不同磷水平下小麦B染色体双端体植株干物质积累和磷效率特征研究

以中国春（CS）及其B染色体组双端体（1BS7BS和1BL7BL））为材料，采用溶液培养法，研究了不同磷水平下各供试材料的干物质积累和磷效率特征。结果表明，与CS相比，丰磷下4BS、6BS、3BL及7BL和低磷下4BS、6BS、7BS、和7BL植株形态及单株干重无明显变化，其他B染色体组双端体植株形态变劣、单株干重降低。丰、低磷下，各双端体单株磷累积量与CS相比多呈减少趋势，表明缺失B染色体长、短臂对小麦的磷素吸收和累积发挥不同程度负调控效应。全磷含量表现为丰磷下4BS和4BL较CS显著增加、5BS较CS显著降低；低磷下5BS较CS显著提高，3BL和5BL较CS显著降低。与CS相比，各双端体植株的磷效率变幅较大，呈与单株磷累积量相反趋势变化，即丰磷下3BS、5BS较CS显著增加，4BS、1BL和4BL较CS显著减少。丰、低磷条件下，多数双端体植株氮钾效率与CS相比也发生不同程度改变。丰、低磷磷下单株干重与磷累积量呈显著正相关，且单株干重与单株叶面积也呈显著正相关。因此，本研究证实，特定B染色体组长、短臂在调控植株抵御低磷逆境中发挥着重要遗传效应，可用单株叶面积作为丰、低磷下植株磷效率的评价指标。

The accumulation of dry matter and phosphorus efficiencies in wheat chromosome B ditelosomic lines under both sufficient- and low-Pi conditions

 Chinese spring (CS) and ditelosomic lines (DL) from B chromosome (1BS-7BS, 1BL-7BL) were used to investigate the accumulation of plant dry matter and phosphorus efficiencies under sufficient-Pi and low-Pi conditions by hydroponics experiment. Compared with CS, the plant phenotypic features and dry weights of 4BS, 6BS, 3BL and 7BL under sufficient-Pi condition and those of  DL 4BS, 6BS, 7BS and 7BL under low\|Pi condition were stable.  The phenotypic features in the other DLs became worese and the dry weight decreased significantly at both  Pi\|supply conditions.   The P accumulation amount per plant in the tested DLs displayed a decreasing trend compared with CS under both  Pi\|supply conditions, suggesting that the deletion of long or short chromosome B arms in wheat were involved in regulating accumulation of phosphorus in the plant. Under sufficient-Pi condition, the total P contents in 4BS and 4BL were significantly higher than that in CS, whereas that in 5BS was significantly lower than that in CS. Under low-Pi condition, the total P content in 5BS was significantly higher than that in CS, whereas that in 3BL and 5BL were significantly lower than that in CS. Compared with CS, the tested DLs relatively showed a higher variation range in plant P usage efficiencies under both sufficient\| and low-Pi conditions, and generally demonstrated a reverse tendency of P accumulation amount in each line of the plant. The P use efficiencies in 3BS and 5BS were higher than that in CS under sufficient-Pi condition, whereas P usage efficiencies in 4BS, 1BL, and 4BL were higher than that in CS under low\|Pi condition. Supply with sufficient Pi or low Pi also changed the efficiencies of N- and K-usage in the DLs to the extent. Positive correlations are significantly observed between plant dry weight and P accumulation, as well as plant dry weight and plant leaf area. Therefore, our results indicate that wheat DLs with deletion play an important role in mediating plant responses to external Pi and genetically in regulating P use efficiencies. Leaf area per plant could be used for evaluating plant P use efficiency under both sufficient\| and low-Pi conditions.