局部根区水分胁迫下钙对冬小麦生长及养分吸收的影响

以小偃22为材料,采用Hoagland营养液进行分根培养试验,研究了局部根区水分胁迫下,钙对冬小麦幼苗生长及养分吸收的影响。设置2个钙水平处理(正常供钙和不供钙)、3种水分处理(正常水分、局部根区水分胁迫和全部根区水分胁迫),共6个处理。结果表明:不论是否水分胁迫,缺钙处理冬小麦幼苗的株高、主根长、生物量、叶绿素相对含量(SPAD值)、相对含水量及地上部N、P、Ca含量和根系N、P、K、Ca含量均显著低于正常供钙处理(P0.05)。正常供钙条件下,局部根区水分胁迫使株高增加4.4%,正常水分、局部根区水分胁迫和全部根区水分胁迫的植株生物量分别为1.54、1.66 g·株-1和0.97 g·株-1,比缺钙处理分别高19.4%、25.8%和4.3%;全部根区水分胁迫下,冬小麦的株高及主根长均显著降低。缺钙条件下,植株对N、P、Ca等养分的吸收显著降低。正常供钙条件下,正常水分、局部根区水分胁迫和全部根区水分胁迫处理地上部全氮含量分别为36.54、36.65g·kg-1和32.70 g·kg-1,比缺钙处理分别高9.5%、6.5%和6.9%;全磷含量分别为7.48、7.51 g·kg-1和6.54 g·kg-1,比缺钙处理分别高3.0%、13.1%和22.7%;全钙含量分别为8.35、8.37 g·kg-1和5.53 g·kg-1,比缺钙处理分别高26.5%、24.4%和19.7%。结果说明钙显著影响冬小麦幼苗生长发育和养分利用,钙可促进局部根区水分胁迫下冬小麦幼苗的生长及其对养分的吸收,缓解全部根区水分胁迫的抑制效应。

Effects of calcium on growth of winter wheat seedlings and nutrient uptake under partial-root water stress

The effects of calcium on growth and nutrient absorption of winter wheat seedlings (Xiaoyan 22) under partial-root water stress induced PEG-6000 by were investigated, using Hoagland solution cultivation with split-root experiment. Ca²⁺ was eliminated by EGTA. Six treatments were set up in this experiment, including a factorial combination of three water stress schemes (no water stress (CK), half-root water stress (HRWS) and total-root water stress (TRWS)) and two calcium treatments (with calcium and without). The results showed that shoot height, taproot length, biomass, relative water content (RWC), relative chlorophyll content (SPAD), and N, P, Ca concentrations in winter wheat seedlings without calcium treatment were significantly lower than those with calcium, regardless of water stress (P<0.05). With the treatment of calcium, plant height in HRWS was increased by 4.4%. Biomass in CK, HRWS, and TRWS were 1.54, 1.66 g·plant^-1 and 0.97 g·plant^-1, respectively, which were 19.4%, 25.8% and 4.3% greater than those without treatment of calcium. Plant height and root length in TRWS became decreased significantly. Without the treatment of calcium, concentrations of N, P and Ca etc. in seedlings were significantly reduced. Total nitrogen of shoot with calcium treatment in CK, HRWS, and TRWS were 36.54, 36.65 g·kg^-1 and 32.70 g·kg^-1, 9.5%, 6.5% and 6.9%, respectively, higher than those without; total phosphorus were 7.48, 7.51 g·kg^-1 and 6.54 g·kg^-1, 3.0%, 13.1% and 22.7%, respectively, higher than those without; above-ground total calcium were 8.35, 8.37 g·kg^-1 and 5.53 g·kg^-1 respectively, 26.5%, 24.4% and 19.7% higher than those without calcium. The results indicated that calcium had significant effects on the development and nutrient use of winter wheat seedlings by promoting growth and nutrient uptake under water stress, relieving the inhibitory effect in the entire root.