Country study Burkina Faso 
Biodiversity 

3.5 SITUATION ON SETTING UP EX-SITU CONSERVATION

Burkina Faso has neither centres of genetic resources, nor a central gene bank. However, it owns a few agencies in charge of the collection, handling, distribution, medium and long term conservation and improvement of plant and animal genetic resources. They are: INERA (in charge conducting and co-ordinating research activities in the domain of environment and agriculture), the University of Ouagadougou (conventional institution in charge, among others, of issues related to nature sciences and rural development), CNSF (National Centre of Forestry Seeds) in charge of providing to research and development good quality forestry seeds, CRPAs (whose main object is the promotion of agriculture and pastoralism in the country's regions).

These structures do not have human and material resources in quality and quantity to fulfil their mission. For example, the station of Farakoba now has only one freezer for the conservation of cereal samples. Another difficulty of these conservation institutions is that almost all of them function on the basis of projects, which does not ensure their sustainability.
At the level of documentation, there is no solid and catalogued basic data. The data are found in the archives of researchers, and today, the data on vulnerable, threatened or endangered species have not been collected with precision for some categories of resources, such as agricultural plants. For this category of plant resources, the status of collections undertaken is limited to what is presented below.

3.5.1 COLLECTIONS

In this report, mention has been made of the collections of cereal, leguminous and tuber plants and of a few ligneous species and fodder plants undertaken in Burkina Faso since1960. Concerning the ex-situ conservation of agricultural plants, INERA has two air-conditioned rooms (now out of use), one at the station of Kamboinsé and another one at the Station of Farako-Bâ. Temperatures vary between 17 and 18°C, and seeds (all species taken together) are preserved there. As far as ligneous plants are concerned, they are preserved by CNSF in three different milieux : ambient temperature, one air-conditioned room and two cold-storage rooms. But in reality, there is no gene bank with a national vocation, having a well structured team. Each Programme of INERA manages its own work germplasm according to improvement objectives, whereas the material preserved at CNSF is particularly in accordance with demand priorities of species. There is no clearly defined national Programme.

3.5.1.1 Cereal collections

3.5.1.1.1 Sorghum (Sorghum bicolor)

A first gathering of local forms of the "Guinensia" type of Sorghum was undertaken by IRAT since 1959 at Saria and later enlarged with other samples kept at Farako-Bâ and 37 non "Guinensia" forms collected in 1967 (Le Conte J., 1967). From the prospecting undertaken by IRAT/CIRAD, INERA now has its disposal :

• 247 ecotypes of medium cycle sorghum at Saria (BALMA D., 1985) ;
• 127 ecotypes of long cycle sorghum at Farako-Bâ, from the first collections of ICRISAT of 1979. At that time 800 local varieties were gathered from Burkina Faso, Niger and Senegal (ICRISAT, 1980). During this period, ICRISAT's Phytogenetic Resources division received at Hyderabad (India) a collection of 210 ecotypes of sorghum from Burkina Faso (Mengesha M.M. and Prasada Rao K. E. 1981) ;
• 389 ecotypes of Sorghum were gathered from the regions of the north, east, and centre of the country by CIRP in 1981 ; this collection was continued in 1982 with DSA by the gathering of 197 ecotypes from the south-west. In 1984, 1985, 1986, U.O./IDR/CIRP gathered about 870 forms of cultivated sorghum and about ten spontaneous forms throughout Burkina Faso.

Evaluation tests were conducted in the field with this material. Thus, taking into account the ecological conditions of the origins of samples, most experiments were carried out on sites close to these conditions. The objectives aimed at by these evaluations usually have a morphological characterisation based on a certain number of criteria and the taking into account of some diseases and parasites. Because of the sparse actions of collection, it cannot be concluded that these samples are representative of natural diversity, and consequently could not satisfy the needs of research. In the same way, as conservation conditions are deplorable, many genetic resources have already been lost for good.

3.5.1.1.2 Millet (Pennistum americanum)

About 200 local ecotypes of millet have been collected by IRAT between 1960 and 1986 throughout the country.

ICRISAT gathered a certain number of traditional cultivars between 1977 and 1981 :

• 551 numbers from an ORSTOM/FAO/ICRISAT collection in Burkina Faso and Niger, were evaluated in 1977;
• 1 112 sampled ears in 108 farms from the Mossi plateau in 1980 and 1981;
• collection of early material (Iniadi) in the south-east of the country in 1981.

A coverage of the regions of the north, east, centre in 1981 and south-west in 1982, permitted to gather respectively 211 ecotypes (with three spontaneous forms) and 76 ecotypes.

New prospecting series throughout the country, have allowed U.O./IDR/CIRP to gather some 333 ecotypes.

The various results show that Burkina Faso ecotypes display a great genotypic variability (cycle, length, width and ear shape, seed colour...), characteristic of the climatic zones roughly corresponding to the latitude. Therefore, one can distinguish :

• in the north (Sahelian zone), early varieties (cycle of 90 to 100 days), with usually long and thin ears having a cylinder shape, a roux yellow seed colour (Gaouri Baleri) or light yellow (Gaouri Daneri). These seeds would be close to the forms of "Haïni" millet from the west of Niger;
• in the south (south-Sudanese zone), varieties with late cycle (120-150 days) having short to medium ears (20 to 80 cm). In the southern and eastern part of this zone (Pô, Diapaga), very early forms of 90 days (Iniadi Millet), with shorts ears (30 to 30 cm) having usually conic form and grey seeds are found;
• in the centre (north- Sudanese zone), semi-late varieties (100 to 120 days), with short and thin, spindle-shaped, conic or cylinder shaped ears (30 to 40 cm). These ears become longer and longer in the north of the Mossi plateau. The colour of the seed may be yellow (Kapelga) or grey (Kassabelga). In the western part of this zone (Nouna), later varieties close to "Sanio" millets (130 to 150 days) are found.

The size of the ecotypes observed at Gampéla (Centre), presents a variation of 124 to 386 cm (ZONGO J. D. et al. 1988). In general, in the south-west the biggest ecotypes are found in the south-west.

The exploitation of the variability of the local ecotypes from the various prospecting made it possible to provide vulgarisation with high performance material in population varieties.

As a result of millet allogamy, the conservation of collections proves to be difficult and is undertaken in lines (live collections), and medium conservation is released in the same conditions as sorghum. Some institutes such as IRAT thought about a permanent collection with farmers in order to preserve variability.

3.5.1.1.3 Maize (Zea mays)

As early as 1962 IRAT gathered a certain number of mainly early local ecotypes from the west and a population from the centre. It remains from this prospecting improved varieties including some which have gone into vulgarisation and others preserved as live collections (BALMA D., 1985).

The 1981 prospecting (CIRP- DSA), also permitted to gather 8 ecotypes from the north, centre and east of Burkina Faso and 153 ecotypes from the southwest.
All this collection, i.e. 201 ecotypes, was handed over to INERA. The results from the evaluation of these collections show that :

• Burkina varieties differ in seed colour (yellow, white, reddish-brown) and the length of their cycle;
• In the centre and east, there is a predominance of ecotypes with more early yellow seeds;
• In the south-west, there is a mixture of white and yellow varieties with a good frequency of the dentate white type;
• there is no marked gradient between cycle length and latitude.

The problem of medium and long term conservation on the spot occurs in the same way as for other cereals because of the limited capacities of freezers.

3.5.1.1.4 Rice (Oryza sativa, Oryza glaberrima)

A total of 527 samples were collected with a predominance of O. sativa (90 %) over O. glaberrima (10 %).

The abandonment of glaberrima is general throughout the country and seems to come from many factors, particularly the length of the cycle, ginning and the presence of more high performance varieties of sativa.

This prospecting also revealed an uneven distribution of rice-growing as well as samples (60 % were collected in the southwest) due undoubtedly to the present distribution of rains in Burkina Faso.

The most popular variety remains the sintane Diofor (cultivated everywhere). One notices a clear predominance of improved varieties in the CRPA of Hauts-Bassins and the persistence of the Konsourou and the series of alkam in the CRPAs of the centre and centre-south.

The prospecting did not permit to collect wild species of the type Oryza barthii and O. longistaminata because of the drying up of their site and also the period (from November 1983 to February 1984) was not favourable for all the regions. A second prospecting would be necessary. The results from the evaluations, taking into account the agronomic and morphological characters and the enzymatic polymorphism, are expected.

3.5.1.2.1 Prospecting and collections of Cowpeas (Vigna sinensis or Vigna unguiculata)

Cowpeas prospecting began in 1977 in Burkina Faso with the collection of about 40 local ecotypes (BALMA, 1985).

In 1981 and 1982, in addition to the prospecting of cereals, respectively 40 ecotypes in the north and about 90 ecotypes in the west, were gathered. At the time the Programme had a collection of 161 local ecotypes called KVu (Kamboinsé Vigna unguiculata).

Evaluations and results: 109 entries of this collection were evaluated in Kamboinsé in 1982 for a few agronomic characteristics at 2 planting dates.
Ecotypes presented the following characteristics:

• 18 usually late and photosensitive entries with big, white and rough seeds (15-63 g/100 seeds) having a lying growth ;
• 45 non- photosensitive entries with creeping growth, early and 4 small ones (10-11 g/100 seeds);
• a leguminous other than Vigna, from the Kerstingiella geocarpa species, with a full cycle of 110 days;
• 45 without flowers.

All the material was tested for resistance to aphids, beetles, Striga, drought and for the production of good quality seeds. A few varieties having displayed good characteristics are used in crossing Programmes:

• Ouahigouya local variety resistant to drought crossed with KN-1 (Kamboinsé Niébé-1);
• Kaya local variety with a good quality seed crossed with Gorom-local for resistance to Striga;
• Kaya local variety with a good quality seed crossed with TVu 2027 for resistance to bruches;
• Kamboinsé local variety resistant to Maruca, crossed with TVu 2027 for resistance to beetles.

KVu-2 and KVu 20-2 entries seem to be the best, the local Gorom variety has gone into vulgarisation for a long time. The varieties considered to be interesting are kept in live collections and regenerated every 2 years.

3.5.1.2.2.Bambara groundnuts Prospecting and Collections (Voandzeia subterranea)

The first prospecting of Bambara groundnuts were undertaken, in addition to the prospecting of cereals in 1982 and 59 local varieties were collected (southwest). In order to start the Programme, 67 introductions from Mali (22), Nigeria (33), Senegal (2) and IITA/Ibadan (10) were also carried out. A total of 45 entries including a local and exotic material was evaluated for a few agronomic characters.

Diseases attacked most of the entries. After evaluations, the selection Programme conducted a certain number of yield tests, which are still going on now.

Bambara groundnut collection (KVs = Kamboinsé Voandzou subterranea) is kept in live collections and renewed every two years.

3.5.1.3 Tubers

Five crops: yam, sweet potato, cassava, araceae (Taro and Macabo) and Souchet (seasoning plant) have been prospected. The evaluations dealt with an important number of morphological characters taking into account the vegetative apparatus and the tuber.

3.5.1.3.1. Yams (Dioscorea spp.)

In each prospected region 10 samples have been collected per cultivar, i.e. about 300 samples of cultivated yam. Local names were given to these cultivars, wild yams were only numbered. Because of the overlap of some samples, the number of cultivars has been reduced to about 50.

Recorded cultivated varieties come from 4 species: Dioscorea cayenensis (80 %); Dioscorea alata; Dioscorea bulbifera; Dioscorea esculenta;

There are 3 groups at the level of wild yams: Diocorea togoyensis, D. dumenterum , D. Abyssinica.

3.5.1.3.2. Sweet potato (Ipomaea batatas)

Collected samples produced 6 clones distributed as follows: 2 clones with white-light white skin, 2 clones with red-light white skin, 1 clone with yellow skin and 1 clone with white-light yellow skin.

3.5.1.3.3. Cassava (Manihot esculenta)

Two clones have been identified, one with a red skin and another with a white skin.

3.5.1.3.4 Taro (Colocasia esculentus)

Only one variety of taro was prospected.

3.5.1.3.5. Macabo (Xanthosoma sagittifolium)

Samples resulted in a rain-fed variety and an aquatic variety.

3.5.1.3.6. Souchet or sugered peas (Cyperus esculentus)

Two varieties were recorded, one with a black skin and another with a yellow skin.

3.5.1.4 Fodder collections

A prospecting was undertaken in 1984 in the north of Burkina (ABOU F. et FOURNIER A., 1984) and permitted to collect 40 taxons including : 23 annual Gramineae, 9 perennial Gramineae, 3 annual Papilionaceae, 3 perennial Papilionaceae and 2 perennial Cyperaceae.

The samplings concerned 148 seeds (grains) and 106 vegetative samples.

An initial evaluation of the production potential of the collected ecotypes was made in 1986. The following results of 24 ecotypes were recorded:

• the local green matter varies from 0.130 T.M.S./ha (for Chloris pilosa ) to 18.7250 T.M.S./ha (for Pennisetum pedicellatum);
• the total dry matter varies from 0.047 (same species) to 5.805 (same species) T.M.S./ha ;
• Panicum laetum and Echinochloa sp. Bearing up to 4 mowings.

3.5.1.5 Ligneous collections

Vulnerable, threatened, endangered or particularly economically important species now benefit from sustained attention. Thus, the seeds of 67 species have been collected by CNSF. Among them the following local species categorised below are concerned by this option:

• threatened species: Acacia senegal, Dalbergia melanoxylon, Pterocarpus lucens;
• vulnerable species: Adansonia digitata, Anogeissus leiocarpus, Bombax costatum, Ceiba pentandra, Khaya senegalensis, Parkia biglobosa, Prosopis africana, Acacia nilotica, Acacia raddiana, Acacia seyal, Acacia senegal, Acacia sieberiana, Tamarindus indica, Sclerocarya birrea and Daniellia oliveri.

Efforts are also being made in order to be able to have seed collections of endangered species, such as Celtis integrifolia and nium obesum (jackal baobab). An ex-situ conservation policy in favour of other important or endangered species is making its way through.

In this way, CNSF, the agency in charge of the supply of good quality seeds to producers and researchers undertook a study aiming at determining the conservation capacity of utilitarian species, in order to make them available as much as possible. The species concerned are: Acacia albida, A. gourmaensis, A. nilotica variety adansonii., A.. nilotica variety tomentosa., A. senegal, Balanites aegyptiaca, Bauhinia rufescens, Ceiba pentandra, Gmelina arborea, Jatropha curcas, Khaya senegalensis, Parkia biglobosa, Parkinsonia aculeata, Prosopis juliflora, Pterocarpus erinaceus, Pterocarpus lucens, Tamarindus indica and Ziziphus mauritiana.
As far as Parkia biglobosa is concerned, a collection from 96 sources including each 25 to 30 separate descents was undertaken in the distribution area of the species in West Africa. In addition, INERA, through the former IRBET owns herbarium collections of which the first are from the fifties, as well as an arboretum. Other collections of the same kind of herbariums were undertaken by specialised institutions for specific needs; this is the case of the Institut du Développement Rural of UO and CNSF.

3.5.1.6 Entomological collections

With regard to the important position of insects in the life of humans, they also benefited from a certain attention. In effect, many species of insects are useful whereas others are harmful. Thus, many institutions whose activities deal with insects realised specific collections. The main structures of this kind are found in the cities of Bobo-Dioulasso and Ouagadougou and listed below.

a) In Bobo-Dioulasso:

• MURAZ Centre, Bobo-Dioulasso;
• INERA research centre of Farakoba and its attached services :
• Cotton Programme,
• Plant Protection Service,
• Plant Protection Laboratory;
• C.I.R.D.E.S.

b) In Ouagadougou:

• the ONCHOCERCOSIS PROGRAMME;
• IRBET now INERA Forestry Production Department;
• The French Institute for Scientific Research and Cooperation Development commonly know as "ORSTOM";
• C.I.R.A.D.;
• C.N S.F.;
• the Laboratory of Applied Entomology of the University of Ouagadougou;
• the Laboratory of Natural History of CNRST;
• the entomological collection of the INERA Station of Saria.

3.5.1.7 Collections of vertebrates

As far as vertebrates are concerned, few collections have been undertaken. Only the Laboratory of Natural History of CNRST has a collection of domestic and wild fauna containing some 6 000 samples of snakes, and an important collection of fishes.