Nitrogen and Phosphorus Efficiency in Wild and Cultivated Species of Wheat

ABSTRACT

The wild and primitive species of Aegilops and Triticum genera are potentially important and not fully recognized sources of a novel variation for wheat breeding. However, less is known on their adaptation to macronutrient shortages. Nutrition- and genotype-dependent variation in the nitrogen (N) and phosphorus (P) efficiency was evaluated among these and cultivated accessions of the Aegilops and Triticum genera. In a factorial experiment, plants were grown in 9 dm³ soil-pots under high and reduced N-P-potassium (K) fertilization. The limited nutrition caused a decrease in uptake efficiency and nutrient concentrations in grains. However, essential increases in the efficiency of N and P utilization in grain mass formation were noticed under the nutrients shortage. The examined accessions exhibited a broad genotypic variation in the efficiency of N and P use and the response to limited fertilization. This variation was also dependent upon ploidy levels, identity and interactions of genomes present. Significant genotype by nutrition interactions were noticed for the uptake efficiencies, nutrient harvest indices and utilization efficiency ratios. The cultivated and primitive, polyploid Triticum species were the most efficient in N and P utilization. The diploid Aegilops and Triticum accessions were unable to use N and P efficiently and only Ae. tauschii accessions exhibited a moderate tolerance to the reduced nutrition. In turn, the wild and primitive tetraploid and hexaploid taxa usually combined high uptake efficiency with enhanced tolerance to nutrients shortage. The results suggest that the tetraploid T. carthlicum, T. dicoccoides, and T. timopheevii and the hexaploid T. sphaerococcum are the most promising taxa for wheat breeding.

Keywords:

• Aegilops
• Triticum
• nitrogen
• phosphorus
• reduced fertilization
• tolerance
• utilization efficiency

ACKNOWLEDGMENTS

The study was in part supported by the State Committee for Scientific Researches, Warsaw (Grant No. 3 P06A 037). We wish to thank Dr. H. Bockelman, NSGC, USDA-ARS, Aberdeen (USA), Dr. D. Wilson, Kansas State Univ., Manhattan KS (USA) and Dr. G. Stefanowska, Agric. Univ., Lublin (Poland) for supplying us with seeds of different species. The skilled assistance of Mrs. M. Kandula, A. Krzemińska, and L. Łagodzińska is greatly acknowledged.

Notes

¹names of the Aegilops and Triticum species according to van Slageren's (van Slageren, 1994) and Dorofeev's (Dorofeev et al., 1979) classifications, respectively

²wild (w), primitive (p) and cultivated (c) species

³accessions signed by PI and CItr – Nat. Small Grains Coll., USDA-ARS, ID Aberdeen; accessions signed by TA-Dep. Plant Pathology, Kansas State Univ., KS Manhattan; others signs – Inst. Plant Genetics, Poznan, PL

⁴used in figures.