Rooting patterns in near-isogenic lines of spring wheat for dwarfism

• Published in: Plant and soil Vol. 197; no. 1; pp. 79 - 86
• Main Authors: Miralles, D.J., Slafer, G.A., Lynch, V.
• Format: Journal Article
• Language: English
• Published: Dordrecht Kluwer Academic Publishers 01.11.1997; Springer; Springer Nature B.V
• Subjects: Adaptation to environment and cultivation conditions; Agronomy. Soil science and plant productions; Alleles; Biological and medical sciences; Biomass; Crop science; Environmental conditions; Field tests; Flowering; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Genetics and breeding of economic plants; Genotypes; Growing seasons; Mass ratio; Plant growth; Plant roots; Plants; Roots; Soil profiles; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Soils; Sowing date; Spikelets; Spring wheat; Varietal selection. Specialized plant breeding, plant breeding aims; Wheat; South America; Argentina; America; Monocotyledones; Root; Lodging; Line (plant); Genetic determinism; Cereal crop; Dwarfism; Allele; Genotype environment interaction; Gramineae; Genetic improvement; Angiospermae; Near isogenic line; Above ground plant part; Spermatophyta; Rooting; Isogenic line; Soil plant relation; Triticum aestivum; Below ground plant part
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1023/A:1004207407979

The effects of Rht alleles on root growth and distribution in isogenic lines of spring wheat (Triticum aestivum L.) are described under different environmental conditions. Above-ground biomass, root length, root dry-weight and their distribution along the soil profile were measured by destructive sampling for growth of aerial biomass and extraction of soil cores containing roots. Field experiments were conducted under non-limiting water and nutritional conditions during two consecutive years, using an early and a late sowing date each year. Dwarfing genes significantly reduced plant height and above-ground biomass at anthesis. In addition, stem mass ratio also was reduced with increases in the allelic dosage. Conversely, total root length and root dry-weight per unit area at anthesis were increased with decreased plant height, therefore, root mass ratio tended to be negatively correlated with plant height. Differences in distribution of root length and root dry-weight through the soil profile among lines were largely confined to the upper soil layers (i.e. the top 30 cm). Differences in root dry-weight were more important than in root length, so that the dwarf line had the highest root mass per unit root length. Furthermore, a significant positive correlation between the root mass ratio and stem mass per unit stem length was found. It is suggested that increases in root mass per unit root length associated with Rht alleles are evidencing a surplus of photoassimilates during stem elongation which are used for thickening the roots due to the lack of alternative sinks. Agronomic implications of this effect are discussed.