Detailed time studies on the distribution of dry matter within a Musa spp. plants ' root and shoot system have not been done. Hence, the influence of genotype and developmental stage on the root system development, plant dry matter distribution and the shoot-root ratio of field grown Musa spp. plants was assessed in this study. Experiments were done at the International Institute of Tropical Agriculture Onne High Rainfall station, Nigeria in an ultisol soil. Plants were assessed at four weekly intervals for the diploid 'Calcutta 4' (Musa AA group) and the plantain 'Mbi Egome' (Musa AAB group). The 'Calcutta 4' plants were in vitro-derived, while the 'Mbi Egome' plants were sucker-derived. In addition, shoot-root dry matter ratio was assessed at flower emergence for seven Musa spp. genotypes including the dessert banana 'Valery' (Musa AAA group), the plantains' Agbagba ' and' Obino l'Ewai' (Musa AAB group), the cooking banana 'Cardaba' (Musa ABB group) and the plantain tetraploid hybrids 'TMPx548-9', 'TMP x 1658-4' and 'TMPx5511-2' (Musa group AAB x AA). There was an effect of type of planting material on the shoot-root ratio of plants in the vegetative stage. For example, juvenile in vitro-derived 'Calcutta 4' plants allocated up to 45% of dry matter to the root system. In contrast, less than 20% of plant dry matter was allocated to the roots of juvenile sucker-derived 'Mbi Egome' plants, while the corm contained up to 70% of plant dry matter. At flower emergence of the plant crop, the shoot portion of the mat (i.e. mother plant and lateral shoots) accounted for approximately 90% of the total dry matter. Thus, evaluation of the shoot-root ratio between similar genotypes should be done at the same morphogenetic age. In addition, variation in shoot-root ratio of the plant crop at flower emergence was observed between genotypes and within Musa groups. However, less variation in the shoot-root ratio was observed for the whole mat at flower emergence of the plant crop, indicating that there was a similar partitioning of dry matter between the mat shoot and root system for the Musa spp. landraces and hybrids. Breeding for a decreased mat shoot-root ratio, under similar environmental conditions, to enhance nutrient and water uptake and plant anchorage may thus be difficultLe detail de la distribution dans le temps de la matiere seche de racines et bourgeons deMusa spp. n 'a jamais ete etudie. Parconsequent, 1 'influence du genotype et le stage de developpement sur les systemes radicalaires, la distribution de la matiere ii:che desplantes, et le taux racines-bourgeons de Musa sur plante dans les champs ont ete evalues dans cette etud~. Les experiences ont etemenees a 1 'IITA station de precipitation elevee, Nigeria sur l' ultisol. Les plantes ont ete mesurees a quatre semaines d'intavalles surlediploide Calcutta 4 (Mussa AA groupe) et les plantains Mbi Egome (Musa AAA groupe )0 Calcutta 4 etait derive in vitro, alors queMbi Egome etait genere sur base de la souche. En plus, le taux de la matiere seche des bourgeons etait evalue a la floraison pour septgenotypes de Musa spp. incluant le dessert Valery (MusaAAA groupe ), les plantains Agbagba et Obino 1 'Ewai (Musa AAB groupe ),la banane destinee a la cuisson Cardaba (Musa ARB groupe) et les plantains tetraploides hybrides TMPx548-9. TMPxl658-4 etTMPx5511-2 (Musa groupe AAB x AA)o 11 y avait un effet du type de materiel plante sur le taux des racines des bourgeons dans laphase vegetative. Par exemple, lajeune plante de calcutta 4 deriveein vitro avaitjusqu'a 45% de la matiere seche des racineso Parcontre, moins de 20% de la matiere seche etait allouee aux racines des jeunes plantes derivees des souches de Mbi Egome, alors queles bulbes contenaient jusqu ' a 70% de la matiere secheo A la floraison, les bourgeons comptaient pour les 90% de la matiere secheapproximativement. Par consequent 1 ' evaluation du taux des racines-bourgeons devra etre faite au meme stage morphogenetique. Fnplus, une variation entre les taux de racines et de bourgeons avait ete observee entre genotypes et entre les groupes de Musa sppoCependant, les variations dans le taux racines-bourgeons de mats a la floraison des plantes, indiques qu'il y avait une partitionequitable de la matiere seche entre les mats et le systeme racines-bourgeons pour les races locales et hybrides de Musa spp. Transformation pour un tanx decroissant raciness-bourgeons, dans les meme conditions environnementales, pour ameliorer le prelevement des nutriments et l' eau par les plantes et leur ancrage serait difficile.

Banana; Plantain; Plant Production; Knowledge Management; Crop Systems

Assimilate Partitioning; Musa Spp.; Shoot-Root Ratio; Assimilation Des Plantes; Musa Spp.; Taux Racine-Bourgeons

Africa; West Africa

Nigeria