HISTORY OF DATE PALMS Date palm ( Phoenix dactylifera L.) has long been one of the most important fruit crops in the arid regions of the Arabian Peninsula, North Africa, and the Middle East. During the past three centuries, dates were also
ChihCheng T. Chao and Robert R. Krueger
Karim H. Al-Juboory
The seeds of two cultivars of Phoenix dactylifera L. (Medjol and Deglet-Nour) were cultured on modified Murashige and Skoog (MS) medium containing 0.5 mg/l NAA and 2.0 mg/l BA. Later they were treated with 25 or 50 pulses of excimer laser radiation. The results indicate that these seeds exhibited significantly less contamination than control. The highest percentage germination for both cultivars was obtained with explants treated with 50 pulses excimer laser radiation. Compared to other treatments, the occurrence of somatic embryo-genesis and shoot regeneration was greater with the Medjol cultivar.
Hussam S.M. Khierallah, Saleh M. Bader, Michael Baum, and Alladin Hamwieh
131 Akkak, A. Scariot, V. Dorello, T. Boccacci, P. Beltramo, C. Botta, R. 2009 Development and evaluation of microsatellite markers in ( Phoenix dactylifera L.) and their transferability to other Phoenix species Biol. Plant. 53 164 166 Al-Jibouri, A
Yuval Cohen, Stanley Freeman, Aida Zveibil, Rachel Ben Zvi, Yaakov Nakache, Shimon Biton, and Victoria Soroker
The inflorescences of date palm ( Phoenix dactylifera ) develop within the crown of the tree, at the base of the leaves, from meristems located as deep as 1 m within the upper part of the trunk ( Tomlinson, 1990 ; Zaid and De Wet, 1999 ). Each
Yousef I. Dlaigan, A.E. Said, and M.A. El-Hamady
Several trials were conducted with the objective of obtaining an explant for the establishment of date palm root culture in vitro. These trials included disinfecting and germinating seeds of three cultivars on several autoclaved culture media, the influence of incubation temperature on different germination parameters, and the quality of roots before excision and after culture in nutrient media. Three culture media were used: distilled water only; minimal organics that consisted of MS salts, 3% sucrose, modified White's organics, 0.01% inositol, and 0.15% activated charcoal; and 1/2 MS salts mixture, 3% sucrose, and 1/2 modified White's organics. All three media were solidified with 0.7% agar. The seeds were incubated at 25 or 35C for germination. The study revealed the difficulty of seed disinfection. We immersed seeds in 20% to 40% Clorox, with two to four drops of Tween-20, for 30 to 60 minutes and then rinsed them four to five times in deionized distilled water before culturing. The minimal organics medium supported optimal growth of excised roots, and incubation at 35C significantly improved germination. The use of 10-mm-long root tips as explants for culture initiation gave the best growth and elongation. In addition, the growth and elongation of excised root tips increased significantly as the distance from it to the apex of the cotyledonary sheath increased.
Hameed Jasim Aljuburi
The study was carried out at the Experimental Station of Agric. Sci. College at Al-oha region. Eight hundred seedlings (7 months old) were chosen for each following cultivars, Lulu, Boman, Barhee and Khalas. The seedings for each cultivars were irrigated weekly with 0, 6, 12, 18 g I.-1 Nacl solution.
The results revealed fresh weight of stems, roots and number of leaves/plant of Lulul, Barhee and Khalas cultivars progressively reduced with increasing Nacl concentration in irrigation water, while dry matter percentage of stems and roots increased and increasing salinity in irrigation water. The results also declared that the seedlings of four date palm cultivars has similar behavior, when exposed to high Nacl concentration in irrigation water during long term.
Jaladet M.S. Jubrael, Sripada M. Udupa, and Michael Baum
Currently, the identification and characterization of date palm varieties rely on a small number of morphological traits, mainly of fruit, which are complex and greatly influenced by the environment. As a result, different varietal names may actually refer to the same variety while different varieties may have the same name. Therefore, new descriptors like molecular markers are required to identify, characterize, and estimate genetic diversity in this crop. Here we used amplified fragment length polymorphism (AFLP) markers to discriminate 18 Iraqi date palm varieties and to estimate the genetic relationship among the varieties. A total of 122 polymorphic AFLP loci were scored, with an average of 17.4 polymorphic loci per primer combination. The use of any one of the four combinations, P101(aacg)/M95(aaaa), P74(ggt)/M95(aaaa), P73(ggg)/M95(aaaa), or P100(aacc)/M95(aaaa), was sufficient to uniquely identify all the varieties. Jaccard's genetic similarity index ranged from 0.108 to 0.756, indicating moderate to diverse relationships. Estimation of average proportion of fixed recessive AFLP loci indicated that most of the loci in variety `Chipchab' were fixed, whereas most of the loci in `Jamal Al-Dean' could be heterozygous and in-between in other varieties. Unweighted pair group method with arithmatic mean (UPGMA) analysis ordered the date palm varieties first into two broad groups at 27% similarity levels. One group consisted of seven varieties and the second group consisted of the remaining 11 varieties of date palm. These results showed that the AFLP technique is an efficient method for varietal identification and estimating genetic relationships in date palm.
Essam A. Mawlood, H.H Hamood, and E.S. Salah
This experiment was conducted to study the effects of bagging on fruit set, fruit characteristics and yield of Khastawi Date Palm CV. Two different types of bags were used: cloth and paper. The spadices were covered immediately at two different times during the first season; one month and the second continued until harvest time. Since positive results were obtained during the season, two extra bagging treatments were added in the second season (2 and 3 months). Unbagged spadices were used as control for both seasons. The results indicated that there were no significant differences between the two types of bags. Moreover, bagging for either two or three months produced positive results in fruit set improvement and yield.
Yousef I. Dlaigen, A. E. Said, and M.A. El-Hamady
Several experiments were conducted in this investigation with the objective of determining the chemical components and the physical state of an optimal medium for the growth and elongation of excised date palm, cv Sukkari, roots. The chemical tests carried out included: Comparison of (MS)-salts with “White's”-salts mixture and different concentrations of (MS)-salts and its chelated iron; sugars; Modified White's Organics; inositol; adenine sulfate; growth regulators; and some antioxidants. The physical tests, on the other hand, included comparison of the growth and elongation of cultured roots in a liquid or on solidified nutrient media. The effects of various pH values were also tested. Roots were cultured in basal nutrient media composed of: (MS)-salts mixture, and (in mg·liter–1): NaH2PO4·H2O, 170; sucrose, 30,000; inositol, 200; Modified White's Organics; adenine sulfate, 120; activated charcoal, 1500; (2,4-D), 1; kinetin, 2. pH was adjusted at 5.7 ± 01. (MS)-salts mixture was found to be superior to “White's”-salts. No significant difference was observed between (1/2MS) and full-strength (MS)-salts. However, twice the concentration was found to be inhibitory. The normal concentration of (MS)-Fe was found to be optimum for root growth and elongation. The optimal concentration most suitable for the growth and elongation of excised date palm roots has been determined for each of: sugars; Modified White's Organics; inositol; and adenine sulfate. The only growth regulator that needs to be added to the nutrient medium is 2,4-D at 0.1–1.0 mg·liter–1. The study showed the importance of the inclusion of activated charcoal to the nutrient medium. The growth and elongation of roots were both stimulated at all concentrations tested. (PVP), on the other hand, was inhibitory at all concentrations tested. Shaken liquid media was recommended for better root growth and elongation at pH 7.0–8.0. Incidentally, the medium developed was found to support the growth and elongation of roots excised from two other cultivars, namely `Khudri' and `Khaias'.
Yousef I. Dlaigan, A.E. Said, and M.A. El-Hamady
The objective of this investigation was to study the effects of some antioxidants on the growth and elongation of in vitro-cultured date palm roots. Several trials were conducted to determine the antioxidant and the concentration of antioxidants used in date palm tissue culture. Three types of antioxidants were tested—activated charcoal, polyvinylpyrrolidone (PVP), and sodium metabisulfite (NA2S2O5)—in various concentrations, singly, or in combinations. The medium used for root culture consisted of MS salts mixture, 1/2 modified White's organics, 60% sucrose, 0.004% inositol, 240 mg adenine sulfate/liter, 1.0 mg 2,4-D/liter, and 2.0 mg kinetin/liter. pH was adjusted at 5.7 ± 0.1. Concentrations of activated charcoal tested (in g–liter–1) were: 0.0, 1, 2, 3, 4, 6, 8, 10, and those of PVP (in g–liter–1) were: 0.0, 5, 10, 20, 40 (with or without 4 g activated charcoal/liter). NA2S2O5 concentrations (in mM) tested were: 0.0, 0.2, 0.4, 0.8, 1.6 (with 4 g activated charcoal/liter). The addition of activated charcoal to the culture medium of date palm roots is of vital importance. Four grams per liter gave the best growth and elongation, and there was no significant difference between it and 10 g–liter–1. No growth or elongation occurred in the control. PVP, however, significantly inhibited growth and elongation of cultured roots at all concentrations tested. NA2S2O5, however, stimulated growth and elongation at 0.2 mM. Higher concentrations inhibited growth and elongation.