Uncommon selection by root system size increases barley yield

Abstract

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

Evaluation of Suitability of Grass Species for Dry Conditions (Water Stress)

“…Also Rychnovská et al (1985) highlights the relation between drought, root formation dynamics, and consequently reduction of the leaf area, photosynthesis and production. Increased production of alfalfa root with a larger root capacity (electrical capacitance) is stated by Chloupek et al (1999);Svačina et al (2014) confirms this in selected material of spring barley. Increasing the electrical capacitance by + 3.9% led to a production response almost two times higher (+ 8.1%).…”

Simultaneous monitoring of electrical capacitance and water uptake activity of plant root system

“…It is important to emphasize that measurement data are comparable only among plants of the same species, grown in the same substrate at the same moisture level in the same time frame (Chloupek et al, 2010). Due to its versatile adaptability, EC measurement can be reliably applicable in various fields of basic and applied plant physiology, ecopysiological and agricultural researches, substituting at least partially the intrusive and labour intensive techniques Cao et al, 2010;Cseresnyés et al, 2012Cseresnyés et al, , 2013aSvačina et al, 2014). CONCLUSIONS 1.…”

Prospects of selection for barley seed vigour as a precondition for stand emergence under dry condition.

“…Significant differences are marked by different letters; different were only combinations U3 (Prestige × Diplom) and U11 (Diplom × Saloon). Svačina et al (2013) used the identical parents and combination as in our study. Evaluation of the general combining ability showed that the use of Saloon and Diplom parents led to an increased root system size in both selection.…”