Reproduction

We typically do not think about plant reproduction but this is the reason I was able to choose the organism for this project. The reproduction phase of the Actinidia deliciosa is what creates the fruit that we eat.
 
The fruits from the vines are only possible because kiwifruit is an angiosperm. As described on the adaptations page, this means that the plant provides protection for the ovules and seeds which later become the fruit but the process begins with pollen.
 
A. deliciosa is dioecious which means that there is only one sex found on each plant and only female plants can bear a fruit if pollinated by a male. Pollen is the male gametophyte that is presented on the anther of a kiwifruit flower.
 
In order for reproduction to progress, the flowers need to be open. The kiwifruit flowers for several weeks in May and June. The males produce useful pollen grains for only the first two to three days after opening while the females are able to receive pollen for seven to nine days after opening. This allows for the chances of pollination to increase, resulting in greater reproduction success.  
 
Pollination is a very important aspect of this concept. The insects in the area, being attracted to the flower (described in adaptations), pick up the pollen grains when they land on the flower and transport them to other flowers. This process can also be accomplished via wind pollination. In either case, the pollen grain is deposited on the stigma where, through a series of events, fertilizes the female gametophyte which sits within the ovary.
 
If pollination and fertilization are successful, there is a period of rapid embryo growth. This initial phase is what determines the shape and size of the fruit. The ovary of the flower, now containing the growing embryo continues to progress and eventually develops into the brown, hairy fruit that we eat. The fruit development phase is actually particularly long, taking most of the summer months.

 The diagram below shows the complete life cycle of an angiosperm.
 

The kiwifruit that is produced is typically two inches in length and oblong or oval in shape. As seen, the skin of the fruit is russet-brown and covered in a thick layer of fine but stiff hairs. The inside of the fruit consists of bright green flesh and a thick white or cream center.
 
The tiny black seeds that surround the center can be replanted and if germination occurs, will produce a mature vine. This new vine can then repeat the process and produce more fruits and seeds.
 
The habitat page touched on some of the conditions needed for successful reproduction. Sunlight is needed for photosynthesis to occur which provides enough energy to produce the egg, pollen and flower. A moist soil is necessary to provide the plant with enough water to produce and grow as well.
 
The reproduction of A. deliciosa is extremely intensive and energy costly but if successful, will produce a fruit to continue to generate more plants or to provide energy for other organisms. These relationships are continued on the next page, interactions.

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