等渗Ca（NO3）2和NaCl胁迫对黄瓜幼苗根系形态及活力的影响

以盐敏感型黄瓜品种‘津春2号’为试材,采用营养液栽培,研究了等渗Ca(NO3)2和NaCl胁迫对黄瓜幼苗根系形态、活力及幼苗生长的影响。结果表明:2种盐胁迫均显著抑制根系的生长,导致根系表面积和根体积大幅下降。在56 mmol.L-1Ca(NO3)2胁迫下,根系生物量下降了29.23%,根系总长度显著降低,但侧根密度与根系平均直径显著增加,根尖膨大短粗,根系整体呈簇生状,根系活力显著上升;而在84 mmol.L-1NaCl胁迫下,根系生物量下降了43.08%,根系总长度下降的幅度小于等渗Ca(NO3)2胁迫的,但侧根密度与根系平均直径均显著减小,根尖纤细,根系外观细小,根系活力显著下降。表明,根系形态的变化与2种盐胁迫对根系造成的不同伤害密切相关,其中NaCl胁迫对根系的抑制程度大于等渗的Ca(NO3)2。

Effects of iso-osmotic Ca ( NO3 ) 2 and NaCl stress on root morphology and activity of cucumber seedlings

In order to investigate the effects of iso-osmotic Ca(NO3)2 and NaCl stress on the morphology,the activity of root and growth of cucumber seedlings,cucumber cultivar’Jinchun 2’(with less salt resistance)was used to carry out the experiment by nutrient solution culture.The results showed that both of salt stress significantly inhibited root growth,and decreased the root surface area and root volume obviously.Under 56 mmol·L-1 Ca(NO3)2 stress the total root biomass declined by 29.23% and the root length decreased significantly,but the lateral root density and average root diameter increased obviously.Root tips became short but swollen,and the whole root grew like clusters and the root activity increased significantly.Meanwhile,under 84 mmol·L-1 NaCl stress the total root biomass significantly decreased by 43.08% and the decline in total root length was less than the isotonic Ca(NO3)2 stress,but the lateral roots density and average root diameter decreased obviously,the root became slender,and the root activity decreased significantly.In conclusion,both salt stress inhibited the root growth and changed the root architecture,and the inhibition of NaCl on root was greater than that of isotonic Ca(NO3)2.