Abstract: Field and pot experiments were conducted by using indica rice varieties with different chalkiness.There were significant differences in root activity among the used materials.Both the chalky grain rate and chalkiness were negatively correlated with root activity expressed as α-naphthylamine oxidation ability(NOA) per gram of fresh root(NOA_fw),NOA per spikelet(NOA_grn),or NOA per sink capacity(NOA_sink).The NOA_sink was more closely related to chalkiness than NOA_fw and NOA_grn when varieties differing greatly in panicle size and grain weight.Application of NO₃^——N fertilizer at heading resulted in higher root activity and reduction of chalkiness.While application of 30 mg/L NaN₃(respiration inhibitor) resulted in reduced root activity and increased chalkiness for GD9501 with more chalky grains,whereas increased root activity and reduced chalkiness for Qinliu′ai with less chalky grains.The chalky grain rate and chalkiness were negatively correlated with root activity at 10 days after heading under different chemical treatments(r=-0.8567^* and r=(-0.9211^**,) respectively).

Key words: chalkiness, root activity, relationship, nitrate nitrogen, sodium azide, rice

摘要： 以垩白不同的籼稻品种为材料，进行了田间试验和盆钵试验。结果表明,垩白不同的品种，其结实期根系活性存在显著差异。垩白米率、垩白度与结实期根系活性呈负相关。在根系活性指标中，库容根活量与垩白的关系最密切，而根系α萘胺氧化力、颖花根活量与垩白的相关性较低。在抽穗期施用硝态氮肥，可以明显提高根系活性，减少垩白。抽穗期施用呼吸抑制剂叠氮化钠，导致多垩白品种GD9501的根系活性大幅度下降，垩白米率和垩白度大幅度提高；但少垩白品种青六矮表现相反。不同药剂处理下，垩白米率和垩白度分别与抽穗后10 d的根系活性呈显著（r=-0.8567*）和极显著(r=-0.9211**)负相关。

关键词: 垩白, 根系活性, 相关关系, 硝态氮, 叠氮钠