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Chromosome number of 2n=18 is reported for P. tarminiana, a new species of Passiflora (subgenus Tacsonia). Several meiotic irregularities were observed, such as presence of univalents, asynchrony in chromosome migration, chromosome bridges, micronuclei and cytoplasm degeneration. Pairing of chromosomes of different size and chromosome secondary association in metaphase 1 also occurred. Micronucleus in prophases and telophases, and chromosome elimination are reported for the first time in Passiflora. Different relative positions of spindles were observed, leading to different tetrad patterns. Pollen staining indicated a high fertility. Reintegration of asynchronous chromosomes in the nucleus and early elimination of unbalanced microsporocytes can explain the absence of correlation between the frequency of irregularities and pollen stainability.

La diversidad morfológica ha sido estudiada en 185 accesiones del género Passiflora subgéneros Tacsonia, Passiflora y Manicata. Para el subgénero Tacsonia, se hicieron estudios complementarios utilizando isoenzimas y marcadores AFLP, y estudios citogenéticos de las tres especies más comunes, P. tripartita var. mollissima, P. tarminiana y P. mixta. P. tarminiana fue descrita como una especie diferente, lo cual fue confirmado por todos los estudios de diversidad. La separación de los subgéneros Tacsonia y Manicata también fue confirmada, asi como la inclusión de especies atípicas o raras, como P. antioquensis, P. tenerifensis, P. pinnatistipula, P. matthewsii, P. bracteosa, P. ampullacea, P. parritae, P. fimbratistipula, P. trifoliata y P. gracilens. Dentro del subgénero Tacsonia, la variación fue muy amplia en P. mixta, limitada en P. tripartita var. mollissima, y más aún en P. tarminiana. P. tripartita var. mollissima y P. mixta mostraron particular afinidad y diferenciación regional en los marcadores morfológicos e isoenzimáticos, con una máxima diversidad intraespecífica y una mínima diferenciación interespecífica en el sur de Ecuador, lo que sugiere un importante flujo génico entre ellas. Por otra parte, irregularidades meióticas fueron más frecuentes en sus híbridos que en los híbridos de P. tarminiana con P. tripartita var. mollissima evidenciando una homología genómica limitada. El tamaño pequeño de los cromosomas (2n = 18) de las tres especies de Tacsonia, cuando se compara con las especies del subgénero Passiflora, crea dudas sobre la validez de la reciente propuesta de reagrupar ambos subgéneros. El análisis de la diversidad morfológica en el subgénero Passiflora no mostró una clara estructura entre las especies estudiadas. En las series Quadrangulares y Lobatae, la agrupación de especies fue coherente, pero no para Incarnatae (separación de P. edulis y P. cincinnata) y Tiliifoliae (separación de P. maliformis). El estudio de P. edulis demostró una diferenciación geográfica limitada, pero muchas diferencias entre sus formas botánicas edidis y flavicarpa. Los datos de evaluación de los frutos no confirmaron la superioridad de una especie de curuba particular. El peso y la acidez de la fruta fueron similares para P. tripartita var. mollissima, P. tarminiana y P. cumbalensis. Los sólidos solubles totales fueron más altos en la última. A pesar de la variación limitada, unas pocas accesiones mostraron valores sobresalientes para estos parámetros. P. tripartita var. mollissima muestra susceptibilidad particular a la antracnosis, mientras que P. tarminiana muestra resistencia. Sus híbridos presentan frutos más pesados y una reacción intermedia. Sin embargo, el mejoramiento es recomendado primeramente al nivel intraespecífico. Los frutos de P. mixta son medianos en relación con los frutos de las especies cultivadas, pero su proporción de pulpa es equivalente.

L'ananas est cultivé dans tous les pays tropicaux et subtropicaux. La production commerciale repose essentiellement sur six variétés. Cayenne Lisse est devenu le pilier de l'industrie de l'ananas en raison de son potentiel de rendement et de ses qualités, tant pour le frais que pour la conserve. La culture de l'ananas a vraisemblablement débuté dans la région Nord de l'Amérique du Sud. Les objectifs de sélection principaux sont la résistance aux maladies, l'amélioration de la qualité du fruit, la recherche de variétés nouvelles. Les cultivars d'ananas étant des clones propagés végétativement, la sélection clonale est la principale méthode d'amélioration des génotypes cultivés. La culture in vitro de l'ananas ne présente pas de problèmes particuliers. Les programmes d'amélioration de l'ananas reposent sur des hybridations avec la variété Cayenne lisse.

Le genre Passiflora est le taxon le plus riche en espèces fruitières. Les espèces cultivées sont les maracujas, la grenadille de montagne, la barbadine, la passiflore à tiges ailées et le curubas. Les principaux objectifs de sélection sont la productivité, la qualité du fruit, la résistance aux maladies et l'adaptation climatique. Les techniques d'amélioration génétique sont fondées sur la reproduction sexuée, la culture in vitro et les techniques de manipulation du génome.

Up till now, pineapple breeding programs based on direct hybridisation have not been efficient in generating new cultivars, The high level of heterozygosity of the cultivars used for hybridisation and the great number of characters evaluated during the selection process have largely contributed to this situation. Heterozygosity can be reduced by selfing the parental varieties to be used for hybridisation. Inflorescences of 'Smooth Cayenne', 'Pérola', 'Perolera', 'Primavera' and 'Roxo de Tefé' were protected before flowering to ensure self-pollination. Seeds obtained were transferred to petri dishes with water agar as substrate, germinated in growth chamber, under 26 to 28°C, 16 hours photoperiod and 1600 lux of light intensity. One hundred and five seedlings were obtained from 'Roxo de Tefé', seven from 'Primavera', two from 'Perolera', two from 'Pérola' and none from 'Smooth Cayenne'. Thirty-one seedlings of 'Roxo de Tefé' were albinos and died after germination. Only 16 out of the 74 remaining seedlings of 'Roxo de Tefé' survived, all of them spiny, as their parent, 12 showing red leaves like the parent and four showing green leaves, thus expressing normal segregation for this monogenic trait. All the seven seedlings obtained from 'Primavera' had spineless green leaves as the parent. Both seedlings obtained from 'Perolera' have green leaves, one of them being spiny and the other spineless, The two seedlings obtained from 'Pérola' resembled their parent but they died during the nursery stage.

'Scarlett', a clone selected from a 'Smooth Cayenne' x 'Manzana' progeny was tested against 'Smooth Cayenne' in Martinique, following an experimental design composed of 50-plant plots, with four replications organised in bivarietal blocks, and repeated six times at a two-month interval. Planting material consisted of 300-350 g suckers, produced from 3,000 vitroplants of each cultivar. 'Scarlett' shows less vegetative development than 'Smooth Cayenne', as expressed in D leaf weight and suckering. The plant is more compact and erect, with completely smooth leaves. Fruits are smaller, which is partially compensated by a better response to floral induction, a much shorter production cycle and more uniformity in fruit weight. The crown is lighter but long and erect. Although peduncle is longer in 'Scarlett', lodging is less frequent than in 'Smooth Cayenne'. Fruit quality is much better, externally as well as internally, with a uniformly bright orange to red colour, a regular and cylindrical shape, flat and relatively large eyes, a uniform golden yellow firm flesh. Core is thinner and flesh texture is less fibrous and crispier. It is sweet and savoury, with a sugar content above that of 'Smooth Cayenne', and comparable acidity values. Ascorbic acid content is higher, The internal gradient of maturity is much less marked than in 'Smooth Cayenne'. Unfortunately, 'Scarlett' seems more susceptible to Penicilliumfuniculosum attacks. A proliferation of slips was observed, which seems to bc an effect of the preliminary in vitro multiplication phase.

Around 1990, 700 preselected 'Smooth Cayenne' x 'Manzana' hybrid clones were transferred from the breeding program in Côte d'Ivoire to Martinique, where a general objective of diversification and specialisation was emphasised, selecting either for the fresh fruit market or for processing. First evaluations, conducted along with multiplication, allowed to discard many clones on the basis of major defects, such as insufficient vigour, multiple crowns, fruit fasciations, recurrent spininess, fruit and fruitlet shape defects, fruit size and lodging, collar-of-slips and knobs, and pulp taste and quality. The remaining 205 clones were evaluated in 20 plant-plots, and compared with 'Smooth Cayenne' and an elite clone that was identified early in the selection process. Most of them showed good vigour and a shorter cultivation cycle, with high sugar content. However variation was still very important and many unfavourable traits were still observed. Twenty-nine clones presenting interesting character combination were selected. They generally showed good vegetative vigour and productivity with good yield and earlier fruiting than 'Smooth Cayenne'. Slip production was reduced by selection while suckering was comparable to that of 'Smooth Cayenne'. Shell and flesh maturation is uniform within the fruit. External colour is highly variable. Gustative quality has been improved in most hybrids, as their sugar content is higher than in 'Smooth Cayenne', while acidity is lower or equivalent. Ascorbic acid is also higher, with a wide variation, up to three or four times the values observed for 'Smooth Cayenne'. Hybrids often produce heavy fruits on long peduncles, which makes them susceptible to lodging. Most hybrids are susceptible to Penicillium funiculosum.

DNA variation was studied in 35 accessions representing 14 species of Passiflora subgenus Tacsonia (including five cultivated species), P. manicata (subg. Manicata), four species of subgenus Passiflora, P. trinervia (subg. Psylanthus), and P. alnifolia (subg. Decaloba). Two primer combinations were retained out of 24 tested. They generated 34 to 80 scorable bands per genotype, for a total of 260 bands on the whole sample. The five wild accessions of P. mixta showed higher polymorphism than those of the cultivated P. tripartita var. mollissima, P. sp'curuba india', and P. pinnatistipula. DNA fingerprints of P. x rosea clearly correspond to the superposition of the bands from its putative parents, P. tripartita var. mollissima and P. pinnatistipula. Cluster analysis is consistent with taxonomical classification into subgenera, with P. manicata intermediate between subgenera Tacsonia and Passijlora, but less so concerning Tacsonia sections. Within this subgenus, P. mixta, P. tripartita var. mollissima, P. sp'curuba india', and P. cumbalensis show particular affinity, as compared with P. pinnatistipula and less common species. Distances between Tacsonia and other subgenera appear limîted as compared to distances within Tacsonia, suggesting the use of other techniques to study the relationships between subgenera.

L'intérêt pour la diversité des fruitiers néotropicaux est lié à leur potentiel pour l'exportation, pour la reconquête d'un marché intérieur en pleine croissance, ou pour la diversification et le développement local grâce à de nouveaux produits, frais ou transformés, Les premiers travaux d'amélioration des fruitiers négligés, comprenant l'inventaire, la collecte, la conservation, la caractérisation et l'évaluation du germoplasme, s'organisent dans les réseaux écorégionaux. Dans le cadre de sa collaboration avec I'IPGRI, le Cirad-flhor appuie surtout les réseaux andin et amazonien, et participe à des projets de recherches sur passiflores, ananas et papayes. Parmi les premiers résultats sur passiflores, on compte l'identification d'une nouvelle espèce cultivée, le développement d'une méthode de conservation des semences par cryoconservation, l'obtention d'hybrides lnterspécifiques et la mise en évidence d'une faible variabilité des curubas cultivées en Colombie et en Equateur.

Isozyme variation was studied in 330 cultivated and wild accessions of banana passion fruit (#P. mollissima#),'curuba india,' (P. sp.), another cultivated type, and related species, #P. mixta#, 'rosy passion fruit' (#P. cumbalensis#), #P. pinnatistipula#, as well as #P. manicata#, from the Andes of Venezuela, Colombia and Ecuador. Six polymorphic enzyme systems (IDH, 6-PGDH, PGM, DIA, PRX, and ACP) revealed 54 zymotypes characterized by the presence or absence of 26 electromorphs. Polymorphism was much higher in the wild species as compared with the cultivated material. Cluster analysis allowed separation of the accessions into eight main groups, three of which correspond to particular types or species: 'curuba india,' #P. cumbalensis#, and #P. pinnatistipula#. Another homogenous group was formed by cultivated material of #P. mollissima#. Two groups were constituted by a mixture of #P. mollissima# and #P. mixta#, including intermediate phenotypes, one dominated by material of Colombian origin, and the other by material of Ecuadorian origin. #P manicata# formed a uniform group, except for two individuals that contributed to a small group with one #P. mollissima# plant. A greater distance appeared between the main #P. manicata# group and #P. pinnatistipula# on one hand and the other groups on the other hand. These results suggest a closer relation between #P. mollissima# and #P. mixta# than suggested by current taxonomical classification.

Multiplication of plant material. The planting program has been completed in Martinique. Vegetative multiplication is progressing, through traditional methods or micropropagation, in Brazil and Venezuela, where systematic evaluation should start in 1999. Agromorphological characterization and evaluation. In Martinique, the number of fully characterized and evaluated clones (96 descriptors) has reached 150. A first comparison shows consistency with results from molecular characterization. Nine promising clones have been multiplied for further field-testing, In Brazil, 49 wild clones or primitive cultivars have been characterized with 89 descriptors, while agronomic evaluation is in progress for 18 cultivars. In Venezuela, agromorphological has been initiated on 23 accessions. Molecular characterization. Screening for resistances. Inbreeding studies. Genetic mapping

From the first observations of the pineapple by European explorers to the classification into #Pseudananas sagenarius# and the seven #Ananas# species prevailing at present, the evolution of pineapple taxonomy has shown considerable variation. Most early botanists named or renamed species from previous dubious descriptions or from particular horticultural types. More recently, the genus #Pseudananas# was created, while horticultural types disappeared from the #Ananas# species. Subsequently, the total number of species increased again as botanical varieties and forms with minor variation were elevated to species rank. The resulting classification is questionable, as neither discontinuous morphological variation nor reproductive barriers exist in the genus #Ananas#.

Le genre #Passiflora# est le taxon le plus riche en espèces fruitières. Les espèces cultivées sont les maracujas, la grenadille de montagne, la barbadine, la passiflore à tiges ailées et le curubas. Les principaux objectifs de sélection sont la productivité, la qualité du fruit, la résistance aux maladies et l'adaptation climatique. Les techniques d'amélioration génétique sont fondées sur la reproduction sexuée, la culture in vitro et les techniques de manipulation du génome

L'ananas est cultivé dans tous les pays tropicaux et subtropicaux. La production commerciale repose essentiellement sur six variétés. Cayenne Lisse est devenu le pilier de l'industrie de l'ananas en raison de son potentiel de rendement et de ses qualités, tant pour le frais que pour la conserve. La culture de l'ananas a vraisemblablement débuté dans la région Nord de l'Amérique du Sud. Les objectifs de sélection principaux sont la résistance aux maladies, l'amélioration de la qualité du fruit, la recherche de variétés nouvelles. Les cultivars d'ananas étant des clones propagés végétativement, la sélection clonale est la principale méthode d'amélioration des génotypes cultivés. La culture in vitro de l'ananas ne présente pas de problèmes particuliers. Les programmes d'amélioration de l'ananas reposent sur des hybridations avec la variété Cayenne lisse