One Century of Interactions Between Intensive Breeding and Genetic Diversity Conservation of Barley

Michaela Benková,Martina Hudcovicová,Ján Kraic,Daniel Mihálik,Lenka Klčová

doi:10.15835/nbha45110577

Abstract

The footprint left by one century of intensive breeding on the phenotype and genotype has been studied in barleys that originated and were developed at the territory of Moravia and south-western Slovakia. The set of barleys (Hordeum vulgare L.) used in retrospective analysis included 106 landraces, obsolete and modern cultivars from the period 1900-2003. The one-hundred year breeding effort resulted to crucial changes of agronomic and technological parameters. The number of spikes m-2, spike density, protein and starch contents were significantly (P<0.05) different in new barleys (developed after the year 1972). Improvement of malting quality was through decreasing of proteins (average annual decline 0.034% year-1) and increasing of starch (average annual gain 0.074% year-1) in grains. Change in genetic diversity has been studied at 27 microsatellite loci with conclusion that nothing adverse happened at these loci during one century of breeding. The oldest barleys were heterogeneous populations, the modern ones were more homogeneous, and moreover introduction of new germplasm within the breeding process has brought new microsatellite alleles. Both, the total number of alleles and average number of alleles per locus indicated that molecular diversity was not reduced by long-term breeding. However, the average number of alleles per genotype pointed to the existence of genetic erosion caused by the gradual replacement of original landraces and local cultivars by modern cultivars. The index of genetic diversity reflected that reduction of genetic diversity from the thirties to the seventies has been turned by breeders in the eighties of the 20th century.

Highlights

Barley (Hordeum vulgare L.) is grown over a broader environmental range and higher on the mountain slopes than any other cereal
Changes in phenotype diversity The analysis of variance confirmed that the year of cultivation did not affected number of spikes m-2, number of grains spike-1, and weight of grains spike-1, spike density, protein content, or starch content (Table 1)
Improvement in grain yield during one century was not achieved by increasing of the weight of grains spike-1

Summary

Introduction

Barley (Hordeum vulgare L.) is grown over a broader environmental range and higher on the mountain slopes than any other cereal. Barley plants underwent intensive breeding for improvement of agronomical traits and technological parameters of grains. Gain from utilizing of limited number of elite parents in crosses was high and improvement was sufficient to encourage continued breeding only within narrow gene pools, even though reduction of genetic variability has been expected. The barley breeding in the former Czechoslovakia (existing from 1918 to 1992) reached really an excellent level after the World War II and has been focused mainly for improvement of agronomical parameters, especially malting quality. The most important milestone was the famous cultivar ‘Diamant’ (Bouma, 1967) derived by mutation (X-ray irradiation) from the cultivar ‘Valtický’ (developed in 1950) with short stem and higher grain yield by 100-1040 kg ha-1 (Mlčochová and Psota, 2008)

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