Date Palm Reaserch Center

Date palm seedlings were exposed to Pb (100, 300 and 600 mg.kg) alone or in combination with salinity (200 mM NaCl solution). The influences of Pb stress individually or combined with salinity stress on growth was examined based on number and length of the roots and leaves of date palm seedlings. Plant appearance was also observed. H 2 O 2 , Malondialdehyde (MDA) and Electrolyte leakage (EL) levels were estimated as oxidative stress markers. Macronutrients (NPK) and micronutrients (Zn, Fe and Cu) as well as Pb accumulation in the root and leaves were estimated. Results showed that 300 and 600 mg.kg-1 Pb inhibited the growth of date palm seedlings by reducing the length of the roots and leaves. A higher degree of reduction was detected in the treatment combining Pb and salinity. The interaction of Pb with salinity increased the contents of H 2 O 2 , MDA, and electrolyte leakage, which are oxidative stress markers in the root and leaves. The increase was more pronounced when 600 mg.kg-1 Pb was applied with salinity. The N and K contents in the treated date palm seedlings decreased with increasing Pb concentration, especially when the treatment was combined with salinity. By contrast, the P content increased. The contents of Fe and Cu decreased when the seedlings exposed to Pb. This effect was more evident when Pb stress was interacted with salinity. An opposite trend was observed for Zn content. Compared with the control, 600 mg.kg-1 Pb increased the Pb accumulation in the roots by 6.43 times and by 7.31 times when combined with salinity. Meanwhile, the Pb accumulation in the leaves increased by 9.91 when Pb stress was applied alone and by 10.88 when Pb was combined with salinity. The main finding of the work: The high level of Pb inhibited the growth of date palm seedlings by reducing the length of the roots and leaves. A higher degree of reduction was detected in the treatment combining Pb and salinity.

Background: Al is a common metallic element found in earth's crust and is a toxic pollutant present at high concentrations in acidic soil, thus affecting plant growth. Despite being well studied as a toxic element, the effects of Al on date palm have not been investigated. This study aimed to assess the toxic effects of different Al concentrations on the development and growth of date palm callus and evaluate the biochemical and molecular response of date palm cells under Al stress. Results: Our study revealed the phytotoxicity of Al concentrations (50, 100, 150 and 200 mg.l-1) on date palm callus. The fresh and dry weight and the number of produced embryos were significantly decreased in response to Al concentration. At 150 mg.l-1 , the embryo number decreased to 1.66 compared with the 19.33 in the control treatment. At high Al concentration (200 mg.l-1), the callus failed to produce any embryo. Biochemical analysis revealed that Al exposure had negative effect on callus. Total soluble carbohydrates, total soluble protein and free amino acids were decreased in plants receiving 200 mg.l-1 Al treatment compared with those in the untreated ones. A similar decline was observed in total soluble protein and free amino acid in response to Al treatment. Significant accumulations of malondialdehyde, H 2 O 2 and peroxidase activity accompanied the increase in Al concentration in cultured tissues, revealing the generation of toxic reactive oxygen species in affected cultures. The genotoxic effect of Al at high concentrations (150 and 200 mg.l-1) was revealed by protein patterns. Conclusion: Our findings revealed for the first time the phytotoxicity of Al to date palm callus. At 200 mg.l-1 , Al prevented the embryo production of date palm callus. At 50, 100, 150 and 200 mg.l-1 , Al negatively affected the biochemical characteristics of date palm callus. At 150 and 200 mg.l-1 , Al induced changes in protein expression. These data showed that the tissue culture technique can be used as a valuable approach in heavy metal toxicity studies.

Soil pollution by heavy metal including lead (Pb) is a widespread problem; and the toxicity of lead as a major heavy metals pollutant to plants has gained a considerable attention around the world. Our study revealed the negative impacts of Pb at various concentrations (2.5, 5 and 10 mg.L-1) on the in vitro growth of date palm plantlets; and mostly on the basis of anatomical analysis. Results showed that the Pb treatment significantly reduced the height and fresh weight of date palm plantlets compared to untreated ones; fresh weight and height of plantlets were 252.33 mg and 4.46 cm in control plantlets reduced to 147.33 mg and 3.50 cm when plantlets grown in medium contain 2.5 mg.L-1. Interestingly, both fresh weight and height were increased to 272.33 mg and 4.03 when plantlets passed from 2.5 to 10 mg.L-1 Pb. Results of anatomical analysis showed no significant difference among all treatments on abaxial and adaxial epidermis, while the upper and lower cuticle layer increased when plantlets were exposed to Pb, these traits decreased when plantlets passed from low to high concentration of Pb. Mesophyll thickness was decreased from 218.90 µm in plantlets grown in medium without Pb to 162 µm in plantlets grown in medium supplemented with Pb at 2.5 mg.L-1 , the mesophyll thickness increased in the plantlets passed from 2.5 to 5 mg.L-1 and reached to 465.16 µm. The same pattern of results was observed in the blade thickness; as well as; the number of vascular bundles and the width and height of vascular bundles. Our results demonstrate the usefulness of in vitro technique in testing and generating a tolerant clone of date palm to lead stress.

Microbial contaminants are the major challenges in plant's in vitro propagation during different stages of culture processes, ZnO-NPs exhibit attractive antibacterial properties due to increased specific surface area as the reduced particle size leading to enhanced particle surface reactivity. The aim of present study was to evaluate the effect of ZnO NPs on microbial contamination; vitrification and growth promoting of date palm cultured tissues. Several concentrations of ZnO NPs were selected to assess their activity. The percentage of shoot formation, the number of proliferated shoot and the percentage of contamination of cultures were investigated, as well as several biochemical characteristics. Twofold of increase multiplication rate of proliferated shoot was observed in ZnO NPs at 150 mg L −1 compared to control treatment. The multiplication rate was 46.6% at control and increased significantly to 86.67% and 93.34% in ZnO NPs before and after sterilisation, respectively. No microbial contamination and vitrification were observed at all ZnO NP treatments compared with control treatment. Biochemical analysis showed that ZnO NPs had no toxic effects at all examined concentrations on date palm cultured tissues. A positive effect was observed in carbohydrates, protein and amino acid accumulations at high ZnO concentration (150 mg l −1). The results provide basis for the application of ZnO NPs in media date palm tissue cultures at 150 mg l −1 .

The study was conducted to evaluate the effect of lead (Pb) stress
alone or in combination with salinity on the anatomical structure of
roots and leaves of Date palm seedlings. Pb was added to soil at 100,
300 and 600 mg/kg concentrations as a pure aqueous solution or
mixed with saline solution at 200 mM. Compared with the control, the
microscopic study of root tissues showed that all treatments caused
a significant increase in the thickness of epidermis, endodermis
and pericycle, whereas the cortex thickness and diameters of the
vascular cylinder, protoxylem and metaxylem decreased significantly.
However, only the phloem diameter was affected significantly by 600
mg/kg Pb with or without salinity. Compared with the control, results
on leaf tissues revealed that treatment with 300 and 600 mg/kg Pb
alone or in combination with salinity led to a significant increase in
the thickness of cuticle layer, upper epidermis and lower epidermis.
Results also showed a significant increase in the diameter of tannin and
palisade cells when treated with 100 mg/kg Pb with or without salinity.
Small vascular bundle diameter decreased significantly in seedlings
exposed to Pb at all examined concentrations with or without salinity.

Soil pollution by heavy metal including lead (Pb) is a widespread problem; and the toxicity of lead as a major heavy metals pollutant to plants has gained a considerable attention around the world. Our study revealed the negative impacts of Pb at various concentrations (2.5, 5 and 10 mg.L-1) on the in vitro growth of date palm plantlets; and mostly on the basis of anatomical analysis. Results showed that the Pb treatment significantly reduced the height and fresh weight of date palm plantlets compared to untreated ones; fresh weight and height of plantlets were 252.33 mg and 4.46 cm in control plantlets reduced to 147.33 mg and 3.50 cm when plantlets grown in medium contain 2.5 mg.L-1. Interestingly, both fresh weight and height were increased to 272.33 mg and 4.03 when plantlets passed from 2.5 to 10 mg.L-1 Pb. Results of anatomical analysis showed no significant difference among all treatments on abaxial and adaxial epidermis, while the upper and lower cuticle layer increased when...

Investigations were conducted on young date palm (Phoenix dactylifera L.) plants derived from tissue culture to evaluate their biochemical responses to cadmium and lead treatments through irrigation water. Changes in date palm metabolisms were observed as a response to heavy metals accumulation, the reductions in photosynthetic pigments as chlorophyll and carotenoides were obvious after 180 days of treatments, compared with the increase in anthocyanin pigments which was twofold more than control plants. It is noteworthy, that Cd and Pb treatments induced a significant decrease in chlorophyll stability index (CSI) to 66.97 and 58.79%, in Cd (9 mg/kg) and P (276 mg/kg), respectively. Stressed P. dactylifera plants tend to accumulate more carbohydrates, free amino acid and proline in their leaves as consequences of heavy metal treatments. Interestingly, the level of total soluble proteins was found to be less, up to twofold, than those in non-stressed plants. An excessive production of...

Date palm is one of the most important trees for economic and social development in many countries and its fruits with high nutritional value. This aimed to determine the role of salicylic (SA) and jasmonic acids (JA) as antioxidants against salt stress. Salt stress was applied with water irrigation to two-year-old date palm offshoots by using 200 mM NaCl alone or in combination with foliar sprays of JA and SA at 1, 2 and 3 mgL-1. Results indicate that salinity at 200 mM NaCl remarkably increased the content of osmolytes (e.g., proline, glycine betaine and soluble sugars) in date palm leaves. Moreover, with the combination of 2 and 3 mg.L-1 SA and 1 mg.L-1 JA with salinity, the osmolyte content was remarkably higher than in salinity treatment alone. When date palm was exposed to salinity alone, the levels of oxidative markers, Malondialdehyde as a lipid peroxidation marker and H2O2 as a ROS accumulation marker, substantially increased compared with the control. Importantly, the leve...

The present study was carried out at a private orchard , in Abu-Al-Khaseeb region –Basrah, during the season of  2008 .The aim was to investigate the  effect  of  bunches bagging by brown paper and spraying of liquorice extract  at  three concentrations of  ( 0 , 5 , 8 ) g l−1,Treatment the trees was done 50 days after  Pollination  , The study included the interaction effect of all factors on  activity of enzymes (invertase and cellulose) and percentage of total and reducing sugars and sucrose  of  two date palm cultivars ( Sayer and Hillawi ) . The results were summarized as follows: treatment of bagging bunches, treatment of spraying with 5 g l−1 liquorice extract and Sayer cultivar increased activity of invertase and cellulase and total and reducing sugars significantly, but sucrose decreased significantly compared with other treatments, interaction effect between the factors were the treatment of  bagging Sayer bunches and the treatment of  spraying bagging bunches with 5 g l−1 liquorice extract significantly increased activity of invertase and cellulase significantly compared with other treatments,while did not significant interaction effect between the factors on study characteristics compared with other treatments.

The present study was carried out at a private orchard , in Abu-Al-Khaseeb region –Basrah, during the season of 2008 .The aim was to investigate the effect of bunches bagging by brown paper and spraying of liquorice extract at three concentrations of ( 0 , 5 , 8 ) g l−1,Spraying the trees was done 50 days from Pollination , The study included the interaction effect of both
factors on some Physical and Chemical Characterizes of two date palm cultivars ( Sayer and Hillawi ) , The results were summarized as follows: The treatments of bagging bunches, spraying with 8 g l−1 liquorice extract , and Hillawi cultivar increased bunch weight significantly, whereas the
interaction effect of spraying bagging bunches at concentrations of 8 g l−1 and the treatment of bagging bunches of Hillawi cultivar increased the bunch weight significantly as compared with the other interaction treatments, The
treatment of bagging bunches significantly increased fruit weight significantly, while the treatment of spraying with 8 g l−1 liquorice extract increased fruit weight significantly , The treatment of bagging bunches, treatment of spraying with 8 g l−1 liquorice extract and treatment of Sayer
cultivar increased total soluble solids significantly, The interaction effect between the factors were spraying bagging bunches with 8 g l−1 liquorice extract significantly increased the total soluble solids as compared with other treatments,while the treatment of bagging bunches and Hillawicultivar significantly decreased protein and tannin content,However , the treatment of spraying liquorice extract with 5 g l−1 decreased Tannin content significantly compared with other treatments .

A field experiment was conducted to investigate the role of sulphur application in salinity tolerance of Date Palm offshoots cvs Berhi and Sayer. The effect of sulphur on plant growth under saline conditions (The average of EC soil of field was (15.93 dS m-1) and to EC water (4.55 dS m-1)), two sulphur levels (100 and 200 g offshoot-1 year.-1 were addition to Soil), The results showed that the sulphur at level of 200g caused a significant increase the offshoot height, leaf area, number of leaves and girth of plant with cv. Berhi compared with control. Also, sulphur application significantly influenced biochemical characteristics such as (Total Chlorophyll, Dry weight, RWC, Carbohydrates, proline concentration soluble protein, peroxidase enzyme activities and endogenous indol acetic acid (IAA) content of two cultivars compared with control. As well as, treatment of sulphur at 200g offshoot-1 year.-1 to Berhi cultivar gave the highest values in these respects. While the results signif...

Abstract: Study was conducted in one of the orchards Abeo Al-Kasseeb of Basrah for the season 2011, to see the effect of spraying of potassium in some of the qualities of the fruits of date palm cv. Hillawi, used tratments (spray spathes flowering after the open pollen and before pollination with concentration of 1 and 2% potassium sulfate) and (sprayed fruits at the stage of hababok with concentration of 1 and 2% potassium sulfate) in addition to tow treatments of control ( spraying distilled water and non-spray). the results showed no significant differences between the tratments in effect on the weight of the fruit and the results showed an increase in fruit weight the effect of treatment in the process of spraying fruit hababok with concentration of 2% potassium sulfate compared to the weight of the fruit in the treatment control. Excelled treatment sprayed fruits at the stage of hababok with concentration of 2% potassium sulfate significantly increased the water content of frui...