低磷诱导下沙棘根系形态构建和光合作用变化

以沙棘(Hippophae rhamnoides L.)实生幼苗为试材,设置正常供磷170 mg/L(HP)和低磷胁迫0.68 mg/L(LP)两种处理,采用沙培盆栽的方式,探讨了沙棘幼苗对低磷胁迫的响应,分析了沙棘幼苗生物量、根系构型及光合特性的差异.结果表明:低磷胁迫显著(P<0.05)增加了植株的根冠比,高达45...

Morphological Construction and Photosynthetic Changes of Hippophaerhamnoides L.Root System Under Low Phosphorus Induction

The seedlings of Hippophaerhamnoides L.were used as test materials,and two treatments of normal phosphorus supply of 170 mg/L(HP)and low phosphorus stress of 0.68 mg/L(LP)were set.The response of Hippophaerhamnoides L.seedlings to low phosphorus stress,and the differences in biomass,root architecture and photosynthetic characteristics of Hippophaerhamnoides L.seedlings were analyzed.The results showed that low phosphorus stress significantly ( P <0.05) increased the root-to-crown ratio of the plants by up to 45%. The low phosphorus had a significant induction effect on the growth and development of seedling roots, and the total root length increased by 18% compared with that under HP treatment, indicating that root growth and development under low phosphorus conditions had an important role in phosphorus uptake by H. rhamnoidesL . seedlings. The low phosphorus stress reduced photosynthetic rate and transpiration rate of H. rhamnoidesL . seedlings by 36% and 46%, respectively;chlorophyll a, b, and a + b of H. rhamnoidesL . seedlings were reduced by 22%, 12.7%, and 20%, respectively, under LP treatment compared with under HP treatment. The maximum photochemical efficiency Fv/Fm and actual photochemical efficiency Y(II) of PSⅡ decreased by 10% and 7%, respectively, compared with those under HP treatment;the photochemical burst coefficient qP and non-photochemical burst quantum yield Y(NO) increased by 1.9% and 7%, respectively, compared with those under HP treatment. In conclusion, under LP treatment, Hippophaerhamnoides L . seedlings responded to low phosphorus stress by self-regulating and promoting root growth.