Abstract: The experiment was conducted to study genetic variation and genetic diversity of Catalpa fargesii f. duclouxii germplasm and put forward reasonable cross breeding strategy. The perennial growth traits and the leaf length, leaf width, lenticel length, lenticel width, lenticel density of 20 clones were measured. The results showed that 1, 2, 3, 4 and 5 a height and 1-6 a DBH were significantly different among clones. Repeatability and genetic variation coefficient of height changed in volatility with years change, however, those parameters of DBH were relatively stable. Repeatability of DBH was higher than height. It indicated that the degree of genetic control of DBH was stronger than height. The genetic diversity index of leaf length and leaf width was high, they were 2.016 and 2.012, respectively. Phenotypic variation coefficients of lenticel length, area and density were more than 20% and the genetic variation coefficient were more than 15%. There was ample morphological diversity among C.fargesii f. duclouxii clones. By the correlation analysis, the lenticel density was negatively correlated with growth, but lenticel size and growth traits had positive correlation. The germplasms were divided into four types by cluster analysis, the first type had maximum lenticel area and the minimum lenticel density; type Ⅱ grew the most slowly, but it had maximun leaf length; type Ⅲ had fastest growth rate and maximun leaf width; and the type Ⅳ petioles were longest.

Key words: Catalpa fargesii f. duclouxii, phenotypic traits, genetic variation, genetic diversity