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1.
Kebebew Assefa Seyfu Ketema Hailu Tefera Henry T. Nguyen Abraham Blum Mulu Ayele Guihua Bai Belay Simane Tiruneh Kefyalew 《Euphytica》1999,106(1):87-97
Three hundred twenty germplasm lines of the major Ethiopian cereal, tef, [ Eragrostis tef (Zucc.) Trotter], were evaluated
for 20 morphological, phenological and agronomic characters in two-replicated randomized complete blocks at Debre Zeit and
Melkassa Agricultural Research Centers in Ethiopia during the 1995 main season. The objectives were to assess the diversity
of the lines, and to estimate the broad sense heritability (H) and genetic advance (GA) of the various characters. The mean
squares of genotypes were highly significant (p ≤ 0.001) for all the traits. The phenotypic and genotypic coefficients of
variation ranged in that order from about 6–40% and 3–23% for days to maturity and grain yield/plant, and days to maturity
and number of spikelets/main shoot panicle, respectively. The cluster analysis grouped the genotypes into 14 major complexes
consisting of one to 183 lines. Of the 19 principal components involved in explaining the entire variation among the genotypes
the first five which had eigenvalues of more than one explained about 73.8%. The first principal component which accounted
for about 34% of the total variance was due chiefly to plant height, culm and panicle length, diameters of the two basal culm
internodes, main shoot panicle mass and grain yield, number of main shoot panicle branches and spikelets, and days to panicle
emergence and maturity. Estimates of H varied from about 22% for length of the lowest main shoot stem internode to 74% for
number of main shoot panicle branches. Values of GA (expected from selection of the superior 5% of the lines and expressed
relative to the means) ranged from about 3% for days to maturity to 36% for number of spikelets/main shoot panicle. Overall,
the study indicated the existence of trait diversity in tef germplasm and this can be exploited in the genetic improvement
of the crop through hybridization and selection.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
Gene action controlling yield and yield‐related traits among tef (Eragrostis tef [Zucc.] Trotter) populations under drought‐stressed and nonstressed conditions 
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下载免费PDF全文 This study was aimed to determine gene action for grain yield and yield‐related traits of newly developed tef populations under drought‐stressed and nonstressed conditions to improve drought tolerance. Ten crosses, along with the parents, were evaluated in the F2 generation under drought‐stressed conditions at Hastebo and Adigdad sites in 2015 and Dura site in 2016 and under nonstressed conditions at Dura site in 2016. Additive gene action predominantly controlled the inheritance of the grain yield and majority of the yield‐related traits under drought‐stressed and nonstressed conditions. Under both test conditions, the genotypes DZ‐Cr‐387 and 9415 were the best general combiners for increased grain yield and morphological traits. Conversely, genotype 222076 was the best general combiner for reduced maturity period only. The selected parents are novel genetic materials for tef breeding programmes to improve grain yield and morphological traits with reduced days to maturity for drought tolerance breeding. The family of the cross DZ‐Cr‐387 × 222076 was selected for high grain yield and early maturity in both the drought‐stressed and nonstressed environments. 相似文献
3.
Fikre Tsion Tesfaye Kassahun Assefa Kebebew 《Journal of Crop Science and Biotechnology》2018,21(4):367-374
Journal of Crop Science and Biotechnology - Knowledge on the extent and pattern of diversity in crop species is a precondition for any crop improvement as it helps breeders in determining apt... 相似文献
4.
Tef is a staple cereal of Ethiopia in high demand by consumers. In order to cope up with this high consumer demand, productivity
per unit of land must increase through the development and use of high-yielding varieties. To this effect, the National Tef
Research Project has long been striving towards the development of high yielding varieties through direct selection from germplasm
and concentrating favourable alleles through hybridization and selection, despite the tedious crossing technique. The objective
of this study was to assess the degree of genetic variation in F2 populations of tef as a basis for improving grain yield. F2 populations from 12 crosses and their parents were grown at the Debre Zeit Agricultural Research Center, Ethiopia, and assessment
was made on eight traits on individual plant basis. Eleven of the 12 crosses showed substantial genetic variation for grain
yield and its components, indicating the potential for improvement through selection. Moreover, grain yield, plant weight
and yield related traits showed moderate to high heritability values (17–80%). In all the crosses, tiller number, panicle
weight, yield per panicle and panicle length showed significant (P ≤ 0.05) and positive association with grain yield. Considering the degree of genetic variation and heritability values, emphasis
should be given to selected crosses in an effort to developing high-yielding tef varieties. 相似文献
5.
Gina Cannarozzi Solomon Chanyalew Kebebew Assefa Abate Bekele Regula Blösch Annett Weichert Dominik Klauser Sonia Plaza-Wüthrich Korinna Esfeld Moritz Jöst Abiel Rindisbacher Habte Jifar Victoria Johnson-Chadwick Ermias Abate Wuyan Wang Rizqah Kamies Negussu Husein Worku Kebede Kidist Tolosa Yazachew Genet Kidu Gebremeskel Brikti Ferede Firew Mekbib Federico Martinelli Hans Christian Pedersen Suhail Rafudeen Shimelis Hussein Muluneh Tamiru Naomi Nakayama Mike Robinson Ian Barker Samuel Zeeman Zerihun Tadele 《Euphytica》2018,214(2):31
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. 相似文献
6.
Ferede Brikti Mekbib Firew Assefa Kebebew Chanyalew Solomon Abraha Eyasu Tadele Zerihun 《Journal of Crop Science and Biotechnology》2020,23(2):107-115
Journal of Crop Science and Biotechnology - A field experiment was conducted to identify drought tolerant, high yielding and stable tef genotypes using drought tolerance indices. Sixty-four tef... 相似文献
7.
Three thousand tef [Eragrostis tef (Zucc.) Trotter] single panicle derived lines representing 60 populations from western and southern parts of Ethiopia were
characterized for panicle form, pigmentation of lemma and anther, caryopsis color, number of main shoot culm internodes, and
counts of florets/spikelet at the basal, middle and apical parts of the panicle at Debre Zeit Agricultural Research Center
during the 1999 main season. The objectives were to assess the diversity patterns of the germplasm with respect to regions
and altitude zones. Among the eight characters, high Shannon-Weaver diversity indices (H’) were noted for anther color (0.71)
and number of apical spikelet florets (0.68), and the lowest occurred for panicle form (0.40). Monomorphism (H’ = 0.00) was
observed for panicle form, lemma color and number of middle spikelet florets each in three different populations. The overall
diversity index for all populations was 0.53. In the analysis of variance of H’ estimates, substantial (p <0.05) regional differences were obtained for lemma color, number of culm internodes, and counts of middle and basal spikelet
florets. Clinal variation was significant for panicle form, lemma and seed color, and for the overall mean of traits. Over
all traits, mean H’ values declined from 0.60 to 0.46 with an increase in the altitude zone of origin from below 1800 to over
2400 meters above sea level. Overall, the study showed substantial diversity in the test tef germplasm.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
8.
Tiruneh Kefyalew Hailu Tefera Kebebew Assefa Mulu Ayele 《Genetic Resources and Crop Evolution》2000,47(1):73-80
A total of 3600 entries of tef [Eragrostis tef (Zucc.) Trotter] germplasm collections representing 36 populations from six regions of Ethiopia were evaluated for phenotypic diversity in six qualitative and phenologic characters. High values of Shannon–Weaver diversity index (
) were recorded for most characters in each population. Monomorphism was high for anther color (purple) and panicle form (loose). Larger variances for
were obtained among regions than among populations within a region from hierarchical analysis of variance. Significant (P<0.05) to highly significant (P<0.01) t-values were observed among
values of some regions for seed color, panicle form and days to maturity. A substantial level of variance (P<0.05) was obtained for populations within altitudinal zones only for days to maturity. Altitudinal zones exhibited similar levels of diversity across characters for these collections. Generally, considerable variations important for tef improvement work have been observed and regions with highest diversity for some traits have been suggested for future in situ or ex situ germplasm conservation works. Although similar mean diversity indices were obtained among regions, they were non overlapping. 相似文献
9.
Kebebew Assefa Hailu Tefera Arnulf Merker Tiruneh Kefyalew Fufa Hundera 《Genetic Resources and Crop Evolution》2001,48(1):53-61
One thousand and eighty tef, Eragrostis tef (Zucc.) Trotter, entries representing 36 populations collected from six central and northern regions of Ethiopia were evaluated at Debre Zeit Agricultural Research Center during the 1995 main season to assess the quantitative trait diversity in the germplasm with respect to collection regions and altitude zones. Hierarchical analysis of variance showed large (p 0.01) variations within populations, and among populations within regions and altitude zones in all the 14 traits studied. The variations among regions were significant (p 0.05) for number of main shoot culm nodes, and panicle branches and spikelets. But only days to maturity, number of culm nodes, diameters of the two basal culm internodes, and harvest index depicted discernible (p 0.05) clinal variability. The 36 populations clustered into six major (75% similarity level) groups consisting of two up to 15 populations. Five principal components (PCs) explained about 81% of the entire phenotypic diversity among the populations. Of these, the first three PCs accounted for about 65% of the gross variance. About 31% of the total variance explained by the first PC alone originated chiefly from variability in main shoot panicle grain yield and length, culm length and diameter of the two basal culm internodes. Likewise, about 23% the variance accounted for by the second PC was due mainly to variations in grain and shoot phytomass yield/plant, and harvest index. Overall, the study demonstrated that tef is a highly versatile crop species and the enormous wealth of quantitative trait diversity in the germplasm indicates immense potential for the genetic improvement of the crop through breeding. 相似文献
10.
Twenty two accessions of barley landrace/farmers' varieties collected from Bale and North Shewa in situ conservation zones were characterised using 18 qualitative and quantitative morphological traits. Phenotypic frequencies for individual qualitative characters across in situ conservation zones, districts, and strategic sites (localities) have shown mixed and some peculiar patterns. Varieties from Bale conservation zone are predominantly white-yellow seeded whereas varieties from North Shewa are purple-black seeded. White-yellow seeded varieties are more frequent in the lower altitude examined, and the purple-black seeded varieties are more frequent at the highest altitude ( 2650 ). While six row types occur at higher frequencies in almost all the sites in North Shewa, the irregular types are dominant at Bale. The highest frequency of six row types is found at an altitude 2650 , whereas the two rowed and irregular types are found below 2650 . Two row types occur at low frequency at both sites. At Bale, glume awn shorter than glume is the most frequent character whereas glume awn longer than glume is more frequent at North Shewa. Glume awn longer than glume appears to increase with increasing altitude. Caryopsis cover is relatively monomorphic with respect to distribution across zones. The covered types are most frequent in almost all altitudinal ranges. Estimates of diversity index (H) for individual qualitative characters suggest that polymorphism is common in varying degrees for most characters, which indicates the existence of wide range of variation. On the basis of cross validation using discriminant function among the quantitative characters, the landrace varieties from North Shewa seem to be more diverse than the ones from Bale. From the results of multiple regression analysis, the zonal variation is significantly associated with all the quantitative morpho-agronomic characters except plant height. The great majority of the varieties from Bale were perfectly identified and named by farmers. The reliability analysis confirmed that there was a remarkable positive degree of consistency between farmers naming of landrace varieties. 相似文献