An experiment was conducted at the United Arab Emirates Univ., in Al-Ain, to study the effect of saline water on the growth characteristics of date palm (Phoenix dactylifera L.) seedings cultivar Lulu-salt alone or a combination of NaCl and indole acetic acid (IAA) or IAA alone were tested with different levels. Then the plant growth characteristics were measured. Hormone did not antagonize the salt effect on shoot length of date palm seedlings. Application of 24 mg·L–1 salt alone or in combination with hormone and 12 mg·L–1 in combination with 0.2 mg·L–1 IAA significantly increased the root: shoot ratio over the control. Irrigation date palm seedlings with saline water alone or in combination with IAA for 80 days resulted in a significant increase in dry matter (percentage) of leaves with salt symptoms, whereas the number of leaves per seedling were reduced over the control. The results also showed that the irrigation of seedlings with 0.15 mg·L–1 IAA in combination with 24 or 12 mg·L–1 salt alleviated adverse effect of salt by increasing or reducing significantly root length or leaves with salt symptoms percentage over using 24 or 12 mg·L–1 salt alone.
Jinggui Fang and ChihCheng T. Chao
DNA methylation plays an important role in the regulation of gene expression in eukaryotes. The extent and patterns of DNA methylation were assessed in the date palm (Phoenix dactylifera L.) mother plants and their offshoots using the methylation sensitive amplified polymorphism (MSAP) technique. Three types of bands were generated using 12 pairs of primers. Type I bands were present in both EcoR I + Hpa II and EcoR I + Msp I lanes; type II bands were present in EcoR I + Hpa II lanes, but not in EcoR I + Msp I lanes; and type III bands were present in EcoR I + Msp I lanes, but not in EcoR I + Hpa II lanes. The total numbers of these three types of bands were 782, 55, and 34. Among these three types of bands, the polymorphic bands were 34, 10, and 0, respectively. The distribution of polymorphic bands among mother-plants and offshoots could suggest the methylation variation occurred to the mother plants and offshoots. The methylation variation during offshoot growth of date palm was characterized as a process involving mainly of demethylation. Hypomethylation of DNA in offshoots compared with mother plants reflects the marked expression of this molecular feature, which may related to gene expression during development of offshoots. The methylation or demethylation status of specific loci in the mother plants and their offshoots might not relate their lineage but occurred randomly.
Aref A. Abdul-Baki, Clyde Wilson, George E. Brown Jr., Lidia M. Carrera, Sam Aslan, Sam Cobb, and Tim Burke
The mineral concentration of bearing `Mejhool' date palm (Phoenix dactylifera L.) trees was investigated with the objective of identifying the cause of browning and dieback of distal parts of the fruit-bearing strands. Tissue analyses of leaves, fruits, healthy and dead portions of fruit-bearing strands indicated that tissue browning and dieback appeared to be associated with a high concentration of certain mineral elements. A comparison of mineral concentration between healthy and dead tissue of the fruit-bearing strands showed no significant increase in K, Cu, B, Zn, and Na, but very high increases in the concentrations of P, Ca, Mg, S, Mn, and Fe. The levels of P, Ca, Mg, S, Mn, and Fe in the distal part of the fruit-bearing strand over a 3-year average were 5, 18, 12, 3, 11, and 2 times, respectively, higher than those in the healthy, proximal part of the strand. Mineral concentrations of leaves and mature fruits were determined for comparison with those in fruit-bearing strands.
Mohammed Aziz Elhoumaizi, Panchanoor S. Devanand, Jinggui Fang, and Chih-Cheng T. Chao
We studied 66 `Medjool' date palm (Phoenix dactylifera L.) accessions from Morocco, six varieties of dates from Egypt, and four `Medjool' accessions and one `Deglet Noor' accession from California to investigate the hypothesis that `Medjool' is a landrace variety in Morocco. We used four sets of fluorescent-labeled amplified fragment length polymorphism (AFLP) markers to examine these accessions. A total of 402 bands were generated, of which 217 were polymorphic (54.0%). The 66 `Medjool' accessions from Morocco shared a minimum of 79% genetic similarity. These results support the hypothesis that `Medjool' is a landrace variety in Morocco and it is not genetically uniform. `Medjool' is the first confirmed landrace variety of date palm in the world. This finding raises the possibility that other date palms may be landrace varieties in different growing areas. Confirmation of a landrace variety in date palm has significant implication for future date palm germplasm collection and preservation. The mechanism(s) generating the genetic variation within `Medjool' accessions remains unknown. One possibility is that spontaneous genetic changes could occur frequently within vegetative tissues like offshoots under high temperature and drought stress.
Vyacheslav Gurevich, Uri Lavi, and Yuval Cohen
Date palm (Phoenix dactylifera L.) is a major tree crop in arid regions of the Middle East and North Africa, having an important impact on the economy of many countries in these regions. Date palms are traditionally propagated through offshoots. The development of propagation methods through tissue culture resulted in massive expansion of date palm plantations. While most trees generated from tissue culture are normal and true-to-type, several typical abnormal phenotypes are detected. The present study applies amplification fragment length polymorphism (AFLP) analysis to characterize the genetic variation of two elite date cultivars, `Barhee' and `Medjool', as well as male clones, propagated from offshoots and through tissue culture. The two cultivars have very distinct AFLP band patterns. Most offshoots, as well as the tissue culture-propagated plants, have very similar band patterns, demonstrating a low level of genetic variation. However, a significant level of genetic variation was detected among `Medjool' plants generated from tissue culture. Several phenotypically abnormal trees were characterized by unique and different AFLP band patterns. The male clones are characterized by a high level of polymorphic bands. Genetic variation was also detected between various tissues of variegated `Medjool' trees propagated from tissue culture. The significance of these results, regarding the mechanism of the phenomenon and its relevance to agricultural practice, is discussed.
Monica L. Elliott
). In Fall 2006, phytoplasma disease symptoms were reported on canary island date palm, date palm ( Phoenix dactylifera ), and wild date palm in southern Hillsborough County, FL (south of Tampa). Molecular analysis of trunk tissue from symptomatic palms
Kwanjai Pipatchartlearnwong, Akarapong Swatdipong, Supachai Vuttipongchaikij, and Somsak Apisitwanich
sequence of date palm ( Phoenix dactylifera ) ( Al-Dous et al., 2011 ; Al-Mssallem et al., 2013 ), a closely related species to Asian Palmyra palm, the numbers of transferable markers for the Asian Palmyra palm could be further expanded. The genetic study
Donald R. Hodel, A. James Downer, and Dennis R. Pittenger
( Phoenix canariensis ), queen palm ( Syagrus romanzoffiana ), and off shoots of date palm ( Phoenix dactylifera ), where cut roots have high survival rates ( Broschat and Meerow, 2000 ; Hodel and Pittenger, 2003 ; Hodel et al., 2003 ). Time of year
Antar Nasr El-Banna, Mohammed Elsayed El-Mahrouk, Mohammed Eraky El-Denary, Yaser Hassan Dewir, and Yougasphree Naidoo
structural proteins during the assembly of the head of bacteriophage T4 Nature 227 680 685 Marsafari, M. Mehrabi, A. 2013 Molecular identification and genetic diversity of Iranian date palm ( Phoenix dactylifera L.) cultivars using ISSR and RAPD markers
Donald R. Hodel
gingerbread palm ( Hyphaene spp.), which are infrequently cultivated, and date palm ( Phoenix dactylifera ) ( Dransfield et al., 2008 ). Aerial branching sometimes occurs in other species, where it is an abnormal phenomenon thought to be the result of