Frost tolerant wheat on the horizon
the genes responsible for providing frost tolerance for wheat,
giving plant breeders hope that damage resulting from wheat frost
could soon become a thing of the past.
The team of US and European scientists aimed to identify genetic factors associated with cold tolerance in wheat. The study results, reported in the March issue of the journal Plant Molecular Biology, suggest that the genes that regulate frost-tolerance are activated at milder temperatures (12 to 15 Celsius, 53 to 59 Fahrenheit) in frost-tolerant wheat varieties than in frost-susceptible varieties. Used to make a variety of food products ranging from bread to pastas, wheat is a key driver of global food inflation. The identification of these genes by the University of California could allow plant breeders to develop wheat varieties that can better withstand cold temperatures. "This is of vital importance in light of growing pressures to increase global food production," said Professor Jorge Dubcovsky, a wheat breeder and geneticist. The scientists used artificial freeze tests, determination of final leaf number and flowering response under increasing daylight regimes to analyse the plant's resistance to cold conditions. They established that wheat chromosome 5AL plays a key role in cold acclimation and frost tolerance. It possesses major genes for freezing tolerance and vernalisation response. Many plant species, including winter cereals such as wheat must go through a prolonged period of cold before flowering occurs; this is the vernalisation process. This ensures that reproductive development and seed production occurs at the optimum environmentally favourable time, normally after winter. However, if temperatures are too cold in winter or in spring, wheat will freeze and the crop will be damaged. "Until now, it has been difficult to develop more winter-hardy varieties because frost tolerance in wheat is a complex trait that is regulated by many genes," Professor Jorge Dubcovsky, a wheat breeder and geneticist, explained. In addition, wheat varieties differ in their responses to low temperatures. Frost is a major economic risk factor for wheat. Low temperatures during winter can be particularly destructive, and even more so in spring as growth is further advanced. Although the International Grains Council (IGC) recently forecast that the 2008/09 wheat harvest will be good, world wheat reserves are still very low. International organisations have recently urged farmers to increase wheat plantings to reduce wheat prices on global markets. However, several factors such as the biofuel boom, which has led many farmers to turn to corn, and wheat's vulnerability to disease and adverse weather conditions, have slowed down wheat's plantings over recent years. Research could make a difference in the life of the growers and might solve some of wheat's problems.