Screening for low phosphorus-tolerant soybean cultivars from the Japanese core collection

Soybean growth is frequently hampered by a lack of phosphorus (P). This study aimed to screen soybean cultivars for low P tolerance using cultivars from the Japanese core collection. Eighty-one soybean cultivars were grown in soil cultures for 25 days after transplanting. The plants were subjected to P treatment (- P treatment: 0 g P2O5 kg(-1) soil; and + P treatment: 1 g P2O5 kg(-1) soil). Shoot dry weight, root length, P concentration, and P uptake were measured at 25 days after transplanting. Low P-tolerant and low P-sensitive cultivars were selected based on multiple criteria, including shoot dry weight, P utilization efficiency, and low P tolerance (LPT) value. The shoot dry weight of 30 soybean cultivars was lower in - P than in + P. The root length showed a significant and positive correlation with P uptake, P utilization efficiency, and dry weight in the - P and + P treatments. The LPT values of soybean cultivars ranged from 8 to 160%. The low P-tolerant and -sensitive soybean cultivars can be used as study materials in future studies to elucidate the mechanism of low P tolerance in soybeans.