Genetic diversity and population structure of date palms (Phoenix dactylifera L.) in Ethiopia using microsatellite markers

An Overview of Date (Phoenix dactylifera) Fruits as an Important Global Food Resource

Dates are the fruits of the date palm belonging to the Arecaceae family; they comprise over 2500 species and 200 genera and constitute an essential part of the daily diet worldwide, with beneficial nutritional, health, and economic values. Several varieties of date palm (Phoenix dactylifera) fruit exist globally, especially in hot and humid regions. This review is an overview of date palms as a significant global food resource, including their historical significance, nutritional composition, cultivation practices, economic importance, and health benefits. The historical journey of dates goes back to ancient civilizations where they were revered for their richness in essential nutrients and natural sweetness. Today, dates are a vital crop in arid regions, contributing substantially to the agricultural economy and livelihoods of communities. This paper further explores the cultivation techniques employed to enhance date production. Furthermore, the nutritional composition of dates is analyzed in detail, highlighting their high content of vitamins, minerals, dietary fibers, and antioxidants. These attributes make dates a delicious treat and a valuable nutritional component, offering numerous health benefits. The potential health effects, including improved digestion, enhanced cardiovascular health, and increased energy levels, are discussed. Additionally, this paper delves into the economic significance of the date industry and its global trade.

Genetic diversity of Moroccan date palm revealed by microsatellite markers

The genetic diversity between 23 Moroccan date palm cultivars collected from the National Palm Collection at the INRA (National Agricultural Research Institute) experimental field in Zagora was assessed using SSR markers that are specifically designed for date palm. Among the 16 tested SSR, 13 were successfully amplified, and were selected to carry out this study. 208 bands were amplified, ranging from 10 to 25 bands per cultivar with an average of 16 alleles per cultivar. The value of heterozygosity of the studied markers ranged from 0.11 to 0.30. The pairwise genetic distances between those cultivars ranged from 0.06 to 0.46. The hierarchical cluster analysis distributed the 23 genotypes into four different groups of one to ten cultivars.

Analysis of genetic diversity and population structure of oilseed crop noug (Guizotia abyssinica) accessions collected from Ethiopia

BACKGROUND

Noug is an Ethiopian indigenous oilseed crop cultivated primarily for its oil and various economic importance. Evaluating the extent of genetic diversity within and among populations is one of the most important steps in breeding and conservation measures. Thus, this study aimed to uncover the extent of genetic diversity and population structure of noug accessions collected from different regions of Ethiopia using microsatellite markers.

METHODS AND RESULTS

A total of 161 accessions from fourteen regions of Ethiopia, including some from Eritrea using 13 microsatellite markers were analyzed. All the 13 microsatellite markers were polymorphic and highly informative with a mean PIC value of 0.82. The analysis generated a total of 158 alleles with a mean of 12.15 per locus. The overall mean of Shannon information index and heterozygosity/gene diversity were 1.57 and 0.74, respectively suggesting the presence of higher genetic diversity across the collection regions. AMOVA revealed that 96.06% of the total genetic variation was attributed to within populations while only 3.94% was attributed to among populations. Likewise, the dendrogram clustering, PCoA, and the model-based population structure analysis didn't exactly corresponded the grouping of the genotypes according to their regions of origin.

CONCLUSION

The microsatellites used in the present study are highly informative and could be targeted for developing markers for future marker-assisted breeding. Genotypes collected from Shewa, Wollo, Gojjam, Tigray, and B/G showed a higher genetic diversity and private alleles as compared to other populations. Hence, these areas can be considered as hotspots which could help for the identification of genotypes that can be used in breeding programs as well as for the implementation of further conservation programs.

Exploring genetic variation among Jordanian Solanum lycopersicon L. landraces and their performance under salt stress using SSR markers

Background

Tomatoes (Solanum lycopersicon L.) are one of the main daily consumed vegetables in the human diet. Tomato has been classified as moderately sensitive to salinity at most stages of plant development, including seed germination, seedling (vegetative), and reproduction phases. In this study, we evaluated the performance and response of 39 tomato landraces from Jordan under salt stress conditions. Furthermore, the landraces were also genetically characterized using simple sequence repeat (SSR) markers.

Results

The studied morphological-related traits at the seedling stage were highly varied among landraces of which the landrace number 24 (Jo970) showed the best performance with the highest salt tolerance. The total number of amplification products produced by five primers (LEaat002, LEaat006, LEaat008, LEga003, LEta019) was 346 alleles. Primer LEta 019 produced the highest number of alleles (134) and generated the highest degree of polymorphism (100%) among landraces in addition to primers (LEaat002, LEaat006, LEaat008). The lowest dissimilarity among landraces ranged from 0.04 between accessions 25 (Jo969) and 26 (Jo981) and the highest dissimilarity (1.45) was found between accessions 39 (Jo980) and both 3 (Jo960) and 23 (Jo978). The dendrogram showed two main clusters and separated 30 landraces from the rest 9 landraces. High genetic diversity was detected (0.998) based on the average polymorphism information. Therefore, the used SSRs in the current study provide new insights to reveal the genetic variation among thirty-nine Jordanian tomato landraces. According to functional annotations of the gene-associated SSRs in tomatoes, a few of SSR markers gene-associated markers, for example, LEaat002 and LEaat008 markers are related to MEIS1 Transcription factors genes (Solyc07g007120 and Solyc07g007120.2). The LEaat006 is related to trypsin and protease inhibitor (Kunitz_legume) gene (Solyc03g020010). Also, the SSR LEga003 marker was related to the Carbonic anhydrase gene (Solyc09g010970).

Conclusions

The genetic variation of tomato landraces could be used for considering salt tolerance improvement in tomato breeding programs. 

Supplementary Information

The online version contains supplementary material available at 10.1186/s43141-022-00327-2.