Parent Selection And Progeny Test In Populus Deltoides Marsh

This study took Populus deltoids germplasm as the main research object, including five parts: genetic variation of important traits and clones selection in Populus deltoids, hydroponics crossing experiments in Populus deltoids, full-sib family experiments in Populus deltoids, study on variation analyswas based on traits of capsule in Populus deltoids, and half-sib family experiments in Populus deltoids.Using multi-trait selection, selected a few clones as parents for crossing, and through full-sib family by combining ability and half-sib family by progeny test, thus chose perior family synthetieally, in order to provide theoretical reference for Poplar breeding. The conclusions were as follows:According to principal component analysis, composite score, membership function and grey relational analysis, we got eighteen clones that were large growth, high wood density and excellent straightness, such as 102-14,101-4,103-3,103-20,66-9,63-13,81-16,81-30,86-10,86-2,86-8,89-2,89-3,89-7,95-33,95-44,96-5,96-10 and so on , by selecting from 202 clones which were from Populus deltoids germplasm.We could find capsules of all the crosses which male parent was S3702 were growing and developing better than others', on the worse environment that room temperature was 30℃and relative humidity was 40%, through hydroponics crossing experiments in Populus deltoids. It showed that hybrid fruit of S3702 could stay at the Condition of high temperature, and low humidity. Typical correlation analysis based on branch nutritional factors and hybrid traits in Populus deltoids showed that the number of flower buds and diameter of female parent branches, had close relationship with the growth and development status of fruit, but nutritional status of branches had no obvious correlation with fruit set rate, and seed germination rate.According to full-sib family by combining ability, it showed that 95-44 and 1-52 which had higher GCA could be used to build seed garden. 94-30&I-35, 1-52&S3244 and T120&95-44 which also had higher SCA could be used to build seed garden,and then crossed to gain superior hybrid which had good diameter and height for genetic selection. Therefore, we not only focused on the growth of parents, but also paid attention to the mating between the parents in order to obtain good progeny in the future.By variance analysis based on the capsule traits in Populus deltoids, the results showed that the difference among 36 families was very large, also reflected that capsule traits were more abundant.The results showed that diameter and height of half-sib families such as 94-18, T15, S373, S3127 was greater, by LSD multiple comparisons. Compwered to I-69, we found 14 half-sib families such as 87-6, 94-18, L232, L28, S3105, S3127, S3226, S3236, S3240, S3319, S3503, S373, S3814, T15 had significant difference, by Dunnet test. These 14 familes could be used for further testing within the family, to seclet good families and individuals for genetic improvement. According to annual seedling growth traits, we could divide 37 half-sib families into three groups by cluster analysis. Among 37 half-sib families, eight half-sib families such as 94-18, S3503, L28, S3127, S3319, S3814, S373, T15 had greater diameter and height.