A team of CSIRO researchers, led by CSIRO Wheat Geneticist, Wolfgang Spielmeyer, has discovered a gene that will help wheat adapt more effectively to Australia’s dry conditions.
By locating the gene responsible for the growth of the coleoptile – the tissue that sprouts from the seed and pushes its way to the surface to form the plant – Dr Spielmeyer’s research will enable breeding companies to breed new wheat varieties that allow coleoptiles to grow longer.
This is beneficial to growers in drier areas, as the longer the coleoptile is, the deeper the seed can be sown, allowing access to damper soil and increasing water efficiency.
“Ultimately, we want to improve water use efficiency and increase yield.”
“The deeper the moisture is in the ground, the further down the seed has to be planted,” Dr Spielmeyer told the ABC.
“Therefore, we need longer coleoptiles in future cultivars of wheat crops so they establish well and grow out to their full potential.”
Dr Spielmeyer said that this genetic information is already in the hands of wheat breeders, which means it won’t be long before new varieties with longer coleoptiles will be ready for trial.
InterGrain Senior Wheat Breeder, Dr Dan Mullan, said that the CSIRO discovery is an exciting development in a constantly improving area.
“The CSIRO is very generous in sharing its information and passing on the details as soon as they have them,” he said.
“It’s an exciting development but this gene isn’t the complete solution, it’s an incremental improvement that has led us much closer to the ultimate goal.”
Dr Mullan said that for breeders and farmers the “ultimate goal” is to build early biomass above ground, which allows the wheat to utilise more of its available resources.
“By increasing the coleoptile length by one to two cm, grain growers can either sow deeper, or continue with their regular sowing practice but have better establishment across the field, resulting in improved above ground biomass,” he said.
“A longer coleoptile will increase the wheat’s ability to emerge from the ground more reliably and help with better establishment in the paddock.”
Dr Mullan said that the new gene will help breeders to reverse a problem caused by semi-dwarf wheats.
“The majority of wheat varieties in Australia are semi-dwarf, which are great for short plant growth and higher yields, but not particularly good for other parts of the plant,” he said.
“While semi-dwarf wheat is a shorter plant with a stronger stalk and improved harvest index, semi-dwarf genes have also been associated with shorter coleoptiles, which means you can’t plant them as deep.
“This can be a challenge for crops being grown in drier soils with receding soil moisture profiles.”
By locating the gene responsible for the growth of the coleoptile, breeders are now able to look at combining the good aspects of semi-dwarf wheat with potential for a longer coleoptile – but Dr Mullan says there’s a long way to go.
“Ultimately, we want to improve water use efficiency and increase yield,” he said.
“So, if we can breed new wheat varieties that can integrate weed competitiveness, increase coleoptile length, and use alternative dwarfing genes we’d be in a very good place.
“This discovery is just another step in the right direction.”