Binomen Art – Actinidia deliciosa (Kiwifruit)

Left: Kiwifruit Binomial Name Spelled With Seeds; Right: Kiwi Seeds Up Close, Remnants of Pollen Tubes Connecting Seeds to Central Axis

In May of this year (2013), we were in Piemonte driving near Saluzzo when we once again encountered the fields of kiwifruit, Actinidia deliciosa commonly grown in this area. When we were here in 2008, it was winter and we came upon some naked vines on a hillside behind Saluzzo and were amazed to find the ground littered with kiwi. This time, we were able to see the vines with their leaves. In a quick glance, the kiwi vines look similar to grape vines. The trick is to look at the leaves: rounded leaves means it's a kiwi.

According to fruit-crops.com, commercial cultivation of kiwi began in New Zealand in 1930 and eventually spread to other countries like Italy, France, United States, Chile and Japan.

The Food and Agricultural Organization of the United Nations gives the harvest area of kiwi in Italy at 1894 Ha in 1984. By 2011, the give the area as 24,930 Ha. That’s more than a 10 x increase. You can read more about kiwis in Italy in the story in the LA Times, Italy’s fuzzy logic pays off. The article (written in 2008) states that more that 80% of Italy’s kiwi production is exported. Kiwi production can leverage the grape-growing infrastructure already in place, yet earn more profit.

And to think that Italians have taken to the kiwi because the green color reminded them of the Italian flag! Speaking of color, the kiwi that is green inside (pericarp) that we typically see in the store is the Hayward variety. Kiwis come in other colors, but don’t seem to be as common at the Hayward.

Kiwi is in the Actinidiaceae family, also called the Chinese Gooseberry family. The family contains mostly temperate and subtropical woody vines, shrubs, and trees native to Asia, Central America, and South America. Quattrocchi says of the generic name:

Greek aktin “ray”, in allusion to the radiating styles.

If you cut the kiwi length-wise, you won’t see the “radiating” styles. A “style” is the middle part of the female part of a flower. It connects the ovary to the stigma.

Geek Part: In female kiwi flowers, the ovary is formed by the fusion of 26 - 41 carpels with each housing up to 40 ovules with an estimated total of 1400 - 1500 ovules per pistil. [1]. The more fertilization that occurs, i.e., pollen reaching ovules, the bigger the fruit. [2]. Go to the paper Pollen Tube Distribution in the Kiwifruit (Actinidia deliciosa A. Chev. C. F. Liang) Pistil in Relation to its Reproductive Process [3] to learn about pollen tubes, pollen tube distributor caps, and the effects of over and under pollination.

[1] Hopping ME. 1976. Effect of exogenous auxins, gibberellins, and cytokinins on fruit development in Chinese gooseberry (Actinidia chinensis Plunch.). New Zealand Journal of Botany 14: 69-75. online
[2] Guédés M, Schmid R. 1978. The peltate (Ascidate) carpel theory and carpel peltation in Actinidia chinensis (Actinidiaceae). Flora (Jena) Abt. B 167: 525-543
[3] Howpage, D, Vithanage V., Spooner-Hart, R.1998. Pollen Tube Distribution in the Kiwifruit (Actinidia deliciosa A. Chev. C. F. Liang) Pistil in Relation to its Reproductive Process. Annals of Botany 81: 697-703. online

Left: Kiwifruit Binomial Name Spelled With Seeds; Right: Generic Name, Actinidia


Left: Kiwifruit End Showing Pollen Tubes Entering Ovary (the Cup); Center: Radiating Locules From Central Axis; Right: Setup for Extracting Seeds


Left: Saluzzo 2008, With Kiwi Vines; Right: View from Saluzzo 2013, Looking Southeast Over the Plain (with Kiwi Vines)