Inheritance in a Diallel Crossing Experiment with Longleaf Pine
| Authors: | E. B. Snyder, Gene Namkoong |
| Year: | 1978 |
| Type: | Research Paper |
| Station: | Southern Research Station |
| Source: | Res. Pap. SO-140. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station. 40 p. |
Abstract
Seven-year-old progeny from crosses among 13 randomly selected parent trees provided genetic information on 51 growth, form, foliage, branch, bud, and pest resistance traits. Presented are he&abilities, phenotypic and genotypic variances, covariances, General Combining Ability (GCA), Specific Combining Ability (SCA), and environmental. correlations for all measured traits. The results were compared to those from wind pollinations and to parent-tree measurements where appropriate.There were significant GCA effects for 35 and significant SCA effects for 25 of the traits; the latter were small and unimportant by comparson. There were almost no maternal, reciprocal, or genetic x environmental (GxE) effects.
Parent-progeny correlation coefficients for traits ranged from 0.0 to 0.9 and were generally proportional to the sib-heritabilities. High genetic correlation between 3-year and 1-year heights further suggests a trend toward a juvenile-mature relation high enough to justify selection of families soon after emergence from the grass stage. This procedure would permit short-term progeny testing of ortets before clonal orchards are installed.
GCA correlations between control- and open-pollinated (OP) families were proportional to sib-heritability values, indicating that wind- pollinated seed resulted in efficient progeny tests. Estimates of GCA. variances from OP's were generally larger than those from crosses.