美洲黑杨与青杨、川杨和卜氏杨人工杂交及杂种苗生长和抗病性状测定

采取室内切枝水培杂交法开展了以美洲黑杨Populus deltoides69号和57号为母本，青杨Pcathayana，川杨P50echuanicn和卜氏杨P口urdomii为父本的杨树派间人工杂交及杂种苗生长和抗病性状测定研究。结果表明：5个杂交组合坐果率、种子发芽率最高可达55％和20％，最低仅为20％和5％，可配性差异较大；5个杂交组合杂种苗生长存在极显著性水平差异：69号×川杨、69号×卜氏杨2个杂交组合杂种苗在苗高、地径生长方面表现最好，其平均苗高分别为2．87和2．38m．平均地径分别为2．57和2．13cm．且均与以57号为母本的2个杂交组合的杂种苗生长存在极显著差异．故可以此初选出优良新品种单株；5个杂交组合杂种苗普遍发病，发病率均达100％，以69号为母本的3个杂交组合杂种苗表现出较低的感病指数．抗黑虎病能力优于以57号为母本的2个杂交组合。

One-year-old seedling traits of Populus deltoides hybrids with P.cathayana, P.szechuanica, and P.purdomii

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 brunriga 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 crosses showed that percentage of fruit set and seed germination ranged from 55%to 20%for the I-69 group and 20%to 5%for the I-57 group. Best growth performances were with 1-69 × P szechuanica having a mean hybrid seedling height of 2. 87 m and I-69×P purdomii(2. 38 m)along with root-collar diameters 2. 57 and 2. 1 3 cm. respectively. The LSD test also showed that hybrid seedling growth for mean height and root-collar diameter of 1-69 was significantly greater(P<0. 01)than the I-57 group. M. brunnea infected 100% of all hybrid seedlings;however, the infection index of the I-69 group was lower. Thus, the I-69 × P. szechuanica. I. 69 × P cathayana, and I-69 × P purdomii crosses have good resistance to M. brunnecaCh, 4 tab. 26 ref. ]