Variety vs. hybrid: what's the difference?
When choosing varieties or hybrids, an agricultural producer first looks for advantages and differences. “There is a well-known opinion that rapeseed varieties and hybrids have the same yield. This is a reasonable opinion, but it was objective 10 years ago,” explains Myroslav Pariy, a breeder and co-founder of VNIS, ”Today, the yield of winter rape hybrids is significantly higher than that of varieties, especially if it is not grown in extreme conditions.
Rapeseed is a cross-pollinated field crop. Rapeseed plants are characterized by “internal” heterosis, as the biological species of rapeseed (Brassica napus) arose as a result of interspecific hybridization of turnip and cabbage. That is why rapeseed has long remained the main oilseed crop in Europe and North America. According to various sources, rapeseed has been cultivated by humans for 2-6 thousand years in both Europe and Asia. Before the transition to fossil fuels, rapeseed oil was used for street lighting in oil lanterns, as it produces a pleasant white light and burns almost smokelessly. Today, the areas of rapeseed use have changed a bit: the food industry, animal feed production, production of lubricants and biodiesel, and we should not forget that rapeseed is an excellent honey plant.
Here it is important to understand that varieties are obtained through the classical approach to breeding through crossing and propagation. “What is the difference between a variety and a hybrid?” explains the VNIS co-founder. - “A variety (in English-speaking countries it is called OP - open pollinated variety) is a homogeneous population of plants, which is essentially a homozygous line. Seed production of varieties occurs through open self-pollination in isolated areas, so if you provide sufficient spatial isolation of rapeseed sowing, the variety can be maintained for several years on the farm and you do not need to buy seeds.”
According to Myroslav Pariy, due to these features of the varieties, farmers have to pay royalties to the originator, the amount of which depends on the harvest or other factors discussed during the purchase of such seeds. But let's be honest, today the regulation of royalty payments to the breeder remains the personal responsibility of the agricultural producer, and often the breeder receives nothing. Therefore, Ukrainian variety breeding remains underdeveloped.
“Unlike varieties, heterotic hybrids are obtained by crossing two homozygous lines. When you buy hybrids, you pay only the price of the seeds, although it is an order of magnitude higher than that of varieties. If we compare the yields of hybrids and varieties, hybrids undoubtedly provide better results, and with each subsequent breeding cycle their productivity increases, new economically valuable traits appear, and this is not without the use of transgenic technologies. Therefore, the future belongs to hybrids,” the breeder emphasizes.
By the way, hybrid rapeseed is a fairly young crop. That is why it is impossible to compare varieties and hybrids in terms of yield within 15-20 years. Myroslav Pariy notes that modern hybrids are superior to varieties not only due to heterosis, but also because they are at least 20 breeding years younger.
Heterosis is the phenomenon of increased vitality, productivity, and yield of first-generation hybrids compared to the original parental components. This phenomenon is successfully used for the production of cross-pollinated crops, such as corn, sunflower, rapeseed, sugar beet, sorghum, cross-pollinated vegetable crops, etc. The use of heterosis on an industrial scale requires controlled crossing of parental components over large areas, which makes it impossible to perform crosses manually.
“It should be understood that male-sterile plants are unable to produce normal pollen due to the absence or underdevelopment of anthers. If you sow a male-sterile form and a fertility restorer in parallel rows in the same field, then as a result of cross-pollination on sterile plants, all the seeds will be hybrid. The parental component, the fertility restorer, is removed from the field immediately after flowering,” VNIS explains.
Since 1989, the rapeseed market has been flooded with heterotic hybrids based on male sterility. VNIS explains that with the discovery of the phenomenon of cytoplasmic male sterility, it became possible to grow heterotic hybrids on an industrial scale. The varieties created before that became the parental components of the first hybrids, and after that, breeders shifted their focus to enhancing the phenomenon of heterosis. Therefore, varieties gradually began to become a thing of the past.
Worthy competition: Ukrainian winter rape hybrids
The Ukrainian rapeseed market is filled with hybrids of foreign and Ukrainian breeding. The latter, by the way, compete well with foreign ones, often even surpassing them in terms of plasticity and yield. In addition, the lower price of Ukrainian hybrids makes them more attractive, especially in regions with unstable weather conditions.
Two years ago, Ukraine became one of the world's top five rapeseed producers. As a rule, most of the world's acreage is planted with first-generation winter rapeseed hybrids, and Ukraine is no exception.
“The introduction and development of heterotic breeding of this important crop occurred in the “black” period of our science, so the share of Ukrainian hybrids in the State Register of Plant Varieties Suitable for Distribution in Ukraine is no more than 3%,” says Myroslav Pariy.
Despite all the difficulties and the fact that the creation and registration of each hybrid requires considerable time and resources, the presence of Ukrainian-bred hybrids in the register shows that the situation is not hopeless: there are institutions in Ukraine that carry out modern breeding work and are quite effective.
“In order to create modern varieties at VNIS, we use all modern methods available to us, including technological and genetic analysis methods. But in our case, the main element in creating new hybrids is a large-scale test in the conditions in which this hybrid will be grown,” explains Myroslav Pariy.
All VNIS hybrids are tested in different soil and climatic zones - a total of eight locations. Thus, VNIS breeders are able to bring to the market those rapeseed hybrids that have technological plasticity and maximum yield in Ukrainian conditions.
“Plasticity and yield are the two main criteria by which we recommend choosing rapeseed hybrids,” emphasizes the breeder. - “At the same time, it is important to sow all hybrids at the optimal time. If there are any difficulties with this, we recommend choosing from the herbicide-resistant imidazolinone hybrids: Parker for early sowing, Blackstone for late sowing, the classic Hulk hybrid can be sown in late terms, and Redstone in early terms.
In addition to sowing dates, in recent years, such an indicator as heat and drought resistance of hybrids has become increasingly important. VNIS used special genetic material from the steppe zone to create the Hulk and Blackstone rapeseed hybrids. Therefore, these two hybrids are especially suitable for growing in the South of Ukraine - in extreme conditions and at high temperatures.
“As a scientific institution, we put high potential in our hybrids, but its realization depends on you, the farmers. It depends on how well you use the technology. It should be remembered that rapeseed is a cruciferous crop, which has a lot of relatives in our area, and therefore a lot of pests. Therefore, only with optimal chemical protection you will be able to realize the potential of VNIS hybrids,” Myroslav Pariy emphasizes.
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