Male fertility in Musa: Pollen quality in diploid banana hybrids

Abstract

Banana production in the East African region is constrained by a variety of pests and diseases. Host plant resistance is the most convenient and effective intervention to circumvent these constraints in banana production. However, male fertility is a major limitation in the genetic improvement of bananas. Pollen quantity and quality are the key attributes in selecting male parents for successful banana crosses. Pollen was collected from 22 candidate diploid banana hybrids and 6 diploid genotypes previously, successfully used in breeding programs. It was examined for pollen quantity, staining with Iodine Potassium Iodide (I₂KI, Lugol stain), and germination frequency on a nectar-water medium. The traits under examination varied significantly (P≤0.05) among diploid banana hybrids. I₂KI-stained pollen frequency ranged between 12.96% for hybrid ‘12506S-1’ to 100% for ‘3162K-1’, while pollen tube germination frequency ranged from 1.67% on ‘2858K-5’ to 95.66% on ‘Calcutta 4’. Relative pollen quantity, I₂KI-stained pollen frequency, and pollen germination frequency were significantly, positively (P≤0.05) correlated. Five diploid banana hybrids, i.e. ‘12506S-29’, ‘Opp2-861’, ‘3162K-3’, ‘3146K-3’, and ‘3146K-2’, were selected as male parents to be incorporated into the breeding programs.