不同能源柳无性系对NaCl胁迫的生理响应

Physiological responses of different willow's clones to NaCl stress

为了探索不同能源柳无性系的耐盐潜力,在盆栽条件下,对1年生能源柳无性系2、4、C、E扦插苗设置NaCl盐分梯度,使其土壤含盐量保持在0、0.2%、0.4%、0.6%、0.8%,并以乡土旱柳为对照,胁迫45d后,对5个无性系的气体交换参数、保护酶活性和有机渗透调节物质进行测定。研究发现:(1)在低浓度盐胁迫下(土壤含盐量0 0.4%),导致各能源柳光合速率降低的是气孔因素;在高浓度盐胁迫下(土壤含盐量大于0.4%),导致各能源柳无性系光合速率下降的主要是非气孔因素。(2)随着土壤盐浓度的增加,各能源柳无性系的过氧化氢酶(CAT)活性逐渐减小,过氧化物酶(POD)活性先增加后减小,而超氧化物歧化酶(SOD)活性呈现增加的趋势,并且4个能源柳无性系在盐胁迫条件下保护酶活性强于旱柳。(3)在土壤含盐量小于0.6%时,4个能源柳无性系的可溶性蛋白含量始终大于旱柳;在整个胁迫过程中,能源柳C的脯氨酸含量始终大于旱柳。(4)与旱柳相比,4个能源柳无性系在土壤含盐量0 0.4%的土壤中都能良好生长,其中能源柳C的耐盐潜力更大,可在土壤含盐量为0.6%的土壤中正常生长。这说明,4个能源柳无性系均可在天津轻、中度盐渍化地区栽培。

We examined the NaCl resistant potential of four energy willow clones（Salix.dasyclados,S.＇Mesu Neko＇,S.fragilis,S.viminalis） and one wild clone（S.matsudana） grown on containers with five soil NaCl concentrations（0,0.2%,0.4%,0.6% and 0.8%）.After 45 days′ salt stress,gas exchange,protective enzyme activities and the organic substance for osmotic adjustment were measured.We found that（1） the decline of photosynthetic rate of four energy clones was caused by stomata factors when soil NaCl concentration 〈0.4%,while it was mainly caused by non-stomata factors when soil NaCl concentration 〉0.4%.（2） With NaCl increasing,the CAT activities of four energy clones decreased consistently;POD activities increased at the lower concentrations and then decreased at the higher concentrations;SOD activities consistently increased.The activity of the protective enzymes of four energy clones was higher than that of S.matsudana under the salt stress.（3） When soil NaCl concentration was lower than 0.6%,the soluble protein content of four energy clones were all higher than S.matsudana,S.fragilis′s proline content was higher than S.matsudana in the whole process of the salt stress.（4） All seedlings from four energy clones grew well in the soil with 0.4% NaCl concentration compared with S.matsudana.S.fragilis showed a better endurance under the salt stress and grew well in the soil of 0.6% NaCl concentration.These results indicate that four energy clones can grow well on light and moderate salt soils in Tianjin.