Acta agriculturae Slovenica, 119/1, 1–10, Ljubljana 2023 doi:10.14720/aas.2023.119.1.2611 Original research article / izvirni znanstveni članek Phenotypic diversity of date palm varieties (Phoenix dactylifera L.) from southwest Algeria estimated by fruit characteristics Kaouther DEBABECHE 1, 2, Abdelaaziz BOUAFIA 1, Abdelaali BENCHEIKH 1 Received March 13, 2022; accepted December 13, 2022. Delo je prispelo 13. marca 2022, sprejeto 13. decembra 2022 1 Scientific and Technical Research Center on Arid Regions, Biskra, Algeria 2 Corresponding author, e-mail: kaoutherdebabeche@gmail.com Phenotypic diversity of date palm varieties (Phoenix dacty- lifera L.) from southwest Algeria estimated by fruit charac- teristics Abstract: This study aimed to identify the genetic diversity of date palm (Phoenix dactylifera L.) in the southwest of Algeria (wilaya of Adrar), as part of the Algerian date palm varieties conservation. The morphological characterization was adopted in terms of quality and quantity of 26 varieties. The main results showed a considerable genetic diversity of date palms in this agricultural territory. 7 cultivars counted in danger of extinc- tion. The cluster analysis brought out significant differences between qualitative and quantitative traits. However, the culti- vars of ‘Deglet Talmine’, ‘Maatouk’, and ‘Timidouele’ produced dates of high quantitative traits, however, of different qualitative traits. Also, some relationships were observed within clusters for other varieties. A variety named ‘Khalt’ was able to produce dates better than many cultivars. This work would help to know the focal traits of the plant genetic resources of date palm and preserve that are in extinction. Key words: Adrar; cluster analysis; cultivar; dates; Phoe- nix dactylifera L.; qualitative characterization; quantitative characterization; variety Fenotipska raznolikost sort dateljeve palme (Phoenix dactyli- fera L.) v jugozahodni Alžiriji, ocenjena na osnovi lastnosti plodov Izvleček: Namen raziskave je bil določiti genetsko razno- likost dateljeve palme (Phoenix dactylifera L.) v jugozahodni Alžiriji (provinca Adrar), kot del programa ohranjanja alžirskih sort dateljeve palme. Morfološka opredelitev 26 sort je bila na- rejena na osnovi kakovostnih in količinskih parametrov. Glavni izsledki so pokazali, da je na tem kmetijskem območju precej- šnja genetska raznolikost dateljeve palme. Sedem sort je bilo opredeljeno kot ogroženih pred izumrtjem. Klasterska analiza je pokazala značilne razlike med kakovostnimi in količinskimi lastnostmi sort. Sorte ‘Deglet Talmine’, ‘Maatouk’, in ‘Timido- uele’ so bile najbolj rodovitne, a z različnimi kakovostnimi la- stnostmi. Znotraj skupin sort so bile opažene še nekatere druge lastnosti. Tako je bila sorta ‘Khalt’ najrodovitnejša. Izsledki te raziskave bodo pomagali prepoznati ciljne lastnosti v naboru sort dateljeve palme za njihovo ohranjanje. Ključne besede: Adrar; klasterska analiza; sorta; Phoenix dactylifera L.; kakovostna in količinska oznaka sort Acta agriculturae Slovenica, 119/1 – 20232 K. DEBABECHE et al. 1 INTRODUCTION The date palm (Phoenix dactylifera L.) is a centu- ries-old crop plant farmed in many desert regions of the world, particularly in West Asia and North Africa (Al- Yahyai & Mumtaz Khan, 2015). Its culture is perennial and classified under the ge- nus Phoenix, a monocotyledonous family Palmae with 36 chromosomes (2n = 36) (Chao & Krueger, 2007). Phoe- nix species are dioecious, with offshoots being the most common propagation method; however, tissue culture and seed are other viable options. Propagation via seeds produces new genotypes or forms of date palm, which are the primary source of date palm variety (Elhoumaizi et al., 2002). Around 3000 date palm cultivars have been identi- fied worldwide (Khierallah et al., 2015) in which 940 cul- tivars were recorded in Algeria (Hannachi et al., 1998). However, Algeria is known for its noble variety ‘De- glet Noor’, which is considered a crop of nutritional qual- ity (Debabeche et al., 2021) with great socio-economic importance 54 % of the total production. It occupies the largest cultivated areas in Ziban, Oued Souf, and Oued Righ (MARDF, 2021). Adrar is the fourth-largest producer of dates in the country, with an annual production of 93568.1  tons in 2020, where there are a number of 3798579 date palms (MARDF, 2021). This rank has decreased mainly due to the exten- sion of the adverse biotic threats. The vascular attack of Fusarium oxysporum f.sp. albedinis W.L. Gordon, (1965) named the bayoud, which is considered the most danger- ous, is widespread in multiple palm groves of the munici- palities of the wilaya also, the anthropogenic and abiotic threats are well noted in this region. Drought is one of the most important environmental stresses causing a signifi- cant drop in crop productivity (Guettouchi et al., 2017; Sarwat & Tuteja, 2017). So, adopting a strategy to pre- serve and restore the plant genetic resources of the date palm is necessary for the state and scientists. A previous survey on identifying genetic diversity of Algerian date palm female cultivars employing mor- phological description was done in the southeast Al- gerian territory. Simozrag et al.(2016) and Bedjaoui & Benbouza (2020) distinguished 96 cultivars in the wilaya of Biskra based on the morphological traits of the vegeta- tive and the fruit part of the date palm. Another morpho- logical identification was made on 175 cultivars in Oued Righ and 56 in Oued Souf (Acourene et al., 2007).Guet- touchi et al. (2017) described 19 cultivars in the wilaya of Boussada and Simozrag & Laiadi (2020) characterized 80 minor cultivars in the wilayas of Biskra and Oued Righ using molecular traits. The characterization combining the morphologi- cal, biochemical, and molecular traits of trees provides definite genetic information to species (Kameswara Rao, 2004) and preserve the genetic heritage of plants (Al- Yahyai & Mumtaz Khan, 2015). One of the most preva- lent approaches for identifying date palm diversity is to use morphological criteria wherein the traits related to the vegetative or the fruit organs have been highly praised for date palm characterization (Elhoumaizi et al., 2002b). In fact, phenotypic diversity is a visible sign of date palm variety. It depicts the interaction impact between genetic variation and the environment (Jaradat, 2011). Considering that this study has been engaged through the investigation and participation in the genetic identifi- cation of the endogenous female accessions of Southwest Algeria. Therefore this work aimed to characterize some of the fruit morphological traits which are accessible to the observer being part of the diversity identification and conservation of the Algerian date palm varieties exist- ing in the wilaya of Adrar and to enrich date palm germ- plasm and develop a suitable breeding strategy. 2 MATERIALS AND METHODS 2.1 PLANT MATERIAL The research was conducted on the fruit of twen- ty six Algerian date palm varieties located in Algeria’s southwest (wilaya of Adrar), between 27 ° 52 ′ 00 ″ N and 0 ° 17 ′ 00 ″ W, with an altitude estimated at 279 m. Adrar has a hot desert climate characterized by a mean annual temperature of 26.7 °C which means annual rainfall bare- ly reached 16.26 mm in 2020. Specific information on local names of date palm varieties, their type of reproduction, distribution, avail- ability of their fruit in the market, and socio-economic value were carried out. A panel of expert provided it from Ben Abbes station of scientific and technical research center on arid regions and the farmers in the wilaya of Adrar (Table 1). 2.2 SAMPLING AND ANALYSIS All the varieties are selected in palm groves of five municipalities of Adrar (Figure 1).The tree’s sampling on each variety depended on their availability from one grove to another, and from 20 groves studied in each mu- nicipality at least 3 replicates were taken from each vari- ety except for ‘Khalt’. Twenty fruits from different bunch- es of each date palm tree were randomly sampled at the Acta agriculturae Slovenica, 119/1 – 2023 3 Phenotypic diversity of date palm varieties (Phoenix dactylifera L.) from southwest Algeria estimated by fruit characteristics fully mature stage. The study was designed on different analyses on a phenotypic basis. The main traits were de- rived from the descriptor list for the date palm (IPGRI et al., 2005), concerning the fruit, including eight quantita- tive traits: fruit and seed sizes (cm), fruit and seed mass (g), and ratios of length and mass of the seed on their fruit also, the dates were identified by qualitative traits: the fruit shape, the fruit peel colour, the fruit consistency and the flesh texture. 2.3 STATISTICAL ANALYSIS Correlations between qualitative and quantita- tive traits of the fruit were obtained with significance Varieties Code Status of reproduction Distribution Harvest Appreciation Marketing Abbad ABB Cultivated Frequent August Excellent Important Abd Salam ASA Cultivated Rare October Excellent Important Adam Bara ABA Cultivated Rare October Excellent Important Adam Bola ABO Cultivated Frequent October Excellent Important Adam Lebled ALD Cultivated Frequent August Excellent Important Adam Mani AMN Cultivated Frequent October Good Medium Adam Osalem AOS Cultivated Infrequent October Medium Medium Cherka CHE Cultivated Frequent October Good Medium DegletTalmine DTN Cultivated Frequent October Medium Important El Mabrouka ELM Cultivated Infrequent October Good Medium Feggous FEG Cultivated Frequent October Excellent Important Hartane HAR Cultivated Frequent November Excellent Important Hemira HEM Cultivated Frequent October Good Important Hija HIJ Cultivated Frequent August Excellent Important Khalt KHL Seedling Unique October Low Low Maatouk MAA Cultivated Frequent October Good Important Tademama TDM Cultivated Frequent October Medium Low Takerbouchte TKB Cultivated Frequent December Excellent Important Taorakhet TAR Cultivated Rare October Low Low Tazerza TZR Cultivated Abundant October Medium Low Timjohar TMJ Cultivated Frequent October Good Medium Timebadda TBD Cultivated Frequent September-October Good Important Timeliha TML Cultivated Frequent October Medium Medium Timidouele TMD Cultivated Frequent October Medium Low Tinaser TNS Cultivated Frequent October Low Important Tinizioua TNZ Cultivated Frequent October Medium Low Table 1: Identification data of the cultivars studied Figure 1: Location map showing the collected date palm varie- ties in the wilaya of Adrar Acta agriculturae Slovenica, 119/1 – 20234 K. DEBABECHE et al. p  <  0.05. Cluster analysis was run for grouping culti- vars that showed dissimilarity in several traits. Cluster- ing was performed on eight quantitative fruit traits and four qualitative traits for everyone, using the Euclidean distance matrix and the un-weighted pair group method with arithmetic average (UPGMA). The qualitative traits were scored based on principal coordinates after doing Correspondence Analysis (CA). All statistical analy- ses were executed using PAST software (Hammer et al., 2001). 3 RESULTS 3.1 CORRELATION PLOT The correlation plot confirmed that the most quali- tative and quantitative traits studied are significantly cor- related in the positive sense (Figure 2). Fruit mass was positively and highly correlated with the fruit size (fruit length and diameter) and the fruit shape as fruit length had a positive correlation with seed length and fruit mass and peel colour of the fruit, and both were negatively correlated with the seed/fruit length and mass ratios. Fruit diameter was positively correlated with fruit’s mass and shape and negatively correlated with the seed/fruit length and mass ratios. Otherwise fruit shape was negatively correlated with the seed/fruit mass ratio. Positive correlation was marked between fruit consistency and flesh texture and another positive cor- relation between seed size and seed mass. 3.2 QUALITATIVE PHENOTYPIC TRAITS The visual observation traits are revealed in Table 2. Qualitative analysis of the dates showed remarkable phenotypic diversity in the shape, colour, consistency, and texture of dates. 65.38 % appeared of subcylindrical shape, 26.92 % were cylindrical, 11.54 % were triangu- lar, 7.69  % were ovate elongated and subspherical, and 3.85 % was spherical. Most dates in maturity were dark in colour: 88.46 % pigmented red to black, and the rest were yellow to amber. Many dates were characterized by consistency from semi-dry to soft, 42.31 % for each one and 15.39 % were dry. However, 53.85 % of dates were of chewiness texture, followed by a cohesiveness texture with 30.77 % and hardiness with 15.38 %. 3.3 QUALITATIVE CLASSIFICATION OF DATE PALM FRUIT Euclidean distance was used to estimate the pheno- typic dissimilarity of the 26 varieties. Dissimilarity levels ranged from 0 to 2.50, determining the variety groups qualitatively related (Figure  3). The cluster analysis of qualitative traits resulted in two main clusters. The first Figure 2: Correlation plot between qualitative and quantitative fruit traits. FSH - fruit shape, COL – peel colour, CON - fruit consistency, TEX - flesh texture, FL - fruit length, FD - fruit diameter, SL - seed length, SD - seed diameter, LR - seed/fruit length ratio, FM - fruit mass, SM- seed mass, MR - seed/fruit mass ratio Acta agriculturae Slovenica, 119/1 – 2023 5 Phenotypic diversity of date palm varieties (Phoenix dactylifera L.) from southwest Algeria estimated by fruit characteristics one is divided into three distinct sub-clusters: dates of ‘Hartane’, ‘Maatouk’, ‘Timjohar’, ‘Tazerza’, ‘Feggous’, ‘Tak- erbouchte’, ‘Taorakhet’, ‘Tademama’, ‘El Mabrouka’ and ‘Adam Bola’ grouped in a sub-cluster shared a dark col- our of peel and soft consistency. They are characterized by an irregular shape and a chewiness and cohesiveness texture. The second sub-cluster contained ‘Abbad’, ‘Ti- nizioua’, ‘Timidouele’, ‘Hija’, ‘Adam Lebled’, ‘Adam Bara’, ‘Timeliha’, and ‘Abd Salam’ were very close, distinguished by the elongated shape of the fruit and colour shades from light to dark. They were similar in the semi-dry consistency and chewiness texture. The third sub-clus- ter recorded ‘Timebadda’, ‘Cherka’, ‘Hemira’ and ‘Adam Mani’, which had independence in fruit shape and peel colour between light and dark. Their dates were of semi- dry consistency and cohesiveness texture. The second cluster was limited to only ‘Adam Osa- lem’, ‘Khalt’, ‘Deglet Talmine’, and ‘Tinaser’ entire of dry consistency and hardy texture compared to the other cluster. Their dates were not necessarily elongated, dis- tinguished by the colour shades from light to dark. 3.4 QUANTITATIVE PHENOTYPIC TRAITS The mean values and standard deviation of quanti- tative traits are reported in Tables 3 and 4. Concerning the size, 61.54 % of dates seemed small Varieties Fruit shape Colour of fruit peel Fruit consistency Flesh texture Abbad Subcylindrical and cylindrical Amber-Brown Semi-dry Chewiness Abd Salam Subcylindrical Yellowish orange-Dark orange-Garnet Semi-dry Chewiness Adam Bara Ovate elongated Yellowish brown-Brown Semi-dry Chewiness Adam Bola Subcylindrical Amber-Dark red Soft Cohesiveness Adam Lebled Subcylindrical Brown Semi-dry Chewiness Adam Mani Subspherical Brown Semi-dry Cohesiveness Adam Osalem Subcylindrical Brown Dry Hardiness Cherka Triangular Yellowish brown Semi-dry Cohesiveness Deglet Talmine Subcylindrical and triangular Brown Dry Hardiness El Mabrouka Triangular Reddish brown with mustard yellow Soft Chewiness Feggous Cylindrical Garnet Soft Chewiness Hartane Cylindrical and subcylindrical Red Soft Chewiness Hemira Subcylindrical Dark red-Garnet Semi-dry Cohesiveness Hija Subcylindrical Yellowish brown-Red Semi-dry Chewiness Khalt Subcylindrical Blonde yellow-Brown Dry Hardiness Maatouk Ovate elongated and triangular Garnet with dandelion yellow Soft Chewiness Tademama Cylindrical Black Soft Cohesiveness Takerbouchte Spherical Garnet Soft Cohesiveness Taorakhet Subcylindrical Black Soft Cohesiveness Tazerza Subcylindrical Garnet Soft Chewiness Timjohar Subcylindrical Black Soft Chewiness Timebadda Subcylindrical and subspherical Honey yellow Semidry Cohesiveness Timeliha Subcylindrical Darkred–Darkbrown Semi-dry Chewiness Timidouele Cylindrical Brown-Garnet Semi-dry Chewiness Tinaser Cylindrical and subcylindrical Yellowish brown Dry Hardiness Tinizioua Cylindrical Brown-Garnet Semi-dry Chewiness Table 2: Qualitative traits of fruit of date palm varieties Acta agriculturae Slovenica, 119/1 – 20236 K. DEBABECHE et al. (3 < l < 4 cm) as demonstrated by ‘Abbad’, ‘Abd Salam’, ‘Adam Lebled’, ‘Adam Mani’, ‘Adam Osalem’, ‘Cherka’, ‘Feggous’, ‘Hija’, ‘Tademama’, ‘Takerbouchte’, ‘Timjohar’, ‘Timebadda’, ‘Timeliha’, ‘Tinaser’, ‘El Mabrouka’ and ‘Taz- erza’, followed by a rate of 34.61  % that were medium- sized (4.1 < l < 5 cm): ‘Adam Bara’, ‘Adam Bola’, ‘Deglet Talmine’, ‘Hartane’, ‘Hemira’, ‘Khalt’, ‘Maatouk’, ‘Taora- khet’, ‘Tinizioua’ and only 3.85 % represented by ‘Timi- douele’ was large-sized (5.1 < l < 6cm). Traits in relation to fruit and seed length were shown that most dates rep- resent a moderate size (0.5 < r < 0.67) except for ‘Timi- douele’, which appears good (r < 0.5), and ‘Timeliha’ was bad (r > 0.67) (Table 3). Table 4 revealed that 73.08  % of the dates had a good weight (m > 8 g) illustrated by ‘Abd Salam’, ‘Adam Bara’, ‘Adam Bola’, ‘Adam Lebled’, ‘Adam Osalem’, ‘Cherka’, ‘Deglet Talmine’, ‘El Mabrouka’, ‘Feggous’, ‘Hartane’, ‘He- mira’, ‘Khalt’, ‘Maatouk’, ‘Takerbouchte’, ‘Taorakhet’, ‘Taz- erza’, ‘Timebadda’, ‘Timidouele’ and ‘Tinizioua’. 23.08 % were moderate (6 < m < 8 g): ‘Adam Mani’, ‘Hija’, ‘Tade- mama’, ‘Timjohar’, ‘Timeliha’, ‘Tinaser’ and 3.85  % rep- resented by ‘Abbad’ was of poor weight (m < 6 g). Traits concerning fruit and seed weight reported that 69.23% of the dates presented a ratio higher than 0.10, an indicator of a large seed volume relative to the fruit. 3.5 QUANTITATIVE CLASSIFICATION OF DATE PALM FRUIT Euclidean distance was used to estimate the pheno- typic dissimilarity of the 26 varieties. Dissimilarity levels ranged from 0.750 to 5.018, determining the accession groups quantitatively related (Figure 4). The cluster analy- sis of quantitative traits resulted in three main clusters. In the first cluster, close relationships were observed among ‘Deglet Talmine’, ‘Maatouk’ and ‘Timidouele’. These dates record high traits of size and mass. However, ‘Timeliha’ in the second cluster was highly different from the two groups generated. Their dates presented very poor quan- titative traits because of the high seed length. The third cluster was more grouped in distinct sub-clusters dis- playing the varieties with medium traits of fruit: ‘Adam Bara’, ‘Adam Lebled’, ‘Hemira’, ‘Khalt’, ‘Hartane’, ‘Taora- khet’, ‘Adam Bola’, which were very closely having the best quantitative traits in this sub-cluster. ‘Tinizioua’, ‘Tazerza’, ‘Cherka’, ‘Timjohar’, ‘Tinaser’ and ‘Adam Osalem’ were grouped in a sub-cluster, particular for dates of high seed mass, and ‘Abbad’, ‘Tademama’, ‘Hija’, ‘Abd Salam’, ‘Taker- bouchte’, ‘Timebadda’ and ‘Adam Mani’ were grouped in another which seems poor. ‘El Mabrouka’ and ‘Feggous’ were clustered and appeared moderate due to their dates’ high seed diameter and seed mass. Figure 3: Hierarchical clustering of Algerian date palm fruit-based on four qualitative traits Acta agriculturae Slovenica, 119/1 – 2023 7 Phenotypic diversity of date palm varieties (Phoenix dactylifera L.) from southwest Algeria estimated by fruit characteristics 4 DISCUSSION The morphological traits of dates present the iden- tity of date palms at the harvest moment. This research was conducted to discover more phenotypic diversity between qualitative and quantitative traits among the in- vestigated varieties. Positive significant correlations were showed between date traits where distinction between varieties has been carried out. Previous similar results were found by Bedjaoui & Benbouza (2020) regarding the positive correlation between fruit mass and seed and fruit length. Discrimination between varieties highly appeared in qualitative terms for the fruit consistency and texture. This diversity is due to plant material’s ability to benefit from a significant genotypic heterogeneity especially as the study region is spread over a large area. But it could also be due to environmental factors (Jaradat, 2011), which include differences in hydro- edaphic factors and crop management, affecting the physico-chemical contents and also the mechanical and rheological traits of the fruit (Ismail et al., 2006) as these factors have an influence on quantitative traits. It should be noted that since the mode of cultivation in the wilaya of Adrar is multi-variety, no special cultivation practice for any variety of date palm can be recorded. Our findings appeared similar to those of Simozrag & Laiadi (2020) where they studied the genetic diver- sity based on nuclear microsatellite markers. Significant diversity was recorded between ‘Cherka’ and ‘Taker- Varieties Fruit length (cm) Fruit diameter (cm) Seed length (cm) Seed diameter (cm) Seed  /  fruit length ratio Abbad 3.59 ± 0.24 2.07 ± 0.11 2.09 ± 0.14 0.73 ± 0.02 0.58 ± 0.00 Abd Salam 3.78 ± 0.18 2.29 ± 0.06 1.95 ± 0.04 0.82 ± 0.01 0.52 ± 0.02 Adam Bara 4.27 ± 0.20 1.68 ± 0.67 2.71 ± 0.14 0.80 ± 0.03 0.64 ± 0.05 Adam Bola 4.47 ± 0.18 2.12 ± 0.10 2.62 ± 0.12 0.76 ± 0.03 0.59 ± 0.03 Adam Lebled 3.85 ± 0.04 2.38 ± 0.11 2.40 ± 0.03 0.83 ± 0.05 0.62 ± 0.01 Adam Mani 3.16 ± 0.14 2.16 ± 0.05 1.76 ± 0.07 0.92 ± 0.02 0.56 ± 0.04 Adam Osalem 3.94 ± 0.05 1.79 ± 0.03 2.33 ± 0.09 0.90 ± 0.08 0.59 ± 0.02 Cherka 3.74 ± 0.25 2.16 ± 0.10 2.04 ± 0.12 0.96 ± 0.05 0.55 ± 0.03 Deglet Talmine 4.52 ± 0.20 2.81 ± 0.17 2.30 ± 0.21 0.87 ± 0.04 0.51 ± 0.06 El Mabrouka 4.02 ± 0.27 2.17 ± 0.25 2.25 ± 0.13 1.18 ± 0.45 0.56 ± 0.01 Feggous 3.91 ± 0.28 2.27 ± 0.11 2.11 ± 0.09 1.08 ± 0.29 0.54 ± 0.02 Hartane 4.46 ± 0.13 2.09 ± 0.05 2.53 ± 0.03 0.84 ± 0.04 0.57 ± 0.01 Hemira 4.36 ± 0.19 2.13 ± 0.10 2.43 ± 0.17 0.89 ± 0.12 0.56 ± 0.06 Hija 3.49 ± 0.07 2.02 ± 0.15 2.06 ± 0.10 0.70 ± 0.04 0.59 ± 0.02 Khalt 4.45 ± 0.51 2.06 ± 0.23 2.61 ± 0.24 0.82 ± 0.08 0.59 ± 0.05 Maatouk 4.19 ± 0.06 2.33 ± 0.02 2.19 ± 0.10 0.88 ± 0.05 0.52 ± 0.02 Tademama 3.49 ± 0.08 2.08 ± 0.45 2.14 ± 0.02 0.82 ± 0.02 0.61 ± 0.02 Takerbouchte 3.10 ± 0.09 2.51 ± 0.17 1.90 ± 0.06 0.88 ± 0.02 0.61 ± 0.03 Taorakhet 4.37 ± 0.15 2.10 ± 0.10 2.54 ± 0.05 0.78 ± 0.04 0.58 ± 0.01 Tazerza 4.03 ± 0.03 2.02 ± 0.07 2.11 ± 0.09 0.89 ± 0.05 0.52 ± 0.03 Timjohar 3.85 ± 0.19 1.57 ± 0.57 2.23 ±0.13 0.90 ± 0.07 0.58 ± 0.03 Timebadda 3.32 ± 0.01 2.18 ± 0.16 1.88 ± 0.08 0.89 ± 0.04 0.57 ± 0.02 Timeliha 3.70 ± 0.43 1.85 ± 0.16 2.64 ± 0.06 0.82 ± 0.11 0.72 ± 0.08 Timidouele 5.10 ± 0.26 2.30 ± 0.10 2.42 ± 0.03 0.81 ± 0.01 0.47 ± 0.03 Tinaser 3.91 ± 0.19 1.86 ± 0.03 2.28 ± 0.05 0.80 ± 0.03 0.58 ± 0.02 Tinizioua 4.36 ± 0.16 2.14 ± 0.01 2.35 ± 0.09 0.88 ± 0.01 0.54 ± 0.02 Table 3: Biometric traits of fruit of date palm varieties Acta agriculturae Slovenica, 119/1 – 20238 K. DEBABECHE et al. bouchte’ varieties and a great diversity between ‘Timeli- ha’, ‘Hartane’, ‘Tinaser’, ‘Deglet Talmine’, ‘Timidouele’ and ‘Hemira’ varieties. It is possible that this diversity may be owing to commercial consideration which is mainly due to the appreciating varieties at the expense of other varieties (Table 1). For some cases, soft consistency negatively af- fects the demand for the fruit and its cultivation. It is only because of the risk of damage to the fruit. It concerned mainly the dates of ‘Tazerza’, ‘Tademama’ and ‘Taorakhet’ varieties in addition, chewiness texture even in dates of semi-dry consistency has the same effect on the dates of ‘Timidouele’ and ‘Tinizioua’ varieties (Table 1),which are proved by Acourene et al.(2007) who indicated that ‘Taz- erza’ variety threatened with erosion in Oued Righ. However, the dry consistency and hardiness texture of the dates are less appreciated than other types but ‘De- glet Talmine’ and ‘Tinaser’ varieties are the most distin- guished ones (Table 1) due to the demand from neigh- boring states. Low production of young shoots throughout the date palm cycle for cultivars of ‘Abd Salam’ and ‘Adam Bara’ is considered a major factor in the genetic decline of date palm. 5 CONCLUSIONS This study revealed an immense wealth of the date palm genetic resources in southwest Algeria. Biodiver- sity analyses using fruit qualitative and quantitative traits showed a high degree of diversity among date palm va- rieties. The cultivars of ‘Deglet Talmine’, ‘Maatouk’ and ‘Timidouele’ produced dates of high quantitative traits despite different qualitative traits. Some relationships were also observed within clusters for the multitude of varieties. ‘Khalt’ variety produced dates of quantitative traits better than some cultivars. Based on these phenotypic results, the breeder could have a primitive idea about the date palm’s choice of plant genetic resources. In this study, 7 cultivars counted in danger of ex- tinction: ‘Abd Salam’, ‘Adam Bara’, ‘Tazerza’, ‘Tademama’, ‘Taorakhet’, ‘Timidouele’ and ‘Tinizioua’. Such work is an overview of the genetic identifica- tion of date palms. Further characterization of the date palm vegetative part is suggested, and biochemical and molecular analysis should be completed to allow precise identification. In situ collections do not suffice with the extension of the adverse threats. There is an urgent need to establish field gene banks to preserve date palm genetic resources less frequented and less in demand, and to provide suit- able germplasm for propagation. 6 ACKNOWLEDGMENT This research work was supported by the Scientific and Technical Research Center on Arid Regions, Biskra, in Algeria. 7 REFERENCES Acourene, S., Allam, A., Taleb, B., & Tama, M. (2007). Invento- ry of the different date palm (Phoenix dactylifera) cultivars Varieties Fruit mass (g) Seed mass (g) Seed/fruit mass ratio Abbad 5.99 ± 1.06 0.73 ± 0.13 0.12 ± 0.01 Abd Salam 8.90 ± 1.23 0.86 ± 0.11 0.10 ± 0.02 Adam Bara 10.38 ± 1.06 1.03 ± 0.22 0.10 ± 0.02 Adam Bola 11.85 ± 0.65 0.88 ± 0.12 0.07 ± 0.01 Adam Lebled 10.49 ± 0.28 0.92 ± 0.22 0.09 ± 0.02 Adam Mani 7.36 ± 0.59 0.93 ± 0.07 0.13 ± 0.00 Adam Osalem 8.31 ± 0.24 0.88 ± 0.10 0.11 ± 0.01 Cherka 8.47 ± 0.81 1.10 ± 0.19 0.13 ± 0.02 Deglet Talmine 22.08 ± 1.49 0.94 ± 0.18 0.04 ± 0.01 El Mabrouka 10.53 ± 2.21 1.23 ± 0.26 0.12 ± 0.01 Feggous 10.66 ± 2.45 1.17 ± 0.29 0.11 ± 0.00 Hartane 10.72 ± 0.92 1.15 ± 0.14 0.11 ± 0.00 Hemira 11.52 ± 0.80 1.02 ± 0.01 0.09 ± 0.01 Hija 7.96 ± 2.13 0.59 ± 0.12 0.08 ± 0.02 Khalt 9.90 ± 3.35 1.09 ± 0.26 0.11 ± 0.02 Maatouk 14.30 ± 0.88 0.93 ± 0.14 0.06 ± 0.01 Tademama 6.53 ± 0.43 0.81 ± 0.06 0.12 ± 0.00 Takerbouchte 9.74 ± 1.12 0.94 ± 0.05 0.10 ± 0.01 Taorakhet 11.74 ± 1.45 0.95 ± 0.11 0.08 ± 0.01 Tazerza 9.52 ± 0.32 1.04 ± 0.06 0.11 ± 0.00 Timjohar 6.15 ± 0.33 0.94 ± 0.06 0.15 ± 0.00 Timebadda 8.57 ± 1.37 0.87 ± 0.10 0.10 ± 0.00 Timeliha 6.60 ± 0.73 1.00 ± 0.23 0.15 ± 0.02 Timidouele 14.63 ± 1.61 0.87 ± 0.10 0.06 ± 0.00 Tinaser 6.66 ± 0.75 0.88 ± 0.09 0.13 ± 0.01 Tinizioua 9.02 ± 0.44 1.07 ± 0.13 0.12 ± 0.02 Table 4: Mass traits of fruit of date palm varieties Acta agriculturae Slovenica, 119/1 – 2023 9 Phenotypic diversity of date palm varieties (Phoenix dactylifera L.) from southwest Algeria estimated by fruit characteristics in the regions of Oued-Righ and Oued-Souf (Algeria). Sci- ence et Changements Planétaires/Sécheresse, 18(2), 135–142. Al-Yahyai, R., & Mumtaz Khan, M. (2015). Date Palm Status and Perspective in Oman. In J. M. et al. Al-Khayri (Ed.), Date Palm Genetic Resources and Utilization: Volume 2: Asia and Europe (Vol. 2, pp. 1–566). Springer Science+Business Media. https://doi.org/10.1007/978-94-017-9707-8 Bedjaoui, H., & Benbouza, H. (2020). Assessment of pheno- typic diversity of local Algerian date palm (Phoenix dac- tylifera L.) cultivars. Journal of the Saudi Society of Agri- cultural Sciences, 19(1), 65–75. https://doi.org/10.1016/j. jssas.2018.06.002 Chao, C. C. T., & Krueger, R. R. (2007). The date palm (Phoenix dactylifera L.): Overview of biology, uses, and cultivation. HortScience, 42(5), 1077–1082. https://doi.org/10.21273/ hortsci.42.5.1077 Debabeche, K., Debabeche, M., & Laiadi, Z. (2021). Impact of water and soil interaction on date quality of Deglet-Noor. Acta Phytotechnica et Zootechnica, 2021(3), 174–184. htt- ps://doi.org/10.15414/afz.2021.24.03.174-184 Elhoumaizi, M. A., Saaidi, M., Oihabi, A., & Cilas, C. (2002a). Phenotypic diversity of date-palm cultivars (Phoenix dactylifera L.) from Morocco. Genetic Resour- ces and Crop Evolution, 49(5), 483–490. https://doi.or- g/10.1023/A:1020968513494 Elhoumaizi, M. A., Saaidi, M., Oihabi, A., & Cilas, C. (2002b). Phenotypic diversity of date-palm cultivars (Phoenix dactylifera L.) from Morocco. Genetic Resour- ces and Crop Evolution, 49(5), 483–490. https://doi.or- g/10.1023/A:1020968513494 Guettouchi, A., Elshibli, S., Haider, N., Nabulsi, I., & Ykhlef, N. (2017). Molecular diversity in date palm (Phoenix dactylife- ra L.) cultivars from Algeria indicated by RAPD and ISSR polymorphisms. Plant Cell Biotechnology and Molecular Biology, 18(1–2), 76–89. Hammer, Ø., Harper, D. A. T. H., & Ryan, P. D. (2001). Past: Pa- leontological statistics software package for education and data analysis. Palaeontologia Electronica, 4(1), 1–9. Hannachi, S., Benkhalifa, A., Khitri, D., & Brac de de Perriere, R. A. (1998). Inventaire variétal de la palmeraie algérienne (Anep (ed.)). CDARS and URZA. IPGRI, INRAA, INRAT, FEM, & PNUD. (2005). Descripteurs du Palmier dattier (Phoenix dactylifera L.). IPGRI. https:// www.bioversityinternational.org/fileadmin/user_upload/ online_library/publications/pdfs/1086.pdf Ismail, B., Haffar, I., Baalbaki, R., Mechref, Y., & Henry, J. (2006). Physico‐chemical characteristics and total quality of five date varieties grown in the United Arab Emirates. International Journal of Food Science & Technology, 41(8), 919–926. https://doi.org/10.1111/j.1365-2621.2005.01143.x Jaradat, A. A. (2011). Biodiversity of date palm. Encyclopedia of Life Support Systems: Land Use, Land Cover and Soil Sciences, 31. http://www.eolss.net/sample-chapters/c10/E1- 05A-66.pdf Kameswara Rao, N. (2004). Plant genetic resources: Advan- cing conservation and use through biotechnology. Afri- can Journal of Biotechnology, 3(2), 136–145. https://doi. org/10.5897/ajb2004.000-2025 Khierallah, H. S. M., Bader, S. M., Ibrahim, K. M., & Al-Jbo- ori, I. J. (2015). Date Palm Status and Perspective in Iraq. In J. M. et al. Al-Khayri (Ed.), Date Palm Genetic Resour- ces and Utilization: Volume 2: Asia and Europe (Vol. 2, pp. 1–566). Springer Science+Business Media. https://doi. org/10.1007/978-94-017-9707-8 Figure 4: Hierarchical clustering of Algerian date palm fruit-based on eight quantitative traits Acta agriculturae Slovenica, 119/1 – 202310 K. DEBABECHE et al. MARDF. (2021). Agricultural statistics (Serie B): Algeria. Sarwat, M., & Tuteja, N. (2017). Hormonal signaling to con- trol stomatal movement during drought stress. Plant Gene, 11, 143–153. https://doi.org/https://doi.org/10.1016/j.plge- ne.2017.07.007 Simozrag, A., Chala, A., Djerouni, A., & Bentchikou, M. E. (2016). Phenotypic diversity of date palm cultivars (Phoe- nix dactylifera L.) from Algeria. Gayana - Botanica, 73(1), 42–53. https://doi.org/10.4067/S0717-66432016000100006 Simozrag, A., & Laiadi, Z. (2020). Genetic characterization of Algerian minor date palms (Phoenix dactylifera L.) cultiva- ted in the oases of Biskra using nuclear microsatellite mar- kers. Jordan Journal of Biological Sciences, 13(4), 441–451.