Studies on rhizome characteristics of germplasm resource of Cynodon dactylon in China

Measurement and analysis were carried out on the depth, density and diameter of rhizomes of 50 accessions of Cynodon dactylon in China. The results showed:1) The variation range of rhizome characteristics was very large and the coefficients of variation of depth, density and diameter were 44%, 41% and 33.7%, respectively; 2) The rhizome characteristics were also obviously positively correlated with each other. The correlated coefficients were 0.73 (P0.01) (diameter and depth) 0.69 (P0.01) (diameter and density) and 0.73 (P0.01) (depth and density); 3) The rhizome characteristics were remarkably linearly correlated with the latitude, too. That is to say, with the increasing of latitude, the rhizomes were deeper, denser and thicker. 4) Four types were determined according to the results of cluster analysis on rhizome characteristics, which were named as follows:shallow (no) rhizome type, thin and shallow rhizome type, deep and dense rhizome type and special deep and dense rhizome type, respectively. This paper also inquired into the relationship between the rhizome characteristics and the low temperature avoidance and the mechanism of the low temperature avoidance of Cynodon dactylon in China.