从以成恢448为轮回亲本，M401为供体亲本构建的回交后代BC1F6筛选出的耐低磷材料（GP9）和低磷敏感材料（GP14）及其亲本用于盆栽试验，设置P2（2.31 mg/kg）、P30（30 mg/kg）和P80（80 mg/kg）3个磷处理水平，以P80处理为对照计算性状相对值，研究不同磷处理浓度对供试材料6个生物学性状的影响。结果表明，P2处理较P30处理更能反映不同材料性状相对值间的差异，宜用于苗期耐低磷筛选。P2处理时，GP9与GP14及其亲本播种后52 d、59 d和66 d的相对分蘖数差异均达极显著水平，建议采用相对分蘖数作为水稻苗期耐低磷筛选的主要鉴别指标。同时，运用相对叶面积、相对绿叶数和相对叶龄进行综合评定。
Phosphorus (P) shortage in soil is a key-limiting factor in agricultural production. There are P-efficiency differences among different rice genotypes, screening and cultivating low-P tolerant cultivars have become very important. To evaluate the screening method and identification indexes, Chenghui 448（GP1）, the recurrent parent, M401（GP4）, the donor parent, low-P tolerant line GP9 and low-P sensitive line GP14 identified from backcross progenies of Chenghui 448/M401 were used in pot soil cultural experiments with three treatments, including the original P concentration of supplied soil (P2, 2.31 mg/kg), and two supplementary P application levels of P30 (30 mg/kg) and P80 (80 mg/kg). The concentration P80 was used as the normal control; the effects of different inorganic phosphorus supply on relative number of tillers, relative leaf area, relative number of green leaves, relative leaf age, relative chlorophyll content and relative plant height of cultivars were investigated. The main results were summarized as follows: Genotypic differences were found distinctly in many traits with P2 treatment, which was better than P30 treatment to distinguish low-Pi tolerant genotypes from those sensitive to P deficiency at seedling stage. Under P2 condition, the differences among the relative number of tillers in different lines for 52 d, 59 d and 66 d were significant, indicating that relative number of tillers may be used as main index for screening and identifying the tolerance to Pi deficiency. In addition, relative leaf area, relative number of green leaves and relative leaf age can be employed to evaluate the tolerance to Pi deficiency in rice germplasm, comprehensively.
全 文 ：