盐旱交叉胁迫对花生生长发育和生理特性的影响

为了探究盐旱交叉胁迫对花生生长发育的影响，以抗旱不耐盐花生品种花育22和抗旱耐盐花生品种花育25为试验材料，通过防雨棚盆栽试验研究了干旱、盐、盐+干旱、干旱后复水+盐等4种胁迫对花生产量、农艺性状、生物量、叶绿素SPAD值、丙二醛含量、活性氧清除能力及渗透调节物质含量的影响。结果显示：各胁迫处理均显著抑制了两个花生品种植株的生长和荚果产量，其中，盐胁迫对花育22生长的影响大于干旱胁迫；盐+旱胁迫下，两个花生品种受伤害程度最大，产量最低。与单一盐胁迫相比，干旱预处理提高了盐胁迫后期花生超氧化物歧化酶和抗坏血酸过氧化物酶活性，增强了植株活性氧清除能力，降低了叶片丙二醛含量，从而缓解盐胁迫对膜系统的过氧化伤害，提高了叶绿素含量，促进了植株生长，增加了干物质积累，最终提高盐胁迫下花生产量。另外，与单一盐或干旱胁迫相比，盐+旱胁迫对花育22和花育25的伤害均加重，而干旱预处理有利于2个品种在盐胁迫下活性氧代谢和光合色素的提高，促进植株的生长，提高植株对盐胁迫的交叉适应能力，从而缓解盐胁迫对花生植株的抑制作用。 

Effects of salt and drought cross stress on peanut (Arachis hypogaea) growth and physiological characteristics

The peanut (Arachis hypogaea) planting in saline-alkali land is often subjected to drought and salt stress due to insufficient freshwater resources or annual rainfall, which seriously affects the production of peanut in saline-alkali area. In order to study effects of cross stress induced by salt and drought on peanut growth and yield, two peanut cultivars with same drought resistance but different salt resistance, low salt tolerance HY22 and HY25 salt resistance HY25, were selected as materials. Experiments were conducted with pot experiments with the treatments under rainproof shelter drought, salt, drought and salt, rewatering after drought and salt stress, respectively. Effects of different stress on yield, agronomic traits, biomass, soil and plant analyzer development, malondialdehyde content (MDA ), scavenging capacity of reactive oxygen species and content of osmoregulation substances of peanut were studied. All the stresses significantly inhibited the growth and pod yield of two peanut cultivars, and effects of salt stress on the growth of HY22 were greater than those of drought stress. Among all the stresses, the salt and drought stress caused the most serious damage on these two cultivars with the worst plant physiological parameters and the lowest yield. Compared with single salt stress, drought pretreatment improved the activity of superoxide dismutase and ascorbate peroxidase in leaves at the late stage of salt stress, enhanced the ability of scavenging reactive oxygen species, reduced the content of malondialdehyde in leaves, and thus alleviated the oxidative damage to membrane systems. Simultaneously, chlorophyll content and dry matter accumulation increased, plant growth was promoted, and the yield of peanut increased. Additionally, compared with single salt or drought stress, the salt and drought stress aggravated the damage of these two peanut cultivars. However, drought pretreatment benefited the improvement of reactive oxygen species metabolism and photosynthetic pigments of both HY22 and HY25 under salt stress, and the pretreatment also helped to improve the ability of cross adaptation of plants to salt stress and to alleviate inhibitory effects of salt stress.