Performance evaluation of secondary triploid Musa hybrids from in-vitro and ex-vitro derived propagules

Abstract

This experiment was carried out at the High Rainfall Station of the International Institute of Tropical Agriculture (IITA) in Onne, Rivers State, Nigeria, to investigate if secondary triploid plantains established using in-vitro excised zygotic embryo propagules and tissue culture will differ significantly from those established by using ex-vitro propagules such as seeds obtained from open or hand pollinated parents. Seeds of secondary triploid plantain hybrids were obtained by crossing tetraploid female hybrids TMP4x 2796-5 and TMP4x 4698-1 by hand pollination with pollen from known diploid males TMP2x 1297-3 and TMP2x 1448-1. Another set of these female hybrids were exposed to open pollination. At maturity, seeds from ripened mature fruits from both methods of pollination had their zygotic embryos extracted and cultured in-vitro. Another set of seeds were grown ex-vitro in the soil. Both in-vitro and ex-vitro derived propagules obtained from open and hand pollinated parents were raised in the tissue culture laboratory and the nursery respectively. Three replications of the 12 treatments of eight-week-old secondary triploids were planted in the field at 3m x 2m spacing using an RCB (randomized complete block) design. Data collected were: number of days to 50% flowering (DTF), time to fruit filling (TFF), plant height and number of leaves at 50% flowering, bunch weight, number of hands/bunches, fingers/ bunch and total yield. Collected data were analysed using ANOVA in RCB design at (P = 0.05) while means were compared with Duncan’s Multiple Range Test at (P = 0.05). Inconsistent individual genotypically significant differences were found in some phenological and vegetative characters, yield constituents and total yield between ex-vitro and in-vitro derived secondary triploids indicating no definitive pattern in responses of the secondary triploids. However, only days to flowering (DTF) showed consistent significant notable differences out of all these traits. Generally, the ex-vitro derived secondary triploids flowered significantly later than in-vitro derived ones. The secondary triploids from open pollinated parental crosses flowered significantly earlier than those obtained from the hand pollinated parental crosses.