o7

http://en.wikipedia.org/wiki/Cloning#Organism_cloning

"The term clone is used in horticulture to refer to descendants of a single plant which were produced by vegetative reproduction or apomixis. Many horticultural plant cultivars are clones, having been derived from a single individual, multiplied by some process other than sexual reproduction.[13] As an example, some European cultivars of grapes represent clones that have been propagated for over two millennia. Other examples are potato and banana.[14] Grafting can be regarded as cloning, since all the shoots and branches coming from the graft are genetically a clone of a single individual, but this particular kind of cloning has not come under ethical scrutiny and is generally treated as an entirely different kind of operation."

potatoes and bananas have both had problems... certain cultivars of bananas I read a few years ago were having issues.Apparently, a type of banana that was popular in the past is now extint or far less widespread -- I got the impresion that the bananna referred to in any literature of the time is actually a different banana than we commonly eat today. In the grocery stores around here there are typically 4 kinds of banana, the commonly eaten iconic yellow type, the plantains, these little bitty guys, and red bananas. Its the iconic yellow sort that is having the problem. Can't remember what it is -- probably a disease, might ahve been fungal.

I think the Great Irish Potato Famine was probably also related to this lack of genetic diversity thing.

"The proximate cause of famine was a potato disease commonly known as potato blight."
http://en.wikipedia.org/wiki/Great_Famine_%28Ireland%29

"The highlands of central Mexico is considered by many to be the center of origin of P. infestans, although others have proposed its origin in the Andes, which is also the origin of potatoes.[8][9] Migrations from Mexico to North America or Europe have occurred several times throughout history, probably linked to the movement of tubers."

Movement of infected crops is a major cause of parasitic/pathogen invasive species dispersal. This is why moving fire wood from one state to another is a /terrible/ idea, and why crop inspectors come to look at a farmers' crops to check for infestations of problem species. If the crops is trees, in a nursery or orchard, the nearby/edge of nearby woods are also checked for pests.

http://en.wikipedia.org/wiki/Potato_blight

"Breeding for resistance, particularly in potato, has had limited success in part due to difficulties in crossing cultivated potato to its wild relatives, which are the source of potential resistance genes."

"Many old crop varieties, such as King Edward potato are also very susceptible but are grown because they are wanted commercially."

"New varieties such as Sarpo Mira and Sarpo Axona show great resistance to blight even in areas of heavy infestation."
New. Probably the disease has not addapted to better feed on them.

"Researchers have found the wild potato species Solanum verrucosum to resist the late blight disease. They aim to make cultivated potatoes resistant to late blight by crossing the wild, resistant strain with the vulnerable, cultivated strain."

Here is the bottom line, and why genetic diversity in food crops is extremely important:

"Implicated in Ireland's fate was the island's disproportionate dependency on a single variety of potato, the Irish Lumper. The lack of genetic variability created a susceptible host population for the organism."

However, there are a wide variety of food crops currently available to anyone wanting to grow their own.

Also, going back to the cloning article: "Parthenogenesis"

I had some stick insects that as a species, almost entirely reproduced by Parthenogenesis. The ones I had were female clones, and most of their species were females.