Evaluation of Wild, Wine, Table, and Raisin Grapevine (Vitis spp.) Genotypes in Gedeo Zone, Southern Ethiopia

Grapevine is one of the major horticultural crops of the world with the cultivated area exceeding 7.5 million ha used for a myriad of products ranging through fresh table grape, preserves, juice, wine, and raisins. The main objective of this study was to introduce twenty-eight grapevine cultivars (ten wild, ten wine, four table, and four raisin grapes) into Gedeo Zone for the first time and ampelographically characterize them in Dilla and Yirgacheffe agroecological conditions in Gedeo Zone, Southern Ethiopia, from August 2018 to July 2021. Ten Vitis abyssinica wild grapevine cultivars were collected from Adama, Addis Ababa, Alamata, Arba Minch, Bahir Dar, Dire Dawa, Gondar, Hawassa, Jimma, and Jinka areas. Additional ten world class wine grapes were gathered from Ziway Castel Winery, and four table and four raisin grapes were also collected from Raya Horti Farm and Koka Vineyard at the same time. The experiment was a 2 × 28 factorial arranged in randomized complete block design (RCBD) with three replications, and data were analyzed using the R-software. The analysis of variance revealed that the interaction of cultivar and location significantly (P < 0.001) affected grapevine plant height, leaf number, number of fruits per plant, and tendril number per vine, while grapevine trunk diameter, flower cluster, root length, and number of suckers per vines were not significantly (P > 0.05) influenced by the interaction of the two factors. Generally, the wine grapevine cultivars had lower canopy such as plant height, leaf number, number of tendrils, and suckering vines while these registered a higher number of fruits per plant, trunk diameter, flower cluster, and root length compared to the wild grapevine cultivars. The results of the present study suggested that Syrah, Chenin Blanc, and Grenache can produce high grapevine berry yield and wine quality in Gedeo Zone agroecology particularly in Dilla location. The wild grapevines collected from Dire Dawa, Arba Minch, Jinka, and Alamata were the potential candidates for the world class wine, raisin, and table grapevines which could open new frontiers in the future for Ethiopian native Vitis abyssinica wild grapevine breeding and genetic engineering that will help to move the national and international viticulture and enology industry forward. As the Ethiopian native grapevines are at the risk of total extinction, adequate conservation strategies are required. Breeding, detailed identification, and introducing the potential grapes in different regions of the country are needed. This finding represents a step forward in efforts to understand hybridization of Vitis abyssinica grapevine with Vitis vinifera and other new world Vitis species.


Introduction
Viticulture is one of the major horticultural industries of the world [1] with the area of cultivation exceeding 7.5 million ha [2] and used for a myriad of products ranging through fresh table grape, preserves, juice, wine, and raisins [3,4]. e grape attains a high concentration of sugar as well as a wide range of aromatic compounds when ripe. On the other hand, the presence of relatively high levels of acids means that the fruit is amenable to many different uses. Approximately 50% of global grape production is used for wine, 36% for table grapes, 8% for raisins, 5% for juice, and 1% to produce other products [5].
Globally, a complex of factors determines the success of a viticulture industry with climate being the dominant one [6]. For the successful production of grapes, the mean annual temperature is the most critical factor. Grapes require hot, dry summers and cool winters [7,8]. An ideal site for vineyard must provide full sunlight [9], with access to good quality water throughout the growing season, protection from excessive winds, and no late spring frosts [10]. Grapes can be cultivated in a wide variety of soils including sandy loam, sandy clay loam, shallow to medium black soils and red loam but respond best to sandy loam soil. In addition, grapevines can grow successfully in a wide range of soil pH (4.0-9.5), but a range of 6.5-8.0 is ideal [11].
Grapevine has been grown in a few parts of Ethiopia since ancient times. Different biotic and abiotic stresses such as climate change, diseases, war, and change of frontiers have resulted in losing hundreds of Ethiopian native grapevine (Vitis abyssinica) cultivars. Yet, the Ethiopian native grapevines are not well registered and researched; instead, they remained as a wild plant and invasive weed [12]. e Vitis abyssinica native grapevines need to be restored, collected, and well registered that could open new frontiers for the future breeding and genetics in viticulture and enology industry. To the best of our knowledge, there is neither a single grapevine plant available nor any grapevine research conducted in Gedeo Zone. erefore, the main goal of this study was to introduce the native wild grapevines and world class wine, raisin, and table grape cultivars to Gedeo Zone and characterize them in Dilla and Yirgacheffe agroecological conditions.

Description of the Experimental Sites.
e experiment was carried out in Dilla, located at 6°24′ 45″ N latitude and 38°18′ 03″ E longitude, and in Yirgacheffe, located at 6°09′ 43″ N latitude and 38°12′ 21″ E longitude districts of Gedeo Zone, Southern Ethiopia ( Figure 1) from August 2018 to July 2021. Dilla and Yirgacheffe have an altitude of 1434 and 1881 meters above sea level and are located at 361 and 399 km south of Addis Ababa, respectively.

Experimental
Procedures. Ten native wild grapevines were collected from Adama, Addis Ababa, Alamata, Arba Minch, Bahir Dar, Dire Dawa, Gondar, Hawassa, Jimma, and Jinka. At the same time, ten world class wine grapes (Syrah, Malbec, Chardonnay, Merlot, Chenin Blanc, Sauvignon Blanc, Cabernet Sauvignon, Semillon, Pinot Noir, and Grenache) were gathered from Ziway Castel Winery. Additional four table grapes (Concord, Cardinal, Perlette, Sugraone) and four raisin grapes (Ruby seedless, ompson seedless, Flame seedless, Crimson seedless) were collected from Raya Horti Farm and Koka Vineyard. Healthy and a pencil-sized vine cuttings were used from one-year-old cane at dormancy period. After careful transporting, grapevine cuttings were cut with five buds each and planted in soil media with 50% top soil, 30% compost, and 20% sand for four months in 30 cm distance each. In their fifth month, the seedling was carefully pruned, roots managed, and transplanted into the well-prepared research sites. e spacings were 1.5 meters between plants and 2 meters between block. Wood poles were erected and wires stretched across the poles to support the vines and for proper grapevine cane and canopy management. All grapevine agronomic practices (watering, weeding, trellising, etc.) were kept in appropriate practice during grape production resulting in safe and healthy food while taking into account economic, social, and environmental sustainability.

Data Collection
Procedures. Grapevine cultivars have been mainly characterized and identified by standard ampelographic descriptors. Samples of grapevines were randomly taken from each treatment for vegetative and yield related parameters. Data were collected for grapevine plant height, leaf number, fruit number per plant, root length, trunk diameter, number of suckers that emerged from the trunk, flower clusters per vine, and tendril numbers. Grapevine plant height was measured from the soil surface to the top most growth points of above ground plant part. Trunk diameter was measured at Veriason grapevine growth stage (north to south and east to west dimension of above ground grapevine trunk). e number of leaves, fruits, tendrils, and suckers per vine was counted and calculated as average. Root length as a pioneer variable for water and nutrient uptake was calculated by measuring the length of orthogonal and diagonal grapevine underground roots.

Statistical Analysis.
e experiment was subjected to two-way analysis of variance in randomized complete block design and data were analyzed using the R-software (version 4.1.1, 2021). Analysis of variance was performed to determine the effect of the independent variables on the dependent parameters at the 5% significance level (P < 0.05).
To determine the significant differences between treatment means, Fisher's range test was applied. Correlation analysis was also computed to record the relationship among the principal components.

Plant Height (m).
e interaction effect of cultivar and location on mean grapevine plant height was highly significant (P < 0.001). e highest plant heights were registered in the wild grapevines collected from Addis Ababa  Figure 2). e result of the present study is in line with [13,14], that clearly and concisely reported that wild grapevines were vigorous compared to the modern grapes.
is might be mainly due to genetic differences among the grapevine cultivars [15], sunlight distribution [9], and poor canopy management [16].
In the current study, it was observed that some wild grapevines could be best candidates of raisin and table grapes based on their plant height. For instance, the wild grapevine collected from Dire Dawa (1.68 ± 0.08) had statistically the same plant height as Crimson seedless raisin grapevine (1.68 ± 0.12) in Yirgacheffe condition. In line with this finding, Dire Dawa wild grapevine (1.84 ± 0.11) had a uniform plant height with Perlette table grape (1.84 ± 0.08) in Dilla condition and with Ruby seedless raisin grapevine (1.84 ± 0.02) in Yirgacheffe. Arba Minch wild grapevine (1.92 ± 0.14) could also be a potential candidate of table or raisin grapevine type which had similar plant height with Perlette raisin (1.95 ± 0.12) and cardinal table (1.87 ± 0.31) grapes in Yirgacheffe. On top of that, plant height of Jinka wild grapevine (2.06 ± 0.02) grown in Yirgacheffe was similar to Sugraone table grape (2.06 ± 0.08) in Dilla condition. In this regard, [17] identified that wild grapevines were used to produce new grapevines resistant to rootstock diseases, drought tolerant, high yield, and best quality through hybridization. Generally, shorter grapevines are recommended in the viticulture and wine industry. is might be due to pruning and training at the right time and in a proper system as a core element to produce high berry yield and make thus wine of good quality [18].

Trunk Diameter (cm).
e main effect of grapevine cultivars on trunk diameter showed a highly significant (P < 0.001) variation, while the interaction effect of cultivar and location was not significant (P > 0.05) ( Table 2). e highest trunk diameter was registered in Syrah (6.23 ± 0.27) followed by Chenin Blanc (5.83 ± 0.29) and Grenache (5.65 ± 0.23), while the lowest trunk diameter was registered in the wild grapevine cultivars collected from Addis Ababa (1.40 ± 0.19) followed by Jimma (1.50 ± 0.19) and Gondar (1.55 ± 0.21) areas. Syrah wine grapevine was thicker by 77.53% than the wild grapevine collected from Addis Ababa. From the wild grapevines, only Dire Dawa wild (2.60 ± 0.30) was a potential candidate for table grape that had statistically the same trunk diameter with Perlette (2.62 ± 0.17) ( Figure 3).
Most of the raisin grapes had statistically the same trunk diameter as the  Figure 4). e results of this study are in line with [19] that adequately explored that grapevine trunk diameter varied according to variety. is might be due to the genetic differences and trunk capacity to absorb water and minerals [15]. e influence of location in mean trunk diameter showed highly significant (P < 0.001) difference. All grapevines grown in Dilla condition had notably higher trunk diameter than grapevines grown in Yirgacheffe agroecology. Apparently, trunk diameter in Dilla (3.60 ± 1.44) was higher by 11.11% than grapevines grown in Yirgacheffe (3.20 ± 1.45) condition ( Figure 5). is could be  e Scientific World Journal  [20,21] that attested that vine trunk diameter was directly influenced by the agroecological site variations.

Root Length (cm).
e main effect of grapevine cultivars on root length showed highly significant differences (P < 0.001), whereas the interaction effect of cultivar and location was not significant (P > 0.05). e longest roots were observed in Syrah (134.73 ± 4.23), Chenin Blanc (125.43 ± 4.62), and Grenache (119.18 ± 3.11), while the shortest roots were found in the wild grapevine cultivars collected from Addis Ababa ( In terms of grapevine types, wine grapes had significantly higher root length, while the minimum values were recorded in the wild grapevines. e raisin and table grapevine cultivars had lower root length compared to the wine grapes but higher root length in comparison with the wild grapevines ( Figure 6). In line with the current findings, [22,23] identified that grapevine cultivars have quite various root lengths and diversified shapes. is might be due to genetic and/or environmental factors influencing on the grapevine root dynamics and pattern [23], root genotype differences, root development and dry matter partitioning, root system, root morphology, root formation, and distribution [24,25]. e influence of location difference in the mean root length of grapevines showed highly significant variations (P < 0.001). All grapevines grown in Dilla condition had notably longer root than grapevines grown in Yirgacheffe agroecology. Accordingly, the root length in Dilla (74.24 ± 31.81) was higher by 6.99% than grapevines grown in Yirgacheffe (69.05 ± 31.14) condition ( Figure 6) that could be due to genetic or environmental factors. In this regard, [22,23] reported that environmental and genetic factors affect the grapevine root size and depth in different locations.

Number of Fruits per Plant.
e interaction effect of cultivar and grapevine growth location on mean number of fruits per plant showed significant differences (P < 0.05). e maximum number of fruits per vine was observed in Syrah (295.76 ± 7.57) and Chenin Blanc (283.59 ± 11.24) grown in Dilla while the minimum number of fruits was recorded in the wild grapevines collected from Addis Ababa grown in Yirgacheffe (16.02 ± 2.06) and Dilla (19.99 ± 2.00) followed by Jimma wild grapevine in Yirgacheffe (24.51 ± 4.73) and Dilla (27.62 ± 4.16) along with Gondar wild grapevine grown in Yirgacheffe (31.79 ± 2.52) and Dilla (36.02 ± 3.04) conditions. e typical Australian Syrah red wine grape in Dilla agroecology scored a higher number of fruits by 94.58% than Addis Ababa wild grapevine grown in Yirgacheffe (Table 1). At a glance, the highest number of fruits per plant was recorded in wine grapevines compared to those in the raisin, table, and wild grapevines grown in both Dilla and Yirgacheffe. e raisin and table grapevines had higher fruit number compared to the wild grapevine cultivars but lower than the wine grapevine cultivars (Figure 7). is is in accordance with [21,26] that reported that wild grapevine cultivars had lower number of fruits per plant, smaller berry size, and weak berry development patterns compared to the modern wine, table, and raisin grape cultivars. is might be due to genetic variations [15], poor canopy management, and vigorous nature of wild grapevine species [13,14]. e data presented above vividly depicts that some wild grapevine cultivars had statistically equal fruit number with potential raisin and  [21] that evaluated wild grapevine and found potential candidates for the modern grapevine breeding that could move the vine and wine industry forward. Generally, the higher fruits per vine was found in the shorter wine grapes while the lower fruit number was recorded in the wild grapevine with long vine height which was supported by [17].

Number of Leaves per Vine.
e interaction effect of cultivar and location on grapevine leaf number showed highly significant (P < 0.001) differences. e maximum leaf number was observed in the wild grapevines collected from Addis Ababa grown in Dilla (164.38 ± 1.53) and Yirgacheffe (160.12 ± 3.60) followed by wild grapevines collected from Jimma (158.38 ± 1.50) and Gondar (152.37 ± 1.53) both grown in Dilla while the minimum leaf number was recorded in Syrah grapevine (30.77 ± 1.60) and Chenin Blanc (33.68 ± 2.08) grown in Yirgacheffe followed by Syrah grapevine grown in Dilla (38.08 ± 2.01) and Grenache in Means within a column followed by the same letter(s) are not significantly different at 5% LSD test ( * * * P < 0.001, * * P < 0.01, * P < 0.05, and ns � P > 0.05).

e Scientific World Journal
Yirgacheffe (39.40 ± 1.49). e leaf number per vine in Addis Ababa wild grapevine grown in Dilla condition was statistically higher by 81.28% than Syrah wine grapevine in Yirgacheffe (Table 1). e findings of this study concisely determined that wild grapevines had significantly higher leaf number per vine while lower leaf numbers were recorded in wine grapevines grown in Dilla and Yirgacheffe agroecological conditions. e raisin and table grapes had a moderate leaf number per vine compared to the wild and wine grapevines (Figure 8). is is in line with [15] that succinctly reported that wild grapevines had huge leaf number and vigorous canopy compared to modern grapevines. is could be mainly due to genetic variations among cultivars and poor canopy management [15]. Sometimes, leaf removal [27] and shoot, cluster, or bunch thinning [28] were suggested as a compulsory agronomic practice to keep the vine healthy and well productive and improve chemical and sensory wine quality  Figure 3: Trunk diameter in grapevine cultivars and grapevine types. Table  Wild Wine Grapevine type Trunk diameter (cm)   e Scientific World Journal [29]. According to [27], vine physiology, berry development, and wine quality were significantly influenced by the timing of grapevine leaf removal. In this study, it was observed that some wild grapevines had similar leaf number to some raisin and table grapes. e wild grapevine collected from Dire Dawa (93.42 ± 3.79) had statistically the same leaf number as Sugraone table grapevine (91.84 ± 0.58) grown in Yirgacheffe. In line with this, Dire Dawa wild grapevine grown in Dilla (101.41 ± 1.55) had an equal leaf number with Cardinal table grape (101.03 ± 2.65) and Ruby seedless raisin grapevine (100.53 ± 1.50) in Yirgacheffe condition and with Flame seedless raisin grapevine (101.11 ± 4.36) in Dilla. Likely, Arba Minch wild grapevine grown in Yirgacheffe (111.04 ± 2.65) had similar leaf number with Perlette raisin in Yirgacheffe (109.43 ± 4.73), cardinal table (112.39 ± 2.08), and omson seedless raisin (112.69 ± 2.48) grapevines in Dilla agroecology. Indeed, leaf number of Jinka wild grapevine (117.21 ± 1.10) grown in Yirgacheffe was also similar to Perlette table grape (117.69 ± 2.52) grown in Dilla condition. In this regard, [13] investigated that wild grapevine had similar vine physiology with modern grapevine cultivars. According to [17], excess leaf number per plant causes several vine diseases, weak berry development, small berry size, and poor wine quality.

Flower Cluster per Plant.
e grapevine flower cluster per plant showed a highly significant variation (P < 0.001) among cultivars while the interaction of effect of cultivar and location was not significant (P > 0.05). e highest number of flower clusters was observed in Syrah (16.32 ± 2.07) and Chenin Blanc (15.31 ± 1.75), while the lowest was registered in the wild grapevine cultivars collected from Addis Ababa (1.17 ± 0.41) and Jimma (1.49 ± 0.55) areas. e number of flower cluster per plant in Syrah wine grapevine was higher by 92.83% than the wild grapevine collected from Addis Ababa (Table 2). e wild grapevines collected from Dire Dawa, Arba Minch, and Jinka were potential candidates for a table and raisin grapes. As a confirmation, Dire Dawa (4.86 ± 0.98), Araba Minch (4.34 ± 0.82), and Jinka (4.04 ± 0.89) wild grapevines had statistically the same number of flower cluster per vine as the table grapevines of Cardinal (4.85 ± 0.75), Concord (5.02 ± 0.89), and Perlette (3.84 ± 0.75). From the raisin grapevines, Ruby seedless (5.81 ± 0.98) had an equal number of flower cluster with the Dire Dawa wild grapevine (Figure 9).
In terms of grapevine types, wine grapes had significantly higher number of flower cluster per plant while the minimum values were observed in the wild grapevines. e raisin and table grapevine cultivars had a lower number of flower clusters than the wine grapes but a higher number compared to the wild grape. Accordingly, some wild grapevines, specially those collected from Dire Dawa, Jinka, Arba Minch, and Alamata areas, were similar in the number of flower cluster to some world-class wine, raisin, and table grapevines (Figure 10). e influence of location variation in the mean number of flower cluster per vine showed also highly significant differences (P < 0.001). All grapevines grown in Dilla condition had notably higher number of flower cluster than grapevines grown in Yirgacheffe. Apparently, the number of flower clusters per vine in Dilla (7.40 ± 4.57) was higher by 17.43% than grapevines grown in Yirgacheffe (6.11 ± 3.85) agroecological condition (Figure 11). is finding was in line with [9,30] that reported that wild grapevines had enormous leaf number compared to modern grapevines. is might be e Scientific World Journal mainly due to genetic variations among cultivars [15], shoot thinning, timing and intensity of elevated temperatures [8], impact of defoliation, temperature conditions at budburst, the extent of primary branching, girdling of shoots, and pollen viability [31]. is is in accordance with the findings of [19] that reported that flower number varied from location to location that might be mainly due to temperature fluctuations [7,8], vine phenology [6], and seasonal variations in grapevine yield components based on pre-and post-flowering weather conditions [32].

Number of Tendrils per Vine.
e interaction effect of cultivar and grapevine growth location on mean tendril number was highly significant (P < 0.05). e maximum   10 e Scientific World Journal number of tendrils per vine was observed in the wild grapevines collected from Addis Ababa and grown in Dilla condition (25.69 ± 0.58) followed by wild grapevines collected from Jimma (24.43 ± 0.54) grown in Dilla while the minimum number of tendrils was recorded in Syrah grapevine (4.87 ± 0.59) and Chenin Blanc (5.14 ± 1.09) both grown in Yirgacheffe. Addis Ababa wild grapevine had statistically higher tendril number by 81.04% than Syrah wine grapevine grown in Yirgacheffe (Table 1). e findings of this study indicated that wild grapevines had significantly higher tendril number while the lowest number of tendrils was recorded in wine grapevines grown in both Dilla and Yirgacheffe. e raisin and table grapevines had higher tendril number compared to the wine grapevines but lower than the wild grapevine cultivars (Figure 12). Similar research findings were reported by [13][14][15] who found significant tendril number differences among grapevine cultivars. is might be due to genetic variations [15], vigorous nature of the vine [13], temperature [7], sunlight distribution [9], and canopy management [16].
In the current study, it was observed that some wild grapevine cultivars had statistically equal number of tendrils per vine with some potential raisin and     [13,17,18] indicated that there was great possibility of selecting a native wild grapevine to produce new grapevines that could be resistant and tolerant to grapevine biotic and abiotic stresses, respectively.

Number of Suckers.
e number of suckers that emerged from each grapevine trunk was significantly influenced (P < 0.001) by cultivar, but the interaction effect of cultivar and location was not significant (P > 0.05). e highest number of suckers was registered in the wild grapevine cultivars collected from Addis Ababa (3.17 ± 1.17), Jimma (2.83 ± 1.17), Bahir Dar (2.69 ± 0.81), and Gondar (2.69 ± 1.21). On the other hand, minimum number of suckers was observed in Sugraone (0.18 ± 0.41), Pinot Noir (0.52 ± 0.54), Cabernet Sauvignon (0.50 ± 0.55), and Crimson seedless (0.67 ± 0.52) grapevines. Fortunately, there were not any suckers recorded in the world class wine grapes of Syrah, Merlot, Grenache, and Chenin Blanc and in the potential raisin grapevine of ompson seedless ( Blanc wine grapes, as well as to Ruby seedless and Flame seedless raisin grapes ( Figure 13).
In terms of grapevine types, wild grapevine cultivars had a significantly higher number of suckers while the minimum values were recorded in the wine grapevines. e raisin and table grapevine cultivars had a higher number of suckers compared to the wine grapevines but lower suckers in comparison with the wild grapevine cultivars collected from different areas of the country. Similar research findings were reported by [13,14,17,33], that found a higher number of suckers in wild grapevines than in wine, raisin, and table grapevine cultivars.
is finding is possibly attributed to genetic factors [15] and/or poor canopy management [16]. e influence of location difference in the mean number of grapevine suckers showed a highly significant variation (P < 0.001). Mainly the raisin grapevines grown in Dilla condition had notably lower number of suckers than those grown in Yirgacheffe agroecology (Table 3). Accordingly, the number of suckers in Dilla (1.08 ± 0.93) was lower by 25.52% than grapevines grown in Yirgacheffe (1.45 ± 1.26). is is in accordance with the findings of [33] that reported that the number of suckers per vine varied from location to location that might be due to temperature fluctuations [7] and water deficit [34].

Conclusion and Recommendations
Grapevine is one of the major horticultural crops used for a myriad of products such as preserves, vinegar, oil, juice, table grape, raisins, and wine. Even though the Ethiopian agroecology is suitable for producing various grapevine cultivars, there was not any grapevine plant or research trial in Gedeo Zone using worldwide or wild grapevines. e Ethiopian native grapevines (Vitis abyssinica) were ignored since the Italian invasion and considered as a weed plant. For this research, ten native grapevines were collected from different areas in Amhara, Tigray, Oromia, SNNPRS, and Sidama regions and used to characterize them in comparison with some world-class wine, grape, and table grapes. In this context, the findings of the study indicated that Syrah, Chenin Blanc, and Grenache wine grapes were the potential cultivars for high berry yield and wine of good quality in Gedeo Zone agroecology, mainly in Dilla location. Accordingly, Dire Dawa, Arba Minch, Jinka, and Alamata wild grapevines were the best candidates for raisin and table grapevines.  Means within a column followed by the same letter(s) are not significantly different at 5% LSD test ( * * * P < 0.001, * * P < 0.01, * * * P < 0.05, and ns � P > 0.05). e Scientific World Journal 13 As the Ethiopian native grapevines are at the risk of total extinction, adequate conservation strategies are required. Breeding, detailed identification of Ethiopian wild grapevines, and introducing the potential wine grapes to different regions of the country are also expected. erefore, the present work represents a step forward in the efforts to understand the hybridization of Vitis abyssinica grapevine with Vitis vinifera and/or other new world Vitis species.
Data Availability e data that support the findings of this study are available upon request to the corresponding author.