Introduction. The worldwide production of banana and plantain, which is estimated to 106 Mt·year–1, relies on a narrow genetic basis. Thus, banana production is fragile regarding emergent diseases, and creation of new varieties of banana stands out as a real necessity for its sustainability. In banana, various improvement strategies aim to create triploid hybrids. The objective of this report is to present a simple in vitro methodology to induce stable tetraploid plants by colchicine treatment, usable as parent for obtaining triploid varieties. Materials and methods. Twenty-one diploid M. acuminata clones and three interspecific M. acuminata / M. balbisiana diploid clones were treated as proliferating culture in liquid medium with 1.25 mM of colchicine for 48 h. Plant screening has been performed by morphological identification in greenhouse, chromosome counts on root tips and flow cytometry on leave blades on vitroplants using propidium iodide staining. Results. Chromosome counts led to distinguish diploid and tetraploid plants but did not afford to detect chimeras. Flow cytometry allowed an early screening of a larger number of plants leading to detect rapidly chimerical plants. It was observed that some stable 2x / 4x cytochimeras are periclinal. Tetraploid clones were obtained with all diploid genotypes. General behaviour of tetraploids in the field was globally weaker than the corresponding diploids. Nevertheless, all the doubled-diploids flowered and crossed with diploid plants to obtain triploid progenies. Conclusion. This study has clearly shown that induction of stable doubled-diploid plants can be obtained from a wide range of genetically different bananas. These results open the way to the systematic use of doubled-diploids by banana breeding programs for the release of enhanced triploid varieties.

Introduction. The technology for citrus rootstock production through improved sowing methods and fertilizer inputs offers greater opportunity in the certified citrus plant production system. Our work evaluated the influence of seed coat removal and different controlled-release fertilizer concentrations on plant emergence and plant growth of two citrus rootstock cultivars. Materials and methods. Decoated and not decoated seeds of Rangpur lime (Citrus limonia Osbeck) and Swingle citrumelo [Citrus paradisi × Poncirus trifoliata (L.) Raf] were sown in 50-cm3 tubes. Fertilizer concentrations were (0, 1, 2, 3, 4 and 5) kg·m–3 of controlled-release fertilizer (NPK 19-06-10) incorporated into the substrate. The experimental layout followed a randomized block design with 2 × 6 factorial (seed coat removal × fertilizer concentration) for each rootstock. Results and discussion. Seed coat removal resulted in faster plant emergence and higher dry weight for both rootstocks. Vegetative growth increased with controlled-release fertilizer concentrations.

Introduction. In São Paulo State in Brazil, there is a demand for pear tree varieties that present fruit complementary characteristics and high adaptation for a subtropical-tropical climate. Thus, our study aimed at evaluating variety selections with better fruit quality and mainly adapted to the different areas of the São Paulo State. Materials and methods. Crosses among Asian [Pyrus pyrifolia (Burm.f.) Nakai] and European (P. communis L.) pear cultivars were made in Brazil from 1992 to 1998 aiming at finding new pear types for subtropical areas of the country. The first interspecific hybrids of the IAC pear breeding program were planted in various regions of São Paulo State, at latitudes from 21° 11’ S to 24° 11’ S and (11 to 200) chilling units (CU). About 20 phenological characteristics were evaluated. The hybrids and their parents were genetically characterized through RAPD markers. Results and discussion. In the progeny of ‘Okusankichi’ × ‘D'água’, the mean age for the first bearing and fruit development period (FDP) were 3.8 years and 137 days, respectively. The fruit characters early ripening, rounded shape, russet-brown skin and crisp flesh were dominant in all crosses of Asian × Asian and Asian × European pear trees. Twenty-six hybrids were selected, of which twelve are still being tested in a subtropical-tropical climate (0–80 CU). Their main characteristics are fruit with rounded, oblate, oblong or pyriform shapes, russet-brown or green skin, and crisp or soft flesh, and plants with medium-high vigor, an upright-spreading form and a fruit development period of from (110 to 160) days. Conclusion. The precocity of hybrids is highly dependent on the parental characteristics and the environmental conditions. A fruit development period close to that of the earliest parent was obtained. In F1 generations from crossings among Asian and European pears, certain characteristics were dominant. The RAPD analysis was efficient at identifying cultivar genotypes, selections and hybrids of pear from different botanical groups.

Introduction. Breeding studies for acerola (Malpighia glabra) improvement aim at obtaining plants that produce fruits with uniform chemical and physical attributes, including high levels of vitamin C, which can provision the market with fresh fruit and frozen pulp. High variability in fruit quality is observed in Brazilian acerola crops, especially those propagated by seeds. In this context, the objective of our research was to evaluate the physical and chemical characteristics of Brazilian acerola genotype fruits. Materials and methods. Sixteen acerola genotypes were studied in Jaboticabal, São Paulo State, Brazil. A completely randomized design with sixteen treatments and six replications was adopted. Each treatment was represented by one genotype. Several parameters related to fruit quality, such as width, length, weight, pulp percentage, soluble solids (SS), titratable acidity (TA), [SS / TA] ratio and vitamin C content, were evaluated in fruits of the acerola genotypes. The results were submitted to variance analyses, the Tukey test and cluster analysis. Results and discussion. There was a statistical difference between the acerola genotypes studied. Three of them stood out as natural sources of vitamin C. In spite of fruit size, two acerola genotypes were found to have potential for fresh fruit production. In a general form, genotypes that presented a high [SS / TA] ratio had low vitamin C content. Conclusion. The acerola genotypes studied in Jaboticabal presented high variability, forming eleven groups in relation to fruit quality parameters.

Introduction. Insect pest identification and understanding of insect pest ecological relationships constitute a basic step for any control measure needed. Some native fruit trees occur naturally in southern Mozambique and the edible fruits are sought after by local communities. Our study aimed at assessing the activity of native fruit tree insect pests during the year and their ecological relationships, providing, for the first time, a faunistic analysis of insect species affecting fruit trees in the region of Maputo, Mozambique. Materials and methods. Entomological surveys were carried out between June 2002 and December 2003 in the Districts of Manhiça, Marracuene, Namaacha and Matutuíne (southern Mozambique). Quadrangular 900-m2 plots were established in fields where Annona senegalensis, Garcinia livingstonei and Vangueria infausta native fruit trees naturally occurred. The number of individual insect pests per fruit, tree and plot was recorded to estimate ecological fauna measurements: the affinity index, association index and simultaneous constancy. Results and conclusion. A total of 1648 insect specimens, belonging to eight insect species, were found while conducting the ecological observations on Annona senegalensis Pers (Annonaceae), Garcinia livingstonei T. Anders (Clusiaceae) and Vangueria infausta Burch (Rubiaceae). Two groups of pests were observed: defoliators and insects attacking the fruits, which represented the majority. Affinity between insect species was observed, with the relationship between Ceratitis capitata Wiedemann and one unidentified species of the Cosmopterigidae family reaching the highest values. C. capitata was also found to have the highest association index with Spatulipalpia monstrosa Balinsky (Lepidoptera: Pyralidae), as well as Carpophilus sp. (Coleoptera: Nitidulidae) and Araecerus sp. (Coleoptera: Curculionidae). C. capitata and Araecerus sp. had the highest simultaneous occurrence in different locations. Cluster analysis also indicated that Ceratitis capitata and Carpophilus sp. had the highest similarity percentage in all samples.

Introduction. Le rythme de croissance des végétaux ligneux est un critère essentiel dans l'établissement de l’architecture de l'arbre et, par conséquent, le port futur de l’arbre. Nous avons réalisé une étude portant sur une analyse dynamique de la croissance primaire et secondaire de l’olivier, tout au long d’une saison de végétation. Matériel et méthodes. La croissance de méristèmes terminaux d’oliviers issus de semis a été suivie. L’étude a porté sur la croissance primaire (allongement et édification de métamères) et sur la croissance secondaire (diamètre basal) de différents types de rameaux. Cette croissance a été modélisée, ce qui nous a permis de développer des courbes de modèles théoriques. Résultats. Les croissances relatives primaire et secondaire ont été caractérisées par des courbes en triple sigmoïde, indiquant trois vagues de croissance principales : deux printanières et une automnale. Elles ont été modélisées par des équations théoriques à neuf paramètres et trois logistiques. La validité de ces modèles a été vérifiée par certains critères de performance des modèles, dont la racine carrée de la moyenne des carrées des erreurs et le critère du maximum de vraisemblance. Conclusion. Le caractère rythmique de la croissance l’olivier a été confirmé.

Introduction. The mango tree is one of the most widespread fruit trees in West Africa. A history of its introduction into that area was recently published. To follow upon this document, the presented analysis was devoted to the principal varieties that are cultivated there today and to the impact of the historical and commercial factors on the varietal composition of the orchards. Some definitions. In precondition to an inventory of the varieties, certain terms making it possible to characterise them were specified (precocity, monoembryony and polyembryony) and some information on the origin of the Floridian varieties was provided. Principal varieties cultivated in West Africa. Four mango variety categories were distinguished: varieties of local or polyembryonic mangos (mangots and Number One), first monoembryonic varieties propagated by grafting (Amélie, Julie, Sabot, Djibelor and Cuisse Madame), and the Floridian varieties, also monoembryonic and propagated by grafting, introduced later and used either for export (Kent, Keitt, Palmer, Zill, Valencia, Smith, Irwin and Haden), or for the regional markets (Brooks, Davis-Haden, Miami Late, Springfels, Beverly, Eldon and Ruby). Each variety was described, like its farming characteristics and its outlets. The composition of the grafted mango tree orchards. This composition is influenced by the historical evolution and the purpose of the fruits that can be eaten, sold on the local, national or subregional market, exported toward the international market or processed in artisanal or industrial units. This orchard composition was specified for Guinea, Mali, Burkina Faso, Côte d’Ivoire, Senegal and Togo.