The Change Of Physiological Indicators On Mulberry Autopolyploid Varieties Under Drought Stress Which Simulated By Peg

Drought induced water stress is one of the important limiting factors that affects plantsurvival, growth and development. Understanding drought damage of plant physiology can beused to know the mechanism of drought-resistant adjustment, and identify the droughtresistance plants material, and speed up the process of plant breeding and biological yield, andimprove the best economic and ecological benefits. Mulberry（Morus spp） is perennialdeciduous woody plants. It is the material basis of silk industry production and has thestronger ability to adapt the environment. Because of the genetic background and characterfeatures is clear, the artificial induction of mulberry homologous triploid, tetraploid andmixoploid materials are the ideal model for research polyploidy resistance. In this study, weuse the New-ichinose mulberry diploid, homologous triploid and mixoploid as theexperimental material, through the tissue culture technology, rapid propagation, and get alarge number of mulberry seedlings, and then using flow cytometry instrument authenticatemulberry ploidy, finally determination of various times body physiological indexes ofmulberry sapling after drought stress treatment. The comprehensive evaluation results can beused to identify the mulberry drought-resistance. This study provides the reference ofmulberry polyploid drought-resistant physiological and biochemical characteristics, droughtresistance identification, and also gives the basis of the effect of polyploidy gene-dosageinfluence on character development. This study consists of three parts:1. Cultivate the tissue culture seedling of New-ichinoseWe use tissue culture technology to cloning the mulberry homologous diploid, triploid,mixoploid. Not only can get a lot of test materials in short term, but also can know the geneticbackground and character features. It gives the ideal model for research polyploidy resistance.2. Using flow cytometry instrument identification the ploidy of test materialsWe use flow cytometry instrument to identify the ploidy of mulberry leaf cell. The resultshowed that the ploidy of diploid, triploid and mixoploid is consistent with previous reports.We increase mulberry ploidy identification methods, and provide cytological evidence forresearching molecular and physiological mechanism of mulberry autopolyploid. 3. The change of physiological indicators on mulberry autopolyploid varieties underdrought stress which simulated by PEG.To understand physiological characteristics and drought resistance the of the polyploidunder drought stress, we use PEG to simulated drought stress environment, and determinedsex physiological indexes of New ichinose mulberry diploid, homologous triploid andmixoploid. The results show that: after drought stress14days, the homologous triploid hadthe highest relative content of water (RWC), SOD and soluble sugar contents, and the lowestrelative electrical conductivity (REC) and MDA contents among3plants, but the prolinecontent was between other plants. The comprehensive evaluation results showed that underwater stress，the mulberry’s resistance strength sequences were triploid(shannxi305)>mixoploid(shannxi402)> New-ichinose diploid.