Spatially structured genetic diversity of the Amerindian yam (Dioscorea trifida L.) assessed by SSR and ISSR markers in Southern Brazil

Dioscorea trifida L. (Dioscoreaceae) is among the economically most important cultivated Amerindian yam species, whose origin and domestication are still unresolved issues. in order to estimate the genetic diversity maintained by traditional farmers in Brazil, 53 accessions of D. trifida from 11 municipalities in the states of São Paulo, Santa Catarina, Mato Grosso and Amazonas were characterized on the basis of eight Simple Sequence Repeats (SSR) and 16 Inter Simple Sequence Repeats (ISSR) markers. the level of polymorphism among the accessions was high, 95 % for SSR and 75.8 % for ISSR. the SSR marker showed higher discrimination power among accessions compared to ISSR, with D parameter values of 0.79 and 0.44, respectively. Although SSR and ISSR markers led to dendrograms with different topologies, both separated the accessions into three main groups: I-Ubatuba-SP; II-Iguape-SP and Santa Catarina; and III-Mato Grosso. the accessions from Amazonas State were classified in group II with SSR and in a separate group with ISSR. Bayesian and principal coordinate analyzes conducted with both molecular markers corroborated the classification into three main groups. Higher variation was found within groups in the AMOVA analysis for both markers (66.5 and 60.6 % for ISSR and SSR, respectively), and higher Shannon diversity index was found for group II with SSR. Significant but low correlations were found between genetic and geographic distances (r = 0.08; p = 0.0007 for SSR and r = 0.16; p = 0.0002 for ISSR). Therefore, results from both markers showed a slight spatially structured genetic diversity in D. trifida accessions maintained by small traditional farmers in Brazil.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ São Paulo, Luiz de Queiroz Coll Agr, Dept Genet, BR-13400970 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biol Sci, BR-09972270 São Paulo, BrazilUniv Calif Davis, Dept Plant Sci MS1, Sect Crop & Ecosyst Sci, Davis, CA 95616 USAUniversidade Federal de São Paulo, Dept Biol Sci, BR-09972270 São Paulo, BrazilFAPESP: 2007/04805-2Web of Scienc

Vegetative and sexual management in food yam production

Meeting: International Society for Tropical Root Crops Symposium, 4th, 1-7 Aug. 1976, Cali, COIn IDL-133

TOWARDS AN EXPERIMENTAL NETWORK FOR YAMS IN THE CARIBBEAN

The cultivation of yams in the Caribbean area confronts problems which are fairly common to many situations. Among the less costly paths for solving these, are adapted varieties. The Plant Breeding laboratory of INRA, based in Guadeloupe, is organizing a network of yam variety experimentation with the cooperation of different institutions (CARDI, Ministries of Agriculture). Two cultivars of D. alata tolerant to anthracnose have been sent and were experimented on in 1985. The results of this cooperation are encouraging. ----- La culture des ignames dans la region caraibe recontre des problemes largement communs a beaucoup de situations. Une des voies les moins coliteuses pour y repondre est l'utilisation de varietes adaptees. Le laboratoire INRA d'Amelioration des Plantes base a la Guadeloupe en treprend, avec le concours de differents organismes (CARDl, Minsiteres de l'Agriculture), la mise en oeuvre d'un reseau d'esperimentation varietale. Deux cu1tivars de D. alata tolerants a l' anthracnose on tete diffuses et experimentes en 1985. Les premiers resultats de cette cooperation incitent a la developper

La patate douce

Cet ouvrage sur la patate douce est à l'origine destiné aux agriculteurs, aux vulgarisateurs et aux acteurs du développement. Aujourd'hui, il est utilisé dans un cadre bien plus vaste, notamment lors de formations ou dans l'enseignement secondaire. Les textes sont clairs et concis. En outre, son format réduit en fait un compagnon idéal sur le terrain

Interactions majeures des agricultures de l'ancien et du nouveau monde

* INRA, centre des Antilles Diffusion du document : INRA, centre des AntillesNational audienc

Root and tuber crops in Guadeloupe

The main root crops grown in Guadeloupe and their annual production rates are indicated. Very few areas of the island are planted to cassava; this root crop is grown in mixed cropping systems (aroids/cassava/cocoa/coffee, aroids/sweet potato/cassava, or cassava/sweet potato) or in monoculture in the north of Grande- Terre, in Marie-Galante, and over the Capesterre-Belle-Eau area of Basse-Terre. Both sweet and bitter cv. are grown. Since the 2nd World War, root crop production in Guadeloupe, especially that of cassava, has declined due to the importation of other carbohydrate commodities, diversification, rise in prices for export crops, lack of growers' associations, and adoption of European and North American consumption patterns. (CIAT)Se presentan los principales cultivos de raices en Guadalupe y sus tasas anuales de produccion. En la isla hay pocas areas sembradas con yuca, la cual se siembra en cultivo mixto (aroides/yuca/cocoa/cafe, aroides/batata/yuca o yuca/batata) o en monocultivo en el norte de Grande-Terre, en Marie-Galante o en el area de Capesterre-Belle-Eau de Basse-Terre. Hay cv. dulces y amargos. A partir de la Segunda Guerra Mundial, la produccion de los cultivos de raices ha disminuido, especialmente la de yuca, debido a la importacion de otras fuentes de hidratos de carbono, diversificacion, alza en los precios de cultivos de exportacion, falta de asociaciones de agricultores y adopcion de patrones de consumo europeos y norteamericanos. (CIAT