| Wetland species mat rush(Juncus effusus L.),an important economic plant,which stems not only had a certain toughness,but also good flexibility,was a kind of high-quality natural fiber with high development and utilization value.It's mainly used as mats and other daily necessities and other knitted materials of artware.Genetic diversity,anatomical structure and mechanical properties were researched in order to provide a theoretical basis for the germplasm evaluation,genetic improvement and utilization of mat rush.The main results were as follows.The results indicated that twenty-three primers were selected from 72 primers which had clear polymorphic bands.A total of 148 brands,among which 130 were polymorphic,were amplified from the 36 materials,and the proportion of polymorphic loci was 87.84%.The genetic similarity coefficient of varieties was between 0.4056 and 0.9441,which showed rich genetic diversity.The UPGMA cluster analysis gave a genetic similarity coefficient of 0.59 for boundaries and the 36 materials were divided into five groups.The first group was divided into three subgroups.The cluster results had connection with regions and cultivars origin.In most cases,materials from the same region were classified into the same group or subgroup.Wild germplasm had a tendency to get together.Wild germplasm was separated from cultivars.The yield per mu of dry mat rush which length was more than 90 centimeters was 597.20~1062.87 Kg.HGL?YD-01?XY-02?XY-03 and XY-01 had higher production.The stem length of eighteen mat rush varieties was 109.88~133.66 centimeters and the diameters of middle stem was 1.10~1.59 mm.In terms of length and diameter,HGL?HB-01?XY-02 and YD-02 varieties had a higher quality and could be the better germplasm resources of J.effusus.The cross section of mat rush stems appeared circular or nearly round.The results showed that the basic structures of stems of eighteen mat rush varieties were roughly the same,and composed of epidermis,elementary tissue,vascular bundle and pith.The elementary tissue included assimilating tissue and the bundle fibers.The vascular bundle was arranged three layers and presented as outer layer,middle layer and inner layer.The number of vascular bundle in the outer layer was largest,but the cross section area was the smallest.The intimal cross-sectional area of vascular bundle was largest,which number of vascular bundle was maximum.The experiment showed that the diameter of the cross section of eighteen mat rush stems was 3.47~4.26 mm,the thickness of elementary tissue,the numbers of large and medium-sized vascular bundles and the diameters(radial expansion)of large and medium-sized vascular bundles were 273.44~381.39 ?m,8.00~15.00,10.00~15.00,310.67~376.06 ?m and 219.33~297.89 ?m respectively.The fiber presented classical spindle cell pattern.It had a thicker cytoderm with bordered pits.The fiber belong to the short fiber.The content of crude fiber of eighteen mat rush varieties was from 34.54% to 39.61%,and the average content was 36.57%.The mechanical properties test showed that the cross section area of eighteen mat rush varieties were between 1.17 mm2 and 2.24 mm2.The maximum tensile force,tensile strength,tensile deformation and Young?s modulus of stems respectively were 55.16~84.07 N,28.51~59.11 Mpa,0.83~1.24 mm and 1367.69~2297.10 Mpa.Compared with other varieties,XY-03?HB-01?XY-04?DY-01?HGL and YZ-01 had the better tensile strength and Young?s modulus in the eighteen varieties.The correlation analysis showed that stem tensile strength and Young?s modulus was high significantly positively correlated(P<0.01)with elementary tissue thickness,the numbers of large and medium-sized vascular bundles,the total numbers of vascular bundles and ratio of wall thickness to radius of fiber,and have little correlated with the crude fiber content.There was little correlation between tensile deformation and tissue thickness,the numbers of large and medium-sized vascular bundles,the total numbers of vascular bundles,the ratio of wall thickness to radius of fiber and the content of crude fiber.A certain relationship existed between the maximum tensile force and elementary tissue thickness,the numbers of large and medium-sized vascular bundles,the total numbers of vascular bundles,ratio of wall thickness to radius of fiber and crude fiber content.The tenacity and flexibility of stems of J.effusus depended on the elementary tissue thickness,the numbers of vascular bundles,the wall of fiber and the connecting form and strength of each organization and cell.The crude fiber content has little relationship with mechanical property. |
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