Phenotypic Diversity in Tef [Eragrostis Tef (Zucc.) Trotter] Accessions from Different Regions of Ethiopia

Seventy nine tef landraces collected from ten administrative zones and seven altitude classes were planted with two improved varieties in simple lattice design at Gute and Bako in 2007 and 2008, respectively to assess the patterns of genetic variation for quantitative and qualitative traits. Loose and fairly loose panicle forms; gray lemma color and brown seed color were abundant across all regions and altitude classes while compact and semi-compact panicles, red and purple lemma color and white seed color were less frequent. Higher Shannon diversity indices were observed for East Gojam, East Wollega, Horro Guduru Wollega, Illubabor and Jimma collections. Mean squares due to genotypes were significantly different for all traits except number of culm internodes, number of spikelet per panicle and number of fertile floret/spikelet at top of the panicle. Genotypes and environments interacted highly significantly (P≤0.01) for number of panicle branches, lodging index, above ground biomass weight, grain yield per plant and harvest index. About 73% of the entire diversity among population was explained by the first six principal components (PCs), of which the first PC explained about 31% of the variation. This originated mainly due plant height, panicle length, culm length, first and second culm internode diameters, days to panicle emergency and days to maturity. Similarly, about 91% and 90% of the variations among regions of origin and altitude classes were explained by the first five and three PCs, respectively. At 50% similarity level, 11 clusters were formed, containing 2-33 landrace populations per cluster, while six tef landraces remain solitary. There is no cluster formed solely either from tef populations of a given region, tef populations collected from similar agro-ecological zones or populations collected from areas with similar soil type. Some neighboring regions were grouped together in one cluster, implying that there are extensive informal seed exchanges or inter-regional migration of farmers with their seed. Some other regions show strong similarity while they are geographically very far away from each other (for instance, South Wello and Horro Guduru Wollega). Six altitude classes were grouped in to two main clusters at about 50% similarity level. However, tef landraces collected from altitude class below 1576 m.a.s.l (class I) remain un-grouped

Genotype by environment interaction and grain yield stability analysis for advanced triticale (X. Triticosecale Wittmack) genotypes in western Oromia, Ethiopia

Genotypes by environment (gxe) interactions are almost unanimously considered to be among the major factors limiting response to selection and, in general, the efficiency of breeding programs. Cognizant of this fact, 15 advanced triticale genotypes and one standard check, Dilfikir, were evaluated at Arjo, Gedo and Shambu localities in 2010 and 2011, and at Getema in 2011, to identify stable high yielding genotypes and the extent of gxe interaction. The analysis of variance using additive main effect and multiplicative interaction (ammi) model revealed highly significant (P≤0.01) variations among environments, gxe interaction and Interaction Principal Component Analysis (ipca-I) but insignificant variations among genotypes and the remaining ipcas. This implies that, the tested genotypes respond differently over environments as the test environments are highly variable. Only the first ipca-I was significant (p < 0.01) and contributed to 43.86% of the total genotype by environment interaction. It is found that genotypes tcl-70 and tcl-77 are high yielding  next to tcl-76, have ipca value closer to zero, Genotype Selection Index (gsi) of 4 each and ammi stability value (asv) of 0.124 and 0.087, respectively. Analysis using Eberhart and Russell model showed that genotypes tcl-70 and tcl-77 have regression coefficients closer to unity (bi= 1.115 and 1.013) and nearly acceptable deviation from regression (s2di = 0.297 and 0.148), respectively. However, the regression coefficients were significantly different (P≤0.05) from unity for tcl-76, tcl-67, tcl-64, tcl-60, tcl-63 and Dilfikir. Therefore, both tcl-77 and tcl-70 genotypes are proposed for possible release and are recommended for wider adaptability; the uppermost yielding genotype tcl-76, is recommended for specific environme

Agronomic Performance and Compatibility of Common Bean Genotypes Intercropped with Maize

Common bean (Phaseolus vulgaris L.) is one of the most important nutritious food and cash crops grown in Ethiopia. This study evaluated the  compatibility of common bean genotypes to intercropping with maize and assessed land use efficiency of mixed cropping for sustainable intensification  of maize-legume based farming systems. Twenty-five common bean genotypes were evaluated under sole and intercropping with a maize hybrid, BH540,  in 2011 and 2012 at Bako. Significant variations were observed among the common bean genotypes for most studied traits under sole and  intercropping conditions. On average, about 88% yield reduction was recorded for the common bean genotypes intercropped with maize as compared to sole cropping. Genotypes  MEXICO235 X PAN-182 and UBR(92)25-13-1 had higher seed yield under both cropping systems and also showed relatively  lower yield reduction due to intercropping, indicating the compatibility of these genotypes for mixed cropping. Seed yield had positive and significant  correlation only with seeds per pod and harvest index under sole cropping, but it had strong positive association with days to maturity, plant height, pods  per plant, harvest index and number of primary braches under intercropping. Maize-common bean ntercropping slightly increased land use  efficiency and land productivity. Genotypes ICTAJU-95-28, UBR (92)25-13-1 and MEXICO235XPAN-182 exhibited relatively higher total land equivalent ratio  (LER) and relative crowding coefficient (RCC) under intercropping. In general, common bean genotypes used in this study were highly affected by the  competition imposed by maize, indicating the need for further research to develop more compatible varieties of component crops and adjust the time of  common bean intercropping with maize

Genetic Variation, Genotype by Environment Interactions and Grain Yield Stability Analysis in Finger Millet Accessions Resulted in the Release of an Improved Variety

The use of multiple data sets, such as morphological, biochemical and molecular in combination with appropriate statistical analysis tools are essential in  identifying inter and intra-species variation to develop improved cultivars. To this end, a total of 150 finger millet accessions, of which 105 were collected  from Ethiopia, 39 introduced from eastern and south eastern Africa and six commercially released Ethiopian varieties were evaluated at Arsi Negele and  Gute research sites in 2011. Among those, 138 accessions were genotyped using 20 Simple Sequence Repeat (SSR) markers at International Crop  Research Institute for Semi-Arid Tropics (ICRISAT), Nairobi, in 2012. Highly significant (P ≤ 0.01) variations were observed among the 150 accessions for  grain yield and other agronomic traits. A total of 199 alleles were recorded with an average of 9.95 alleles per microsatellite locus and polymorphism  information content (PIC) of 0.57 was observed. Hierarchical clustering based on major phenotypic traits revealed that the majority of accessions from  the same region and adjoining geographical region shared strong phenotypic similarity and thus grouped together. Weighted Neighbor Joining based on  SSR data grouped the test accessions into three major clusters that were not entirely based on geographical origin. Based on the magnitude of  phenotypic and genotypic diversity and blast disease tolerance, 30 finger millet genotypes were selected for further evaluation at multi-location (Arsi  Negele, Assosa, Bako and Gute) in the 2012 and 2013. Additive Main effect and Multiplicative Interaction (AMMI), and Genotype and Genotype by  Environment Interaction (GGI) biplot analysis revealed that Acc. 203544 was found to be the most stable and highest yielding (3.16 ton ha-1), with yield  advantage of 13.7% over the best standard check, Gute (2.78 ton ha-1). Thus, this accession was officially released with the name “Addis-01” and  recommended for production in the test environments and similar agro-ecologies in the country

Genotype by Environment Interaction and Grain Yield Stability Analysis for Finger Millet (Eleusine coracana (L.) Gaertn) Genotypes from Western Oromia

Crop yield is a complex trait influenced by a number of component characters along with the environment directly or indirectly. Genotype performance  depends on its genetic potential and the environment where it is grown. Genotypes by environment (GxE) interactions are generally considered to be  among the major factors limiting response to selection and the efficiency of breeding programs. Ten advanced finger millet genotypes and one standard  check were evaluated at Bako and Gute research center for three years (2013-2015) and at Bilo Boshe for one year (2014) with objectives of identifying  high yielding and stable genotypes. Analysis using additive main effect and multiplicative interaction (AMMI) model revealed highly significant (P≤0.01)  variations among environments, genotype and GxE interaction. This implied that the tested genotypes respond differently over environments as the test  environments are highly variable. Only the first IPCA-I was significant (p ≤0.01) and contributed 41.57% of the total genotype by environment interaction.  It is found that genotypes 214995 and BKFM0063 are high yielding and IPCA value closer to zero, an indicator of stable yield performance across years  and location. Analysis using Eberhart and Russell regression model showed that genotypes 214995, BKFM0063 and BKFM0052 were the most stable  candidates with better grain yield of 2.99, 2.70 and 2.53 ton ha-1, regression coefficients of 0.9879, 1.22 and 0.9459 and reasonably acceptable deviation  from regression 0.0321, -0.01135 and 0.0607, respectively, further confirming that these genotypes are stable and widely adaptable. Genotype and  genotype by environment interaction biplot (GGE) also portrayed the stability of Acc. 214995. Overall, the AMMI, Regression and GGE Biplot revealed  similar results and both 214995 and BKFM0063 genotypes were proposed for possible release. Finally, 214995 was released and recommended for the  test environments and similar agro-ecologies of western Ethiopia based on farmers preferences, stable yield performance and disease tolerance across    locations

A Large-Scale Genome-Wide Association Analyses of Ethiopian Sorghum Landrace Collection Reveal Loci Associated With Important Traits

The eastern Africa region, Ethiopia and its surroundings, is considered as the center of origin and diversity for sorghum, and has contributed to global sorghum genetic improvement. The germplasm from this region harbors enormous genetic variation for various traits but little is known regarding the genetic architecture of most traits. Here, 1425 Ethiopian landrace accessions were phenotyped under field conditions for presence or absence of awns, panicle compactness and shape, panicle exsertion, pericarp color, glume cover, plant height and smut resistance under diverse environmental conditions in Ethiopia. In addition, F1 hybrids obtained from a subset of 1341 accessions crossed to an A1 cytoplasmic male sterile line, ATx623, were scored for fertility/sterility reactions. Subsequently, genotyping-by-sequencing generated a total of 879,407 SNPs from which 72,190 robust SNP markers were selected after stringent quality control (QC). Pairwise distance-based hierarchical clustering identified 11 distinct groups. Of the genotypes assigned to either one of the 11 sub-populations, 65% had high ancestry membership coefficient with the likelihood of more than 0.60 and the remaining 35% represented highly admixed accessions. A genome-wide association study (GWAS) identified loci and SNPs associated with aforementioned traits. GWAS based on compressed mixed linear model (CMLM) identified SNPs with significant association (FDR ≤ 0.05) to the different traits studied. The percentage of total phenotypic variation explained with significant SNPs across traits ranged from 2 to 43%. Candidate genes showing significant association with different traits were identified. The sorghum bHLH transcription factor, ABORTED MICROSPORES was identified as a strong candidate gene conditioning male fertility. Notably, sorghum CLAVATA1 receptor like kinase, known for regulation of plant growth, and the ETHYLENE RESPONSIVE TRANSCRIPTION FACTOR gene RAP2-7, known to suppress transition to flowering, were significantly associated with plant height. In addition, the YELLOW SEED1 like MYB transcription factor and TANNIN1 showed strong association with pericarp color validating previous observations. Overall, the genetic architecture of natural variation representing the complex Ethiopian sorghum germplasm was established. The study contributes to the characterization of genes and alleles controlling agronomic traits, and will serve as a source of markers for molecular breeding