干旱和盐胁迫对花生干物质积累及光合特性的影响

为明确干旱和盐胁迫对花生生长发育及光合特性的影响,以花育25为试验材料,采用盆栽试验,设置正常供水(75%田间最大持水量,CK)、中度干旱胁迫(45%田间最大持水量,D)、盐胁迫(75%田间最大持水量,土壤含盐量0.3%,S)、旱盐胁迫(45%田间最大持水量,含盐量0.3%,DS)4个处理,研究开花期干旱和盐胁迫对花生光合特性和干物质积累的影响。结果表明,与CK相比,中度干旱胁迫降低了花生叶片的相对含水量、净光合速率(Pn),增加了叶片的SPAD值、光补偿点(LCP)和暗呼吸速率(Rd);盐胁迫降低了花生叶片的相对含水量、Pn和SPAD值,增加了LCP和Rd;随着胁迫时间的延长,DS处理的叶片相对含水量、Pn、SPAD值、LCP和Rd的变化趋势与盐胁迫基本一致。干旱胁迫结束复水10 d后,D处理的各项指标与CK无显著差异;但旱盐胁迫与盐胁迫间差异显著,干旱胁迫结束复水10 d时,旱盐胁迫的叶片相对含水量和Pn分别较盐胁迫降低1.57%、16.67%,LCP和Rd较盐胁迫分别升高78.07%、45.78%。旱盐胁迫降低了花生主茎高、侧枝长和植株干重的V_max(最大生长速率)和T_m(V_max出现时间),单株荚果产量较CK降低41.10%。干旱和盐胁迫对花生单株产量和出米率存在显著的交互作用,旱盐互作加剧了盐胁迫对花生植株生长的危害,因此盐胁迫下种植花生应在开花期及时灌水、防止盐分和干旱双重胁迫。本试验结果为盐碱地花生种植的合理灌溉和高产稳产提供了理论指导。

Effect of Drought and Salt Stress on Accumulation of Plant Dry Weight and Photosynthetic Characteristics

In order to clarify the effects of growth and photosynthetic characteristics of peanut under drought and salt stress at flowering stage, Huayu25 was used as experimental material set up four treatment: normal water supply (CK: 75% maximum field water holding capacity), moderate drought stress (D: 45% maximum field water holding capacity), salt stress (S: 75% maximum field water holding capacity and soil salinity 0.3%), dry salt co-stress (DS: 45% of the field maximum water holding capacity and 0.3% salt content), potted experiment was carried out to study the change in peanut growth and photosynthetic characteristics due to the stress of drought and saline at flowering stage.The results indicated that comparred with CK, the relative water content,net photosynthetic rate (Pn) were reduced under D treatment and SPAD,optical compensation points (LCP) and dark respiration rate (Rd) were increased.Meanwhile,the relative water content,Pn and SPAD was decreased and LCP and Rd was augmented under S treatment.The trends of the relative water content,Pn,SPAD,LCP and Rd under the treatment of drought-salt double stress (DS) were consistent with S treatment.The indicators of D treatment had no significant difference with CK in 10 days after the rehydration, but DS treatment had significant difference with S treatment.For instance,the relative water content and Pn were decreased by 1.57% and 16.67%, respectively. LCP and Rd was increased 78.07% and 45.78%, separately. DS treatment reduced the Ⅴ_max and T_m of peanut main stem height,lateral branch length and plant dry weight.Meanwhile its yield of single plant pod was 41.10% lower than CK.The drought stress and salt stress had significant interactive effects of the yield and kernel rate.The effects of salt stress on the growth of peanut plants were aggravated by drought.Drought was more harmful to peanut growth and yield formation under salt stress.Therefore,the peanut planting in saline-alkali land should be timely irrigated to relieve the stress of salt and drought at flowering stage.Therefore, this study provided a theoretical guidance for reasonable irrigation,high yield and stable yield for the peanut planting in saline-alkali land.