Biodiversity, Genetic Diversity, and Genetic Resources of Date Palm

Abstract

Phoenix dactylifera L. is composed of genetically discrete clones representing thousands of cultivars without the benefi ts of a dynamic mutationrecombination system; its genetic resources are the most important component of biodiversity in its natural habitats; these include modern cultivars, landraces, obsolete cultivars, breeding lines, and related wild species. Cultivated Phoenix is closely related to a variable aggregate of wild and feral palms distributed over a wide desert belt across the Middle East and North Africa. Genetic diversity and genetic structure of the species gene pool complex have been shaped and greatly altered by human and natural selection, clonal propagation, and spatiotemporal exchange of germplasm. The mixed sexual-clonal propagation system acted on the sexual traits, impacted the genetic structure of populations, and may have resulted in the accumulation of domesticated traits in the date palm. Traditional oases continue to play a vital role in the maintenance and enrichment of date palm biodiversity, genetic diversity, and genetic resources through multiple processes and dynamic conservation practices. However, with the advent of modern plantations emphasizing elite cultivars, a better understanding of the intraspecifi c genetic variation of date palm and its distribution in oasis agroecosystems is essential for the conservation and sustainable utilization of its biodiversity and genetic resources. In-depth assessment of the genetic vulnerability of date palm to biotic and abiotic stress requires knowledge of the extent and distribution of its genetic diversity, both of which depend on the species evolution and its unique breeding system, past genetic bottlenecks, and ecological, environmental, and anthropogenic factors.

Traditional oases in Northern Africa as multifunctional agroforestry systems: a systematic literature review of the provided Ecosystem Services and of the main vulnerabilities

“…Deglet Nour in Tunisia (Hamamouche et al 2018;Benaoun et al 2014;Liu 2003), but is also associated to local fruit tree species and varieties (Allam and Cheloufi 2013) or to wheat landraces cultivated in the Saharan oases (Zaharieva et al 2014). Loss of agrobiodiversity can affect the livelihood of local farmers, since the loss of genetic diversity also means a reduced resilience and resistance to pests, diseases, drought, and climate change (Jaradat 2015); in addition, having different date varieties means that not all the dates ripen in the same period, so small farmers can better organize the agricultural operations and can have a better distributed income over time and less depending on the market price fluctuations. Social-related issues (depopulation, loss of traditional knowledge and of cultural heritage) also represent major threats (16.1%) especially in marginal areas, with negative consequences not only for the cultivated part of the oases but also for the related architectural heritage (Gado et al 2010).…”

Date Palm Pollen: Features, Production, Extraction and Pollination Methods

“…The Assyrians of ancient Mesopotamia practiced artificial pollination of date palms as early as 4500 B.C. [12,61]. Their method of pollination was to place strands of male inflorescences into the strands of female inflorescences.…”

Genetic diversity of sugar palm (Arenga pinnata) derived from nine regions in Indonesia based on SSR markers

“…Genetic diversity can be attributed to gene variations within a population or between populations passed down between generations. Natural selection, spontaneous mutations, gene flow, genetic drift, and inbreeding can affect the population's genetic diversity (Jaradat 2015). The highest genetic diversity is owned by the population of Bangka with a value of Ne 1.811 and He 0.355.…”