高氯酸盐胁迫对水稻生长发育和养分吸收的影响

通过土培盆栽试验,研究了0.2、2.0和4.0mmol/kg 3种浓度下高氯酸盐胁迫对两个水稻品种的生长发育和吸收主要养分元素氮、磷、钾的影响。研究发现:(1)高氯酸盐对水稻生长的抑制程度随高氯酸盐处理浓度的增高而加重,且随着处理时间的延长,水稻的受害症状也越来越明显,到分蘖期时,3个浓度组对赣糯香生长的抑制率分别为3.08%、33.39%和39.03%,对IR65598-112-2生长的抑制率分别为9.18%、21.07%和34.97%。(2)各浓度处理组(赣糯香0.2mmol/kg组除外)都显著抑制了两品种水稻的分蘖。(3)各浓度处理组水稻始穗时间都比对照组晚,其中高浓度处理组晚了1个月。(4)IR65598-112-2对高氯酸盐的胁迫表现出更早的反应和对低浓度污染物的敏感性,而赣糯香表现出相对较强的抗性。(5)高氯酸盐对水稻根部的伤害比对地上部的伤害更严重。(6)高氯酸盐处理减少了水稻各器官的生物量,降低了水稻各器官中养分元素总氮和总磷的总积累量。研究表明,高氯酸盐污染可抑制两品种水稻的生长和分蘖,延迟其发育,降低水稻对养分元素的积累,其植物毒性效应与污染物的浓度、处理的延续时间、水稻品种及不同植物器官都有关系。

Effect of perchlorate stress on the growth and development of rice and its nutrient uptake

Two rice varieties with varied perchlorate-sensitivity were selected to study their response when exposed to perchlorate-contaminated environment. Gannuoxiang is a perchlorate-resistance rice variety while IR65598-112-2 is a perchlorate-sensitive rice variety. A pot experiment was conducted to study the effects of perchlorate stress on plant growth, development and nutrient uptake. Perchlorate with three concentration levels at 0.2, 2.0 and 4.0 mmol/kg was added to the soil for different treatments at the end of recovering stage after transplanting. Results showed that (1) the higher the concentration of perchlorate in soil, the higher the rate of growth inhibition of the two rice varieties. The symptom of the perchlorate effect on rice was more and more obvious as time went on. The rates of the growth inhibition were 3.08%, 33.39%, 39.03% to Gannuoxiang and 9.18%, 21.07%, 34.97% to IR65598-112-2 under the three concentration levels of perchlorate in the tillering stage of rice. (2) The rice tiller number of all treatments except Gannuoxiang at 0.2 mmol/kg level decreased significantly. (3) All perchlorate treatments delayed heading and maturity. The delay reached about one month under high level perchlorate treatment. (4) IR65598-112-2 showed earlier respond to perchlorate and more sensitive to low concentration of perchlorate than Gannuoxiang. (5) The phytotoxic effect of perchlorate on rice root was more serious than on its aboveground parts. (6) Perchlorate pollution significantly decreased the biomass of rice. The accumulation of total nitrogen and total phosphorus was reduced markedly. In conclusion, perchlorate pollution can decrease the growth and tiller number of the two rice varieties, delay their development, consequently, result in low biomass and low accumulation of nutrient. The phyto-toxicity of perchlorate to rice not only depended on the pollutant concentration and its duration, but also on the specific rice varieties and its organs.