K2SiO3促进梭梭生长并增强其抗旱性

通过修正1/2 Hoagland营养液配方加入K2SiO3的(KCl对照)方式,以蛭石为基质进行溶液培养,研究了硅(Si)元素在多浆旱生植物梭梭(Haloxylon ammodendron)生长和抗旱性中的生理作用。结果显示,与相应KCl对照相比,外加一定浓度的K2SiO3对梭梭的生长有促进作用,其中15 mmol·L-1 K2SiO3对梭梭生长的促进作用最大,而50 mmol·L-1以上的K2SiO3的处理(KCl对照)显著抑制了梭梭的生长(P0.05)。与未施肥和30 mmol·L-1 KCl相比,15 mmol·L-1 K2SiO3 处理的梭梭株高分别增加了20.2%和11.4%,分枝数分别增加了41.4%和21.6%;鲜重分别增加了39.1%和14.5%,含水量分别增加了35.2%和13.8%。在不同强度渗透胁迫下,与30 mmol·L-1 KCl对照相比,15 mmol·L-1 K2SiO3处理显著提高了梭梭的抗旱能力,使同化枝中丙二醛含量和相对电导率显著下降,减轻了渗透胁迫对梭梭生长造成的伤害。与对照和施加30 mmol·L-1 KCl的植株相比,当渗透势分别为 -0.5(轻度)、-1.0(中度) 和 -1.5 MPa(重度)时,15 mmol·L-1 K2SiO3处理的梭梭株高分别增加了24.7%和10.1%,26.4%和13.8%,24.2%和12.9%;鲜重分别增加了43.6%和15.7%,52.7%和15.0%,59.3%和20.1%;同化枝中丙二醛含量则降低了26%和12%,32.8%和17.2%,31.3%和17.2%,相对电导率降低了26.7%和13.3%,41.2%和23.5%,47.5%和25% (P0.05)。研究结果表明,适量浓度的K2SiO3处理能促进梭梭的生长并通过降低同化枝中相对电导率和丙二醛含量的积累来增强梭梭的抗旱性。

K2SiO3 promotes the growth and improves drought resistance of Haloxylon ammodendron

In the study, the vermiculite was used as substrate and the modified 1/2 Hoagland nutrient solution containing K2SiO3 (KCl as control) was irrigated to study the physiological effects of silicon (Si) on the growth and drought resistance of the succulent xerophyte Haloxylon ammodendron. Results showed that the low concentration of K2SiO3 (KCl as control) stimulated the growth and 15 mmol·L-1 K2SiO3 (30 mmol·L-1 KCl as control) was the optimum concentration, while ≥50 mmol·L-1 K2SiO3 significantly inhibited the growth of H. ammodendron. Compared with the control and 30 mmol·L-1 KCl, 15 mmol·L-1 K2SiO3 significantly increased plant height by 20.2% and 11.4%, branching numbers by 41.4% and 21.6%, fresh weight by 39.1% and 14.5%, and water content by 35.2% and 13.8%, respectively(P0.05). Under different osmotic stress (-0.5,-1.0 and -1.5 MPa), 15 mmol·L-1 K2SiO3 (30 mmol·L-1 KCl as control) significantly improved the drought resistance and alleviated the harmful effects of H. ammodendron by decreasing the content of MDA and relative conductivity in assimilating shoots. Compared with the control and 30 mmol·L-1 KCl, 15mmol·L-1 K2SiO3 significantly increased plant height by 24.7% and 10.1%, 26.4% and 13.8%, 24.2% and 12.9%, respectively, and fresh weight by 43.6% and 15.7%, 52.7% and 15.0%, 59.3% and 20.1%, respectively, while the MDA concentration in assimilating shoots significantly decreased by 26% and 12%, 32.8% and 17.2%, 31.3% and 17.2%, respectively, and relative conductivity by 26.7% and 13.3%, 41.2% and 23.5%, 47.5% and 25% in the mild (-0.5 MPa), moderate (-1.0 MPa) and severe osmotic stress (-1.5 MPa), respectively(P0.05). The results showed that a certain amount of K2SiO3 (KCl as control) could promote growth and improve the drought resistance of H. ammodendron by decreasing the relative conductivity and MDA content in assimilating shoots.