Research On The Adaptability Of Four Bamboo Species Under Salt Stress

Four speices of one-year-old bamboo were studied, including Phyllostachys vivax,Phyllostachys glauca, Phyllostachys aureosulcata and Pleisblastous fortunei which were fromthree different saline zones. The difference of growth indexes, internal anatomy, and elementdistribution were compared among the four bamboo speices to evaluate the saline adaptability.Firstly, through comparing the differences of morphological indicators and water contentin each organ under different salt concentrations, the morphological indexs of P. vivax show nosignificant differences at2.206g·kg^-1and0.975g·kg^-1saline soil, while these indexes droppedsignificantly when the salt content was at4.281g·kg^-1. Most morphological indicators of S.fortunei changed dramatically, when the souble salt contents were at2.128g·kg^-1and0.96g·kg^-1. The variance of morphological indexes of P. fortunei reached the maximum, P. glaucaand P. aureosulcata were smaller, and P. vivax was the minimum. In summary, themorphological indicators and water contents of P. fortunei decreased remarkbly when the saltcontents were between0.9g·kg^-1and4.3g·kg^-1, the growth was seriously affected; the growthof P. vivax had been affected slightly by the salt stess, and it revealed the best growthperformance; P. glauca and P. aureosulcata the secondly.In order to reveal the anatomical changes under salt stress, the root, rhizome, stump, andleaf of four bamboo speices were scaned by the ESEM. The results indicated that there were nosignificiant difference was found from P. vivax in2.206g·kg^-1and0.975g·kg^-1soil saline, butsignificiant difference were found when the soluble salt contents of soil were at4.281g·kg^-1and0.975g·kg^-1. For P. vivax, the depth of root endodermis had the biggest increase amplitudeof29.19%, while the area of vascular bundle hold the biggest amplitude reduction of20.70%among all the anatomical indicators. There were no remarkble differences in P. aureosulcatawhen the soluble salt content of soil were at4.152g·kg^-1and2.413g·kg^-1, while remarkbledifferences were found when the soluble salt content of soil were at4.152g·kg^-1and0.969g·kg^-1. Meanwhile, rhizomeand stump, tube diameter and vascular bundle diameter of P. glaucafollowed significiant differences among three different salt contents. For P. glauca, the depth ofroot endodermis had the biggest increase amplitude of26.72%, while the area of vascular bundle hold the biggest amplitude reduction of25.12%among all the anatomical indicators.Together, the order of salt tolerance was P. vivax was ranked most remarkable in salt-resistant,followed by P. aureosulcata, P. glauca and S. fortunei.Plus, the analysis for the contents of total K⁺, Ca²⁺, Na⁺, Mg²⁺and elements ratio indifferent organs showed that the contents of Na⁺, Na⁺/K⁺, Na⁺/Mg²⁺, Na⁺/Ca²⁺in differentorgans from four bamboo species increased varily with the different soil salinity, while thecontents of K⁺, Ca²⁺, Mg²⁺decreased at different salinity. On the whole, the decreasingamplitude of K⁺, Ca²⁺, Mg²⁺of P. fortunei was the maximum, P. glauca and P. aureosulcatawere the secondly and P. vivax was the minimum; the increasing amplitude of Na⁺, Na⁺/K⁺,Na⁺/Ca²⁺, Na⁺/Mg²⁺of P. fortunei was the biggest among three bamboo species.Morever, subordinate function, principal components analysis and gray interactinganalysis were also performed to evaluate the adaptability and tolerance of four bamboo speicesin the saline enviroment. The results of subordinate function revealed that the sequence ofsaline adaptability was: P. vivax, P. aureosulcata, P. glauca, P. fortunei. Through the principalcomponents analysis, the sequence of adaptability and tolerance was: P. vivax, P. glauca, P.aureosulcata, P. fortunei. Based on the principal component analysis,16indicators intimatelyrelated to salt tolerance were screened out. The final results of gray interacting analysisrevealed that the sequence of adaptability and tolerance was: P. vivax, P. glauca, P.aureosulcata, P. fortunei.In conclusion, through researching the growth indexes, anatomical indicators and elementdistribution of four bamboo speices in three different saline zones, our study showed that P.vivax presented the best growth performance and stable anatomical structure when the soil saltconcentration rang from0.9g·kg^-1to4.3g·kg^-1, it had the minimum accumulation of Na⁺andthe degree of elements imbalance. However, P. fortunei had worst performance. It wassuggested that the selecting sequence of bamboo species was P. vivax, P. glauca, P.aureosulcata when planting trees in the coastal beach, and P. fortunei was not is notrecommended.