New generation hybrid wheat varieties, which have been on the radar for some time, are set to become a commercial reality in key wheat-growing countries.
At least three companies are hoping to have the new hybrid wheat varieties for sale in strategic parts of the world by the early 2020s, following significant investment into better genetics and breeding methods.
Bayer, Syngenta and Dow DuPont are all working hard on their respective hybrid breeding programmes. Farmers in Europe, North America and Australia are likely to be among the first to benefit when the varieties are launched.
The new generation hybrids will join existing hybrid wheats already on the market, such as the Saaten Union varieties, which have had some commercial success in the UK and Europe since they were introduced.
These have paved the way and shown that there can be yield improvements, as well as greater consistency and stability, when they are grown in appropriate situations and in the right way.
Hybrid wheat is a cross between two carefully selected pure wheat lines, so each hybrid variety has genes from both parents. This enhanced genetic package means it expresses hybrid vigour, or heterosis, as it grows.
Because conventional wheat is a self-pollinating crop, it does not cross-pollinate with other wheat varieties. Its flowering biology is such the anther, ovary and stigma all reside in the same flower compartment, so the pollen doesn’t have to travel.
To produce hybrids, plant breeders have had to sterilise the anther in order to get plants to cross-pollinate. In this situation, the pollen has to move, so great care has to be taken during the breeding and multiplication stages, to ensure that the female and male lines are placed correctly.
Hybrid varieties already on the market are produced using a chemical hybridising agent, which is a growth regulator that interferes with pollen production. In contrast, most of the varieties in development will be produced using a genetically controlled sterility system.
This new system will be key to hybrid wheat’s success and has an advantage when it comes to seed production, which has been the Achilles heel for all the chemical systems to date, claim the researchers working on genetic hybridisation.
But even with today’s technology, bringing hybrid varieties to the market can take years. As already mentioned, breeders have to suppress pollen formation in one parent line by making it sterile, to produce hybrids.
That means the female line and the male line have to be grown in close proximity to each other, in order to ensure that cross-pollination takes place. For this, breeders need to get as near to 100% fertility as possible – a difficult and onerous task.
To date, hybrid wheat is grown across an estimated 405,000ha in Europe. Most of it is in France, with a lesser amount in Germany and a very small area in the UK.
The reasons for growing it are numerous, believes Saaten Union, which points out it has found a place where there are production challenges and on more marginal sites, where its greater resilience means it has performed very well.
Benefits of hybrid vigour can be seen in better-developed root systems, more even plant establishment, increased tillering, early maturity and greater resistance to stress and disease, as well as other attributes which come from the combination of characteristics, such as better standing ability, it claims.
Seed rates can be reduced by 30% compared to conventional varieties – offsetting the higher cost of the seed due to its complex production process.
Countries tipped to be suitable for growing the new hybrid wheats include the UK, France, Germany and other European states, as well as North America, Canada and Australia and New Zealand.
Not surprisingly, there has been investment in breeding stations and solutions in these areas, as the large life sciences companies get to grips with genetics and focus on the countries which will give them a return on their investment.
France is expected to be the first European country to have Bayer’s new hybrid wheats, reveals the company’s Adrian Cottey, but others won’t be far behind. “Some parts of Europe will be just ahead of the UK,” he confirms. “But we are developing varieties specifically for the UK, selected in local growing conditions, rather than hoping that Continental wheats will work.”
He anticipates it will be 2023-4 before they are launched in the UK, which is the same time as Canada.
Bayer has a network of seven breeding and research facilities worldwide, all of which are working on hybrid wheat. Three are in the US, three are in Europe and one is in Australia – reflecting the locations where hybrid wheat has an obvious place.
Each will be working with germplasm and parent lines suited to the particular region, so the resulting varieties are produced for the local market.
When they arrive, hybrid wheat varieties will be accompanied by yield and grain-quality improvements over conventional wheat, stresses Mr Cottey, as well as greater consistency and the opportunity to include added value traits.
These traits will help hybrids cope with environmental stresses, such as heat and drought tolerance or winter hardiness, but may also add herbicide tolerance and specific pest/disease resistances.
It’s important to realise hybrid varieties will be part of the mix of genetic and chemical solutions that future wheat production needs, as it faces a whole host of global challenges from climate to rising demand and competition from other crops, he notes.
“Hybrid wheat will allow farmers to be much smarter about what they do,” says Mr Cottey. “They will facilitate the strategic use of genetics on-farm, which together with improved agronomy and digital tools, will transform wheat growing.”
However, growers keen to take advantage of their development will have to be prepared to grow hybrid wheat varieties on suitable sites and in the right way, or they could be in for disappointment.
“They are unlikely to be the answer to every problem,” he says. “Their best fit is expected to be where conditions are tough – whether that’s due to a later drilling date, the rotational position of the crop or site limitations, such as altitude.”
In his view, the yield stability they offer will be just as important as the yield increase. “Production will become more reliable and predictable in a wide range of environmental conditions.”
Higher seed costs will be offset by the yield increase, which Bayer anticipates will be between 3-10% for most. Grain quality is tipped to be better too, as hybrids have lower levels of fusarium due to their increased ear fertility.
“The complicated seed-production system means hybrid seed is more expensive,” he acknowledges. “But advances have been made and the genetically controlled sterility system is bringing the costs down, as well as giving a higher, more reliable seed yield.”
Bill Angus of F1 Seed has been tasked with developing new, high-yielding germplasm to feed into Bayer’s UK hybrid programme. He is using fast-track systems wherever possible and is concentrating on flowering biology, to enhance seed production.
“Pollen transfer is essential. We are getting wheats to throw out their anthers and become promiscuous. The females are receptive for eight to 10 days in UK conditions.”
His breeding objectives include high-yield potential, resistance to septoria and orange wheat blossom midge and getting a strategy implemented for male plant development, as this has been a sticking point.
To help with this, breeding processes have been speeded up, where possible. “Single seed descent is used routinely, rather than double haploids, and we have out of season nurseries for spring or low vernalisation types.”