Genotypic differences in root morphology and phosphorus uptake kinetics in Brassica napus under low phosphorus supply

• Published in: Journal of plant nutrition Vol. 33; no. 5-8; pp. 889 - 901
• Main Authors: Hu, Yifan, Ye, Xiangsheng, Shi, Lei, Duan, Haiyan, Xu, Fangsen
• Format: Journal Article
• Language: English
• Published: Philadelphia, NJ Taylor & Francis Group 07-04-2010; Taylor & Francis; Taylor & Francis Ltd
• Subjects: acid soils; Agronomy. Soil science and plant productions; Biological and medical sciences; Brassica napus; calcareous soils; cultivars; dry matter accumulation; Economic plant physiology; Efficiency; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; genetic variation; genotype; kinetics parameters; Metabolism; Metabolism. Physicochemical requirements; Nitrogen, phosphorus, potassium fertilizations; nutrient availability; nutrient deficiencies; nutrient uptake; nutrient use efficiency; Nutrition. Photosynthesis. Respiration. Metabolism; P utilization efficiency; phosphorus; phosphorus acquisition; Phosphorus fertilization; phosphorus fertilizers; plant morphology; Plant physiology and development; rapeseed products; root morphology; root systems; roots; Soil-plant relationships. Soil fertility. Fertilization. Amendments; temporal variation; uptake mechanisms; Genetic variability; Phosphorus fertilization; Cruciferae; Plant nutrition; Dicotyledones; Angiospermae; C3-Type; Non metal; Vegetals; Root; Nutrient recovery; root morphology; Phosphorus; phosphorus acquisition; Nutrient uptake; Acquisition; P utilization efficiency; Group VA element; kinetics parameters; Morphology; Vegetative apparatus; Brassica napus; Spermatophyta; Kinetics; Kinetic parameter; Oil plant (vegetal)
• ISSN: 0190-4167; 1532-4087
• DOI: 10.1080/01904161003658239

Application of phosphorus (P) fertilizer is important in crop production because of the low bioavailability of phosphorus to plants in both acidic and calcareous soils. Although rapeseed (Brassica napus) is generally sensitive to P deficiency, different cultivars differ widely in this respect. Differences in P uptake and utilization between two rapeseed cultivars, one P-efficient ('97081') and one P-inefficient ('97009'), were evaluated in solution culture by studying the changes in root morphology and parameters of P uptake kinetics in response to low-P stress. The P-efficient cultivar had lower Km and Cmin values and higher Vmax and developed longer and denser lateral root hair with greater number of root tips and branches under low-P stress, which resulted in a better developed root system and more efficient uptake of P. That, in turn, led to higher concentration and accumulation of P in the plants, culminating in higher biomass production. However, P utilization efficiency (biomass production per unit P accumulated in plant) of the P-efficient '97081' was lower than that of '97009' when P was deficient. These results suggest that P efficiency in rapeseed is due to a better developed root system as well as efficient uptake of P.