Firew Mekbib

Genetic erosion of sorghum ( Sorghum bicolor (L.) Moench) in the centre of diversity, Ethiopia

The Ethiopian region is characterised by a wide range of agro-climatic conditions, which accounted for the enormous resources of agro-biodiversity that exist in the country. The most important of these resources is the immense genetic diversity of the various crop plants in the country. Of these, one of the most on farm genetically diverse crops is sorghum. Since the advent of formal breeding in particular after green revolution, genetic diversity of most crops has been threatened worldwide. In order to assess on farm genetic erosion (GE), various research methodologies were employed. These were focused group interviews with 360 farmers, on farm monitoring and participation with 120 farmers, key informant interviews with 60 farmers and development agents, and semi-structured interviews with 250 farmers. Besides, diversity fairs were done with over 1200 farmers. Notwithstanding the complexity of assessing GE, it was assessed by various methods; namely, by temporal method (comparing 1960 and 2000 collections), area method, and semi-structured interview method at individual, community or wereda level and causes of varietal loss from other various perspectives. Farmers perceived GE as the reduced importance of the variety as indicated by lower proportion in the varietal portfolio. The five most important factors for varietal loss at individual farmers’ level were reduced benefit from the varieties, drought, Khat expansion, reduced land size and introduction of other food crops respectively. GE was not affected by wealth groups and ecological regions. Farmers do not make simple replacement as a strategic mechanism for genetic resources management. GE at regional level was quantified by temporal and spatial method. There was a complementation not rivalry between farmer varieties (FVs) and improved varieties (IVs). The whole process of GE is explained by three models, namely: Bioecogeographic enhanced genetic erosion model, Farmer induced genetic erosion model and Farmer-cum-bioecogeographic genetic erosion model. As aforementioned, sorghum genetic erosion behaviour is completely different from other food crops such as tetraploid wheat. The prediction in the late seventies that complete erosion of FVs by IVs by the end of the eighties, the principle of GE that competition between IVs and FVs, favours the former and results in the replacement of the latter is not valid in the context of sorghum in Ethiopia. Hence, maintenance of the on farm genetic diversity of sorghum is a reality but GE is rhetoric.

Genetic enrichment, a new concept in genetic resource management: the case of sorghum (Sorghum bicolor (L.) Moench) in Ethiopia

The importance of maintaining and conserving genetic resources around the world is a well-established fact. Typically, in situ and ex situ conservation are the means applied to maintain genetic diversity in food crops. Notwithstanding the contribution that the ‘green revolution’ has made towards food security throughout the developing world, it has also been singled out as one of the major causes of genetic erosion. The amount of genetic diversity and rate of genetic erosion is quantified in various crops in different parts of the world, in particular in the crop centres of diversity. However, no one has reported on ‘genetic enrichment’ (GEn) – the reverse process of genetic erosion. In order to assess the on-farm genetic enrichment of sorghum, various research methodologies were employed, including focussed group interviews with 360 farmers, key informant interviews with 60 farmers and development agents, and semi-structured interviews with 250 farmers. In addition, diversity fairs were organised with over 1200 farmers. In order to quantify the level of GEn by comparative methods, germplasm collections were initiated in 2000. GEn is described here as the process of addition of genetic variability at gene, gene-complex or varietal level. GEn is a common practice among farmers; in fact, farmer interviews showed that 49.6% had practised GEn. The amount of GEn practised varied by crop ecology but not by farmers wealth. GEn by variety name and number showed a rate of 2.86% and 1.67% yearly, respectively, which means 2.8 and 1.7 varieties per year are enriched on a regional level. The concept, level of use and supporting evidence of GEn as well as the reasons farmers are practising GEn are outlined. Three models are suggested for the process of GEn, namely the bio-ecogeographic genetic enrichment model, the farmer-induced genetic enrichment model and the farmer-cum-bio-ecogeographic genetic enrichment model. These models explain the factors that shape on-farm genetic enrichment. GEn is practised in order to counteract varietal loss and hence balance the in/out flux of varieties on farms. It is a dynamic process that proceeds according to the prevalent bio-economic and socio-cultural circumstances, dictated by the availability of varieties, and the bio-physical and socio-economic environment of the farmers. In order to enhance farmers’ GEn, reduce genetic erosion and maintain on-farm genetic diversity, the management and utilisation of genetic resources have to be integrated.

GGE Biplot Analysis of Multi - environment Yield Trials of Durum Wheat ( Triticum turgidum Desf.) Genotypes in North Western Ethiopia

This experiment was done to identify the most stable durum wheat genotype(s) as well as desirable environment(s) for durum wheat ( Triticum turgidum var. durum Desf.) research in north western Ethiopia. Grain yield performance of the tested genotypes were evaluated at four locations (Adet, Debretabor, Gaint and Simada) using randomized complete block design with three replication for two consecutive years (2010 and 2011). Combined analysis of variance showed that grain yield was significantly affected by environments (E), genotypes (G) and GE interactions. The first two principal components (PC1 and PC2) were used to create a two - dimensional GGE biplot and explained 45.67% and 32.71 % of the total sums of squares of GE interaction, respectively. The ‘which - won where’ feature of the GGE biplot suggested that the existence of three durum wheat mega

Molecular diversity and population structure of the Ethiopian lentil (Lens Culinaris Medikus) genotype assessment using SSR markers

Knowledge of genetic diversity in germplasm is essential for formulating effective germplasm collection, conservation, utilization strategies in and crop improvement programs. It also provides an opportunity to take corrective steps infusing new genes to avoid risks associated with a narrow genetic bases. Genetic diversity analysis of 119 lentil genotypes of including 83 germplasm and 36 exotic genotypes from International Center for Agricultural Research in the Dry Areas was studied using 27 primers of simple sequence repeat (SSR) marker. Molecular analysis of variance showed variations of 82% within and 18% of the among population variance was explained. Degree of polymorphism observed among the populations was 100%. A total 122 alleles were detected, with 2 to 7 alleles per locus, with a mean of 4.52 alleles per locus. The estimated gene diversity value for 27 loci was 0.64. The average Shannon’s information index value of 1.19 was obtained showed the existence of high genetic variation within the genotypes. The genetic similarity indices ranged from 0.21 to 1.00. The SSR markers showed an average polymorphic information content (PIC) value of 0.58. Cluster analysis grouped the genotypes into five major clusters as distinct genetic populations. Diversity analyses revealed the existence of a high level of genetic variation among genotypes. This molecular diversity information provides a basis for future germplasm collection, utilization, and conservation strategies in gene banks and introducing exotic germplasm to widen the genetic base of the current lentil breeding population.

A Look into Genetic Diversity of Enset (Ensete ventricosum (Welw.) Cheesman) Using Transferable Microsatellite Sequences of Banana in Ethiopia

Microsatellite sequences are one of the best options for the study of genetic diversity in plant species. However, because of the high cost of their development, it is important to test whether existing sequences from related species can be exploited. Enset (Ensete ventricosum (Welw.) Cheesman) has remained largely unimproved partly due to lack of its genetic information, thus there is a need to study the genetic diversity of current accessions and build on it to develop new cultivars/varieties with desired agronomic traits. Transferability of 71 SSR loci from banana (Musa accuminata) to enset was investigated using 220 Enset accessions. Among the 71 SSRs tested, 12 (16.9%) were successfully transferable to enset. Eleven (16.9%) of these were used to examine the diversity of the 220 enset accessions that had been collected from eight different zones in Ethiopia.

Technology generation to dissemination: lessons learned from the tef improvement project

Indigenous crops also known as orphan crops are key contributors to food security, which is becoming increasingly vulnerable with the current trend of population growth and climate change. They have the major advantage that they fit well into the general socio-economic and ecological context of developing world agriculture. However, most indigenous crops did not benefit from the Green Revolution, which dramatically increased the yield of major crops such as wheat and rice. Here, we describe the Tef Improvement Project, which employs both conventional- and molecular-breeding techniques to improve tef—an orphan crop important to the food security in the Horn of Africa, a region of the world with recurring devastating famines. We have established an efficient pipeline to bring improved tef lines from the laboratory to the farmers of Ethiopia. Of critical importance to the long-term success of this project is the cooperation among participants in Ethiopia and Switzerland, including donors, policy makers, research institutions, and farmers. Together, European and African scientists have developed a pipeline using breeding and genomic tools to improve the orphan crop tef and bring new cultivars to the farmers in Ethiopia. We highlight a new variety, Tesfa, developed in this pipeline and possessing a novel and desirable combination of traits. Tesfa’s recent approval for release illustrates the success of the project and marks a milestone as it is the first variety (of many in the pipeline) to be released.

Sugarcane production under smallholder farming systems: Farmers preferred traits, constraints and genetic resources

Abstract Smallholder sugarcane production sector is under researched and underdeveloped with limited industrial link and support. The objectives of this study were to assess the current state of sugarcane production, farmers’ perceived production constraints and preferred traits, and to collect germplasm grown by smallholder farmers in southern Ethiopia for strategic breeding and conservation. The study was conducted across 16 administrative zones, 28 districts and 56 peasant associations involving 560 smallholder sugarcane growers in southern Ethiopia using a participatory rural appraisal approach. Sugarcane genetic resources were collected through structured sampling. Findings from this study indicated that monocropping was identified as the predominant sugarcane farming system. Respondent farmers prioritized drought tolerance (21%), increased cane yield (20%), early maturity (18%), marketability (17%), and high biomass (14%) as the top preferred traits of sugarcane. Ninety diverse sugarcane landraces were collected from homesteads of smallholder farmers. Findings from this study would serve as baseline information towards sugarcane research and development emphasizing the constraints and preferences of smallholder sugarcane growers in Ethiopia or similar agro-ecologies. This is the first study to report farmers preferred traits and constraints, and genetic resources of sugarcane under smallholder farming systems in Ethiopia.

Agromorphological Traits Variability of the Ethiopian Lentil and Exotic Genotypes

Understanding the genetic relationships and diversity of Ethiopian lentil in relation to lentil from other countries is important in attempting to widen the genetic base of germplasm in the country. The objectives of this study were to generate information on agromorphological variability, to estimate PCV, GCV, heritability, and expected genetic advance of quantitative traits of lentil. 228 genotypes with different population types were studied for 11 agromorphological traits and rust disease severity score for two seasons (2011-2012) over three locations. The analysis of variance showed highly significant variations () among genotypes for all characters studied. As per genetic parameter values, four groups of character were deduced. It is inferred that the exotic genotypes introduced from ICARDA showed rich genetic bases for 100-seed weight, number of seeds per plant, seed weight per plant, resistance source for rust, and high yielder in high yielding environment, where rainfall is not a major problem. Use the Ethiopian accessions for developing cultivars that could be used in double cropping and drought prone areas.

Farmers' Breeding of Sorghum [Sorghum bicolor (L.) Moench] in the Center of Diversity, Ethiopia: II. Selection Process, Criteria and Methods

ABSTRACT Sorghum is one of the main staple crops of the worlds poorest and most food-insecure people. Ethiopia being the center of origin and diversity, farmer breeding is an established system in the region. As of 1957, Formal Breeding (FOB) has released over 16 varieties. Of these, seven were from introduction and nine were from selections of landraces. The farmers did not accept the varieties developed for the intermediate and highland areas. Adoption of improved varieties is only in the lowlands and was only 12.7%. This low level of adoption was due to a lack of appropriate varieties and dissemination system that caters to socio-economic and biophysical environments of the farmers. To bridge this gap, understanding farmer breeding process, methods, selection, criteria and environments becomes imperative. To understand these, various research methods were employed. These were focus group interviews with 360 farmers, direct on-farm participatory monitoring with 120 farmers, key informant interviews with 60 farmers and development agents; and semi-structured interviews with 250 farmers. The farmer breeding (FAB) develops multipurpose varieties that have been accepted by a majority of the farmers. In eastern Ethiopia, FAB is enhanced by the high on-farm genetic diversity. The various selection criteria identified by crop ecologies and farmer needs to be used by the formal Breeding (FOB). Farmers use four different breeding methods; namely, introduction, which is the selection method used across farmers; simple mass selection, modified mass selection, modified bulk selection, and pureline selection are practised by 50%, 6.4%, 5.2% and 46% of the farmers, respectively. Besides directional, disruptive and abruptive selection modalities are in use by the farmers for various traits. Farmers undertake both negative and positive selection. The number of heads selected varied by farm size. Besides, selecting for number of heads, 43.8% of the farmers selected uniform head types, and 45% mixed, whereas 14.5% selected uniform and mixed head types, depending on the selection methods used. The types of sorghum needed by all cropping systems are not the same. Hence, specific varieties have been selected by the farmers to fit into different cropping systems. In summary, some of FAB practices need to be adopted by FOB for developing acceptable varieties.

Analysis of Biochemical Composition of Yams ( Dioscorea spp.) Landraces from Southwest Ethiopia

Yams make a significant contribution to food security and medicinal importance in developing countries. In Ethiopia, there is insufficient scientific study on biochemical composition of Ethiopian yams. In order to fill the knowledge gap, this study was conducted to assess the biochemical composition of yams collected from Southwest Ethiopia. Flour from storage tuber of 36 yam landraces collected and the samples run in duplicates. Data on 14 biochemical traits were collected and subjected to various data analysis. Results of the analysis of variance indicated significant variation (p<0.01) among the landraces on organic matter, total nitrogen, protein, fat, carbohydrate, total phosphorus, total energy, tannin and saponin contents. The flour moisture contents ranged from 17.75 to 27.47% with a mean of 22.03%. The ranges of dry matter (15.80 to 27.28%), organic matter (21.38 to 43.56%), ash (1.13 to 3.56%), organic carbon (0.63 to 1.98 g), crude fiber (0.41 to 2.05%), total nitrogen (1.00 to 1.32%), protein (6.25 to 8.28%), fat (0.09 to 0.65%), carbohydrate (12.71 to 33.94%), total phosphorus (23.7 to 53.0 mg/100 g), total energy (92.66 to 173.30 kcal/100 g DM), tannin (19.80 to 181.0 mg/100 g) and saponin (2.31 to 13.94 mg/100 g) contents. The cluster and distance analysis of biochemical traits showed the existence of eight divergent groups. The maximum inter cluster distance was found between clusters VI and VII (133.59), followed by clusters V and VI (109.19), clusters II and VI (105.22), clusters I and VI (100.42), and clusters III and VI (89.25) in order of magnitudes. Maximum genetic divergence between the clusters points out the fact that hybridization among the landraces included with them would produce potential and meaningful hybrids and desirable segregants. Besides, investigation of the existed yam landraces based on molecular marker analysis is vital for better assessment of genetic diversity of yams in Ethiopia.