| Bamboos are generally known as Bambusodeae plants of the Gramineae family.There are more than 70 genera and 1200 species of bamboos in the world,mainly distributed in tropical and subtropical regions,and a few in temperate and cold zones.Bamboo is widely used in gardening landscape in the south,but seldom in the north,mainly because of the drought and lack of rain in the north.Water is the main limiting factor of bamboo growth in the north.In this paper,In this paper,three scattered bamboo species,Phyllostachys nigra,P.aureosulcata,P.iridescens,and two dwarf bamboo species of Sasa pygmaea and S.fortune were selected as experimental materials from ornamental bamboo species commonly used in garden greening.The effects of water stress on leaf leaf morphology,water content,and physiological indexes were studied and analyzed.The results of the research were as follows:(1)The changes of potted seedlings soil water content were measured to evaluate the degree of water stress.The soil water content of P.nigra decreased the fastest.The rehydration test was carried out,the soil water content of each bamboo species increased sharply and then decreased.The results showed that the soil water content of each bamboo species increased sharply and then decreased,and S.pygmaea and S.fortune recovered the fastest.(2)From the morphological indexes of leaf color,leaf shape and variegated leaf,the change rate of S.pygmaea was the slowest,and the drought resistance was the best.According to the degree of leaf curl,the curl ratio of S.pygmaea leaves was the least,and the resistance was the best.From the point of view of the leaf share,S.fortune has the fewest variegated leaves and the best resistance.(3)The effects of water stress on physiological indexes including water content,MDA content,soluble sugar content,chlorophyll content and chlorophyll fluorescence were measured.The leaf water content of the five ornamental bamboos showed a decreasing trend under the water stress,and the leaf water content of the five ornamental bamboos increased again after rewatering.The MDA content of five kinds of ornamental bamboo decreased first and then increased,among which the accumulation of P.nigra was the largest,and the drought resistance was the worst,while that of S.fortune was the least and the resistance was the best.The content of soluble sugar also showed the phenomenon of post-decline,the accumulation of P.nigra was the most,and the accumulation of S.fortune was the least.Therefore,the drought resistance of P.nigra was the worst,and the drought resistance of S.fortune was the best.From the whole decline trend of chlorophyll content,the decrease of P.aureosulcata f.spectabilis was the largest,the decrease of S.fortune was the smallest,the drought resistance of P.aureosulcata f.spectabilis was poor,and the drought resistance of S.fortune was the best.According to the changes of the maximum photosynthetic efficiency(F_v/F_m)of the visual index of chlorophyll fluorescence parameters,the value of five ornamental bamboo decreased after the start of water stress,the biggest change was S.pygmaea,the smallest change was S.fortune,the drought resistance of S.pygmae was poor,and the drought resistance of S.fortune was better.(4)Comprehensive evaluation.Combined with membership function method and principal component analysis(PCA),the comprehensive evaluation of each bamboo specie was carried out,and the D value of S.pygmaea was the highest.The D values of P.nigra,P.aureosulcata f.spectabilis,P.iridescens,S.pygmaea and S.fortune were 0.0360,0.6209,0.4044,0.6656 and 0.7318,respectively.Therefore,the drought resistance of S.pygmaea and S.fortune were the best,and the drought resistance of P.nigra was the worst. |
PDF Full Text Request