摘要：For turf, lower nitrogen (N) inputs and plants bred for increased N use efficiency (NUE) are essential. The objectives of this study were to investigate diverse bermudagrass accessions for growth response, N accumulation and partitioning in N limiting conditions, as well as to determine the phenotypic traits associated with the variability in tolerance to low N supply. Four bermudagrass cultivars [i.e.，4Yangjiang’，4SuzhiNo.4’，4Nanjing’ common bermudagrass (Cynodon dactylon (L.) Pers), and 4Suzhi No. 25 hybrid bermudagrass (C. transvaalensis x C. dactylon)] were grown at two N levels [0.5 mmol.L-1 (low) and 5 mmol.L-1 (control)] in a hydroponic experiment, and the responses were compared with 'Tifway5 hybrid bermudagrass (C. transvaalensis x C. dactylon). For all accessions at the low N level, the shoot density (except for 'Yangjiang5) and the leaf length and width decreased, whereas the NUE increased. Additionally, at the low N level, total plant dry weight (TPDW) was not significantly different from that of the control; however, the portions of dry weight and accumulated N allocated to verdure other than roots increased. Associated with the variability in tolerance of diverse bermudagrass cultivars to the low N supply, principal component analysis revealed that the relative values (from the comparison between the low level of N and the control N) of leaf width (LW), TPDW, total clipping accumulated N (TCAN), verdure accumulated N (VAN), and total clipping NUE (TCNUE) accounted for much of the variation for both levels of N levels and different accessions. Accession 'Yangjiang5 was the most tolerant to N limitation with relative values of TPDW, VAN, and TCNUE that were significantly higher than those of the 'Tifway5 hybrid. The tolerance to low levels of N for accessions ‘Nanjing’，4Suzhi No. 4’ and 4Suzhi No. T were not significantly different from that of the 4Tifway’ hybrid, with relative values of TPDW and VAN that were not significantly different from thoseof 4Tifway.
