Screening for internal phosphorus utilisation efficiency: comparison of genotypes at equal shoot P content is critical
Progress in improving the internal phosphorus utilisation efficiency of crops has been limited, which may be due to poor screening methods that allow differences in P uptake among genotypes grown in soil to mask genotypic differences in shoot biomass produced per unit of shoot P (PUE). We investigated alternative soil and hydroponic screening methods for their capacity to produce a consensus ranking of genotypes with regard to PUE.
Six rice genotypes previously identified in hydroponic screening studies as being high, intermediate or low in PUE were screened using multi P rate hydroponic and soil-based experiments.
Comparisons made at each rate of soil-P supply produced estimates of PUE strongly biased by P uptake differences among genotypes. Using multiple-rate data to derive response functions per genotype showed that similar P content was achieved at different rates of P supply but that high-PUE genotypes clearly separated from intermediate- and low-PUE genotypes if equal P content was used. Ranking analysis suggested that results obtained from soil agreed well with those from the hydroponic study.
PUE was significantly influenced by genotype and P supply, but there was no significant genotype x P supply interaction. Hence, we conclude that screening genotypes using hydroponics at one or two P supply levels is the most cost- and time effective means to screen large numbers of rice genotypes for PUE.
KeywordsGenotypic difference Hydroponics Phosphorus efficiency Phosphorus use efficiency Nutrient utilisation efficiency Rice
- Rose TJ, Wissuwa M (2012) Rethinking internal phosphorus utilization efficiency: a new approach is needed to improve PUE in grain crops. Adv Agron 116:183–215Google Scholar
- Wissuwa M, Kondo K, Fukuda T, Mori A, Rose MT, Pariasca-Tanaka J, Kretzschmar T, Haefele SM, Terry J. Rose TJ (2015) Unmasking novel loci for internal phosphorus utilization efficiency in rice germplasm through Genome-Wide Association Analysis. PLOS OneGoogle Scholar
- Yoshida S, Forno DA, Cock J (1976) Laboratory manual for physiological studies of rice. International Rice Research Institute, ManilaGoogle Scholar