Entity

Time filter

Source Type


Letta T.,University of Bologna | Letta T.,Sinana Agricultural Research Center | Olivera P.,U.S. Department of Agriculture | Maccaferri M.,University of Bologna | And 7 more authors.
Plant Genome | Year: 2014

Wheat stem rust rapidly evolves new virulence to resistance genes. Recently emerged races in East Africa, such as TTKSK (or Ug99), possess broad virulence to durum cultivars, and only a limited number of genes provide resistance. An association mapping (AM) study conducted on 183 durum wheat accessions has allowed us to identify 41 quantitative trait loci (QTLs; determination coefficient [R2] values from 1.1 to 23.1%) for seedling resistance to one or more of four highly virulent stem rust races: TRTTF, TTTTF, TTKSK (Ug99), and JRCQC, two of which (TRTTF and JRCQC) were isolated from Ethiopia. Among these loci, 24 are novel, while the remaining 17 overlapped with loci previously shown to provide field resistance in Ethiopia and/or chromosome regions known to harbor designated stem rust resistance designated loci (Sr). The identified loci were either effective against multiple races or race specific, particularly for race JRCQC. Our results highlight that stem rust resistance in durum wheat is governed in part by loci for resistance across multiple races, and in part by race-specific ones (23 and 18, respectively). Collectively, these results provide useful information to improve the effectiveness of marker-assisted selection towards the release of durum wheat cultivars with durable stem rust resistance. © Crop Science Society of America.


Teshome E.,Sinana Agricultural Research Center | Fininsa C.,Haramaya University | Sahile S.,University of Gondar
Asian Journal of Plant Pathology | Year: 2013

Owing to its high protein content, fab a bean (Vicia fabae L.) leaves' phylloplane harbors many microorganisms besides Botrytis fabae which could have antagonistic potential. The use of chemical fungicides against chocolate spot has been a common practice, but negative effects to the environment forces a search for alternative options. The objective of this study was to explore fungal isolates residing on faba bean leaves and evaluate their antagonistic potential against B. fabae. For this matter, 236 leaf samples were collected from different districts of West Hararghe and Bale zones, which yielded 72 fungal isolates. These isolates were evaluated for their biocontrol potential against B. fabae in vitro. ANOVA (Analysis of Variance) for Antibiosis, percent growth inhibition, growth rate and parasitism tests showed significant difference (p<0.0001) among fungal isolates. In antibiosis test, two isolates, Trichoderma harzianum and Penicillium spp. formed higher mean inhibition zone of 7.33 and 7.00 mm, respectively and the highest mean colony growth inhibition were recorded from T. harzianum (69%) and T. oblongisporum (58.1%) over the control. Trichoderma spp. showed higher mean growth rate (14-16.67 mm day-1) than any of other fungal isolates and on the other hand higher mean diameter of lysed mycelium (12 mm) was recorded from Aspergillus spp. and Penicillium spp. This study revealed higher distribution of biocontrol agents and their antagonistic ability over B. fabae, in Ethiopia. Particularly Trichoderma spp. showed better potential in controlling B. fabae and can be further evaluated for its commercialization, either alone or as a component of integrated disease management. © 2013 Academic Journals Inc.


Abinasa M.,Sinana Agricultural Research Center | Ayana A.,Oromia Agricultural Research Institute | Bultosa G.,Haramaya University
African Journal of Agricultural Research | Year: 2011

Information on the extent of genetic variability and heritability as well as correlation among agronomically important traits is a requirement to design a suitable plant breeding method. The present research was conducted at Sinana, Southeastern Ethiopia during the 2009 main crop growing season. The experimental material consisted of 16 durum wheat genotypes tested in a randomized complete block design with three replications. Twelve agronomic traits were included in the investigation. Highly significant differences were revealed among durum wheat genotypes for all traits studied, suggesting the possibility of improving durum wheat for these traits. Plant height and number of kernels per spike showed the highest phenotypic and genotypic coefficients of variations and genetic advance, whereas, days to maturity and test weight had the lowest values. Plant height exhibited highest heritability value of 98.3% while number of spikelets per spike showed minimum value of 36.4%. The genotypic correlations estimated showed positive association of grain yield with days for heading (r=0.50), harvest index (r=0.69) and kernels number per spike (r=0.81). Harvest index (1.13) and biomass (0.81) exhibited the highest positive and significant direct effect on grain yield. Hence, these traits could be considered as suitable selection criteria for the development of high yielding durum wheat varieties. © 2011 Academic Journals.


Letta T.,University of Bologna | Letta T.,Sinana Agricultural Research Center | Maccaferri M.,University of Bologna | Badebo A.,Debre Zeit Agricultural Research Center | And 4 more authors.
Theoretical and Applied Genetics | Year: 2013

Pucciniagraminis f. sp. tritici, the causative agent of stem rust in wheat, is a devastating disease of durum wheat. While more than 50 stem rust resistance (Sr) loci have been identified in wheat, only a few of them have remained effective against Ug99 (TTKSK race) and other durum-specific Ethiopian races. An association mapping (AM) approach based on 183 diverse durum wheat accessions was utilized to identify resistance loci for stem rust response in Ethiopia over four field-evaluation seasons and artificial inoculation with Ug99 and a mixture of durum-specific races. The panel was profiled with simple sequence repeat, Diversity Arrays Technology and sequence-tagged site markers (1,253 in total). The resistance turned out to be oligogenic, with twelve QTL-tagging markers that were significant (P < 0. 05) across three or four seasons. R2 values ranged from 1. 1 to 11. 3 %. Twenty-four additional single-marker/QTL regions were found to be significant over two seasons. The AM results confirmed the role of Sr13, previously described in bi-parental mapping studies, and the role of chromosome regions putatively harbouring Sr9, Sr14, Sr17 and Sr28. Three minor QTLs were coincident with those reported in hexaploid wheat and five overlapped with those recently reported in the Sebatel × Kristal durum mapping population. Thirteen single-marker/QTL regions were located in chromosome regions where no Sr genes/QTLs have been previously reported. The allelic variation identified in this study is readily available and can be exploited for marker-assisted selection, thus providing additional opportunities for a more durable stem rust resistance under field conditions. © 2013 Springer-Verlag Berlin Heidelberg.


Didita M.,Sinana Agricultural Research Center | Nemomissa S.,Addis Ababa Institute of Technology | Gole T.W.,Environment and Coffee Forest Forum ECFF
Journal of Forestry Research | Year: 2010

Floristic composition and vegetation structure were described for the woodland vegetation around Dello Menna, Bale zone, southeast Ethiopia. A total 50 (20 m × 20 m) quadrats were sampled to identify and describe plant community types, species diversity, richness and evenness and to relate the identified plant community types with some environmental factors and describe the population structure of woody plant species. In each quadrat, data on species identity, abundance, height and Diameter at Breast Height (DBH) of woody plant species, altitude and slope were recorded. Vegetation classification was performed using PC - ORD software package. Sorensen's similarity coefficient was used to detect dissimilarities among communities. Shannon - Wiener diversity index, species richness and Shannon's evenness were computed to describe species diversity of the plant community types. Results show that a total of 171 vascular plant species representing 53 families were recorded. Fabaceae is the dominant family represented by 13 genera and 26 species (15%) followed by Asteraceae, Lamiaceae and Anacardiaceae with eight species each (4.6%). Based on the results of vegetation classification, three plant communities (Dalbergia microphylla community, Grewia bicolar- Acacia brevispica community, and Combretum molle-Combretum collinum community) are recognized and described. Species richness, diversity and evenness varied among the plant communities. Species richness and diversity exhibit a bell - shaped pattern along altitude. Species turn over among communities more or less follow altitudinal gradients. Tukey's pairwise comparison of means among the plant community types shows significant variations in altitude, implying that altitude is one of the most important factors determining the distribution of plant communities. The community Dalbergia microphylla type exhibits the highest species richness and diversity. Analysis of population structure of the dominant species reveals various patterns. Future research directions and recommendations are suggested for the sustainable utilization of the vegetation. © 2010 Northeast Forestry University and Springer-Verlag Berlin Heidelberg.

Discover hidden collaborations