Castrated Seeds Explained

Do you ever harvest the seeds from the fruit you buy from the supermarket and try to germinate them? Green-thumbed gardeners have a better chance at succeeding than most, but even if the seeds do germinate, the chances of them producing the same fruit as their parent plant are relatively slim. A Granny Smith apple seed has a one in one hundred chance of making Granny Smith apples!

Centuries of breeding and production methods have had a significant influence on the genetics of humanity’s favorite foodstuffs, many of them favorable. But where a fruit farmer at the turn of the 20th century could reasonably expect to influence his crop and perhaps that of his neighbours, food production today is a global enterprise that has a genuine and potentially catastrophic influence on the existence of species themselves.

Anyone seeking a monopoly on food production has to contend with the fact that almost anyone can grow a plant from seed. Patents protect the profit margins of patent holders, but suing farmers is a costly process and success isn’t guaranteed. The less expensive solution is to ‘switch off’ a seed’s ability to grow. What could go wrong?

Grafting

So, how did we get here? It’s fair to say we’ve been genetically engineering plants for millennia, to varying degrees. Grafting, the process of attaching the upper portion of one plant (the scion) to the lower part (the rootstock) of another plant, is believed to date back some 4,000 years. Asexual propagation is common enough in nature and plants do graft naturally to one another in a process called inosculation, but grafting today is far removed from its natural precursor.

In commercial terms, grafting has a host of advantages; primarily hardiness, disease resistance, and precocity – the ability to produce fruit without having to wait years for a seedling to mature.

Seeds from the fruit of grafted plants contain the genetic data of both the scion and the rootstock. When these seeds are successfully planted, they tend to favor the rootstock. With apples, that often means their fruit will likely be inedible crab apples. Years of hybridization means these seeds often contain the genetic data of numerous varieties and cultivars.

Hybrids

Many of the fruit and plant varieties we enjoy today are hybrids born of grafting and cloning. Hybrids are generally sterile as a result of polyploidy; a condition where abnormal cell division results from an uneven number of chromosome sets, preventing the creation of balanced gametes.

In a commercial sense, this is fantastic; it means you’re not handing your customer the means to compete with you every time you sell them a piece of fruit full of seeds. Then again, why give them a chance, even if it’s one in a hundred?

Seedless fruits are a product of parthenocarpy; the production of fruit without fertilization. Originally a naturally occurring mutation, highly-prised seedless fruits are propagated through grafting and cuttings, as well as by artificial pollination and through the introduction of external hormones. No more picking seeds out of your teeth or worrying about pesky home growers cutting off your cash; right up until a disease rips through your crop. But that’s someone else’s problem in the future, right?

Feminized Seeds

The sale of seeds is a massive industry in itself. Where the fruit and flower of female plants are the prised product at the end of the process, an errant male could easily fertilize your crop.

Feminized seeds are produced by crossing two females with one another. They have the added advantage of preserving the characteristics of their mothers.

Gibberellins are hormones that induce male flowers in female plants. Silver nitrate modifies ethylene levels in plants, causing the switch to maleness without the disadvantage of male genes. Since neither parent has a Y chromosome, the resultant seeds are guaranteed to be female.

With aeons under her belt, Mother Nature always finds the way. None of these techniques can be 100% guaranteed. Humankind has never been one to let anything get in the way of rampant capitalism though, and we’ve still got two big guns to set against the biodiversity that underpins life itself; brutality and sneakiness.

Radiation

Strictly speaking, radiation treatment extends the shelf life of foods and prevents the spread of pathogens and fungi. Exposing foodstuffs to gamma radiation isn’t widely discussed, perhaps for obvious reasons, but it is widely practiced.

Potatoes, in particular, are a staple around the world and they spend a fair amount of time in storage before they reach your plate or the processing plant. Irradiation irreversibly inhibits cell division and multiplication; which is excellent for preventing breakdown and sprouting, but not so great when it comes to the

Potatoes, in particular, are a staple around the world and they spend a fair amount of time in storage before they reach your plate or the processing plant. Irradiation irreversibly inhibits cell division and multiplication; which is excellent for preventing breakdown and sprouting, but not so great when it comes to the cell multiplication necessary for creating life. Look for the Radura symbol on food packaging if you’re wondering whether the food you’re eating has been irradiated.

Terminator Seeds

Genetic Use Restriction Technologies, or GURTs, represent the bleeding edge of genetically modified foodstuffs. Developed in the nineties by the USDA and the Delta and Pine Land Company, a subsidiary of Monsanto, GURTS imbue genetically modified plants with a genetic ‘switch’. The switch induces infertility in second-generation seeds, or only allows them to become fertile in response to exposure to a particular, proprietary agent.

Dubbed terminator technology or suicide seeds, names which are incredibly unpopular with their proponents, suicide seeds are billed as a biosafety measure that will prevent GM-crops from accidentally spreading into the wider environment.

Around the time that they were being developed, Monsanto was famously suing Percy Schmeiser, a Canadian canola farmer, for failing to pay them royalties for their Roundup-tolerant canola, a product which he had never purchased. It was a costly battle for Monsanto which brought to light the fact that they weren’t above stooping to base intimidation.

Widespread outrage and outright horror at the prospect of terminator technology has seen it shelved and outright prohibited in certain countries. Today, it remains ‘not yet commercially available’.

Bio

Dr. Callie Seaman is a plant-obsessed Formulation Chemist at AquaLabs – the company behind SHOGUN Fertilizers and the Silver Bullet plant health range. She has been in the hydro industry for 15 years in research development and manufacturing and had previously worked on the VitaLink range. She has a Ph.D. in fertilizer chemistry and a BSc (HONS) in Biomedical Sciences and loves nothing more than applying this knowledge to pushing the boundaries of nutrient performance.