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Genetic diversity and grain protein composition of tetraploid wheat (Triticum durum Desf) germplasm from Ethiopia

Hailu, Faris (2011). Genetic diversity and grain protein composition of tetraploid wheat (Triticum durum Desf) germplasm from Ethiopia. Diss. (sammanfattning/summary) Alnarp, SLU : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae, 1652-6880 ; 2011:102
ISBN 978-91-576-7646-7
[Doctoral thesis]

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Abstract

The extent and patterns of genetic diversity in landraces of tetraploid wheat germplasm collected from major wheat-producing regions of Ethiopia were assessed with the use of agromorphological,phenol-qualitative traits, grain proteins and molecular markers. The extent of genetic erosion of landraces in tetraploid wheat germplasm from Ethiopia was also evaluated.

Field evaluation of agro-morphological characters and laboratory analysis of grain proteins and molecular markers (ISSR) revealed the presence of broad genetic variation among accessions grown in different regions of Ethiopia. Based on the agro-morphological traits, all accessions included in the study were clustered into 15 clusters, with nine accessions remaining solitary. The first 5, 4 and 3 principal component analyses were involved in explaining most of the variation between region of origin, species and altitudinal classes, respectively. Biomass yield per plot, nature of awn, days to heading, lower glume shoulder width, kernel (seed) colour and stand count at emergence were consistently important in explaining the variation in all
accessions studied across region of origin, species and altitude class. Of the phenologic and qualitative traits evaluated in all accessions across the region of origin, the highest Shannon-Weaver diversity index (H′) was mainly due to plant height, a major agronomic character in
durum wheat, except for landraces from Arsi and Bale, where it was due to awn colour.

Characterisation of Ethiopian tetraploid wheat germplasm for glutenin sub-unit composition resulted in identification of novel alleles at the Glu-1 locus. About 39% of the durum wheat studied contained Glu-A1x sub-units, which are rare in other durum wheats.Although there is monomorphism in a number of accessions for gliadin and glutenin subunits, in this study the B genome was found to be more polymorphic than the A genome.

Analysis of DNA polymorphism with ISSR primers produced 128 polymorphic bands and allowed a separation of 60 accessions of tetraploid wheat genotypes. The Nei genetic distance
for all accessions varied from 0.0090 to 0.8574 and that for region of origin from 0.045 to 0.138. Molecular characterisation of four species of Triticum using ISSR revealed that these species were clearly separated, with T. durum being the most diverse, followed by T. turgidum,
T. aethiopicum and T. dicoccon in that order. Triticum durum was more closely related to T.turgidum than to the other species.

The broad diversity in tetraploid Ethiopian wheat germplasm demonstrated here can be utilised in genetic improvement of the crop through selection and hybridisation. However, this
broad genetic diversity is being threatened by genetic erosion. For conservation and practical application reasons, it is necessary to embark on more comprehensive and systematic germplasm collection from all over Ethiopia, with ex situ conservation and appropriate in situ
conservation at the site of origin of landraces. This would also help to prevent genetic erosion arising from landraces being replaced by improved varieties of hexaploid and/or tetraploid wheat.

Authors/Creators:Hailu, Faris
Title:Genetic diversity and grain protein composition of tetraploid wheat (Triticum durum Desf) germplasm from Ethiopia
Series/Journal:Acta Universitatis agriculturae Sueciae. Agraria (1401-6249)
Year of publishing :2011
Volume:2011:102
Number of Pages:38
Papers/manuscripts:
NumberReferences
IHailu, F., Merker, A., Harjit-Singh, Belay, G. & Johansson, E. 2006. Multivariate analysis of diversity of tetraploid wheat germplasm from Ethiopia. Genetic Resources & Crop Evolution 53(6), 1089-1098
IIHailu, F., Johansson, E. & Merker A. 2010. Patterns of phenotypic diversity for phenologic and qualitative traits in Ethiopian tetraploid wheat germplasm. Genetic Resources & Crop Evolution 57(5), 781-790
IIIHailu, F., Johansson, E., Merker, A., Belay, G., Harjit-Singh, & Zeleke, H. 2006. Composition of and variation in high- and low- molecular weight glutenin subunits, and omega gliadins in Ethiopian tetraploid wheat germplasm Plant Genetic Resources 4(2), 134-143
IVHailu, F., Merker, A., Belay, G. & Johansson, E. 2005. Molecular diversity and phylogenic relationships of tetraploid wheat species as revealed by inter-simple sequence repeats (ISSR) from Ethiopia. Journal of Genetics & Breeding 59, 329-338
VHailu, F., Johansson, E. & Persson Hovmalm H. (manuscript). Assessment of genetic erosion: A case study of tetraploid wheat landraces from Ethiopia.
Place of Publication:Alnarp, SLU
Publisher:Dept. of Plant Breeding and Biotechnology, Swedish University of Agricultural Sciences
ISBN for printed version:978-91-576-7646-7
ISSN:1652-6880
Language:English
Additional Information:Additional family name: Tessema. Not mentioned at the title page of the thesis.
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:F Plant production > F30 Plant genetics and breeding
Subjects:Obsolete subject words > NATURAL SCIENCES
(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Genetics (medical genetics to be 30107 and agricultural genetics to be 40402)
Agrovoc terms:triticum durum, genetic diversity within species, land races, plant protein, germ plasm, genetic erosion, ethiopia
Keywords:gentic diversity , genetic erosion, grain protein, composition, tetraploid wheat, Ethiopia
URN:NBN:urn:nbn:se:slu:epsilon-e-293
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-293
ID Code:8485
Department:(LTJ, LTV) > Plant Breeding and Biotechnology (until 121231)
Deposited By: Faris Hailu Tessema
Deposited On:07 Dec 2011 10:40
Metadata Last Modified:02 Dec 2014 10:48

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