Effects Of Community Composition On Population Characteristics, Individual Morphology And Resistance Of Thlaspi Arvense L.

With the rapid development of Chinese economic level and the continuous improvement of people's living standards,people's pursuit of quality of life and general health level is also gradually improving,and then put forward requirements for the rational development and utilization of wild Chinese medicine and food resources.In view of the problems of undeveloped herbal medicinal plant resources and poor growth environment in China,it is of great practical significance to explore the environmental factors affecting the growth and development of herbal medicinal plants.we take Thlaspi arvense L.in Qinghai-Tibet Plateau as the research object in the paper,four square squares?A,B,C,D?of 6x6m² were set up to determine the morphological,physiological and photosynthetic characteristics of Tibetan cockroaches under different communities.The effects of different communities on plant population characteristics,individual morphology and physiological differences were analyzed,and the most suitable for wild cockroaches was discussed.The long environment provides a theoretical basis for the introduction,domestication and rational cultivation of wild cockroaches.The measurement results show that:?1?Population characteristics:Community composition has a very significant impact on the population number,distribution coefficient,population area and population density of Thlaspi arvense L.population?P<0.01?.In the environment of low soil water content,the population number and area of the population decrease,and soil water content has no effect on the distribution coefficient and population density of the population.?2?Component traits:Community composition had significant effects on the root,stem and leaf of Thlaspi arvense L.?P<0.05?.Among the four communities A,B,C and D,root,stem and leaf traits showed a downward trend,and community composition had the most significant effects on the total stem length,leaf width and longest root length of Thlaspi arvense L..?3?Biomass structure:In the four communities,community composition had no significant effect on seed biomass?P>0.05?,but had significant difference in other biomass and all biomass allocation ratios of Thlaspi arvense L.?P<0.05?.Low water content environment promoted the accumulation of biomass,and low light stress inhibited the accumulation of biomass.?4?Physiological characteristics:Community composition had significant effects on SOD,POD,CAT,T-AOC activities and the contents of H₂O₂,MDA,OPC and TP of Thlaspi arvense L.?P<0.05?.In different communities,low soil moisture promoted the activities of SOD and POD,increased the contents of MDA,H₂O₂ and T-AOC,and high light was beneficial to the increase of CAT activity and TP content.?5?Photosynthetic characteristics:Community composition had significant effects on P_n,G_s,C_i,T_r,WUE and L_s of Thlaspi arvense L.?P<0.05?.Under high light,the photosynthesis of Thlaspi arvense L.plant is strong,which makes its C_i value increase.When CO₂ reaches saturation or even excess,the stomatal opening degree decreases,transpiration rate and stomatal limit value decrease,which seriously affects the normal photosynthesis of Thlaspi arvense L.plant.When light intensity decreases,the values of Thlaspi arvense L.plant gradually return to normal;in low water content community,Thlaspi arvense L.plant maintain normal development and growth of organism by increasing WUE during the photosynthesis.In summary:the effects of different community composition on the population characteristics,individual morphology and photosynthetic physiology are significant.Under the environment of high illumination intensity and low soil moisture content,the characteristics of the Thlaspi arvense L.plant are higher,which is suitable for artificial cultivation.After artificial cultivation,we can adjust light and soil moisture according to the growth conditions of the Thlaspi arvense L.,so as to ensure the good growth and development of the Thlaspi arvense L.