Ten Year Progression of Musa Breeding from 1987 to 1997: 1. Pollination Success and Seed Production (Fecundity) Patterns among Multiple Ploidy Crosses

Aims: To create genetic variability, produce seeds and ultimately develop disease resistant and agronomically desirable hybrids with good organoleptic quality bunches.

Study Design: Multiple hand pollinations/ crosses in possible combinations of 2x, 3x and 4x as maternal/ seed and paternal/ pollen parents.

Place and Duration of Study: International Institute of Tropical Agriculture High Rainfall Station (IITA), Onne, Rivers State, Nigeria. 1987 to 1997.

Methodology: Utilizing over 320 landraces, varieties, cultivars, clones/ genotypes and IITA accessions obtained from plantain and banana growing regions worldwide, scientists performed numerous hand pollinations/ crosses in possible combinations of 2x, 3x and 4x as maternal/ seed and paternal/ pollen parents every day.

Results: There were significant differences (P=.05) in number of seeds produced when diploids were used as maternal parents. Overall, 2x-2x produced 11times more seeds than the 2x-3x, and 54times more seeds than the 2x-4x. The 2x-2x crosses had double seed production maxima when crosses took place in June and July (8,300 seeds) and August and November (6,200 seeds) indicating a high level of fecundity. Only 2x-2x showed significantly positive correlation between seed production and pollination success (r = 0.617*). When triploids were maternal parents, there were significant differences (P=.05) in number of seeds produced. On average, 3x-2x produced 4times the number of seeds obtained from 3x-3x and 27times more than 3x-4x crosses. Seed production from triploids was 32times less than from diploids. The 3x-3x exhibited positively significant correlation between seed production and pollination success (r = 0.595*). With tetraploid maternal parents, there was significant difference (P=.05) in seed production when the male parent was diploid. High seed production (3,000-4,000) was achieved when pollination took place from June to October in the 4x-2x crosses. Seed production and pollination success in the 4x-2x were positively and highly significantly correlated (r = 0.865**).

Conclusion: In all crosses, diploid males produced the most seeds and pollination success increased as ploidy of maternal parent increased from diploid to tetraploid especially with diploid males.