Characterization of Potato (Solanum tuberosum L.) Cultivars Grown in Eritrea Using Morphological, Molecular and Nutritional Descriptors

Abstract

Potato is one of the most important and widely grown vegetable crops in Eritrea. The crop contributes to food security directly as a food source and also as a cash crop. There is limited information in the country that could be utilized for enhancing productivity. The main objective of this study was to document existing potato production practices, and to assess diversity among potato cultivars grown by farmers using morphological, molecular and nutritional traits. Information on the existing potato production practices was obtained from the farmers through a diagnostic survey using a semi-structured questionnaire and focus group discussion. Useful information, on farming practices and major constraints were collected. The results indicated that there were variations on the farming practices and cultivars grown between the two Zobas (counties) surveyed. Majority of the respondents faced challenges in obtaining farm inputs especially quality seeds (91%), fertilizers (87%) and pesticides (90%). As a result most farmers kept their own harvest for use as seed in the following season. Moreover, pest incidence particularly, late blight infection (97%) and cut worm infestation (87%) were reported in all the visited villages posing major problem to farmers. Twenty one cultivars were characterized using 33 agro-morphological descriptors. The bi-plot analysis classified the materials into four groups while the Unweighted Pair Groups Method with Arithmetic mean (UPGMA) clustering grouped them in to three where G-II and G-III were merged together at 92% Euclidean similarity level. The grouping helped to identify materials that share the same characteristics and/or that are closely related and vice versa. It was noted that there was no distinct relationship between the cluster groups and geographic origin of the materials. In addition, farmers’ cultivars sharing the same name could be grouped in different clusters. The molecular characterization was conducted using 12 SSR markers. A total of 91 alleles were amplified with an average of 8 alleles per marker. All of the farmers’ cultivars from Eritrea were clearly distinct from each other showing high genetic diversity as explained by the diversity index (h). Potato cultivars from Eritrea appeared to cluster separately from the other check vii samples from Kenya and Rwanda, which reflect a contribution from the tuberosum germplasm prominent in temperate regions. Analysis of raw and boiled farmers’ potato cultivars for nutritional traits indicated wide variations among themselves. Some of the cultivars exhibited higher values for protein (47%), dry matter content (60%) and phosphorus (40%) than their mean average. Boiling significantly (p<0.001) reduced the levels for most of the nutritional traits. Results on characterization of the potato cultivars grown in the country using morphological, molecular, as well as nutritional traits indicated that the materials were diverse and contained traits of interest which could be exploited in future breeding program.