Response Of Electrophysiological Properties Of Broussonetia Papyrifera (Linn.) L'hér.ex Vent.and Morus Alba L. To Drought

Plants in many areas of China suffer from different degrees of drought,limiting the development of agroforestry,and adversely affecting the ecological environment and the agro-forestry economy.This makes the selection of drought-resistant plants and drought-resistant pioneer plants to be a hot issue to be resolved.Therefore,how to comprehensively,timely,and accurately characterize the drought resistance of crops under drought stress remains to be studied.Plant electrophysiological signal transmission is widespread in plants and is the first reaction of plants to various external environmental incentives.The use of electrophysiological characteristics to characterize the plant's stress resistance and to characterize its relationship with environmental factors can enable information exchange between humans and plants,and provide a theoretical basis for characterization of plant drought resistance.In this study,the changes of electrical signals and physiological and biochemical of plants under drought stress were monitored,and the response of plants'electrophysiological properties to drought stress was tested under external excitation conditions.At the same time,photosynthetic and fluorescence indexes of plants were also studied.Test to verify the feasibility of the experiment.?1?Research on the acquisition of plant electrophysiological signals and the screening of instruments.?2?Study the effect of extrinsic motivation on the electrical parameters and tension of Broussonetia papyrifera?Linn.?L'Hér.ex Vent.and Morus alba L.leaves.The leaves of Broussonetia papyrifera and Morus alba under drought stress were selected as experimental materials,and the electrophysiological parameters and leaf water potential under different excitation were measured.?3?Study the electrophysiological parameters and leaf water potential of plants under different gradients of drought stress.In this experiment,four water gradients were set up,the soil water content was 55%-60%?T1:mild drought?,40%-45%?T2:moderate drought?,25%-30%?T3:severe drought?and 70%-75%?CK group?of field water holding capacity respectively.The electrophysiological parameters,leaf water potential and photosynthetic indexes of plants were measured under continuous drought.The results of the test were as follows:?1?Experiments showed that the best detection frequency of LCR of plants was3KHz,the best measuring voltage was 1.5V and the optimal holding force was 3-4N.A parallel plate capacitance sensing device for detecting physiological and electrical parameters of plants under specific clamping force was designed and verified.?2?Under salt stimulation,Morus alba had stronger salt resistance to NaCl,Na₂SO₄ and mixed salt than Broussonetia papyrifera,but there was no significant difference under mild Na₂SO₄ salt damage.Under mild salt damage,the relative salt resistance of Broussonetia to 3 types of salt was mixed salt>Na₂SO₄>NaCl,and that of Morus alba was mixed salt>NaCl>Na₂SO₄;under moderate salt damage,the relative salt resistance of Broussonetia to the 3 types of salt was Na₂SO₄>NaCl>mixed salt,and that of Morus alba was mixed salt>Na₂SO₄>NaCl;in severe salt damage,the relative differences in salt tolerance of 3 kinds of salt of Morus alba and Broussonetia were not significant.It also indicated that the resistance of the same plant to different salts was significantly different.The salt resistance of the plant was not only specific to the species,but also hasd the specificity of salt.In addition,the two plants with pH stimulation showed different resistance.From the change of leaf tension of two kinds of Morus alba plants in 4 pH solutions,it can be seen that the resistance of the Broussonetia tree to acid and alkali was stronger than that of the Morus alba,which indicated that the Morus alba is more seriously poisoned by acid,and the Broussonetia was more suitable for alkaline conditions.?3?The drought tolerance threshold of Broussonetia papyrifera was 14 days,and that of Morus alba was 7 days.When the soil moisture content was 40%⁴5%,the water of the Broussonetia papyrifera could be watered,and the Morus alba was55%⁶0%.This showed that the drought resistance of the same plant under different gradients of drought stress was significantly different,and the drought resistance of the plant was species-specific.Under T1,T2 and T3,the drought resistance of Broussonetia papyrifera was 5.048,3.985,and 3.502;the drought resistance of Morus alba was 4.278,3.060,and 2.891,respectively.Therefore,the experiment showed that the drought resistance of Broussonetia papyrifera was stronger than that of Morus alba.?4?Under different gradients of drought stress,the change of photosynthetic rate of Broussonetia papyrifera and Morus alba were similar to that of capacitance and leaf tension.The physiological capacitance and leaf tension of T1,T2 and T3groups were significantly correlated with photosynthetic indexes?P<0.05?,while CK group was not significant.In addition,there was a good correlation between physiological capacitance,leaf tension and fluorescence parameters under different gradient droughts.The physiological capacitance and leaf tension of T1,T2 and T3groups were significantly correlated with the fluorescence index?P<0.05?,while the CK group was not significant.By comparing the correlation coefficients of the two plants,the changes in the physiological parameters of the plants and the strain of the leaves under drought stress could reflect the drought resistance of plants.