Publication Date:
1991-12-01
Description:
Forty-two Eurasian Scots pine (Pinussylvestris L.) clones in a Nebraska seed orchard were observed over 3 years for the phenology of pollen release and seed-cone receptivity and for the production of cones and filled seed. A preliminary investigation had indicated that seed yields were less than expected, and nonsynchronous flowering phenology due to wide genetic diversity was considered as a possible cause. The clones were divided into six regions based on geographic origin and analyzed for variation between regions and between clones within regions. Most variation in cones per tree and filled seeds per cone was due to differences between clones. Most variation in weight per seed was due to differences between regions. The order in which clones began releasing pollen and became receptive remained the same from year to year, but the duration of these events differed between years. Results indicated that nonsynchronous flowering phenology due to genetic diversity is not a likely cause of low seed yield. Seed crops (19.3 kg/ha, 97 000 seeds/kg) were not necessarily lower than should be expected, but 90% of a given year's crop was produced by an average of only 26 clones. With the paternal contribution of each clone to the seed crop unknown, collecting and sowing seed separately by clone is recommended.
Print ISSN:
0045-5067
Electronic ISSN:
1208-6037
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Permalink