The formation of the seed is part of the process of sexual reproduction, which involves the fertilization of an ovule located inside the portion of the female flower called the gynoecium by pollen produced by male flowers.
In dry mature seeds, the hard, leaky outer layer of the coat the outer integument acts like a cage, while the thin inner layer of the coat the inner integument , which is lined with a cuticle, is impermeable to water and provides an almost complete envelope surrounding the embryo and endosperm. Only wild species of bananas — and under certain circumstances cultivars that have residual fertility — produce seeds.
The seed, like the one of the wild species, Musa balbisiana , has an extremely durable, wrinkled coat, the only opening of which is sealed by a shortened conical micropylar plug, also called an operculum see figure. The seed coat consists of a thick hardened, but leaky, outer integument, and a thin inner integument, on the inner surface of which is a thick cuticle. Seeds of wild bananas are usually less than 1 cm in diameter 1. The seed has two chambers: the larger one containing the endosperm and the embryo, and the smaller one the chalazal mass.
Apart from a small discontinuity of parenchymatic tissue, the chambers are separated by the inner integument and cuticle. At the micropylar end, the inner integument projects into the micropylar canal 2 , forming a cap to the larger chamber. While size, colour and shape varied, a study of 20 species of wild and edible bananas found this basic seed structure and anatomy in all of them 5.
The chalazal mass, which in fresh seeds was observed to be "full of water", shrivels upon drying 5. The basic external requirements for germination are water, oxygen and an appropriate temperature.
The germination of a seed begins with water uptake imbibition , followed by embryo expansion along its axis through cell elongation, and ends with the breaking-through of the seed coat by the embryo root radicle , then shoot plumule.
In the banana seed, the endosperm disappears within two weeks and within three weeks, the seedling has a lateral root system, and a prominent shoot 6 , in which the first leaves have elongated beyond the cotyledonary sheath 7.
By the fourth week, the seedling is dependent on the root system for inorganic nutrition 6. Water must enter the chamber containing the embryo and endosperm before germination can occur. Experiments have shown that the seed's outer integument is leaky since rupturing the outer integument of Musa acuminata seeds by sandpapering did not increase the absorption of water.
Where, and under what circumstances, water penetrates the inner integument is unknown. In many non-banana species it happens via water gaps 9. In bananas, water gaps might develop around the micropylar plug 10 , or in the area of the chalazal mass, where the inner integument is discontinuous, and parenchymatic tissue separates the outer and inner chambers 2. The structure of the banana seed with its leaky outer integument means that the seed imbibes but the embryo and endosperm might not absorb water because of the impermeable inner integument and non functional water gaps.
While seeds will not germinate without imbibing water, imbibition does not necessarily lead to germination. Non-viable seeds, for one, will not germinate. Seed viability in a narrow sense refers to viability of the embryo, but it can be extended to include absence of the embryo or the endosperm, or absence of a functional connection between the embryo and endosperm. A seed has one living component, the embryo. To germinate, not only does the embryo have to come into contact with water, the seed also has to be non-dormant.
Rinse your harvested seeds in warm running water to remove any remaining banana flesh, then place them into a small collection bowl lined with a paper towel to air dry. Jeffrey Brian Airman is a writer, musician and food blogger. A year veteran of the restaurant industry, Airman has used his experience to cover food, restaurants, cooking and do-it-yourself projects. Airman also studied nursing at San Diego State University.
Share this article. Tip The popular yellow banana variety know as the Cavendish contains small remnants of undeveloped seeds. Warning Bananas need to grow under very strict environmental conditions and may not thrive in every garden.
The banana flower appears in the sixth or seventh month. Unlike other fruit like apples which have a growing season, bananas are available all year round. Most bananas exported are grown within 30 degrees either side of the equator. The plants need rich, dark and fertile soils with steady moisture in the air and ground and good drainage.
Banana plantations are predominantly found in Latin America. They require huge investment in infrastructure and technology for transport, irrigation, drainage and packing facilities. On the other hand, in the Eastern Caribbean, farmers tend to use smallholder production. This system is less capital intensive and more labour intensive, and is present because the physical features of the area mean it is not possible to use the plantation system.
Growing bananas is, in general, labour intensive. It involves clearing jungle growth, propping of the plants to counter bending from the weight of the growing fruit, and irrigation in some regions.
As well as an intensive use of pesticides, the conventional production process involves covering banana bunches with polyethylene bags to protect them from wind, insect and bird attacks, and to maintain optimum temperatures. At the packhouse they are inspected and sorted for export. Buyers of fruit in the UK want unbruised bananas and so very high standards are set.
If the bananas do not meet these standards they are usually sold locally at a much lower price. In order to increase shelf life, they are transported at a temperature of Humidity, ventilation and temperature conditions are also carefully monitored in order to maintain quality.
When the bananas arrive at their destination port they are first sent to ripening rooms a process involving ethylene gas and then sent to the shops. Bananas and other tropical fruit like pineapples are grown in the tropical regions of Africa, Latin America, the Caribbean, and the Pacific. The fruit represents an important source of income for these countries.
In recent years, Guatemala has expanded rapidly to overtake Colombia in export volumes. Typically, Central American bananas are grown on large-scale monoculture plantations covering several hundred hetares each.
This form of production uses high levels of chemical inputs to increase crop yield. Labour conditions can be very poor, with workers required to work long hours for wages that are insufficient to meet basic needs. The large plantations are also frequently responsible for damaging environmental impacts.
Ecuador , Colombia and Peru are the only countries among the major Latin American exporters that still have small banana farmers exporting alongside the large-scale plantations. Across South America, and especially in Peru, some 10, small farmers sell to the world market, often thanks to organic and Fairtrade certification. In Ecuador, the smallholders often fulfil a kind of buffer function for the big banana exporters: they buy from small producers when the demand on the international market is high, but if there is less demand, the small producers are often forced to sell their produce at a loss.
The largest Caribbean exporting country, the Dominican Republic, has a mix of small farmers, medium-scale and even a handful of large-scale plantations, although around two thirds are produced organically. The banana trade has been crucial to the economies of the Caribbean region. Banana plantations were established over 60 years ago by the British. Although most Windwards bananas are produced under Fairtrade conditions , the volumes are now too low to have the same positive effect on rural communities that they had for the first decade of the 21st century.
Fleshy bracts, purplish-to-greenish in color, eventually shed and give way to the first flowers that are functionally female. Edible cultivars like the ones listed above have fast-growing ovaries that develop without pollination into clusters of fruits, some of which can produce seeds. The last flowers, functionally male, come next. When you plant rhizomes, the time from shooting to fruiting is typically days depending on the cultivar, temperature, and the moisture of the soil.
When grown from seeds, expect to wait 14 months or more. Grant, Amy. Com , 29 Jan. Williamson, Lauren. Au , 26 Nov. Accessed 5 Aug. Mehta, P. Actively scan device characteristics for identification. Use precise geolocation data. Select personalised content. Create a personalised content profile. Measure ad performance. Select basic ads. Create a personalised ads profile. Select personalised ads.
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