Incompatibility in spruce hybridization
Date
1971
Authors
Kossuth, Susan V., author
Fechner, Gilbert H., advisor
Parke, Robert V., committee member
Fults, Jess Lafayette, 1910-, committee member
Wood, Donald, committee member
Journal Title
Journal ISSN
Volume Title
Abstract
Strobili of reciprocally crossed Picea engelmannii Parry were periodically collected for microscopic study. The development of ovules from unpollinated blue spruce strobili was also studied. Ovules from unpollinated blue spruce strobili began to break down nine days after the mid-period of strobilus receptivity. First, the female gametophyte became necrotic, usually protruding into the nucellus; then the nucellar cap, and finally the chalazal nucellus, broke down. Breakdown of the chalazal nucellus was usually preceded by a proliferation of the cells immediately surrounding the female gametophyte cavity. Blue spruce ovules, which did not receive any Engelmann spruce pollen though the strobili had been pollinated, followed this same sequence of breakdown, and although the female gametophyte became cellular, most cells contained no nuclei and little cytoplasm. Furthermore, the female gametophyte in these ovules did not usually protrude into the nucellus. Some blue spruce ovules, containing germinated Engelmann spruce pollen, did not reach the egg stage. In others, an empty corrosion cavity formed, but In other ovules the female gametophyte showed no further development beyond the egg stage and degenerated. There seemed to be an inhibition of Engelmann spruce pollen germination and/or growth of the pollen tube, in the blue spruce nucellus, which almost always prevented fertilization. Most of the interspecifically crossed Engelmann spruce ovules also degenerated at an early stage of development. Two different conditions were observed in these ovules: 1) Some contained a female gametophyte consisting entirely of very large cells. 2) Others contained a greatly shrunken nucellar cap, but a developed female gametophyte. These two conditions were also observed in the crossed blue spruce ovules, but not simultaneously in the same ovule. The average number of seeds per control-pollinated blue spruce cone was 278, and the average for open-pollinated cones was 302. This difference was not statistically significant according to a T-test. Control-pollinated blue spruce seed showed only a 0.48 percent germination, whereas seed from open-pollinated blue spruce showed 42.5 percent.
Description
Covers not scanned.
Print version deaccessioned 2021.
Print version deaccessioned 2021.
Rights Access
Subject
Hybridization
Spruce
Citation
Associated Publications
Meiman, James R. Little South Poudre Watershed and Pingree Park Campus. Colorado State University, College of Forestry and Natural Resources (1971). http://hdl.handle.net/10217/70382