[An approach to the screening index for low phosphorus tolerant rice genotype].
Screening and breeding low phosphorous (P) tolerant rice genotype is one of the effective alternatives to alleviate the scarcity of mineral P resource and to increase the utilization efficiency of P fertilizer. Selecting a simple and scientific screening index plays an important role in the screening and breeding program. In this study, a hydroponic culture experiment and a field trial were carried out to approach the screening index for low P tolerant rice genotypes. The results showed that among all the rice characters studied, total dry weight demonstrated a significant genotypic variation at both normal and low P supply (the CV was 21.73% and 19.54%, respectively). Relative total dry weight (low P supply/normal P supply) also demonstrated significant genotypic variation (CV was 19.60%), which was significantly correlated to relative root dry weight, relative plant height, relative total P uptake, relative shoot P accumulation, relative P utilization efficiency and relative P concentration (P < 0.01). Therefore, the relative total dry weight of rice would be an important evaluation or screening index for the low P tolerance ability of rice at its seedling stage. The relative total dry weight of rice in hydroponic culture system was not correlated to the relative grain yield (minus-P/plus-P) in field trial, which meant that it could not be used as an index to evaluate the low P tolerance ability of rice. The internal P utilization efficiency of rice grown in low P solution was significantly correlated to that of rice grown in P-deficient soil (r = 0.798 * *, n = 8). Therefore, screening rice genotypes by using internal P utilization efficiency of rice grown in low P solution at seedling stage as screening index and subsequently testing in field trial would probably be an effective alternative to screen rice genotype with high P utilization efficiency.
Li
Yongfu
Y
Key Laboratory of Subtropical Soil and Plant Nurtrition of Ministry of Agriculture, Zhejiang University, Hangzhou, China. yongfuli@zju.edu.cn
Luo
Ancheng
A
Wang
Weimu
W
Yang
Changdeng
C
Yang
Xiao'e
X
D005838:Genotype; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism*; D036226:Seedlings
D010758:Phosphorus