الفهرس 
INTRODUCTION
Artificial pollinationOnly 14 pages are availabe for public view
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Abstract
This study was conducted in Experimental Fruit Orchard, Department of Horticulture, Faculty of Agriculture, Assiut, Egypt, during three successive growing seasons 2008, 2009 and 2010, on some male and female date palm seedling as well as Zaghloul date palm cultivar. Male and female seedlings were represented by five and six palms, respectively, which were almost of the same age and uniform in growth. Zaghloul palms were 34 years old. The palms of seedling and Zaghoul cultivars were in good physical condition, free of insect, damage and diseases. All palms were grown on clay loam soil with good drainage system. This study was carried out in three experiments.
I- First experiment:
This experiment was conducted to evaluate some male and female date palm seedling types. Evaluation of the present males based on their vegetative growth and morphological aspects of spathes, as well as pollen viability and germination. whereas, evaluation of female seedling involved vegetative growth and fruiting. In addition, using RAPD to determine DNA fingerprinting to compare these seedling type with Zaghoul cultivar.
2- Second experiment:
This experiment was undertaken to effect of pollinizer types on fruiting of Zaghloul date palm and seedling palm types. Six seedling palm and four palms of Zaghloul cultivar that are uniform in vigour and in good physical condition, free of insect damage and diseases were selected. The number of spathes per palm were adjusted to ten by removing excess earliest, latest and smallest clusters for achieving five pollination treatments.
Pollen was obtained from five different local male palms that previously evaluated. Pollination was achieved by inserting 10 male strands into each of the female bunch and applied at 4 days upon spathe-cracking. Ten bunches on each female seedling types and Zaghloul received pollen grains from the five different males (two bunches for each male).
3- Third experiment:
The main objective of this experiment was innovated on untraditional method in date palm pollination which combined both mechanical pollination and fruit thinning effects. Eight date palms that are uniform in vigour and in good physical condition, free of insect damage and diseases were selected. The number of spathes per palm were adjusted to nine by removing excess earliest, latest and smallest clusters for achieving of the following nine treatments:
T1- 1.5 (g/L) pollen + 0.2 g boric acid + 10% Egyptian treacle.
T2- 1.5 (g/L) pollen + 0.2 g boric acid + 10% vinasse.
T3- 1.5 (g/L) pollen + 20 g ascorbic acid + 10% Egyptian treacle.
T4- 1.5 (g/L) pollen + 20 g ascorbic acid + 10% vinasse.
T5- 3 (g/L) pollen + 0.2 g boric acid + 10% Egyptian treacle.
T6- 3 (g/L) pollen + 0.2 g boric acid + 10% vinasse.
T7- 3 (g/L) pollen + 20 g ascorbic acid + 10% Egyptian treacle.
T8- 3 (g/L) pollen + 20 ascorbic acid + 10% vinasse.
T9- Hand pollination by inserting10 strands/bunch (traditional).
These treatments were applied on same palm. Pollination was uniformed in respect of the source and method to avoid residues of metaxenia.
Hand pollination as well as pollination treatment sprays were applied at the forth day of spathe cracking. Sprays of pollen suspensions are thoroughly applied to the bunch by small hand sprayer (1/2 liter capacity) at the amount of 50 ml/bunch. To prevent contamination of pollens, after the spraying of pollen suspension, every bunch was bagged by paper bags which is removed after four weeks. The experiment was set up in a complete randomized block design with nine replications of one bunch each.
(A) Yield parameters:
1- Initial and Horticultural fruit set %:
The number of set fruit or retented fruit per strand was counted using 10 strands per spathe after thirty days from pollination. As well as at harvest time.
2- Bunch weight:
All bunches were harvested at full colour stage (Khalal) during the first week of September for Zaghloul, in the three experimental season. The average bunch weight (in kg) was determined for each pollenizer.
B- Fruit properties:
Samples of 30 fruits were picked at random from each bunch for the determination of physical and chemical characteristics.
1- Physical characteristics:
Physical characteristics included the determination of:
a- Average of whole fruit and seed weight (in gm), then pulp percentage was calculated.
b- Average of fruit length (L) and fruit diameter (D) were measured by vernier caliper (in cm), then the fruit shape index was calculated.
2- Chemical characteristics:
Chemical characteristics included:
a- Total soluble solids (T.S.S.) by a hand refractometer.
b- Reducing and total sugars were evaluated according to Lane and Eynon titimetric Method.
c- Total titratable acidity % was determined as citric acid.
C- Spathe male morphology:
1 - Spathe weight (in kg). 2 - Spathe length (in cm).
3 - Spathe width (in cm) 4 - Number of strands/spathe
5 - Length of strand 6 - Number of flowers/fresh strand
D- Pollen grains characters:
Five nature spathes of every male were collected as soon as they crashed, and were dried at room temperature.
1- Pollen viability
Pollen viability was tested with acito-carmen-staining.
2- Pollen germination:
Pollen germination test was done using a medium containing 7% sucrose + 10 ppm Boron + 1 % Agar in Petri dishes.
E- Male and female Morphological Characteristics:
1- Palm height and girth:
The height and the trunk girth for each male and female palms used were measured in meters.
2- Leaves number:
The number of leaves per palm was counted and recorded.
3- Leaf Morphology:
Morphology of leaves was studied on four full grown leaves per palm (one leaf at each side). Measurements included:
1- Leaf length (m), number of pinnae, number of spores, proportion (%) of leaflets and/or spines area to rachis length.
2- Average length of pinnae and spine (in cm) were determined as follow = 8 leaflets (4 at each side) at either the top, middle and the base of rachis were randomly collected and measured.
In addition 16 spines on each leaf were used to determine average spines length.
4- Spathes number
The number of spathes of date palm males used in pollination were recorded at blooming.
The obtained results could be summarized as follow:
First experiment:
1- Male
A- Vegetative characteristics:
Palm height was differented where, the fourth male palm had the highest one compared to other male types. On the other hand, the third male palm was the shortest palm.
Moreover, the annual leaves number per palm were variability, where, the third male palm produced more annual leaves than other male palms. Vase versa, the fourth one gave the least annual leaves number.
The first male palm had the highest leaf area, where, the third male palm had the lowest value and other three male palms had intermediate values.
B- Spathes number and their characteristics
The number of spathes of seedlings male palm ranged between 17 to 21 in the different males. The second male palm produced the highest number while the fifth male palm had the lowest ones.
The spathe width attained (29.3, 29.7, 33.3, 32.7 and 30.0 cm av. the three studied seasons), respectively. The spathe length was longest in the first male palm and shortest in both the third and fourth compared to other males. Moreover, the spathe width was highest in both the third and fourth male palms compared other males.
The first male palm gave the longest strand, while the fourth one gave the highest flowers number/strand. Contrarly, the second male had the shortest strand and the first produced the least flowers number/strand.
C – Pollen grains characteristics
Pollen grains of the first male recorded the highest percentage. While, the fifth male revealed the least percentage and both the second and the fourth gave intermediate value.
The germination percentage took a similar trend to that of viability percentage. There was a positive relationship between pollen viability and germination.
II- Female type characteristics:
A. Vegetative characteristics:
Zaghloul palm had the highest one compared to other investigated seedling palms. On other hand, the third seedling palm was the shortest one.
The first seedling palm was the fattest ones, vase versa, the third seedling was the thinnest palm compared to other studied palm types.
The fourth seedling palm produced more annual leaves compared other seedling and Zaghloul palms. Contrarly, the Zaghloul palm produced the less annual leaves whereas, the second, third and fifth seedling palm gave the intermediated values of leaves.
Zaghloul palm had the least leaf area where its had the least pinnae number/leaf and the least pinnae area. Contrary, either the sixth or third seedling palm had the highest leaf area, where they had the highest pinnae number and the highest pinnae area.
The second and third seedling palm type had the highest leaf surface expansion.
B- Morphological spathe characteristics:
All studied palm types produced similar spathe in long where their length were ranged 0.93 to 1.10 m.
The spathe width was highest in the first seedling female type compared to other studied palm.
The strands number varied from 107 to 65 strand, where the flowers number varied from 42 to 66 flowers.
The third seedling palm produced highest strands number per inflorescence. Contrary, the Zaghloul palm produced the least number of strands compared to all seedling palms. Moreover, the second seedling palm gave the highest flowers number per inflorescence, where, the fourth seedling palm gave the least number of flowers compared to other studied palm types.
C – Fruiting
The fifth and first seedling types were the highest in their fruit set percentage in comparison to other seedling types or Zaghloul cultivar. On the contrary, the fourth seedling palm was the least in its fruit set percentage compared other studied types.
Zaghloul palm was highest and significantly increased in its fruit retention compared to the first, fifth and fourth seedling palm types.
The highest heaviest fruit and its flesh percentage were recorded for the fourth seedling type compared to other seedling types and Zaghloul cultivars. On the other hand the first seedling palm type gave the lowest weight one, whereas, the second one gave the least values of flesh percentage.
The highest values for this trait were recorded for the first seedling type. However, the sixth seedling type had the lowest one compared to other studied types. Both the second and fifth seedling palm types intermediate values. No significant difference were recorded among the first, third and fourth seedling types, as well as, the second and fifth. Zaghloul cultivar had a significantly higher values than the sixth seedling palm type.
Fourth and sixth seedling types get the highest fruit length. whereas, fourth seedling types get the highest fruit diameter. Moreover, the second, fifth and sixth seedling type get the highest shape index. On the contrary, the first seedling type gets the least values of fruit length and shape index and the second as well as the third seedling type gets the least values of fruit diameter of these studied parameters.
The fourth and first seeded female types get the highest S.S.C %, with out any insignificantly differences, whereas, the sixth and Zaghloul cultivars gave the least values of S.S.C %.
The fruits of the fourth and fifth seeded female types contained the highest acidity %, whereas, the third seedling type and Zaghloul cultivar had the least values of acidity %.
Fourth seedling types get the highest total sugars percentage. whereas, Zaghloul cultivars highest reducing sugar percentage. Moreover, the second, seedling type get the highest non reducing sugar percentage. On the contrary, the third type gets the least values of total sugar and reducing sugar percentage and Zaghloul cultivars gets the least values of non reducing sugar percentage of these studied parameters.
General evaluation:
A- Seedling males:
The third and first male palms gained the highest score recording (92.9 and 92.2 unit) respectively.
The least total score was recorded for the fifth male palm (78.6 units), ascendingly followed by the fourth male palm (82.8 units) and the second male palm (86.8 units).
B – Seedling females types and Zaghloul cultivar:
The second female seedling gained the highest score recording (88.1 units). It could be arranged the obtained scores in a descendingly order as follow (88.1, 79.2, 76.9, 76.6, 73.3, 72.5 and 68.5 units) for the second, sixth, fourth, third, first, fifth female seeding palms and Zaghloul cultivar, respectively.
Cluster analysis of the cultivars based on RAPD analysis:
The twelve date palm cultivars examined, can be arranged into two main distinct groups. The first group contains all females and Zaghloul cultivars that subdivided into five sub-clusters. The first sub-cluster contains female 4 and zaghloul cultivars, which separated at 0.851 value of similarity, the second sub cluster contains female 2 and 3 cultivars, which separated at 0.81 value of similarity. The third, fourth and fifth clusters contain females 1, 5 and 6. The second group contains all males cultivars studied that subdivided into three sub-clusters, male 3 and 4 cultivars grouped in first sub-cluster, which separated at 0.926 high value of similarity. The second sub-cluster contains male 1 and 5, which separated at 0.777 value of similarity, and the third sub-cluster contain the male 2 cultivar only, which separated at 0.837 value of similarity with the first sub-cluster in the same group.
Second experiment
1 – Yield:
The first, second and third male palms were the best males to pollinated the sex studied seedling types and Zaghloul cultivar in this area.
The fifth, first, second and third seedling palm types as well as Zaghloul cultivar get the highest fruit set percentage, whereas, the fourth seedling type gave the lowest ones.
As, interactions between pollen type and female parent, it mentioned that the first and second were the best for the first, second and third seedling palm types, whereas, first and third were the best for Zaghloul date cultivar. On other hand, the first male was the best for the fifth seedling palm type, whereas, the third male was the best male for the fourth and sixth seedling palm types.
Pollination with pollen grains either the first, second or the third male palm significantly increased the fruit retention percentage and consequently bunch weight of sex seedling palms and Zaghloul palm than pollination with the fourth or fifth male palms.
The highest fruit retention was obtained from the first male palm, whereas, the lowest values was noticed due to use pollen grains the fifth male. No significant differences on the fruit retention due to pollinate with pollen grains of either the first or third males, as well as fourth or fifth males.
The fruit retention took a similar trend to that of initial fruit set percentage. There is a positive correlation between initiation fruit set and ultimate fruit retention.
The second, third and sixth seedling types had higher in their bunch weight compared to other seedling types. On the contrary, bunch weight of the fourth seedling type was the lowest ones. However, Zaghloul as well as the fifth and the first seedling palms gave the moderate bunch weight.
Pollen of the first male are the best pollinazer for the first, third and fifth seedling palm types as well as Zaghloul cultivars, where gave the highest fruit retention percentage compared to other males pollen used. Moreover, the third one was the best male to pollination of the fourth and sixth seedling types compared other males.
Pollen either of the first, second or third male palm significantly increased the bunch weight of all studied female types than other pollen sources in the three studied seasons. On other hand, pollen of the fifth pollinator significantly decreased bunch weight compared to other pollinators.
2- Fruit quality:
The heaviest fruit weight was recorded due to use pollen grains of the fifth male. The vice versa, the lightest one obtained due to pollen grains of the third ones. No significant differences were found due to pollination with pollen of the fifth or the fourth, as well as third, second or the first male palms.
Flesh percentage significantly increased when used pollen of fifth or third male compared the pollen of first male. No significant differences were among the pollen of the fifth and third male as well as first, second and fourth male palms.
Highest heaviest fruit and its flesh percentage were recorded for the fourth seedling type compared to other seedling types and Zaghloul cultivars. On the other hand the first seedling palm type gave the lowest weight one, whereas, the second one gave the least values of flesh percentage.
The pollen grains of fifth male was the best to pollination of the second, third and the fourth seedling female types. whereas, the fourth male was the best one for the first, fifth and sixth seedling type as well as Zaghloul cultivar which gave the best fruit weight and flesh percentage compared to other combinations.
The longest fruit length was recorded due to use pollen grains of the fourth male. The vice versa, the shortest one obtained due to pollen grains of the third ones. No significant differences were found due to pollination with pollen of the fifth , the fourth or first, as well as third, second or the first male palms.
whereas, fruit diameter insignificant increased when used pollen of fifth or fourth male compared to the other male types. On the other words No significant differences were among the pollen of any male palms.
Moreover, shape index insignificant increase when used pollen of fourth male compared to the other male types. No significant differences were used pollen any male palms.
The highest values fruit length and its diameter were recorded for the fourth seedling type compared to other seedling types and Zaghloul cultivar. On the other hand the first seedling palm type gave the lowest length one, whereas, the third gave the least values of fruit diameter and the first gave the least values of shape index.
All combinations either fifth or fourth males with all studied female types significantly the fruit length compared to other combinations, also all combination of either fifth or fourth males gave the highest fruit diameter compared to other combinations. Moreover all combination of either fourth or fifth males gave the highest shape index compared to other combinations.
The highest value of soluble solids contents was recorded due to use pollen grains of the third male palm compared to comparable values that obtained of other male palms. Using pollen grains of the third male palm resulted in a more announce, significant increase in the soluble solid contents. No significant differences were detected between using pollen grains of either the third, second or the fifth male palm, as well as the fourth or the first one.
The highest values for this trait were recorded for the first seedling type. However, the sixth seedling type had the lowest one compared to other studied types. Both the second and fifth seedling palm types intermediate values. No significant difference were recorded among the first, third and fourth seedling types, as well as, the second and fifth. Zaghloul cultivar had a significantly higher values than the sixth seedling palm type.
The highest soluble solid contents were found when the pollen grains of the third male palm used to pollination the first, second and fourth seedling palm types. Also, using pollen grains of the fifth male for pollination of the sixth seedling type and Zaghloul cultivar. In addition, the second male is the bet pollinizer for the fifth seedling type, whereas the first male is the best one for pollination the third seedling palm type compared to other pollinazers.
The highest value of acidity % was recorded due to use pollen grains of the fourth male palm compared to other values that obtained of other male palms. The lowest value was recorded due to use pollen grains of the first male palm.
The highest values for this trait were recorded for the sixth seedling type. However, the Zaghloul cultivar had the lowest one compared to other studied types. Both the second and third seedling palm types intermediate values.
The highest acidity percentage were found when the pollen grains of the first male palm used to pollination fourth seedling palm types. On the other hand, the least values of this trait were detected due to use pollen grains of the first male on Zaghloul cultivar.
The highest value of total sugars percentages were obtained due to use pollen grains of the fifth male palm compared to values that obtained of other male palms. whereas the highest value of reducing sugar percentage was recorded due to use pollen grains of the second male palm compared to comparable values that obtained of other male palms. Theremore the highest values of non reducing sugar percentage was recorded due to use pollen grains of the third, fourth and fifth compared to comparable values that obtained of first and second male palms.
The highest values of total sugar were recorded for the first and third seedling types. However, the sixth seedling type had the lowest one compared to other studied types.
whereas the highest values for reducing sugars percentage were recorded for the Zaghloul cultivar. However, the second seedling type had the lowest one compared to other studied types. Both the fourth and fifth seedling palm types intermediate values.
The highest values for non reducing sugars percentage were recorded for the first seedling type. However, Zaghloul cultivar had the lowest one compared to other studied types.
The highest total sugars were found when the pollen grains of the fifth male palm used to pollination third seedling palm types. On the other hand, the least values of this trait was detected due to use pollen grains of the first male on third seedling palm types. Moreover the highest reducing sugars were found when the pollen grains of the second male palm used to pollination Zaghloul cultivar. whereas the least values of this trait was detected due to use pollen grains of the first male on third seedling type. On the other hand, the highest non reducing sugars were found when the pollen grains of the third and fifth male palm used to pollination first and third seedling palm types. On the other hand, the least values of this trait were detected due to use pollen grains of the second male on Zaghloul cultivar.
Third experiment:
Fruit set and fruit retention were significantly decreased due to pollination by using suspension of pollen grains either of 1.5 or 3.0 g/L with boric acid or ascorbic acid along with either Egyptian treacle or vinasse compared with traditional pollination (T9).
The reduction on fruit weight/bunch was associated with decreasing the pollen grain suspension concentration from 3 to 1.5 g.
The results indicated that there are insignificant differences in fruit weight/ bunch due to pollination by using 3 g pollen compared with traditional hand pollination. On the other hand, data concerning the effect of using either boric acid or ascorbic acid, as well as, Egyptian treacle or vinasse, show that insignificant differences in initial fruit set, fruit retention and fruit weight/bunch due to pollination by using pollen grains suspension.
Thus, from the economic point of view should be used vinasse, where it is available and cheap. In addition, start background scanning is to reduce the environmental pollution which could be occurred by excess of industrial wastes.
There was an improvement of the fruit physical quality in terms of increasing the fruit weight and dimensions by using a pollen grains suspension compared to the traditional pollination (control).
No significant differences in physical fruit properties were observed due to either vinasse or Egyptian treacle.
Pollination by pollen grains suspension was significantly improved the fruit chemical constituents in terms of increasing the soluble solids and sugar contents and reduction of total acidity percentage compared to pollination by traditional pollination. The improvement of these fruit traits was associated with the reduction of pollen grains suspension concentration from 3 to 1.5 g/L. Using pollen grain suspension at 1.5 g plus both 2 g ascorbic acid and 10% vinasse gave the maximum values of soluble solids and sugar contents, whereas, using traditional hand pollination gave the minimum values. Moreover, all treatments incompained with ascorbic acid or vinasse gave the higher values of these readings than incompained with boric acid or Egyptian treacle.
Conclusion
Seedling male differ greatly in the morphological characteristics of the spathes and strands. It could be concluded that there was a positive relationship between leaves number and spathes number spathes weight and strands number as well as strands length and flowers number for each strand. Also, there was a positive relationship between viability, germination and fruit setting. In additional, there were a significant positive correlation between fruit set and both fruit retention or bunch weight. Contrary, there was a significant negative correlation between fruit set and quality.
The results of the present study indicate that, the RAPD method is a fast and relatively simple process for marker identification in date palm.
The five primers used in the present work detected high level of polymorphism (87.5%). Such high level of polymorphism could provide the date palm breeders with environmental dependent DNA markers, which be regarded as essential tool for selection.
The results suggest that small number of RAPD primer could be used for distinguishable date palm genotypes.
from this study may be recommended the importance of the inventory of seedling strains for the date palm, and vegetative propagation of superior of them as well as the use of male 1, 2 and 3 where it is the best pollinizers as well as pollination of Zaghloul date palm using pollen grain suspension concentrations at 1.5 g/L plus 2 g ascorbic acid along with 10% vinasse was sufficient to get a high yield with good fruit quality. The advantages of such pollination method reduces the labors and duration of pollination. It does not require a highly trained labors as with the traditional technique.