盐碱胁迫冬油菜的主导因素分析

Analysis of the key stress factors in winter rape under simulated salinity-alkalinity mixed condition

用4种盐分为A因素(NaCl、Na2SO4、Na2CO3和NaHCO3的依次盐分组成摩尔比为A1(1∶9∶9∶1)、A2(1∶1∶1∶1)、A3(9∶1∶1∶9)和A4(1∶1∶9∶9)与5种盐浓度为B因素(盐浓度B1、B2、B3、B4和B5分别为10、20、30、40和50mmol.L-1)的双因素试验,模拟20种不同盐度和pH的盐碱条件处理冬油菜"陇油6号"(Brassica campestris cv.Longyou No.6)的种子和幼苗7d后,测定其种子发芽率、幼苗叶片细胞膜透性、丙二醛、脯氨酸、可溶性蛋白含量和根系活力等指标。结果表明,随着处理盐浓度的增加,种子发芽率、幼苗根系活力和可溶性蛋白含量降低,叶片细胞膜透性和脯氨酸的含量增加;降低和增加程度由A1～A4大体增强,不同盐组成处理间差异显著(P<0.05)。用盐度(Na+)、pH值、CO32-和Cl-代表盐碱混合条件所有胁迫因素,胁迫因素与胁变指标间均具有高度线性相关性。pH值、盐度(Na+)和CO32-是盐碱混合条件对冬油菜胁迫的主导因素,而Cl-的胁迫作用也不可忽略。

Strain index of seed germination rate. seedling leaf cell membrane permeability. MDA content. proline content, soluble protein content and root activity of Longyou No. 6 seeds and seedlings were determined between A factors of 4 kinds of salt for NaCl, NaeSO4, Na2CO3 and NaHCO3, composed of salt mole ratio for Al（1 ： 9 ： 9 ： 1）, A2（1 ： 1 ： 1 ： 1）, A3（9 ： 1 ： 1 ： 9） and A4（1 ： 1 ： 9 ： 9） and B factors of 5 kinds of salt concentration for B1（10 mmol· L^（-1））, B^（20 mmol · L^（-1））, B3（30 mmol · L^（-1））, B4（40 mmol · L^（-1））and B5 （50 mmol · L^（-1）） of the double factors. Twenty kinds of salinity and different pH of saline conditions were simulated to treat winter rape No. 6 seeds and seedling 7D. The results showed that 20 kinds of salinity were from 10 to 50 mmol · L^（-1） and pH was between 8.50 and 10.24. Seed germination rate, seedling root activity and soluble protein content were decreased and leaf cell membrane permeability, MDA content and proline content were increased with the increasing of the concentration of salt treatment. The degree of increase and reduction became higher among A1 to A4 in turn. The different salt composition in treatment reached significant difference （P^0.05）. All stress effect factors under saline mixed conditions were caused by salinity （Na＋ ）, pH, CO32 and Cl-. Stress factors of saline-alkali and strain index of Longyou No. 6 seeds and seedlings had high linear correlation. The dominant factors of winter rape stress were pH.satinity （Na＋）.CO3·（2-） and stress effect on winter rape Longyou No. 6 of Cl- could not be ignored.