Potatoes are one of the world's most biodiverse staple crops. In the Andean region, which is called the birthplace of the potato, there are more than 4500 varieties belonging to seven different types. However, that number is declining at an alarming rate, with both traditional local varieties cultivated by farmers for millennia and the ancient ancestors of wild potatoes disappearing. Scientists insist: it is very important to preserve the genetic diversity of plants, this is a necessary condition for ensuring the development of agriculture.
One way is to preserve varieties in vitro. The International Potato Center (CIP) maintains the world's largest and most diverse in vitro collection, with 12 potato samples stored in its genebank. In addition to this, CIP has created a collection of cryobanks, in which 000 samples are stored.
“While in vitro and field collections are good for maintaining genetic diversity in the short to medium term, it can be an expensive and unreliable solution in the long term,” explains Rainer Vollmer, cryopreservation expert at CIP. “Specimens stored in vitro must be constantly multiplied under sterile conditions; field collections are vulnerable to stress. Thus, cryopreservation is an economical and reliable alternative to biodiversity conservation. Today one person can freeze 300-450 potato shoots in one working day. "
Cryopreservation uses liquid nitrogen (196 ° C) to rapidly freeze tiny tissue samples from sterile seedlings in vitro.
Scientists at the CIP have updated the protocol for cryopreservation of potatoes by testing various methods of processing samples before such samples enter the cryobank (for example, adding sucrose or cryoprotectants to help the samples withstand the cold). The results showed that although the addition of sucrose had no discernible effect, the cold treatment before freezing increased the recovery rate of the samples after thawing by 14%.
“Of course, maintaining potato diversity is only one of the goals. It also needs to be used in breeding programs to help farmers cope with issues such as crop disease and climate change. The availability of a variety of cross-breeding material is one of the most important elements in developing new and improved varieties. "
An example is the Victoria potato variety. Before its appearance, late blight could destroy up to 60% of the crop in Uganda. Variety Victoria was developed using samples from CIP, its main advantage is its resistance to late blight. Over the past 15 years, Victoria has contributed approximately US $ 1 billion to the Ugandan economy.
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