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.

Development of Microsatellite Markers and Analysis of Genetic Diversity and Population Structure of Colletotrichum gloeosporioides from Ethiopia.

Twenty three polymorphic microsatellite markers were developed for citrus plant pathogenic fungus, Colletotrichum gloeosporioides, and were used to analyze genetic diversity and population structure of 163 isolates from four different geographical regions of Ethiopia. These loci produced a total of 118 alleles with an average of 5.13 alleles per microsatellite marker. The polymorphic information content values ranged from 0.104 to 0.597 with an average of 0.371. The average observed heterozygosity across all loci varied from 0.046 to 0.058. The gene diversity among the loci ranged from 0.106 to 0.664. Unweighted Neighbor-joining and population structure analysis grouped these 163 isolates into three major groups. The clusters were not according to the geographic origin of the isolates. Analysis of molecular variance showed 85% of the total variation within populations and only 5% among populations. There was low genetic differentiation in the total populations (FST = 0.049) as evidenced by high level of gene flow estimate (Nm = 4.8 per generation) among populations. The results show that Ethiopian C. gloeosporioides populations are generally characterized by a low level of genetic diversity. The newly developed microsatellite markers were useful in analyzing the genetic diversity and population structure of the C. gloeosporioides populations. Information obtained from this study could be useful as a base to design strategies for better management of leaf and fruit spot disease of citrus in Ethiopia.

Response of carnation (Dianthus caryophyllus) cultivars to different postharvest preservatives.

Experiments were conducted to assess the effect of selected pulsing solutions on the days to flower bud shrinkage, leaf wilting and petal edge drying occurrence of carnation cultivars (Green-Go and Galy). The pulsing solutions used for this investigation were Silver Thiosulfate (STS) (0.2, 0.6, 1 mM) and also ethanol (6, 8, 10%), both received equal amount of sucrose (10%). Besides, to simulate the actual practice of the farm (0.4 mM Silver Thiosulfate (STS) plus 0.3 mM T.O.G) was used as a standard control. Senescence symptoms such as flower bud shrinkage, petal edge drying and leaf wilting were monitored. The results obtained showed that 1 mM STS plus 25 g sucrose achieved rapid petal edge drying for Green-Go cultivar. On the other hand, positive effects were also observed in days to flower bud shrinkage extended by 6 mM Silver Thiosulfate (STS) plus 25 g sucrose and being in par with 8% ethanol plus 25 g sucrose for Green-Go cultivar. Subsequently, the standard control, 0.6 mM Silver Thiosulfate (STS) plus 25 g sucrose and 8% ethanol plus 25 g sucrose attended comparable increment on the days to leaf wilting occurrences.