title: Genotypic Differences in Phosphorus Efficiency and the Performance of Physiological Characteristics in Response to Low Phosphorus Stress of Soybean in Southwest of China.
abstract: Southwest of China is one of the major soybean (Glycine maxL.) production regions in China with low availability of soil phosphorus (P). Whereas little information is available on P-efficient soybean genotypes in this region, even though using P-efficient soybean genotypes is a sustainable P management strategy for enhancing yield and P use efficiency. To assess the genetic variation on P use efficiency, 274 soybean genotypes were employed to compare the yields and P acquisition potentials in the field. Additionally, 10 representational genotypes (5 P-efficient genotypes and 5 P-inefficient genotypes) were grown in hydroponic media containing low P treatment (0.05 mM L-1) and high P treatment (0.25 mM L-1) to further investigate P assimilation characteristics and the related mechanisms of P-efficient soybean genotypes. In the field trial, the models described the relationships between yield and seed P concentration (R2= 0.85), shoot P accumulation (R2= 0.84), HI (R2= 0.82) well. The yield, seed P concentration and shoot P accumulation ranged from 5.5 to 36.0 g plant-1, from 0.045 to 0.93% and from 0.065 to 0.278 mg plant-1, respectively. In the hydroponic trial, P-efficient genotypes under low P treatment showed significantly better plant growth, P accumulation and root: shoot ratio than P-inefficient genotypes. Simultaneously, total root length, specific root length, root surface area and root volume of P-efficient were significantly greater than P-inefficient under low P treatment. Higher rate of organic acid exudation and acid phosphatase activities was observed in the P-efficient soybean genotypes under low P condition when compared to the P-inefficient soybean genotypes. It indicated that significant genetic variation for P use efficiency existed in this region, and the P-efficient soybean genotypes, especially E311 and E141, demonstrated great tolerance to P deficiency, which could be potential materials using in improving production and P use efficiency in low availability of soil P region.
authors.affiliation: College of Agronomy, Sichuan Agricultural University Chengdu, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhou
authors.affiliation: College of Agronomy, Sichuan Agricultural University Chengdu, China.
authors.forename: Yongli
authors.initials: Y
authors.lastname: Du
authors.affiliation: College of Agronomy, Sichuan Agricultural University Chengdu, China.
authors.forename: Shoaib
authors.initials: S
authors.lastname: Ahmed
authors.affiliation: College of Agronomy, Sichuan Agricultural University Chengdu, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Liu
authors.affiliation: College of Agronomy, Sichuan Agricultural University Chengdu, China.
authors.forename: Menglu
authors.initials: M
authors.lastname: Ren
authors.affiliation: College of Agronomy, Sichuan Agricultural University Chengdu, China.
authors.forename: Weiguo
authors.initials: W
authors.lastname: Liu
authors.affiliation: College of Agronomy, Sichuan Agricultural UniversityChengdu, China; Key Laboratory of Crop Ecophysiology and Farming System in Southwest, Ministry of AgricultureChengdu, China.
authors.forename: Wenyu
authors.initials: W
authors.lastname: Yang
keywords: Glycine max; acid phosphatase; organic acids; phosphorus; root morphology; yield