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以水稻(绿旱1号)为供试材料,通过对根系形态及生物量分配的测定,探索了汞胁迫下水稻根系生长对缺氮、缺磷和铁膜诱导的响应。结果发现:减少氮、磷供应和铁膜诱导均可促进水稻根系的生长,其中根长分别提高了35.8%、75.3%、102.2%,根表面积分别提高了46.6%、47.8%、60.8%,根冠比分别从对照组的22.1%提高到29.9%、27.3%、28.23%。与此同时,在汞胁迫条件下(0.5 mg Hg(II)·L-1),减少氮、磷供应及铁膜诱导的处理对水稻根系生长的影响没有达到显著水平。单独的汞胁迫处理对水稻根系的生长有抑制作用,但效果并不显著。另一方面,在汞胁迫且减少氮磷施用的条件下,进行铁膜诱导能够促进根系的生长,表现为:铁膜诱导处理提高了汞胁迫下缺氮水稻的根长,增幅为64.6%;对于汞胁迫下的缺磷水稻,铁膜的形成对根长、根表面积、根尖数均有提高作用,增幅分别为74.9%、56.5%和94.7%。研究表明:汞胁迫对水稻根系的生长有抑制作用,减弱了水稻根系对养分缺乏的响应,而铁膜的生成可以在一定程度上减弱汞离子对根系的危害。
Rice (Lvhan No.1) was used as test material. Root morphology and biomass allocation were measured to explore the response of rice root growth to nitrogen, phosphorus and iron deficiency induced by mercury stress. The results showed that reducing the supply of nitrogen and phosphorus and the induction of iron film all could promote the growth of rice roots. The root length increased by 35.8%, 75.3% and 102.2%, and the root surface area increased by 46.6%, 47.8% and 60.8% The crown ratio increased from 22.1% in the control group to 29.9%, 27.3% and 28.23% respectively. Meanwhile, under the condition of mercury stress (0.5 mg Hg (II) · L-1), the effect of reducing nitrogen and phosphorus supply and iron film-induced treatment on root growth of rice did not reach significant level. Mercury stress alone inhibited the growth of rice roots, but the effect was not significant. On the other hand, under the conditions of Hg stress and reduced application of N and P, the induction of iron film can promote the growth of root system. The results showed that the iron film induced treatment increased the root length of nitrogen - deficient rice by 64.6%. The formation of iron film had an effect on the root length, root surface area and root tip number of P-deficient rice under mercury stress, increasing by 74.9%, 56.5% and 94.7%, respectively. The results showed that the mercury stress inhibited the growth of rice roots, reduced the response of rice roots to nutrient deficiency, and the formation of iron membrane could weaken the damage of mercury ions to the roots to a certain extent.