Zinc link made in barley breeding (4/23/2008)

Chromosomal regions conferring zinc efficiency in barley, recently identified by three WA researchers, could have important implications for improving the zinc status of the human diet.

Behzad Sadeghzadeh, PhD student and Professor Zed Rengel, both of the School of Earth and Geographical Sciences, Faculty of Natural and Agricultural Sciences (FNAS) at The University of Western Australia (UWA), worked with Dr Chengdao Li from the Department of Agriculture and Food WA (DAFWA) on the project.

Professor Rengel said the discovery of genetic markers contributing to improved barley productivity and nutritional quality in zinc-deficient environments is promising because as an essential trace element for humans, zinc has a crucial role in more than 300 enzymes in the human body.

According to Professor Rengel, zinc is vital for physical and mental development, fertility, vision and resistance to infections, yet many of the world's soils and therefore foods are zinc-deficient.

"Zinc deficiency is a problem in many developing countries and is the fifth leading cause of diseases, especially diarrhoea and pneumonia in children."

Mr Sadeghzadeh, whose PhD is supported by the Government of Iran, discovered that some barleys grow and yield well, even in zinc-deficient soils, because they are zinc efficient and have zinc-dense seed.

A doubled-haploid population of 150 barley lines derived from a cross between a zinc-inefficient Australian cultivar, 'Clipper' and a zinc-efficient Algerian wild barley, 'Sahara 3771', were screened for seed zinc content under field conditions at UWA's Shenton Park Field Research Station.

Comprehensive molecular mapping of doubled-haploid populations, using 302 markers, enabled Mr Sadeghzadeh to identify quantitative trait loci for zinc accumulation in barley seed.

"Two regions on chromosome 2H in barley associated with zinc concentration and content in seed could explain 45 per cent and 59 per cent of the total variation in the seed zinc concentration and content, respectively," he said.

"Identifying molecular markers linked to genetic loci controlling seed zinc will allow more rapid and efficient screening of barley lines than traditional techniques.

"By selecting lines with zinc-dense seed, barley breeders will be able to produce cultivars that yield better in zinc-deficient soils and also contribute required amounts of zinc to the human diet," Mr Sadeghzadeh said.

Note: This story has been adapted from a news release issued by The University of Western Australia

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