Relationship Between Cold Resistance And Morphological Characteristic Of Zoysia Japonica

Zoysiagrass is a warm-season turfgrass with many excellent characteristics,but it is less cold-resistant than cold-season turfgrass.The changes of physiological indexes(semi-lethal temperature,malondialdehyde,soluble sugar,soluble protein)of different organs(leaf,stem,stolon,rhizome)of six zoysiagrass germplasm materials under low temperature stress were measured in this experiment.The study evaluated the comprehensive cold resistance of test materials by membership function method,and explored the relationship between comprehensive cold resistance and morphological characteristics(morphological index,appearance character,biomass)of zoysiagrass by correlation analysis.Specific findings were as follows:(1)The order of comprehensive cold resistance of six zoysiagrass germplasm materials was wild-type 4>Zenith> wild-type 2,wild-type 3> wild-type 1,Qingdao.(2)The morphological characteristics of stem,stolon,rhizome,and reproductive branch(total number of stem,total number of stolon,total number of rhizome,total length of stolon,total length of rhizome,total branch of rhizome,total weight of rhizome,reproductive branch height,inflorescence length)and the leaf length had no significant correlation with cold resistance;the leaf width was significantly negatively correlated with the cold resistance of the stolon.The rhizome of six zoysiagrass lines were mainly distributed in the soil layer of 0?5 cm underground.The order of the total number of stems of different germplasm materials was same: the total number of stem> the total number ofrhizome> the total number of stolon.The greater the total number of stem of the same material,the lower the total number of stolon.The total number of rhizome,the total length of rhizome,the total number of rhizome branch,and the total weight of rhizome of the same germplasm material based on October sampling were all higher than May.(3)The grass index of the tested material was significantly positively correlated with the cold resistance of stem and rhizome.The coefficients were 0.822 and 0.848,respectively.The green period of the tested materials was significantly positively correlated with leaf cold resistance,stem cold resistance,rhizome cold resistance,and stolon cold resistance.The order of the green period of six zoysiagrass germplasm materials was: wild-type 4> Zenith> wild-type 3> wild-type 2> Qingdao>wild-type 1,of which wild-type 4 green period was up to 195 days,the minimum green period for wild-type 1 was 171 days.(4)The biomass of six zoysiagrass germplasm materials had no significant correlation with cold resistance.Rhizome biomass was significantly negatively correlated with leaf biomass,but was significantly positively correlated with stolon biomass.The characteristics of the biomass allocation of six zoysiagrass germplasm materials for different organs were leaf biomass,rhizome biomass> stem biomass,stolon biomass.The research results provide a theoretical basis for breeding cold-resistant zoysiagrass lines,expanding the application range of zoysiagrass in the north and rapidly identifying the cold resistance of turfgrass in production practice.