A new aspect of genetic diversity of Indonesian oil palm (Elaeis guineensis Jacq.) revealed by isoenzyme and AFLP markers and its consequences for breeding

Oil palm (#Elaeis guineensis$ Jacq.) plays an important economic role in some countries of Southeast Asia like Indonesia, which is the world's second producer of palm and palm kernel oil. The quality improvement of planting material needs a better understanding of the genetic relationships between genotypes from differents populations used in the breeding programmes. In this study, 48 parents, representative of four populations used in Indonesia Oil Plam Research Institute (IOPRI) breeding programmes, were analysed with five selected AFLP primer pairs and four isoenzymatic systems. One hundred and fifty eight scorable band levels were generated of which 69 (61%) were polymorphic. AFLP allowed us to identify off-type descendants which were excluded from analysis. The use of unbiased Rogers distance clearly separated the four studied populations. The Neighbor-Joining method re-groups two African populations wich are known as originating from different regions. Nevertheless, the variability revealed is in accordance with oil palm breeders' knowledge. The results obtained with AFLP showed that the crosses among the African sub-population, which is excluded in oil palm reciprocal recurrent selection (RRS) breeding programmes, may be more interesting than the crosses between the African and the Deli populations. (Résumé d'auteur

Agronomical and molecular characterization of banana germplasm Caracterização agronômica e molecular de germoplasma de bananeira

The objective of the present work was to characterize banana accessions from the Germplasm Bank at Embrapa Mandioca e Fruticultura Tropical (Brazil), using agronomical, physical and physicochemical characteristics of fruit and simple sequence repeats (SSR) markers. Twenty-six accessions were analyzed, in which high genetic variability was found, especially for the agronomical characters number of fruit and weight of bunch. Accessions with high contents of carotenoids (diploid 'Jaran'), polyphenols (triploid 'Caipira' and tetraploid 'Teparod') and vitamin C (diploid 'Tuugia' and an unknown triploid AAA) in the fruit were identified. Thirteen microsatellite primers revealed an average of 7.23 alleles, which showed high variability. A dendrogram was prepared using the Gower algorithm for the distance matrices obtained from the agronomical, physical and physicolchemical analysis of fruit and SSR markers. Adopting the average genetic divergence as the cut-off point, three clusters were found: G1, formed by the diploids 'Jaran', 028003-01 and M-48; G2, by the diploids 'Malbut' and 'Ido 110'; and G3, by 21 tri-and tetraploid accessions, including one diploid, 'Tuugia'. The triploids with the B genome 'Thap Maeo', 'Walha', 'Pacha Nadan' and 'Champa Madras' were grouped in G2. Results from this work can be used for breeding hybrids with good agronomical traits and fruit quality.<br>O objetivo deste trabalho foi caracterizar acessos de bananeira do Banco de Germoplasma da Embrapa Mandioca e Fruticultura Tropical, por meio de características agronômicas, físicas e físico-químicas dos frutos e por marcadores "Simple sequence repeats" (SSR). Foram analisados 26 acessos, nos quais observou-se ampla variabilidade genética, em especial para número de frutos e peso de cacho. Foram identificados acessos com altos teores de carotenoides (diploide 'Jaran'), polifenóis (tetraploide 'Teparod') e vitamina C (diploide 'Tuugia' e um triploide AAA desconhecido). Os 13 iniciadores microssatélites testados apresentaram uma média de 7,23 alelos, que apresentaram alta variabilidade. Com uso do algoritmo de Gower, foi elaborado um dendrograma com as matrizes de distância obtidas por meio das análises agronômicas, físicas e físico-químicas dos frutos e análises moleculares. Com a divergência genética média usada como ponto de corte, foram identificados três agrupamentos: G1, formado pelos diploides 'Jaran', 028003-01 e M-48; G2, pelos diploides 'Malbut' e 'Ido 110'; e G3, pelos 21 acessos tri-e tetraploides, incluindo-se um diploide 'Tuugia'. Os triploides com genoma B 'Thap Maeo', 'Walha', 'Pacha Nadan' e 'Champa Madras' agruparam-se no G2. Os resultados obtidos podem ser utilizados no melhoramento genético, para o desenvolvimento de híbridos com boas características agronômicas e qualidade de frutos