Indoor artificial crosses for two groups of Populus deltoides (I-69 and I-57)(female):I-69 with P. cathayana,P. szechuanica,and P. purdomii(male) and I-57 with P. cathayana and P. szechuanica were carried out in the spring of 2006. Then,in September 2007,growth performance,and infection from Marssonina brunnea fungi on the 1-year-old hybrid seedlings were tested. with a 30 cm ×40 cm seedling space design having 10 seedlings per plot and 3 replications using an ANOVA with an LSD test. Results among the five ...