Ornamental Banana (Musa ornata): Seed and seedless fruits

posted in: Plants | 2
Longisection of Musa ornata fruit without pollination.
Longisection of Musa ornata fruit without pollination. Scale in mm.

Banana plants are parthenocarpic, meaning that fruits are produced without pollination. As there is no fertilisation of the ovules, the fruits are seedless (above). Parthenocarpy (literally meaning virgin fruit) is the plant equivalent of parthenogenesis in animals (development of the embryo without the egg being fertilised, sometimes termed virgin birth).

Isolated stamens from male flowers with a Stingless bee collecting pollen.
Isolated stamens from male flowers with a Stingless bee collecting pollen.

In an earlier post, it was stated that Stingless Bees (Trigona sp.) may be the pollinating agent (above). However, as no seeds form in the fruits they visit (top), it is obvious that they are not effective pollinating agents . Furthermore, bagging the inflorescence to keep off these bees similarly result in fruits without seeds (below).

Musa ornata inflorescence bagged to keep  pollinating agents out.agents from
Musa ornata inflorescence bagged to keep out pollinating agents.

The Olive-backed Sunbird (Cinnyris jugularis) regularly visits the flowers for the nectar. Because their bill is a little too short to access the nectar if it is to probe from the top of the flowers, they resort to stealing nectar by probing the flowers around the base (below). As the bill does not make contact with the pollen, there is no pollination of subsequent flowers the sunbird visits.

Male Olive-backed Sunbird at ...
Male Olive-backed Sunbird at male flowers – note scar of earlier probe at the base of the flower on the right.

Artificial pollination by transferring pollen to the stigmatic surfaces of female flowers resulted in fruits bigger than the normal unpollinated ones (below).

Artificially pollinated fruits right and unpollinated fruits left.
Artificially pollinated fruits right and unpollinated fruits left.

The artificially pollinated flowers produce fruits packed with large, black seeds (below).

Fruit packed with seeds when flower was artificially pollinated.
Fruit packed with seeds when flower was artificially pollinated. Scale in mm.

YC Wee
Singapore
4th August 2017

2 Responses

  1. Hello WC: Mistake in title of posting: Musa ornata

  2. Corrected. Thanks Kim.

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