouo
    AU  - Emmanuel Youmbi
    Y1  - 2024/09/20
    PY  - 2024
    N1  - https://doi.org/10.11648/j.plant.20241203.13
    DO  - 10.11648/j.plant.20241203.13
    T2  - Plant
    JF  - Plant
    JO  - Plant
    SP  - 66
    EP  - 75
    PB  - Science Publishing Group
    SN  - 2331-0677
    UR  - https://doi.org/10.11648/j.plant.20241203.13
    AB  - Context: Salinity is in coastal, arid and semi-arid regions a major constraint in the productivity and agricultural development around the world. Objectifs: The objective of this study is to evaluate the effect of salinity on the growth, the nutritional value of the fruits of three okra (Abelmoschus esculentus L.) cultivars including two local (Javia and Parkwa) and a hybrid variety (Hire). Methodology: This is how four solutions of different NaCl concentrations from 0, 60, 120 to 240 mM were used to water okra plants at the four-leaves stage and this for two months in completely randomized device with four repetitions. Results: The results have differneces and similarities between the three varities during saline treatments. Salinity causes a decrease in growth, performance yield (from 0 to 240 mM NaCl to 28%, 23.6% and 22% in Parkwa, Hire, Javia cultivars respectively), mineral elements, antioxidants components and accumulation of Na content (to 45% in Parkwa, 23% in Hire and 18.4% in Javia from 0 to 240 mM NaCl) and flowering period (from 0 to 240 mM NaCl to 27.5%, 23.1% et 21.9% in Parkwa, Hire, Javia respectively). The reductions generated by salt have been less strong in Javia and Hire cultivars while the reductions were stronger at Parkwa cultivar. In addition, NaCl, at high concentrations, advantage of osmoticum accumulation involved in the osmotic ajustement mechanisms and would also serve as osmoprotector. Accumulation of osmolytes is salinity tolerance index that explains the maintenance of good water status in okra. Conclusion: Cultivars Javia and Hire were the most salt tolerant while the Parkwa was the most sensitive. The good behaviour of Javia and Hire varieties in the face of salinity can be considered for their use to better enhance the sahelian and coastal areas.
    
    VL  - 12
    IS  - 3
    ER  - 

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Author Information
  • Department of Biology Science, Faculty of Science, University of Maroua, Maroua, Cameroon

  • Department of Biology Science, Faculty of Science, University of Maroua, Maroua, Cameroon

  • Department of Biology Science, Faculty of Science, University of Maroua, Maroua, Cameroon

  • Department of Biological Sciences, Faculty of Sciences, University of Bamenda, Bamenda, Cameroon

  • Department of Biology Science, Faculty of Science, University of Maroua, Maroua, Cameroon

  • Department of Botany, Faculty of Science, University of Douala, Douala, Cameroon

  • Department of Biology and plant Physiology, Faculty of Science, Laboratory of Biotechnology and Environment, Unit of Physiology and Plant Improvement, University of Yaoundé I, Soa, Cameroon

  • Abstract
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    1. 1. Introduction
    2. 2. Materials and Methods
    3. 3. Results and Discussion
    4. 4. Conclusion
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  • Abbreviations
  • Acknowledgments
  • Author Contributions
  • Conflicts of Interest
  • Appendix
  • References
  • Cite This Article
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