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Rice breeding for african highlands



Rice breeding for african highlands

A project entitled “Study of constraints linked to rice growing at 
high altitude and development of adapted varieties” lead by Prof. 
J. Bouharmont of Université Catholique de Louvain, Belgium, in 
partnership with other scientific institutions in France, Burundi, 
Madagascar and Togo, was carried out under the European Union 
(D.G.XII) STD2 scientific programme.
Rice cultivation has recently been developed in highland regions of 
some tropical countries, thus bringing into evidence several 
previously unknown or poorly known problems regarding the crop. The 
STD research project was set up in order to evaluate the major 
constraints to rice cropping in the water-logged areas of Burundi 
and in the irrigated and rainy ricelands of the Madagascan 
highplains and to bring together several previous isolated research 
efforts in order to develop consistent strategies of rice breeding 
for these environments. The project brought together six 
institutions: Université Catholique de Louvain (Belgium), 
CIRAD-IRAT (France), Université de Bujumbura and Institut des 
Sciences Agronomiques (Burundi), Centre National de la Recherche 
Appliquée au Développement Rural (Madagascar) and Direction de la 
Recherche Agronomique (Togo).
Agroclimatic conditions and specific pathogens were identified as 
the most limiting factors. Climatic conditions related to altitude 
conditions mostly determine the incidence of diseases, and cold by 
itself can severely reduce fertility.
Pyricularia oryzae in the hottest regions and Pseudomonas 
fuscovaginae in the coldest regions were identified as the most 
important pathogens, though secondary pathogens were also 
recognized. For the two above mentioned diseases, selection 
constitutes the only available mean of control. While Pyricularia 
oryzae is a quite well known fungal disease, P. fuscovaginae is a 
poorly known bacterial disease. Therefore, most efforts have 
concentrated on this pathogen, aiming to the study of its 
epidemiology, the extraction and purification of toxines, the 
development of serological tests and the development of inoculation 
and screening procedures. In this purpose, the results suggest that 
one of the isolated toxines may be used for the screening of 
tolerant rice genotypes, either at the plant or the cellular level.
For cold tolerance, laboratory screening procedures, applied either 
to plantlets or cell cultures, gave rather encouraging results. 
They proved to correlate positively with field screening results 
and, on the other hand, somaclonal variation induced by in vitro 
cell culture produced, in some instances, heritable cold tolerance 
expression. In fact, the breeding potential of induced variation in 
tissue culture for adaptation characters such as cold tolerance is 
often questioned as far as most variants are unable to pass their 
tolerance to their offsprings, the same is to say, they are not 
true genetic mutants. Mutants for other agronomic traits, such as 
growth habit, panicle lenght, weight of 1000 grains and resistance 
to Pyricularia, were also selected from in vitro cell culture.
The above mentioned insights in both the epidemiology of 
Pseudomonas fascovaginae and the potential of somaclonal variation 
for the isolation of useful agronomic mutants, clearly increased 
the range of rice breeding technics for highland tropical regions.
Several agronomists and biologists joined in the project. In 
particular, african researchers were offered training facilities 
and the opportunity for a PhD degree. Moreover, annual meetings 
allowed fruitful scientific exchange, and counted in the presence 
of other countries, such as Rwanda, Zaire and Nepal. 
Within these projects several publications have been issued.

For further information please contact:

Prof. J. Bouharmont
Université Catholique de Louvain
Address: 1, Place de l’Université
B-1348 Louvain-la-Neuve, Belgium
Phone: +32-10-47 21 11
Telex: UCLB 59037

Contract number TS2-A-046