06 Courier 2 | 11 BioScience BioScience 2 | 11 COurier 07 cannot change the fact that for the second consecutive year, and for the fifth time in the past seven years, the world’s fields have provided less wheat than is demanded by the consumer. Deficits like this are not a problem for the time being: as things were generally the other way around until recently, we still have adequate stocks for the moment. Nevertheless, the indications are that the growing world population will make it more common for wheat production to fail to meet demand. This year, for the first time, there will be seven billion people on the planet. For 2050, demographers predict nine billion people on Earth. And they will all want to eat their fill. How can wheat production be increased? An expansion of the area under cultivation is unlikely: on the contrary, the global area under wheat is currently lower at 225 million hectares than it was in the early 1980s. Projected climate change scenarios also suggest that there will be additional pressure on yields. For some regions, experts anticipate longer dry periods, higher temperatures and in some cases, new plant disease epidemics. So one thing is clear: if wheat production is to rise, the amount harvested per hectare must increase. However, the experts agree that no significant improvement can be achieved without the help of new varieties. And this is exactly what Bayer CropScience is working on. “In recent decades, industry has been focusing mainly on crops such as corn and soybean. The development of new, improved varieties of wheat has attracted relatively few resources. That’s something we now want to change urgently,” says Dr. Marcus Weidler, Segment Manager for Cereals Seeds & Traits at Bayer CropScience. He explains that this new development will hinge on three factors: first, improved nutrient utilization by the plants; secondly, resistance to abiotic stresses such as drought and heat; and thirdly, higher yields. Clearly, the first two of these also have a positive effect on yield. Nevertheless, it would also still be useful to optimize the quality of the wheat kernel, for example by improving the protein content or specific flour and baking properties. For Oleksandr Lyubovets, a farmer from the Ukraine, one of the most important criteria when choosing a suitable wheat variety is how well the plants get through the cold Eastern-European winter. However, optimizing one of mankind’s most important crop plants isn’t a simple matter. And it certainly won’t be a solo effort. “That’s a Herculean task”, says Weidler. “No single company or institution has all of the resources needed.” But Bayer CropScience has managed, within a short time, to obtain numerous highlyqualified partners around the world, and it now enjoys a powerful network. First, there are the partners who bring with them the raw material – the “germplasm”, as Weidler and his associates call it. This refers to the seed lines that provide the basis for breeding new varieties with improved properties. “Through the University of Nebraska in the U.S., the SORT and EUROSORT companies in the Ukraine and RAGT Semences in France, we now have access to a wide range of wheat lines for a variety of growing regions,” explains Weidler. Each of these partners brings their own breeding program and experience with them. Other network partners such as the Israeli company Evogene and the Australian Commonwealth Scientific and Industrial Research Organization (CSIRO) bring technological know-how to our joint work on improving properties. Among the specialisms of the Israeli company Evogene are systematic processes for identifying sections of the plant genome that play a special role in dealing with external stresses. To this end, the researchers challenge stress-resistant test plants with, for example, excessive light, high temperatures, saline soils or extreme dehydration. They then use a special trick to find out which genes are most active under these conditions. The genes, which are sometimes found in plant species completely different from the crop of interest, are then particularly interesting for breeders who want to change that crop – wheat for example – so that it can better cope with heat, salinity or drought. That is exactly what Bayer Crop Science gains from its cooperation with the plant genomics experts at Evogene: an indication as to which genes might be worth incorporating into the wheat genome in order to promote specific properties. Another research focus is the hunt for genes that lead to more efficient nitrogen use. Farmers who have to supplement their crop’s nitrogen would certainly welcome an improvement in nitrogen utilization. Varieties that use nitrogen more efficiently are more environmentally-friendly, because the production of nitrogen fertilizer is very CO 2 - and energy-intensive. Focus on nutrient use efficiency and drought tolerance The uptake of nutrients such as nitrogen and phosphorus is also something the CSIRO biologists are working on in Canberra. The campus in the Australian capital has about 50 greenhouses in which the CSIRO Department of Plant Industry is conducting its research. Alongside their work on sugar cane, grapevine and cotton, wheat research is a major topic. Among other things, the CSIRO researchers have already systematically investigated the impact of drought on numerous wheat varieties and have, for example, developed methods for making the varieties grown in northern Australia more drought-tolerant. “At the moment, we’re trying to develop new semi-dwarf wheat varieties”, explains CSIRO-researcher Dr. Bill Taylor, describing one of the current projects. The first varieties with this characteristic arose during the Green Revolution, and they were a breakthrough then because of their greater stability and harvest potential. But they also showed a few drawbacks: e.g. they only formed a relatively Farmer Christoph Büren grows wheat on 160 hectares in the Marne département in France. His hopes for the future include wheat varieties that are more drought-tolerant without compromising on yield. small first true leaf. Today’s popular practice of no-tillage cropping has many advantages, but sensitive wheat seedlings at the first true leaf stage often fail to find ideal growth conditions among the stubble, and they only develop patchily. “To improve the situation, we are looking to develop plant types that have larger coleoptiles , but which still only reach a height similar to that of current semidwarf varieties,” explains Taylor. A second disadvantage of the earlier semi-dwarf varieties was the widespread germination of wheat grains still in the ear, for example if the wheat could not be harvested on time because of the presence of excessive moisture. “It is important to strengthen seed dormancy and to prevent premature germination,” says Taylor. When it comes to questions like this, Taylor and his colleagues have been an important research partner for Bayer CropScience since 2009. Farmer Byron Richard’s experience over the last 20 to 30 years has convinced him of the special importance of drought-tolerance as a desirable characteristic in new wheat varieties. Richard’s farm in North Dakota, USA includes a wheat-growing area of 4,200 hectares. Finding the right genes is only the first step. The next step is to test these characters against other genomic backgrounds. “The typical model species for our initial tests is thale cress,” explains Dr. Michael Metzlaff, Head of Research Liaison Management for Bayer Crop- Science in Ghent, Belgium, whose aim is to connect Bayer CropScience’s own Research department with worldleading laboratories in plant research. Arabidopsis plants into which promising genes have been incorporated are already growing in the Ghent laboratories. One day, some of these genes might be found in modern wheat lines. Breeders have always known that it takes patience to create new varieties with specific characters. But thanks to modern molecular biology, the Bayer scientists can now truncate some of the breeding steps. For example, it’s now no longer necessary to wait until the descendants of a crossing attempt are fully-grown and all of their properties are discernible. Using so-called DNAmarker technology, Bayer researchers can already check at a very early growth stage which descendants of a cross carry the desired genetic trait – and which don’t. “This means that you can take important decisions earlier about which plants you want to continue to work with,” is how Marcus Weidler sees the benefit of so-called molecular breeding. The farmers’ long wish-list Still, it’ll take a few more years until we can make the improved varieties available to farmers, says Marcus Weidler. But the farmers themselves already have some concrete ideas. “New varieties should be more drought-resistant and capable of using nitrogen more efficiently,” says Byron Richard from North Dakota, who anticipates more problems with drought in the future, despite the recent wet spring. “But increased drought tolerance must not be gained at the expense of other desirable qualities, such as the natural ability of wheat to compete against weeds,” cautions Neale Postlethwaite from Australia. And Oleksandr Lyubovets from the Ukraine is hoping for varieties that are not so susceptible to frost in the absence of snow cover. What unites them all though is the desire for higher yields. t Karl Hübner