燕麦根系对缺磷胁迫的适应性反应

采用溶液培养的方法,在燕麦苗期,研究了磷素充足供应和缺磷胁迫两种条件下根系形态指标的变化。结果表明,经过30d的缺磷胁迫,燕麦根系生物量显著低于充足供磷处理,但根系总长并未表现为缺磷处理显著低于充足供磷处理,而且根冠比、比根长却表现为缺磷处理显著高于磷素充足供应处理。缺磷条件下比根长的增加与根轴直径的减小是一致的,因此根轴横向生长减弱可能是导致缺磷燕麦根系比根长增加的原因。由于比根长的增加意味着消耗同样的同化产物,却可以形成具有较大吸收范围的根系,因此燕麦根轴直径减小、比根长的增加是燕麦对缺磷胁迫的适应。

Adaptive Response of Oat Root System to Phosphorus Deficiency

Nutrient solution culture was employed to investigate the response of oat seedling roots to phosphorus deficiency. The results showed that after 30 days of treatment, the roots biomass of oat with P deficiency was significantly lower than that of oat supplied with sufficient P, however, the total root length of P-deficiency oat was not significant lower than high-P oat''s. It also showed that root /shoot ratio and specific root length for P-deficiency oat were higher than for high-P oat. Smaller root diameter for P-deficiency oat root axes was coincident with the higher specific root length, so it can be the reason for higher specific root length of P-deficiency oat. It is well known greater specific root length implies the root system exploring more soil for P with same assimilates consumption, therefore, the decrease of root diameter and increase of specific root length can be thought as the adaptive response of oat seedling to P deficiency.