الفهرس 
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Abstract
Date Palm Is One Of The Most Important Crops In Many Regions Around The World . The Date Palm Trees Are Essential Integral Component Of Farming System In Dry And Semiarid Regions And Can Be Produced Equally Well In Small Farm Or As Lager Scale Commercial Plantation Unites . The Tremendous Advantages Of This Blessed Tree Are Its Resistance To Many Diseases Tolerance To Many Biotic And Abiotic Stresses Its Requirements For Limited Inputs Long Term Productivity And Its Multiple Purpose Attributes . No Wonder The Date Palm Tree Has Been Part Of The People Daily Life In Many Countries Especially In The Middle East The Gulf Region And North Africa . It has been Providing The Shelter The Food Animal Feeding And Even The Medicine For The People Of Such Regions . Dates Were Cultivated In Ancient Lands from Mesopotamia To Prehistoric Egypt . Possibly As Early As 6000 B.C. Nowadays Date Palm Cultivations Have Been Extending To Many Parts Of The World Reaching To East And South Africa .
Field experiments of this investigation were carried out on date palm (Phoenix dactylifera L.) Zaghloul cultivar growing grown in Edco district, El_Behera Governorate during the two successive seasons 2007 and 2008.
In an attempt to:-
1- Further document the metaxenic effects in date palm.
2- Provide new explanation about the involvement of some phytohormones in such changes in fruit quality characteristics due to the variations in male pollens.
3- Identify contain phytohormones that could be applied to improve fruit quality of date palm.
Two previously studied pollinators were used in this study, named here a A and B. The experiment was designed as randomized complete blocks with four replications (each spath as one replication) in addition to the control (non-pollinated spathe). Changes of six phytohormones in the flesh of the fruit were assessed over time following pollination date and set until maturity (full coloration or the khalal stage). These phytohormones were: Gibberellic acid (reported as GA3), Indole acetic acid (IAA), ABA, Zeatin, Kinetin, in addition to Benzyl adenine. Furthermore, Physical and chemical characteristics of the fruit were monitored over time in the beginning of coloration (the end of Kimri stage) until maturity. In parallel to that, the same physical, chemical and phytohormonal changes were assessed in fruits of non-pollinated spathes using the same number of replications. The duncen multiple test was used to compare the means at 0.05level. The obtained results could be summarised in the following points
1. Fruit Physical characteristics:
The data revealed that fruit weight, flesh weight, rag weight and fruit size were significantly influenced by the type of used pollinator regardless the time since pollinator A caused a significant increase in fruit weight , flesh weight, rag weight and fruit size as compared with pollinator B. Meanwhile, pollinated spathes had remarkably greater fruit weight, flesh weight, rag weight and fruit size as compared with the non-pollinated spathes. As the fruit progressed from the kimri to the khalal stage, there was a continuous increase in that fruit weight, flesh weight, rag weight and fruit size from one sampling date to another until harvest
2. Fruit Chemical characteristics:
A- T.S.S:-
The data showed that fruits produced with pollinator A tended to posses more soluble solids as compared with those on spathes pollinated with pollinator B and there was a significant increase in TSS from one sample to another until harvest as shown from the time factor analysis.
B- Sugars:-
The data revealed that total, reducing and non-reducing sugars were significantly altered by conducting the pollination when compared with non-pollinated spathes. However, the difference in total and non-reducing sugars tended to increase by using pollinator A when compared with pollinator B with a significant difference. Moreover, the time factor indicated that there was a significant increase in total sugar, reducing and non-reducing sugars until maturity. Moreover, there was no significant difference in reducing sugars in the fruits of spathes pollinated with either pollinator A or B. Meanwhile, both pollinators resulted in significant reducing sugars as compared with fruits of non-pollinated spathes
C-Tannins:-
The data revealed that using either pollinator A or B did not make a significant difference in terms of their influence on tannins content. However, non-pollinated spathes had
Significantly greater tannin contents in their fruits as compared with those fruits on pollinated spathes in a consistent manner. The time factor data indicated that there was a significant decrease in tannin content in the fruit until the period preceding maturity (after 186 days of pollination).
D- Fruit Acidity:-
Changing the type of pollinator did not affect fruit acidity whether the used pollinator was A or B. Moreover, non-pollinated fruits had significantly higher acidity than fruits of pollinated spathes. Data of the time factor in the same tables revealed that there was a significant decline in titratable acidity after pollination afterward acidity ceased to change after 186 days of pollination.
E- Vitamin C Content:-
The data revealed that vitamin C in the fruits of pollinated spathes tended to be higher than in non-pollinated spathes. Moreover fruits of pollinator A had greater amount of vitamin C than those of pollinator B in a significant manner. The time factor data indicated that there was a different trend for vitamin C increments between the two seasons since in the first one vitamin C ceased to increase after 174 days of pollination while in the second season, this vitamin continued to increase in a significant manner until harvest.
F- Anthocyanin content in the fruit:-
Fruits of pollinated spathes had significantly higher anthocyanin content than those of non-pollinated spathe . Moreover, spaths pollinated with pollinator A tended to have greater amount of anthocyanin in the fruit relative to those fruits of pollinator B especially in the first season. The time factor data indicated that anthocyanin content in the fruit, was increasing over time from one sample to another which ceased after 186 days of pollination in the first season or continued to increase until the harvest sample in the second season .
G- Chlorophylls Content in the fruits:-
There was a trend of lower chlorophyll a, b contents in fruits produced under pollinator A when compared with those produced by spathes pollinated with pollinator B. Moreover, non-pollinated spathes had fruits with higher chlorophyll a, b contents than pollinated spathes, it was evident that there was continuous decline in chlorophyll content over time as the fruit progressed from the kimri stage to the Khalal stage, but not necessarily in a significant manner from one sample to another.
H- Crude Fiber Content:-
The data revealed that spathes pollinated with pollinator A had significantly greater crude fibers than those pollinated with pollinator B. However, pollinated spathes maintained their higher crude fibers content when compared with non-pollinated spathes. Data of the time factor indicated to a significant-progressive increase in crude fibers of the fruits as they progressed from the Kimri to the Khalal stage (maturity).
3-Phytohormones Change:
A- Gibberellic acid:-
Pollinated spathes by pollinator. A had significantly greater GA3 content than that pollinated with pollinator B while the highest content was found in fruits of non-pollinated spathes. In the first season, however a typical trend of results was not obtained in the second season. Meanwhile, there were two district peaks of GA3 in fruits of pollinated spathes as compared with only one peak of GA3 increase in fruits of non-pollinated spathes.
B- Indole Acitic Acid:-
Spathes pollinated with pollinator A resulted in higher 1AA content in the fruit as compared with using pollinator B in a consistent manner. However, 1AA content in seedless friuts (without pollination) was not consistent, a compared with fruits of pollinated spathes.
C- Abscissic Acid (ABA) Content:-
Fruits of pollinator B had significantly grearer ABA than those of pollinator A in both seasons.Meanwhile fruits of non-pollinated spathes had consistently greater amount of ABA as compared with fruits of pollinated spathes. Changes over time, proved that ABA tended to increase in the friut after pollination then declined again as the fruit tended to go through the kimri stage of development with a clear pattern especially in the frist season.
D- Zeatin Content:-
Spathes pollinated with pollinator A had significantly greater zeatin content than those pollinated with pollinator B. However, non-pollinated spathes did not show a consistent patter in fruit content of zeatin, as compared with that of pollinated spathes. Furthermore ther was a clear peak of Zeatin content in all types of fruits which coincided with the initiation of the enlargement phase in pollinated spathes.
E- Kinetin Content:-
The values and trends of kinetin in the fruit varied between the two seasons, since there was no significant difference in such phytohermone between pollinated and non-pollinated spathes in the first season only. In the second season, fruits of spathes pollinated with pollinator A had much higher content of kinetin as compared with those in the spathes pollinated with pollinator B.
F- Benzyladenine Content:-
The data showed that benzyladenine content in the fruits of spathes pollinated with pollinator A had significantly greater amount than those fruits of spathes pollinated with pollinator B. Even non-pollinated spathes contained fruits with much less benzyladenine than fruits of pollinator A. With regard to the time factor, the data revealed that benzyl adenine by the end of Hababouk reached to a peach in the fruit.
This study reached to the conclusions that pollinators have their metaxenie effects especially on fruit weight , size , and flesh weight and pollinator A was superior to pollinator B in that regard. It was also revealed that some phytohormones might be involved in such metaxenic effects especially GA3, IAA, zeatin and benzyl adenine while abscissic acid was greatest in fruits of non-pollinated spathes as compared with fruits of pollinated spathes. These results could be utilized to recommend pollinator A to ”Zaghloul” date spathes and may reveal the significance of applying such phytohormones (GA3, IAA ,zeatin and benzyladenine) at the beginning of cell enlargement phase (or the Kimri stage) to obtain similar enhancement of such fruit characteristics.