非均匀盐胁迫对番茄幼苗耐盐性的影响

为了研究非均匀盐胁迫下番茄幼苗的光合特性和根系生长发育的状况,采用分根水培系统,设置3个总盐胁迫水平(NaCl浓度)处理——无盐胁迫(0)、中度盐胁迫(0.4%)和重度盐胁迫(0.6%),按照左右两侧根系处于非均匀和均匀胁迫两种方式分成6个处理:T1(0,0)为对照,T2(0.1%,0.3%),T3(0.2%,0.2%),T4(0.1%,0.5%),T5(0.2%,0.4%),T6(0.3%,0.3%),测定各个处理下番茄的光合指标、生物量、Na~+和K~+含量以及根系生长参数等。结果表明:(1)随着盐胁迫的加重,叶片中Na~+含量增加,K~+含量、光合指标、生物量和根系生长指标均依次降低;(2)在总盐(NaCl)浓度相同时,与左右两侧根系均匀盐浓度胁迫相比,非均匀胁迫下叶片中Na+含量显著降低(P0.05),气孔导度(Gs)与均匀胁迫下无显著差异,但净光合速率(P_n)、蒸腾速率(T_r)均增加,T2比T3处理下的P_n、T_r分别增加了4.88%和3.83%,T4处理下叶片的P_n、T_r分别比T6处理增加了13.51%和8.25%,T5处理下叶片P_n比T6处理增大了7.83%,T_r无显著差异;(3)当总盐浓度一定时,非均匀胁迫比均匀胁迫下两侧根系的总根长、根表面积、根体积以及总干物质量均有所增加。研究结果表明非均匀胁迫较均匀胁迫显著提高了番茄的耐盐性,这为番茄在盐碱地上的生长提供了耐盐胁迫的理论依据。

Effects of Non-uniform Salt Stress on Salt Tolerance of Tomato Seedlings

In order to study the photosynthetic characteristics and root growth of tomato seedlings under non-uniform salt stress，the experiment adopted a split-root hydroponic system，and 3 salinity levels were conducted in the experiment including no salt stress（0），moderate salt stress（0.4%），severe salt stress（0.6%）. Each level divided into 6 treatments in accordance with the non-uniform and uniform salt stress of left and right root system，T1（0，0）as the control group，T2（0.1%，0.3%），T3（0.2%，0.2%），T4（0.1%，0.5%），T5（0.2%，0.4%），T6（0.3%，0.3%）. Photosynthetic indices，biomass，Na+ and K+ content and root growth parameters were measured under various treatments. The results showed that：（1）With the aggravation of salt stress，the content of Na+ in leaves increased，and the content of K+，photosynthetic index，biomass and root growth index decreased in turn；（2）Compared with uniform stress，Na+ content in leaves decreased significantly（P < 0.05），the stomatal conductance（Gs）was not significantly different from that under the uniform stress，but the net photosynthetic rate（Pn）and transpiration rate（Tr）increased. Compared with T3 treatment，the Pn，Tr increased by 4.88% and 3.83%，respectively. Under T4 treatment，the Pn，Tr of leaves increased by 13.51% and 8.25% respectively compared with T6，and the Pn of leaves under T5 treatment increased by 7.83% compared with T6，Tr increased not significantly；（3）The total root length，root surface area，root volume and total dry weight of both sides of roots increased under non-uniform stress when the centration is certain. The study indicated that non-uniform stress could improve the salt tolerance of tomato，which provided a theoretical basis for the growth of tomato in saline-alkali soil.