On-farm diversity, use pattern, and conservation of enset (Ensete ventricosum) genetic resources in southern Ethiopia.

BACKGROUND: Enset is an important source of food and is consumed by about 25 million people as a staple or co-staple food crop mainly in southern parts of Ethiopia. Large numbers of enset landraces exist in different administrative zones of Ethiopia with a wide range of altitudes and agroclimatic zones. However, limited information is available on the diversity, distribution, and utilization pattern corresponding to the diverse ethnolinguistic as well as sociocultural communities of the country. Hence, this study was devised to explore and document the richness of farmers' tradition and practice on the diversity and distribution of enset landraces on the farm level and selection pattern for different purposes regarding the production, utilization, and conservation of enset genetic resources. METHODS: The study was conducted in four major enset-growing administrative zones of Ethiopia, namely Hadiya, Kembata-Tembaro, Gurage, and Silte. A total of 240 farm households were surveyed using individual interviews, 18 key informant interviews, 36 focus group discussions with 5 participants, and direct on-farm field observations for data collection. Considering that enset has a rich cultural background and indigenous knowledge, ethnobotanical research approach was applied to data collection and analysis. The Shannon-Weaver, Simpson, Pielou, and Jaccard's similarity indices were used to evaluate the diversity and similarity of the landraces as well as using descriptive statistics in SPSS Ver. 24. Preference in direct matrix ranking was also used to compute and rank the enset landraces most preferred by the people in the context of specific use value in the study area. RESULTS: A total of 282 farmer-named enset landraces have been identified, with a range from 2 to 32 on individual homegardens. The largest number of landraces was found in the Hadiya Zone (86), while the lowest was scored in the Silte Zone (57). The Shannon diversity index (H') ranged from 3.73 (Silte) to 3.96 (Hadiya). Similarly, landraces revealed a very narrow range of variances in Simpson's 1-D diversity index, and it ranged from 0.963 (Silte) to 0.978 (Hadiya). Likewise, the similarity index ranged from 0.24 to 0.73 sharing 16-47 landraces in common. Of the 282 landraces, 210 (74.5%) were recorded in more than one zones, whereas 72 (25.5%) had narrow distribution being restricted to a single zone. CONCLUSIONS: Farmers have established long-term practices and experiences in cultivation, utilization, and conservation of a diverse group of enset landraces to fill their domestic and market purposes in each zone. The variation is likely to be related to agroclimatic differences, ethnicity factors, food cultures, and historical backgrounds. Therefore, to facilitate on-farm conservation as well as sustainable utilization of the enset genetic resources, farmers need to be supported by different stakeholders for all their worth and also in crop improvement programs.

In Vitro Regeneration of Korarima (Aframomum corrorima (Braun) P. C. M. Jansen): A Threatened Spice and Medicinal Herb from Ethiopia.

Developing an in vitro regeneration system is very important to increase production and productivity of plants as well as for the conservation of rare and threatened medicinal plants like korarima (Aframomum corrorima (Braun) P. C. M. Jansen). To date, no study dealing with in vitro indirect regeneration system of korarima has been reported. Thus, in this study, we developed an efficient and reproducible protocol for in vitro regeneration of korarima via callus. The procedure involved soaking seeds in 50% H2SO4 for 16 h that resulted in 92.5% germination on plant growth regulators (PGRs)-free half-strength Murashige and Skoog (MS) basal medium after a month. Shoot and rhizome induction rate of 93.75% was obtained on the MS medium containing 1.5 mg/l BAP in combination with 0.1 mg/l IBA after five weeks. Whitish yellow friable callus was obtained from rhizome culture taken from in vitro grown plantlets. The MS medium containing 2.0 mg/l 2, 4D in combination with 0.5 mg/l kinetin, resulted in 77.5% callus induction. The shoot regeneration rate of 45% was obtained from callus on the MS medium containing 2.0 mg/l TDZ in combination with 0.5 mg/l IBA. The mean shoot number of 10.83 per explant was obtained upon multiplication on the MS medium containing 1.5 mg/l BAP with a mean shoot height of 5.37 cm. The best rooting responses were obtained on half MS medium supplemented with 0.5 mg/l IAA resulting in a mean number of root of 18.59, mean root length of 9.71 cm, and mean shoot height of 7.32 cm. The plantlets showed 75% survival efficiency after acclimatization. The present regeneration protocol offers a conceivable system towards effective conservation and genetic improvement of the crop by increasing the efficiency of genetic transformation.

The Genetic Diversity of Enset (Ensete ventricosum) Landraces Used in Traditional Medicine Is Similar to the Diversity Found in Non-medicinal Landraces.

Enset (Ensete ventricosum) is a multipurpose crop extensively cultivated in southern and southwestern Ethiopia for human food, animal feed, and fiber. It has immense contributions to the food security and rural livelihoods of 20 million people. Several distinct enset landraces are cultivated for their uses in traditional medicine. These landraces are vulnerable to various human-related activities and environmental constraints. The genetic diversity among the landraces is not verified to plan conservation strategy. Moreover, it is currently unknown whether medicinal landraces are genetically differentiated from other landraces. Here, we characterize the genetic diversity of medicinal enset landraces to support effective conservation and utilization of their diversity. We evaluated the genetic diversity of 51 enset landraces, of which 38 have reported medicinal value. A total of 38 alleles across the 15 simple sequence repeat (SSR) loci and a moderate level of genetic diversity (He = 0.47) were detected. Analysis of molecular variation (AMOVA) revealed that only 2.4% of the total genetic variation was contributed by variation among the medicinal and non-medicinal groups of landraces, with an FST of 0.024. A neighbor-joining tree showed four separate clusters with no correlation to the use-values of the landraces. Except for two, all "medicinal" landraces with distinct vernacular names were found to be genetically different, showing that vernacular names are a good indicator of genetic distinctiveness in these specific groups of landraces. The discriminant analysis of the principal components also confirmed the absence of distinct clustering between the two groups. We found that enset landraces were clustered irrespective of their use-value, showing no evidence for genetic differentiation between the enset grown for 'medicinal' uses and non-medicinal landraces. This suggests that enset medicinal properties may be restricted to a more limited number of genotypes, might have resulted from the interaction of genotype with the environment or management practice, or partly misreported. The study provides baseline information that promotes further investigations in exploiting the medicinal value of these specific landraces.

In vitro propagation of Securidaca longipedunculata (Fresen) from shoot tip: an endangered medicinal plant.

BACKGROUND: Securidaca longipedunculata Fresen is an indigenous medicinal plant in Africa that has an important place in both traditional and modern medicine. This plant is endangered because of high seed dormancy, low germination rate, and over exploitation. Therefore, micropropagation method is important to address these problems. The objective of this study is to develop a micropropagation protocol for S. longipedunculata from shoot tip explants. RESULTS: Among different Clorox concentrations, seeds sterilized with 10% Clorox for 10 min resulted in 85% decontamination and 80% germination. Among different media used to evaluate the rate of seed germination, seeds that were de-coated and transversally cut at the tip and cultured on basal MS medium resulted in 100% germination. The highest percentage of shoot initiation (87%) was obtained on MS medium containing 1.0 mg/l 6-Benzylaminopurine (BAP). The highest mean shoot number per explant (8.5 ± 0.69) was achieved on MS multiplication medium containing 1.5 mg/l BAP in combination with 0.1 mg/l Indole-3-butyric acid (IBA). The highest mean number of roots per explant (3.73 ± 0.69) was obtained on MS medium containing 2.0 mg/l Indole-3-acetic-acid (IAA). Among plantlets transferred to greenhouse, 60% survived after acclimatization. CONCLUSIONS: This micropropagation protocol can be used for mass propagation of S. longipedunculata that contributes to its conservation and genetic improvement.