GENETIC DIVERSITY OF CAMEROONIAN BREAD WHEAT CULTIVARS (TRITICUM AESTIVUM L.) REVEALED BY SSR MARKERS
Honoré Tékeu3, Eddy M. L. Ngonkeu1,3, François P. Djocgoué 3, Aletta Ellis2, Venasius Lendzemo1, Lezaan Springfield 2, Gilles Béna 5, Agnieszka Klonowska5, Diégane
Diouf4, Willem C. Botes2 and Lionel Moulin5
1Institute
of Agricultural Research for Development, PO Box 2123, Yaoundé, Cameroon
2Department of Genetics, Stellenbosch University, Private Bag X1, Matieland, Stellenbosch, 7602, South Africa
3Department of Plant Biology, University of Yaoundé I, PO Box 812, Yaoundé, Cameroon
4Laboratoire Commun de Microbiologie de Dakar, Centre de recherche IRD/ISRA/UCAD, Route des Hydrocarbures, Bel Air, PO Box 1386, Dakar, Sénégal
5IRD, CIRAD, Univ. Montpellier, Laboratoire des Interactions Plantes-Microorganismes-Environnement (IPME), 911 Avenue Agropolis 34394 Montpellier, France
INTRODUCTION
The global demand for wheat will increase by 60 % in 2050 (FAO, 2013). To meet this growing demand, wheat production can be increased through
agricultural intensification in the growing areas. To this end, Rajaram et Hettel (1994) have delimited 12 Mega environments (MEs) or favourable zones for wheat
cultivation, where 3 are exploitable in Cameroon. Among them, the main Cameroonian areas exist in North, North-western and Adamawa regions. In Adamawa, the
SODEBLE company was established in 1975 in order to reduce the country's dependence towards imports of wheat flour. Before its closure, this Company had
produced high yielding wheat lines (3.5 t/ha) resistant to major fungal diseases (Monthé and Habas, 1980). Twelve of these bread wheat varieties were evaluated for the
agronomic traits in the Northwest Region (Ayuk-Takem, 1984). However, the assessment of the genetic diversity is a key prerequisite for studying the adaptation of
populations to new environmental conditions, and therefore for the selection of new varieties. In this context, the use of SSR markers combines many desirable marker
properties such as abundance, high levels of polymorphism (unlike RFLP), very good reproducibility (compared to RAPD), and co-dominance (contrary to the AFLP
for which codominance is not exploitable), but also an even coverage of the uniform genome and the specificity of amplification. The present investigation aimed to
estimate the levels of genetic diversity within bread wheat varieties grown in Cameroon.
MATERIALS AND METHODS
RESULTS Table 2. Description of the wheat SSR markers
Fig.1. Map showing the 12 Mega environments for wheat breeding programs in
Africa and collecting of the used wheat cultivars from farmers in Cameroon
Table 1. Wheat cultivars used and their origins
No
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Samples' names
Ngm 2
Fuanb2
Babankit
Alexander wonder
Fuanb1
Sonalika
Fuanb3
Fuanb4
HGW
BBT2
WASSANDE 2
Vrack
Ngderem4
Ngderem1
Ngderem3
IRAT 10
RIBA
Region
Adamawa
Northwest
Northwest
Northwest
Northwest
Northwest
Northwest
Northwest
Northwest
Northwest
Adamawa
Northwest
Adamawa
Adamawa
Adamawa
Northwest
Northwest
Number of alleles
Alleles
Locus
Position
frequency
Xwmc 11
1A, 3A
0,29
Xwmc 59
1A, 6A
0,18
Xwmc 177
2A
0,18
Xgwm 190
5D
0,18
Xgwm 437
7D
0,18
Xgwm 539
2D
0,24
Xdgm 125
4D
0,65
Xwmc 331
4D
0,82
Barc 133
3B
0,65
Xgwm 133
6B
0,35
Xgwm 644
6B
0,29
Mean
0,36
PIC: Polymorphism Information Content
14
12
10
8
6
4
2
0
0,00
Village
Wassande
Fuanentui
Smal Babanki
Boyo
Fuanentui
Wassande
Fuanentui
Fuanentui
Abongphen
Abongphen
Wassande
Bambui
Wassande
Wassande
Wassande
Bambui
Boyo
Number of
alleles
8
10
13
9
10
8
2
2
4
4
7
7
Gene
Diversity
0,83
0,89
0,90
0,87
0,88
0,83
0,46
0,29
0,52
0,72
0,79
0,72
PIC
0,81
0,87
0,89
0,86
0,87
0,81
0,35
0,25
0,47
0,67
0,76
0,69
y = 15,413x - 4,1707
R² = 0,8
0,20
0,40
0,60
0,80
1,00
Gene diversity
Fig. 3. Correlation between gene diversity and the number of alleles detected
DNA genomic extraction, SSR and statistics analysis
Fig. 4. Neighbor-Joining dendrogram of 17 wheat accessions based on
genetic distances computed from SSR markers.
DISCUSSION The results obtained in this study provided new information on the
relationships between the Cameroonian bread wheat cultivars. SSR markers showed a
high level of polymorphism and sufficient information to discriminate the bread wheat
cultivars grown in Cameroon. This genetic diversity could be considered in developing
programs for the selection and improvement of wheat in the agro-ecological zones.
Morphological and phenotypic studies will also be required to couple with our results
of molecular analyzes. Wheat production should be increased through agricultural
intensification in the favorable growing areas in Cameroon.
REFERENCES
Ayuk-Takem J., 1984. Rapport d’activités annuelles de IRA, Bambui. 1982-1986.
FAO, 2013. How to feed the world in 2050.
Monthe E., Birie habas J., 1980. O.R.S.T.O.M. Fonds documentaire No 17751. 40p.
Rajaram S. and Hettel G. P., 1994. Wheat Breeding at CIMMYT: Wheat special report N° 29.
Ciudad Obregon, Sonora, Mexico 21-25 March, 1994.