Effects Of Salt Stress On Growth Physiology Of Wild Strawberry

In order to analyze the growth and physiological response of strawberry and compare Fragaria pentaphylla and F.moupinensis of the tolerance to salt stress?this paper adopted potted method,using F.pentaphylla and F.moupinensis as experiment materials and using the form of artificially adding single NaCI salt,the photosynthesis physiological chracteristics and growth traits of seedlings were analyzed under different concentration of NaCl?0.00%,0.025%,0.05%,0.1%,0.2%?.Strawberry biomass,root growth,chlorophyll content and chlorophyll fluorescence parameters and photosynthetic gas exchange parameters,antioxidant enzymes and the contents of malondialdehyde indicates the growth and physiological indexes of salt resistance.The results show that:1.?1?Under salt stress,the seedlings'root morphological traits such as root length,root surface,root volume,and biomass were suppressed while those under 0.1%and 0.2%NaCl concentration were significant lower that those under control.The decreasing amplitude of biomass of F.pentaphylla with the increasing of salt concentration were higher than those of F.moupinensis,indicating that the effects of salt stress on the accumulation of organic matter of F.moupinensis is less than that of F.pentaphylla.2.P_n,Tr and G_s in the leaves of seedlings decreased significantly with the increase of salt concentration,but C_i increased significantly,that the stomatal limitation might be the main reason of the suppression of the photosynthesis of both species.3.the leaf chlorophyll content in the leaves of the seedlings decreased significantly with the increase of salt concentration.the increment of F₀ and the decrement of F_v/F_m and F_v/F₀ in the leaves of F.pentapylla were greater significantly than those of F.moupinensis,suggesting that F.moupinensis had high ability to adjust the response of plant to light under salt stress environment.4.With the increasing salt concentration,P_nmax?LSP of strawberry leaves decreased and the light saturation point LCP increased,suggesting that salt stress could narrow the scope of the light usage.caused strawberry narrow scope of the using of light.At the highest concentration,the incremental of LCP of F.pentapylla was greater than that of the F.moupinensis,indicating that F.pentapylla had stronger ability to use weak light than F.moupinensis.In conclusion,P_nmax,LSP,AQE of F.moupinensis are higher than those of F.pentapylla,and the decrement of P_nmax,LSP and AQE are less than those of F.pentapylla,indicting that F.moupinensis has stronger photosynthetic capacity than F.pentapylla,easier to accumulate organic material under salt stress showing high salt tolerance.5.Under the same intensity of salt stress,F.moupinensis and F.pentapylla plasma membrane permeability and the accumulation of malondialdehyde content change basic is consistent,both increase with the increase of salt concentration F.moupinensis increase the extent of not less than F.pentapylla.The accumulation of free proline content,SOD and the change trend of POD were consistent with the increase of salt concentration and then decreased.The increase of strawberry in the southwest was also greater than that of the F.apentaphylla.The experiment showed that F.moupinensis was more salt-tolerant than the F.pentapylla.