摘要
将中性盐 Na Cl和 Na2 SO4 、碱性盐 Na HCO3和 Na2 CO3按不同比例混合 ,模拟出 3 0种盐度和 p H各不相同的盐碱生态条件 ,并对羊草苗进行盐碱混合胁迫处理。测定其日相对生长率 (RGR)等 7项胁变指标 ,用数学方法分析盐度、缓冲量等各种胁迫因素与诸项胁变指标间的相互关系。结果表明 :3 0种处理均匀覆盖了总盐度 5 0～ 3 5 0 mmol/L,p H 7.1 4～1 0 .81范围内的各种盐碱条件。用盐度、缓冲量、p H和 [Cl- ]即可代表盐碱混合胁迫的所有胁迫作用因素。诸胁变指标与这 4因素间均具有高度线性相关性。4因素对胁变的贡献明显不同 ,其中缓冲量和盐度是决定性的主导因素 ,p H和 [Cl- ]的作用明显次之 ,有时甚至可以忽略。不同胁变指标与各因素的关系也有所不同。分析结果表明 :对于盐碱混合胁迫来说 。
According to the salt components in extent alkaline soil in the west of Jilin Province of China, two neutral salts NaCl and Na 2SO 4 and two alkalic salts NaHCO 3 and Na 2CO 3 were selected for this study. The selected salts were mixed in various ratios according to the varying ranges of salinity and pH in the natural soil and the tolerability of Aneurolepidium chinense (Trin.) Kitag to the salt\|alkaline stress. Six treatment groups (labeled as A,...,F) with gradually increased proportion of alkalic salt were set. And in each group, five concentration treatments were 50, 125, 200, 275 and 350 mm respectively. The sum total was 30 combinations with different salinity and pH. Seeds of A. chinense. were collected from a natural grassland located in the west of Jilin Province of China and were sown in 17 cm ( D ). plastic pots of washed sand. All pots were put outdoors and artificially kept out of rain. The seedlings were grown under natural conditions by the sand culture method, and sufficiently watered with Hoagland nutrient solution every two days. Evaporated water was replenished with distilled water at other times. Each pot retained 40 plants. When the seedlings were 4 weeks old, they were subjected to stress. The seedlings growing uniformly (96 pots) were selected and randomly divided into 32 portions with 3 pots per portion (3 replications). Among the 32 portions, 1 portion was a control (CK); 1 portion was used to determine the growth index at beginning treatment; others 30 portions were various stress treatments and were labeled as A1, A2...F5 respectively. Control plants were maintained by watered with nutrient solution; various stress treatments all took nutrient solutions containing stress salts as the treatment solutions. Stress treatments were performed at 4:00～5:00 p.m., by watering the plants thoroughly with 500ml of treatment solution, divided 3 times for a pot. From next morning, the amount of evaporated water was determined by weighing and the evaporated water was replenished with distilled water every day. Sampling was taken after 7 d of treatment. The physiological indices of RGR (the relative growth rate), tillers, rhizomes, electrolyte leakage rate in leaves and the contents of Na +, K +, and proline in shoots were determined. Taking the RGR of control as 100%, the percentages of the RGR of various treatments relative to control were calculated. The pH values of various treatment solutions were determined with a digital pH meter.The buffer capacity was equal to the millimole amount of H + needed to make the pH of 1 L treatment solution dropped to equal with the control by titrating with HCl. The data obtained all were the average of 3 replications. A statistics analysis on correlation coefficient and multivariate regression was performed by using a program Microsoft Excel. A regular changing of pH values was shown in 30 salt combinations. The pH values increased from group A to group F with increasing alkali salt proportion. Within a treatment group, pH values increased with increasing total salt concentration. The range of pH values among groups is greater than within a group. In consideration of the main toxic ion Na +, its concentration increased as 112 5 mmol/L per concentration treatment; the Na + concentrations are 75, 187 5, 300, 412 5, and 525 5 mM corresponding to the five salt concentrations in a treatment group. In consequence, 30 salt\|alkaline conditions with different salinity and pH were established. Their salinity coverage is from 50 mmol/L to 350 mmol/L; [Na +] coverage is from 75 mmol/L to 525 mmol/L; pH coverage is from 7 14 to 10 81. Because the salt component, salinity, and pH in the 30 simulated salt\|alkaline conditions were similar with the conditions in natural salt\|alkaline soil, these simulated salt\|alkaline conditions reproduced the natural complex salt\|alkaline conditions. The way to establish complex salt\|alkaline conditions was a practicable method for researching complex salt\|alkaline stress.
出处
《生态学报》
CAS
CSCD
北大核心
2002年第8期1323-1332,共10页
Acta Ecologica Sinica
基金
吉林省科技发展计划资助项目
国家重点基础研究发展规划资助项目 (G1 9990 1 1 70 0 )
