Chili peppers were domesticated at least five times by prehistoric peoples in different parts of South and Middle America. The major species on a world scale is undoubtedly Capsicum annuum, but other domesticates remain of local importance (Pickersgill 1989).

Genetic resources for the improvement of any given domesticated pepper include, firstly, conspecific accessions (both wild and domesticated); secondly, domesticated peppers belonging to other species and their conspecific wild relatives; and thirdly, wild species which have never been domesticated. All species can probably be intercrossed through conventional sexual methods, though manipulations such as bridging crosses, change in ploidy level and embryo rescue may be needed. Chromosomal structural changes are common between and, to a lesser extent, within species.

Interspecific and some intraspecific hybrids are usually at least partially sterile and interspecific transfer of genes on those chromosomes involved in structural changes may be hampered. Collection of genetic resources of Capsicum is proceeding actively, but evaluation and classification of these resources are lagging behind our understanding of how to utilize them. As major collections are grown and evaluated for morphological and other characters, our present limited knowledge of the geographical distribution of diversity, in general, and of useful characters, in particular, should improve. Isoenzyme studies of these collections should show the extent to which domesticates are genetically depauperate compared to their wild relatives and should provide information on breeding systems, organization of genetic variation, and markers useful in breeding programs.

Analyses of these data will improve our understanding of how the presently available genetic resources of capsicum came into being and how they may best be maintained.

THE DOMESTICATED SPECIES OF CAPSICUM
The domesticated species of Capsicum comprise two species (C. baccatum L. and C. pubescens R. and P.), which are clearly distinct by any taxonomic criterion, plus a species complex, which is currently treated as containing three independently domesticated species (C. annuum L., C. frutescens L. and C. chinense Jacq.).

Capsicum annuum
This species was domesticated in Mexico and is the most important cultivated pepper in Mexico and adjacent countries. It is the most important species on a world scale, since it includes all the commercially important sweet peppers and many spice types. It has two non-pungent (non-hot) forms; the Bell, and the Wax and the Pimento peppers, as well as the hot form; the Jalapeno and the NuMex, that are present throughout much of the world.

Capsicum frutescens
Peppers, which are morphologically identical to wild C. frutescens, are grown or exploited throughout much of Latin America. These peppers have also been introduced to the Old World and are grown where extreme pungency is required, for example for oleoresin extraction. This species is mainly represented by two cultivars, Tabasco and Malagueta. Tabasco is the most common cultivar of Capsicum frutescens. The Malagueta is a popular cultivar in Brazil. It is not related to Aframomum melegueta, the melegueta or Guinea pepper, from Africa, which is related to ginger.

Capsicum chinense
This is the most variable of the domesticated species and the most widespread within Latin America. Large-fruited, thick-walled types, which are used fresh, are common in the West Indies and some other parts of the Caribbean, while in coastal and montane parts of the Andean region thin-walled types which are used dried also occur. Fruit can be extremely pungent and aromatic, with persistent pungency when eaten. The best-known cultivars are the very hot Habanero peppers.

Capsicum baccatum
This species is grown on a garden and field scale in South America, particularly in Peru, Bolivia and Brazil. The dried orange fruits of escabeche peppers are perhaps the most common condiment in Peru, while the mild-flavoured, large, thick-walled fruits of chapéu de frade are sold fresh in markets of southern Brazil.

Capsicum pubescens
This is the highland pepper found throughout the Andean region and now grown also in the highlands of Middle America. It has pungent fruits with thick pericarps and large moisture content. The most common cultivar is the Rococo peppers.

Economic Potential of the Different Domesticates
It seems to have been largely historical accident that has led to the Middle American peppers C. annuum and C. frutescens being grown throughout the world, while the South American domesticates C. chinense and C. baccatum have remained little known outside their native continent.

Acknowledgment
Thanks are due to Graeme Casselton for permission to use the pictures shown above.

Descriptors
The IBPGR has published a descriptor list (IBPGR 1991) for pepper based on several seasons of testing at AVRDC. Accessions of germplasm collected within the Caribbean were described (CARDI 1991) using the IBPGR descriptors.

CARDI's HOT PEPPER BREEDING PROGRAMME

In 1989, in an effort to boost the production and export of a certain variety of hot peppers in the East Caribbean, seeds were obtained from Jamaica and CATCO of what was supposedly the, "Scotch Bonnet" cultivar. Seeds from the Jamaica source produced yellow-fruited hot peppers with the required pungency and flavour. About 15% of the fruits expressed the "Scotch Bonnet" shape. The other lot of seeds produced red fruits of predominantly "lantern" shapes. It was clear that the two source populations contained genes from the pure "Scotch Bonnet" which was crossed with other populations for sometime. It was, therefore decided to attempt to improve these two source populations in Antigua while producing seeds at the same time. The populations were multiplied and disseminated by CARDI under the name of "West Indies Hot Pepper." CARDI's selection efforts started in Antigua in the last 1980s and have resulted in the cultivar called West Indies Red with Scotch Bonnet in its parentage

Between the 1989 and August 1992 planting in Antigua, four cycles of selections were achieved in the population of red fruits and three cycles in the yellow-fruited population, which began to exhibit reduced vigour. The market was also showing a preference for the red fruits.

CARDI's Breeding Programme which is coordinated out of Barbados as the site of CARDI's Centre for Research on Plant Genetic Resources begun to lend a sharper focus and to accelerate the production of improved hot pepper cultivars for the Caribbean. The primary beneficiaries remain the CARDI countries.

There are eight research groups functioning in a coordinated network in the region and focusing on hot pepper improvement.

New Hot Pepper Lines for the Caribbean
Three breeding lines have been selected, described and named as follows:
· Caribbean Green
· Caribbean Red
· Caribbean Purple

Tolerances to diseases and pests
Just like the base population from which they were selected, all three lines exhibited high levels of tolerance to the Gemini viruses, bacterial and fungal wilts in the open field with natural infestations. They also stood up against whitefly, aphids, thrips, mites and stinkbugs.

High aroma and pungency
The lines possess unique aroma and organoleptic qualities, which are characteristic of the Scotch Bonnet group.

High yielding
All the lines averaged 20,000 kg/ha of fresh berries in large-scale plantings; this yield was three times higher than the standard average yields obtained by farmers in Barbados.

In Barbados, CARDI is involved in selecting Cayenne pepper for processing. A Factsheet prepared by Herman Adams, B. Clarke, L. Paulraj, C. Roberts and D, Sisnett is reproduced below.

Progress in the Selection of Cayenne Pepper for Processing Background

The Cayenne pepper is a group of cultivars which belongs to a sub-specie of Capsicum annum and which is used for the production of dried and ground hot pepper. CARICOM manufacturers of curry powder and other condiments imported ground hot pepper from extra-regional sources. However, the agro-ecological and socio-economic conditions in the Caribbean are ideal for the cultivation and processing of Cayenne peppers to replace imports and develop an export capability.

Origin
CARDI imported germplasm from the Asian Vegetable Research and Development Center (AVRDC) and 20 pure lines were evaluated during 1999 in Barbados.

Description and Performance
The results of the evaluation to date have shown 6 of the pure lines (Table 1) to be of high general adaptability to local conditions, and their berries were of a very high quality. The food processing laboratory of the Barbados Agricultural Development and Marketing Corporation (BADMC) collaborated to process the berries. Drying and grinding tests produced ground hot pepper of very high quality. The long and thin berries (See Table 1 and photographs of the berries) dried well. The ground product retained the dark red pigmentation and the aroma of the berries.

Table 1. Some characters of the Caribbean Cayenne elections. Mean values of length and width of berries were computed from 10 randomly chosen berries.

Plant Ideotype
(See Table 2 and photographs of plants)
Plant heights of the Caribbean Cayenne Selections ranged from 83-107 cm, plant canopy width from 102-159 cm whilst West Indies Red was shorter (80 cm) and its canopy width was narrower (97 cm). The plants flower at 39 days after transplanting which is the same for West Indies Red. The duration of harvest is at least 3-4 months, the same as for West Indies Red. Harvest can be prolonged to more than 6 months with consistently high-level management.

SELECTIONS

Table 2. Mean values of 5 randomly chosen plants showing plant height and canopy width of the Caribbean Cayenne Selections and West Indies Red.

Year-round adaptability
Owing to the fact that these selections are photoperiod insensitive, they can be planted in any month of the year providing there is adequate soil moisture.

Multiple harvests
Harvests can be spaced at fortnightly intervals. The minimum number of pickings is 6-7 and these can be extended.

Disease and pest resistances
These lines were bred at the AVRDC for resistances as shown in Table 1. Bacterial Wilt (BW) is of particular importance during wet weather in the Caribbean. The lines are being tested also for the virus diseases such as the geminiviruses, which are important in the region.

Main Production Practices
Land preparation, weed management and pests and disease control are basically the same as for West Indies Red. However, plants could be spaced wider at 90 cm x 50 cm to give about 22,200 plants/ha (about 10,000 plants per acre). Rainfed crops are to be timed for transplanting to take place at the onset of the rains. Drip irrigation is highly recommended. The supply of fertilizers through the drip lines (fertigation) also reduces the cost of application. It is good practice to apply foliar fertilizers containing micro-nutrients together with compatible insecticides and fungicides. Chemical analyses should be done on soil samples to determine the best kinds and rates of fertilizers for each field. Crop and field rotations are essential to prevent the build-up of virus diseases, in particular. For this same reason, fresh seeds should be obtained from a certified outlet since many diseases are seed borne and recouping seed from the previous crop is fraught with dangers.

Further Developments
Multi-seasonal and multi-locational tests will be carried out over the region. Responses to geminiviruses have to be specifically tested. Agronomic practices will be further refined paying special attention to the use of irrigation water, fertilizers and integrated pest management methods.

Availability
Pure and clean seed will be maintained to meet the needs of farmers and other users, by CARDI.