Genetic resources a national treasure – one that lives, grows and reproduces

By Helen McMenamin

 

Most national treasures are carefully stored and just photographed and looked at occasionally. Canada’s genetic resources are stored with great care, but parts are always in use, being tested, shared and regenerated – under careful supervision. Every time a new disease or a new pest affects a crop, we expect scientists to develop a solution. Often that means finding a source of resistance and using it to breed a new variety that isn’t affected by the disease or has less severe symptoms.

We tend to assume the scientists have stocks of many seeds somewhere, but we don’t worry much about where. Breeders usually have drawers full of small samples, but they also send samples to our national seed bank, which is much more than a storage vault. Dr. Ken Richards found just how much more is involved when the former bee specialist took on the role of Research Manager of Canadian Gene Resources. Over the previous century, Agriculture Canada scientists had accumulated over half a million seed samples – material they had developed and gathered from colleagues around the world.

Seed samples are relatively simple to maintain, but even seed doesn’t remain viable indefinitely at normal temperatures. Some seed, like lettuce, is only viable for a year or two, other crop seeds last longer – 35 to 50 years for oilseeds and sunflower and as much as 100 years for tomato and cereals.

There are about 1300 germplasm banks around the world, each with its own focus, but most try to back up their collections by sending samples of seed to other seed banks in different countries. Canada’s gene bank is focused on food and medicinal crops, along with disease organisms and now livestock germplasm. Just in case there’s a major catastrophe, seed banks around the world share their samples – the seed bank at Svalbard is designed as storage of last resort, safe from rising seas, high temperatures, power failures, volcanoes and other natural disasters. Early in the Syrian War staff of the ICARDA (International Centre for Agricultural Research for Dry Areas) seed bank took great risks to smuggle seed to safety in other countries. Afghanistan was not so fortunate – its seed bank was lost in US bombing.

Richards’ first task in 1998 was moving the collection from Ottawa to the University of Saskatchewan. To move the collection safely each sample was split and one sample was shipped by air and the other by truck, just to be sure at least part of every sample arrived safely. Saskatoon was chosen as the home of Canada’s gene resources because of the concentration of specialists in all the agriculture sciences there. Scientists and grad students can use material from the collection in their research and in turn boost the value of the collection. Also, the U of S has North America’s only university course on managing genetic resources.

The collection has grown since then, with seed from a thousand plant species with many samples of each from around the world. It has world mandates to preserve barley with 39,000 different types and for oat with 29,000 samples. In an effort to make that collection more valuable to breeders and others, scientists searched their oat germplasm for oats resistant to crown rust and stripe rust, either of which can be very damaging to oat crops. The scientists tested all 29,000 oat samples in the collection and found three resistant samples – all wild relatives of the crop. It won’t be easy for breeders to develop rust resistant oat varieties, but the knowledge of which samples have and don’t have resistance increases the value of the collection. Scientists are also looking at nutritional value, nutriceutical content and other characteristics of plants in the samples – even documenting such obvious things as whether the plants are hairy or waxy, how tall or bushy they are.

“Everything we can tell a breeder about our samples gives them a head start on their project,” says Richards. “We know a lot about some crops – the entire genome of rice is known and it’s well-understood, but when we look at wild relatives it’s a different story. We don’t know much about their genetics, for some species we don’t even know how they reproduce – does it self-pollinate or must it outcross? The more documentation we can develop on our collection, the more valuable it is.”

Searching turns up gems – four types of lentils are resistant to anthracnose. Brassica carinata, Ethiopian mustard, was developed as a biofuel crop thanks to a single dedicated researcher and one genebank sample. Chickpea breeders are close to producing cultivars with ascochyta resistance. Another chickpea sample has levels of a nutriceutical that protect against heart attack as well as prescription drugs.

Distribution of seed to breeders and other scientists around the world is a big part of genbank work. Both receiving and sharing seed is complex, requiring developing and complying with international treaties, working with CFIA and ensuring the seed is free of disease organisms.

As seed from is used for viability testing, sharing with breeders or other studies fewer and fewer seeds are left, or seed viability drops and seeds have to be regenerated. Some samples can be grown out in simple breeder plots, but open-pollinated crops like alfalfa, sunflower and canola have to be netted with their own bees for pollination. Native food species like wild rice and grasses have been added to the seed collection in the last few years, but they only grow in very specific habitats, so regenerating them takes special conditions.

The gene resources collection includes potatoes, berries, fruit bushes and trees that don’t breed true from seed. These are kept in special isolation nurseries and greenhouses in BC and Ontario and potato is kept as tissue cultures.  Germplasm of disease organisms is also needed, so scientists can prepare for new disease strains or test new varieties. Most viruses and fungi can be preserved in liquid nitrogen, others have to be in living hosts – plants grown in isolation nurseries and greenhouses.

 

Genebank wants out-of-favour semen and embryos

The livestock germplasm collection is relatively new program in Canada’s Gene Resources, only active for 7 or 8 years. Some animals are living in small herds kept as rare breeds, mainly on hobby farms, but the program is searching for germplasm of old breeds of cattle, sheep, pigs and horses, as well as donkeys, goats, chickens and other poultry, bison and elk.

Traits that aren’t valued in livestock today may be needed at some time in the future, just as dairy breeds that produced high butterfat were set aside in the past and might fit today’s needs very well.

“We don’t want any animals that aren’t already in Canada, “ says Richards. “But, older breeds and genetics that are no longer popular, especially if pedigrees are available, are very much wanted for the collection.”

Samples of semen that may be lost in the bottom of a tank may be quite valuable to the gene bank. If you arrange to send them to the genebank they qualify as gifts to Canada and can earn you a considerable tax receipt.  Samples of horse semen are also wanted, especially that of breeds that are currently less popular, such as Arabs.

Preserving germplasm of some livestock presents quite a challenge because some breeds fell out of favour before techniques for freezing their semen and embryos were developed. Dr. Carl Lessard who heads the program has developed techniques for preserving elk and bison semen and harvesting their embryos.