International audienceMost agronomy practices such as fertilization, irrigation, and soil treatment involve plant root interactions. However, the role of plant roots is rarely assessed during agricultural experiments due to the lack of suitable methods. Plant varieties with a larger root system use soil water and nutrients in dry environments more effectively than varieties with a smaller root system. Such large root varieties can be developed by breeding. Therefore, we evaluated the effects of selection for large or small root systems in 12 barley populations developed via the mutual crossing of four parents in the F3 generation as a response to selection in the preceding F2 generation. Root system size was analyzed by measuring electrical capacitance. Results show that our selection method was effective because the progeny of plants with larger root systems also had larger root systems. Conversely, the progeny of plants with smaller root systems also had smaller root systems. The average differences were +40 and −43 % in the parental segregating generation and +4 and −2 % in the progeny. The root system size impacted the grain yield, which showed a twofold greater response to selection. Indeed, plants with a root system increase of 3.9 % exhibited a yield increase of 8.1 %. Some varieties transmitted larger root systems to their progeny, and some transmitted smaller root systems. Thus, we show that the method used enabled the comparison of root system size in the same crop, in the same soil, and at the same time, which is particularly suitable for selecting root system size in practical breeding. We do not know any other suitable method for the repeated evaluation of intact plants and harvesting of seeds from the selected plants. Root system size has not yet been reported by other authors as a selection criterion in practical breeding, with the exception of root crops such as sugar beet and carrots

This article does not have an abstract.

Breeder's rights: Plant Select, spol. s r. o., Hrubčice, Czech Republic Breeder and maintainer: Plant Select, spol. s r. o., Hrubčice, Czech Republic Pedigree: Nordus × HerisBreeding method: Selection method and testing in preliminary and official tests were identical as in Bojos variety. The plant progeny selected in F 3 , denominated 2.5, constituted Radegast variety and this line also established maintenance breeding. During the trials the variety was labelled HE 8795, and in 2005 it was registered under the name Radegast in the Czech Republic and in the Slovak Republic. Disease resistance:The Radegast variety is resistant to powdery mildew (Erysiphe graminis) -gene mlo, medium resistant to net blotch (Pyrenophora teres) and to scald (Rhynchosporium secalis), and medium susceptible to brown rust (Puccinia hordei). Malting quality:In the course of official malting tests (2002)(2003)(2004) Radegast variety showed an optimum extract content (82.5%). The activity of proteolytic and amylolytic enzymes was on an above-standard level or on an optimum level. B-glucan content in wort was on a low level and friability values were on a lower level. The variety has optimal clarity of wort. Based on the results Radegast variety has been included in the class of malting varieties -5 points of Malting Quality Index (MQI) suitable for the production of beer of Czech type.Grain yield: In official trials the Radegast variety had an average yield in all production regions -Czech Republic: maize growing region 100%; sugar beet and cereal growing regions 101%; potato and forage crop growing region 100% in relation to the average of control varieties Tolar and Heris; Slovak Republic: maize growing region 101%; sugar beet and cereal growing regions 98%; potato and forage crop growing region 103% in relation to the average of control varieties Annabel, Nitran, Progress and Madonna. Other characteristics:The Radegast variety is a malting medium-late variety. The length of the plant is medium (77 cm). Resistance to lodging is medium and resistance to stem breaking is high. The variety has the grain of a large size (TKW 48.0 g) and high yields of sieving fractions above 2.5 mm (90%). The palea is straw yellow in colour and finely wrinkled.Small quantities of seeds for research and breeding purposes can be obtained from the variety breeder and maintainer.

No abstract

Laudis 550 is a mid-late malting spring barley variety, medium resistant to lodging and medium resistant to stem brackling. It is resistant to powdery mildew, medium resistant to brown rust, leaf blotch complex and scald. The variety reached 7.2 points of the malting quality index (to the registration date) and it is recommended by the Research Institute of Brewing and Malting, Plc for production of beer with the protected geographical indication České pivo (Czech beer).