It isn’t often in this world, that you can get something for ‘nothing’. Where one plus one, makes three. It would definitely take some slight-of-hand, a parlour trick -or, just maybe, genetics
Ahhh, yes, genetics. The world of miracles. For countless eons of time, Mother Nature -and, Father Time, have astounded us with the ‘hidden secrets’ only to be found deep within the DNA of living organisms.
A hybrid is where two different parents come together to produce something unique. And hybrid vigour is when offspring is something exceptionally better than either parent. This ‘better’ can take many forms including improved traits such as growth rate, biomass accumulation, increased yields, stress tolerance, and disease resistance, for example. Hybrid vigour is probably best represented in the business of seed production, and there is barely a crop that hasn’t been improved with the efforts of breeding; we have become, quite expert.
The combination and recombination of genetic material can often result in some spectacular results. Mother Nature has been ‘hard-at-work’ for a long, long time in the ‘kaleidoscopic’ mixing of genetic material. Science, has been ‘hard-at-work’, for a long, long time, at being more ‘calculated and cunning’ in the approach of mixing genetic material -building on past success, and taking all the short-cuts.
In simple terms, hybrid vigour refers to the improved activity and survival of the hybrid offspring ...the tendency of hybrid offspring to have superior biological function to that of their parents. In the world of genetics, the phenomenon of hybrid vigour is known as heterosis (out-breeding enhancement). Hybrid organisms (crossbreeds) are those born as a result of the combination of the traits of two organisms of distinct varieties, breeds or species, through sexual reproduction.
In the genetic world, there can be 2 or more forms for the same specific trait or gene. These are known as alleles. And one allele can dominate while suppressing the other that is undesirable and recessive. And so, breeders have a balancing act in finding the desirable genes (alleles) and introducing them into a particular plant without losing something else in the process, as some traits may not be stable.
The effects of heterosis (out-breeding) in plants can be classified as quantitative, physiological and biological. Quantitative examples are increase in size, yield and genetic vigour; such hybrids generally grow larger and healthier than their parents; for example, fruit size in tomatoes, head size in cabbage, cob size in corn. Physiological effects can result in better adaptability, greater resistance to disease and pests, better flowering and maturity -tomato hybrids developing ‘earlier’ than either parent.
And, hybrid vigour is not just restricted to the plant world -as animal breeding has been just as impressive. Plant and animal breeders exploit heterosis by mating 2 purebred lines that have certain desirable traits. The first generation offspring generally show the most for the desired characteristics of both parents. However, this vigour may decrease, if the hybrids are mated together; so, the parental lines must be maintained and crossed for each new crop.
There was a time when 100 bushels of corn per acre was considered to be a pretty good yield, and 200 bushels an acre, mere fantasy. Now, 200 bushels an acre is an expectation in most cases, and pushing the limits each and every year. Weather notwithstanding, and improved cultural practices aside, the big gains in yields have -simply put, being the result of breeding -better seed. Most all soybean and corn varieties are hybrids of one sort or another. Everybody seems to be winning.
However, with hybrid seed production, these genetic ‘darlings’ are usually proprietary and owned by the originator -most often being large corporations. Accordingly, the farmer must ‘pay to play’. That said, and for the most part, there is something of a ‘symbiotic relationship’ between all concerned. It is called business. One dependent upon another, for profitability.
The process of hybridization is important biologically because it increases the genetic variety (number of different gene combinations) within a species -which, is necessary for evolution to occur. If climatic or habitat conditions change, individuals with certain combinations may be eliminated while others will survive and prosper. In this way, the appearance or behavior of a species may gradually be altered. Mother Nature is patient and measured in her approach. Mankind, more aggressive -always in a hurry.
There has been much talk in recent years about climate change -and this year, in particular. Geneticists -and science generally, will be hard-at-work trying to adopt and adapt those specific seed characteristics necessary to ‘accommodate’ what is most certainly coming our way. Hale to the seed, and the ‘magic’ found within, by plant breeders. Once again, our very survival depends upon it.