Physicochemical and microbiological characteristics of kitoza, a traditional salted/dried/smoked meat product of Madagascar

Kitoza samples collected from producers in Madagascar were analyzed for their physicochemical and microbial properties. Lactic acid bacteria and coagulase‐negative staphylococci were the two codominant populations with average counts of 6–7 log cfu/g. Good hygienic practices were sometimes lacking but samples were not contaminated with Salmonella, Clostridium perfringens, and Bacillus cereus and only once with Listeria monocytogenes. Staphylococcus aureus was found occasionally with higher counts in salted/dried products than in salted/smoked products. Moisture, protein, fat, and salt contents varied considerably and were on average 41.5, 43.5, 14.3, and 3.3 g/100 g, respectively, and water activity was 0.893 on average. Smoked kitoza showed higher moisture content compared to dried kitoza. Most of the smoked kitoza had a water activity higher than 0.9 which is not in accordance with their storage at ambient temperatures. Benzo(a)pyrene content was above 2 µg/kg in 11 out of 30 smoked samples (17 ± 16.5 µg/kg on average)

Dioscorea orangeana (Dioscoreaceae), a new and threatened species of edible yam from northern Madagascar

International audienceA new species of yam (Dioscorea orangeana Wilkin) is described and illustrated. It differs from D. comorensis R.Knuth by having undulate leaf margins and a broader torus and tepals in both the male and female flowers. In female flowers of D. orangeana the floral stipe between the ovary and the torus is shorter than in D. comorensis. The tuber morphology of the species is atypical among Malagasy species in that there are several digitate lobes rather than a single tuber per growing season, although more research is needed on tuber morphology. D. orangeana is reported to be edible. It is endemic to the Forêt d'Orangea near Diego Suarez (Antsiranana) in Antsiranana Préfecture. Its conservation and sustainable use are thus matters of concern

Grass survey of the Itremo Massif records endemic central highland grasses

Despite the substantial area covered by grasslands in Madagascar (65%), the taxonomy of the grasses (Poaceae), which represent the main plant component of these vegetation types, is still understudied. Inventories and detailed specimen identification work from 1 2 localities in the Itremo Massif Protected Area allowed us to compile a list of grasses present in the area. In total, members of eight subfamilies, 56 genera, and 99 species have been recorded from the Itremo Massif. Grasslands cover 75% of the Itremo Massif Protected Area and are dominated by Panicoideae (65%) and by C4 plants. The genera Eragrostis and Panicum, with nine and eight species respectively, are the best represented genera in Itremo. Eragrostis betsileensis and Tristachya betsileensis are the two species known to be local endemics. Twenty species are endemic to the central highlands, and a further 1 4 species are restricted to Madagascar. Five ecological groups of grasses were identified in the Itremo Massif: shade species in gallery forests, open wet area species, fire grasses, anthropogenic disturbance associated grasses and rock-dwelling grasses. Grasslands of the Itremo Massif are likely to be at least partly natural as shown by their richness in terms of endemic and native grass species. Conservation of such grasslands is thus an important issue, not only for grasses but for all species that inhabit these open canopy habitats

Diversity of aphyllous Vanilla species in the south-west Indian Ocean region: a challenge for orchid taxonomy, evolution and conservation research

The pantropical genus Vanilla is a member of the Orchidaceae family, one of the largest and most ancient families of angiosperms in the world. It originated in America and differentiated in America, Africa and Asia. About 126 species of Vanilla have been catalogued since the discovery of the genus: 25 can be found in Africa, 31 are indigenous to Asia, New Guinea and Pacific islands, and 70 are distributed in tropical America. The south-west Indian Ocean (SWIO) region, a biodiversity hotspot for orchids, is home to 9 native species of the genus with 7 aphyllous species and 2 leafy species. These 7 aphyllous are represented by two species with yellow flowers (V. humblotii, V. perrieri) and five species with white flowers (V. madagascariensis, V. bosseri, V. decaryana, V. phalaenopsis, V. roscheri). Recent molecular phylogenetic studies showed that these aphyllous species form a recent monophyletic group. Morphological descriptions of these aphyllous species in databases (MNHN, RBG Kew, Tropicos..) and in scientific publications are based on a limited number of individuals. The morphological traits (petals, sepals, label, and stems) are very similar between species and do not provide reliable identification despite possible flower size differences. Moreover, the species have more or less the same flowering period (October-December) and their geographical distribution areas overlap in Madagascar, increasing the probability of finding some sympatric species such as V. madagascariensis, V. bosseri and V. perrieri, and therefore possible hybrids. As the available information on genetic structuring and phylogeny of these species is insufficient, the resolution of their taxonomy is problematic. Aphyllous Vanilla species from the SWIO islands are thus an excellent model for understanding the evolution of orchids. For their conservation and to confirm the identity of these aphyllous species, an integrated approach with classical taxonomy using a large number of samples, intense fieldwork on biology and ecology, and molecular studies using variable markers is currently underway

Impacts du type de sol, d’un cyclone dévastateur et d’une plante pionnière envahissante sur la diversité des ligneux d’une forêt pluvieuse malgache de basse altitude

Impacts du type de sol, d'un cyclone dévastateur et d'une plante pionnière envahissante sur la diversité des ligneux d'une forêt pluvieuse malgache de basse altitude. - Deux relevés de toutes les plantes ligneuses (diamètre ≥ 5 cm) ont été effectués en octobre 2005 dans la Réserve Spéciale de Manombo (forêt de basse altitude, au sud-est de Madagascar), l'un sur une parcelle (50 × 50 m) sur sable blanc, l'autre sur une parcelle (50 × 48 m) sur sol ferralitique d'origine volcanique (basaltique). La forêt sur sol sableux est utilisée par les villageois tandis que la parcelle sur sol basaltique, qui a subi peu d'action anthropique (sauf la disparition des lémuriens), fut dévastée par un cyclone en janvier 1997 et se trouve envahie par l'espèce pionnière introduite Cecropia peltata. On compte 37 espèces pour les 453 tiges de la parcelle sur sol sableux et ca 145 espèces pour les 777 tiges de la parcelle sur sol basaltique. La composition floristique diffère bien davantage entre ces deux parcelles qu'entre les relevés effectués sur des parcelles de 50 x 50 m dans les Réserves Spéciales d'Analamazaotra (à 1 000 m d'altitude) et d'Ambohitantely (à 1 500 m d'altitude) éloignées l'une de l'autre de 200 km. La diversité des espèces ligneuses de la parcelle de Manombo sur sol basaltique non seulement n'a pas été diminuée par le passage du cyclone mais, qui plus est, les espèces d'origine de cette forêt sont en train de surcimer et vont probablement remplacer l'espèce envahissante Cecropia peltata

Sites à Lémuriens sacrés en pays Sakalava, au nord-ouest de Madagascar : réactualisation des données et implications dans les programmes de développement et de conservation

The two sites in northwestern Madagascar, where Ramanantsoa (1976) observed sacred lemurs, were revisited in order to assess the present status of Eulemur macaco and the possible impact of human beliefs and practices on conservation. All the sacred relationships towards lemurs described in 1976 are still in practice, and very similar descriptions about the benefic (or malefic in case of non-respect) effect of the sacred lemurs have been quoted by our informants. A direct impact on lemur conservation, and utilisation of study sites for scientists, as suggested by G.-A. Ramanantsoa, do not appear as realistic options, considering the remote location of both sites. In contrast, a further study of religious practices concerning lemurs should he an important contribution for shaping sustainable development programmes involving local populations.The two sites in northwestem Madagascar, where Ramanantsoa ( 1976) observed "sacred lemurs", were revisited in order to assess the present status of Eulemur macaco and the possible impact of human beliefs and practices on conservation. Ali the sacred relationships towards lemurs described in 1 976 are still in practice, and very similar descriptions about the benefic (or malefic in case of non-respect) effect of the "sacred lemurs" have been quoted by our informants. A direct impact on lemur conservation, and utilisation of study sites for scientists, as suggested by G.-A. Ramanantsoa, do not appear as realistic options, considering the remote location of both sites. In contrast, a further study of religious practices conceming lem urs should be an important contribution for shaping sustainable development programmes involving local population

Adaptations and evolution of a heritable leaf nodule symbiosis between Dioscorea sansibarensis and Orrella dioscoreae

Various plant species establish intimate symbioses with bacteria within their aerial organs. The bacteria are contained within nodules or glands often present in distinctive patterns on the leaves in what is commonly referred to as leaf nodule symbiosis. We describe here a highly specific symbiosis between a wild yam species from Madagascar, Dioscorea sansibarensis and bacteria of the species Orrella dioscoreae. Using whole-genome sequencing of plastids and bacteria from wild-collected samples, we show phylogenetic patterns consistent with a dominant vertical mode of transmission of the symbionts. Unique so far among leaf nodule symbioses, the bacteria can be cultured and are amenable to comparative transcriptomics, revealing a potential role in complementing the host’s arsenal of secondary metabolites. We propose a recent establishment of a vertical mode of transmission in this symbiosis which, together with a large effective population size explains the cultivability and apparent lack of genome reductive evolution in O. dioscoreae. We leverage these unique features to reveal pathways and functions under positive selection in these specialized endophytes, highlighting the candidate mechanisms enabling a permanent association in the phyllosphere