The Preliminary Research Of Tetraploid Fodder Clones Of Robinia Pseudoacacia In Regional Trial

Tetraploid fodder clones of Robinia Pseudoacacia, which were cultivated by Korea scientists, as new wooden fodder cultivars were introduced into China in 1997. Its utilization value as wooden fodder plant in disadvantage area in northwest China should be evaluated by regional experiment. To provide scientific basis for its further spreading in other regions, the regional trial is carried out in 9 sites, which will represent the main reforestation sites in Gansu and Ningxia provinces with poor natural condition. The branch and leaf traits ( the longest new branch length, the leaflet numbers on the branch, dry weight of all leaflets on the branch etc), leaf nutrients content (crude fat, crude ash, crude protein, N, P and K etc) and soil property and nutrients content were investigated and measured respectively in the 9 experimental places in our research. The analysis results are as following: (1) there is significant difference in most of the branch and leaf traits among the experimental places and materials, the tetraploid clones are better than the common Black Locust (as CK) in primary traits such as leaflet numbers per compound leaf, leaf morphological volume index, leaflet numbers on the branch and sum dry weight of leaflet on the branch, the traits of fodder clones are 1.32, 1.499, 1.331, 2.539 times as that of CK respectively. (2) there is no significant difference in nutrients content between tetraploid Black Locust clones and CK, which shows that the leaf nutrients content of tetraploid clones are similar as CK in nutrients utilization. (3) the fodder clones of Black Locust are better than CK in the traits from the whole level, which shows that it is potential to sprend in the regions that the experimental sites respect. (4) the content of most of leaf nutrients varies greatly among the experimental places, which shows that they were strong influenced by the site conditions. (5) there is no obvious differences in the content of crude protein and crude fat as the dominating factors for fodder plant mong trail sites, which indicates that it can be popularized for the tetraploid clones. (6)With correlation analysis between the meteorological, soil factors and the traits of fodder clones, annual evaporation, relative humidity and annual precipitation have significant effect on branch and leaf traits, and temperature has the most significant effect on nutrients content; soil texture is the most important on branch and leaf traits among soil factors, and it grows best in sandy; the soil pH and the content of available K and organic matter attach the importance on leaf nutrients content. (7)The site selected by PCA method for proper to branch and leaf traits and good leaf nutrition is the loam of forestry centre of Chenghao in Huachi county of Qingyang district and Yinguang Company that respect the regions.