root system size Research Papers (original) (raw)

Most 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... more

Most 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 analysed 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.

Wheat is a major source of protein for human food, a critical issue at a time when mankind is growing by 77 million people per year. Wheat was domesticated approximately 10,000 years ago and has been systematically bred for about 200... more

Wheat is a major source of protein for human food, a critical issue at a time when mankind is growing by 77 million people per year. Wheat was domesticated approximately 10,000 years ago and has been systematically bred for about 200 years.However, this breeding selection has been done using only aerial plant parts. Indeed, wheat roots, the hidden half of plant, were not considered in breeding programs due to the lack of an appropriate method. Here, we evaluated roots of 18 wheat populations. The root system size was measured by its electrical capacitance directly in field. The plants in third and fourth generations were evaluated during shooting and heading. Then plants were selected for large and small root system. In dry conditions, progeny of plants with large and small root system had yields of 17.1 and 10.9 g per plant in the third generation and 18.5 and 10.0 g per plant in the fourth generation. Our results show that the progeny of the plants selected for large roots have larger roots than their parents, also in next generation. Similarly, the progeny of small root plants have smaller roots. The selection process showed a greater response for larger root system size. This response can be evolutionarily advantageous and make selection easier than, for example, selection for grain yield. Our unique method enables accurate, repeated evaluation and harvest of selected plants. Selection for higher wheat root system size can be easily used to breed for drought tolerance and higher efficiency of water and fertilizer use.

High seed vigour is a precondition for fast and homogenous field emergence and good malting quality in barley. The aim of this study was to (i) assess the possibility of selection for greater vitality of barley seeds (Hordeum vulgare L.)... more

High seed vigour is a precondition for fast and homogenous field emergence and good malting quality in barley. The aim of this study was to (i) assess the possibility of selection for greater vitality of barley seeds (Hordeum vulgare L.) in conditions of drought and cold, (ii) to quantify the relationship between the size of the root system of the parental plants and seed vigour of progeny. The root system size was measured by its electrical capacitance directly in field. The seed vigour of four spring varieties of malting barley and their mutual 12 combinations was assessed in three variants (without drought stress, under drought stress of -0.2 MPa and -0.5 MPa), in two years (2012 and 2013) and on the two locations (Hrubčice and Želešice). The vigour of 12 combinations from two locations was compared with vigour of their parents. Highly significant correlation was found in 2012 between the vigour of the mothers and their progenies (r = 0.832; P = 0.01), between that of fathers and of their progenies (r = 0.882; P = 0.01) and between the vigour of both parents and their progenies (r = 0.894; P = 0.01). The correlation between seed vigour combinations in F 3 generation (harvest 2012) and in F 4 generation (harvest 2013) was r = 0.886. This is another evidence for potential effective breeding for the seed vigour.