Genetic Diversity and Population Structure, Trait Interrelationships, Yie Stability and Socioeconomic Importance of White Lupin (Lupinus Albus L.) Landraces in Ethiopia
| dc.contributor.advisor | Tesfaye, Kassahun (PhD) | |
| dc.contributor.author | Atnaf, Mulugeta | |
| dc.date.accessioned | 2018-07-16T08:04:32Z | |
| dc.date.accessioned | 2023-11-08T16:39:07Z | |
| dc.date.available | 2018-07-16T08:04:32Z | |
| dc.date.available | 2023-11-08T16:39:07Z | |
| dc.date.issued | 2017-06 | |
| dc.description.abstract | White lupin (Lupinus albus L.) is one of four economically important species of the Lupinus genus, and has been traditionally cultivated for several thousand years along the Nile valley, including Ethiopia. Lupins are known to perform multifaceted functions, such as for human food and beverage, livestock feed, ecological importance, pharmaceutical values and social contributions. In Ethiopia, white lupin has been sustaining quite long in the farming system, and is produced exclusively by smallholder subsistence farmers. However, despite it has long been produced in the country, the crop received little attention by different development actors and have several undesirable characteristics. To address these, setting up practical lupin breeding program targeting the aforementioned major lupin production constraints is quite essential and necessary. Hence, the present study attempted to avail various pertinent socioeconomic and genetic and/or breeding information which are fundamental to realize lupin improvement in the country. Detailed baseline survey involving 303 households sampled from white lupin production areas of north western Ethiopia was conducted, to ascertain the extent of lupin production constraints and document farmers experiences and practices on lupin cropping, processing and utilization and marketing. Study results identified the major production practices and constraints to lupin production in the areas. The results would form a useful guide for the development of well‐tailored breeding objectives for the improvement of white lupin for Ethiopian farmers and consumers. This approach is useful not only to document farmers experiences and practices, but also ensures participation of farmers to develop demand led lupin technologies. A phenotyping experiment aiming at characterizing the landraces using agronomic and phenological traits which comprises 143 landrace accessions was under taken at Merawi, Ethiopia. Further characterization of genetic diversity and population structure of 212 landraces using 15 polymorphic SSR markers were done. Another experiment with objectives to evaluate the performance and stability of white lupin landraces in different locations; and characterize white lupin growing environments in Ethiopia was conducted at six different locations in north western Ethiopia. The phenotyping and over‐locations experiments were considered to understand the relationships among traits, and to document trait profile of white lupin landraces. Phenotypic characterization revealed that Ethiopian white lupin landraces were significantly different for most of the traits studied, and a significant number of local accessions performed as high as 5 metric tonnes per hectare of grain yield. Cluster analysis showed that landraces were grouped into 17 clusters of different sizes, of which five were singletons. Some landraces were grouped together regardless of their geographic origin. On the other hand, landraces from Awi, South Gondar and West Gojam were distributed over many clusters. Genetic distances between many pairs of clusters were significant, justifying crosses between parents from them would be desirable genetic recombinations. Molecular characterization further revealed the genetic diversity vested on the landraces. The SSR markers revealed 98 from 212 landraces, with an average of 6.5 alleles per locus. The average gene diversity was 0.31. Twenty eight landraces harbored one or more private alleles from the total of 28 private alleles identified in the 212 white lupin accessions. Seventy‐seven rare alleles with a frequency of less than 5% were identified and accounted for 78.6% of the total allele detected. Analysis of molecular variance (AMOVA) showed that 92% of allelic diversity was attributed to individual accessions within populations while only 8% was distributed among populations. At 70% similarity level, the UPGMA dendrogram resulted in the formation of 13 clusters comprised of 2 to 136 landraces, with the two control genotypes and five landraces remaining distinct and ungrouped. Population differentiation and genetic distance were relatively high between Gondar and populations collected by Australians. High level of gene flow (Nm), ranging from 10.60 to 31.46, was detected between the four major populations namely West Gojam, Awi, East Gojam and Gondar. A model‐based population structure analysis divided the white lupin landraces into two populations. All Ethiopian white lupin landrace populations, except most of the landraces collected by Australians and some from Awi, were grouped together with significant admixtures. The study also suggested that 34, as core collections, were sufficient to retain 100% of SSR diversity. Higher heritability and genetic advance as percent of mean was observed for grain yield, indicating the possibility of improving this trait through selection. Different patterns of associations and accession by trait interactions were observed in different environments. However, genotype by trait biplots consistently indicated that grain yield had positive associations with most of the traits; especially, with number of pods per plant, plant height and seeds per pod. The study identified some accessions with desirable performances as good for specific trait and/or trait groups that could be considered as sources of genes for the traits they have best performed. The genotype by environment interaction study depicted that the white lupin landraces studied had differential performances at different test locations implying the presence of crossover interaction. The first two principal components (PC1=41.6% and PC2=21.8%) of the genotype plus genotype by environment interaction (GGE) explained 63.4% of the GGE sum of squares. Two white lupin growing mega‐environments were identified in north western Ethiopia. All test locations were found to be representative with different degrees of reliability whereby Fenote Selam and Dibate were found to be most representative. In addition, all test locations, except Mandura and Injibara had generally similar and good discriminating power. Fenote Selam and Dibate were found to be the most representative and discriminating environments and are characterized as most desirable test locations for white lupin improvement in north western Ethiopia. Genotype 2 (G2) was found to be the highest yielding and most stable landrace across the test environments, and hence identified as most desirable genotype for production. Key words: Discriminating power, Ethiopian farming system, Farmers' experiences, Genotype by location interaction, Genotype by Trait, Landrace populations, Mega‐environment, Representativeness, White lupin. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/123456789/8683 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa Universty | en_US |
| dc.subject | Discriminating power | en_US |
| dc.subject | Ethiopian farming system | en_US |
| dc.subject | Farmers' experiences | en_US |
| dc.subject | Genotype by location interaction | en_US |
| dc.subject | Genotype by Trait | en_US |
| dc.subject | Landrace populations | en_US |
| dc.subject | Mega‐environment | en_US |
| dc.subject | Representativeness | en_US |
| dc.subject | White lupin | en_US |
| dc.title | Genetic Diversity and Population Structure, Trait Interrelationships, Yie Stability and Socioeconomic Importance of White Lupin (Lupinus Albus L.) Landraces in Ethiopia | en_US |
| dc.type | Thesis | en_US |