Flowering in a jack pine seedling seed orchard increased by spraying with gibberellin A4/7

1983 ◽  
Vol 13 (6) ◽  
pp. 1056-1062 ◽  
Author(s):  
Robert A. Cecich

Jack pine (Pinusbanksiana Lamb.), in a 3-year-old orchard established with accelerated-growth seedlings, were sprayed with gibberellin A4/7 (GA4/7) in an Aromox–ethanol solution during the 1981 growing season. Seven treatment periods were evaluated: the entire growing season, shoot elongation, bud development, early (first half) and late (second half) shoot elongation, and early and late bud development. Three concentrations of GA4/7 (200, 400, and 600 mg•L−1) were applied in all combinations with treatment periods. Three treatments increased female flowering: 400 and 600 mg•L−1 GA4/7 sprayed the entire growing season and 600 mg•L−1 sprayed during bud development. The number of pollen clusters was increased by spraying 400 and 600 mg•L−1 GA4/7 during any treatment period except early shoot elongation and late bud development or during shoot elongation (400 mg•L−1 only). The 200 mg•L−1 GA4/7 increased pollen clusters only if sprayed during early bud development or the entire growing season. The percentage of trees bearing pollen increased with all concentrations of GA4/7. The 1982 shoot growth of trees sprayed in 1981 during shoot elongation or the entire growing season (all GA4/7 levels pooled) was significantly less than control-tree growth or that of trees in the other treatment periods. The best treatment for increasing both male and female strobili was 600 mg•L−1 GA4/7 sprayed during bud development.

1976 ◽  
Vol 52 (6) ◽  
pp. 283-289 ◽  
Author(s):  
C. W. Yeatman

A program of provenance testing, seed production and genetic improvement of jack pine was developed in the Baskatong region of western Quebec through sustained collaboration among government forest services and forest industry. Research plantations demonstrated, within a period of 10 years from establishment, the superiority in growth, cold hardiness and disease resistance of regionally adapted local seed sources. Critical differences were evident between provenances from the Boreal Forest Region and those from the adjacent Sections of the Great Lakes — St. Lawrence Forest Region.A 300-acre (120 ha) seed production area was created within a genetically superior jack pine population of natural origin in the Côte Jaune area west of Lake Baskatong. Within this population, 325 plus trees were selected, marked and recorded over two years by student crews employed in the summer. Seed harvested from the felled plus trees will be used to create a seedling seed orchard and to establish progeny tests. The plus trees are to be grafted for controlled breeding among selected progeny-tested clones at a later date. This cooperative program of tree improvement will ensure the future supply of high quality seed that will maintain and enhance the value of the forest resource.


New Forests ◽  
2008 ◽  
Vol 36 (3) ◽  
pp. 285-298 ◽  
Author(s):  
Y. H. Weng ◽  
K. Tosh ◽  
G. Adam ◽  
M. S. Fullarton ◽  
C. Norfolk ◽  
...  

1987 ◽  
Vol 17 (11) ◽  
pp. 1408-1415 ◽  
Author(s):  
Robert A. Cecich ◽  
Edmund O. Bauer

The time from emergence of an ovulate strobilus to collection of viable seeds can be reduced to as little as 9 months instead of the usual 16 months spread over two growing seasons. The procedure is called the "shortened reproductive cycle." Two-year-old jack pine (Pinusbanksiana Lamb.) seedlings, grown under accelerated growth conditions, were brought into a greenhouse in the fall, where the environment simulated natural photoperiod and temperature conditions encountered during a growing season, including the approach of fall and winter. Ovulate strobili that subsequently emerged were pollinated and "2nd-year" cones, derived from those strobili, were collected the following September. The yield of filled seeds per cone was low and germination success was variable. The seedlings derived from the shortened reproductive cycle appeared to be normal and produced their own ovulate strobili 14 months after germination. Exposure to the greenhouse environment stimulated pollen production but decreased production of ovulate strobili 1 year after transplanting to the nursery. Flowering during the shortened reproductive cycle procedure was further promoted with gibberellin A4/7 application at the end of terminal shoot elongation in the greenhouse during the winter. Ovulate strobili were observed 6 months later in the nursery.


2012 ◽  
Vol 42 (7) ◽  
pp. 1404-1409 ◽  
Author(s):  
Pengxin Lu ◽  
Wayne Bell ◽  
Paul Charrette ◽  
Megan Thompson

Growth and tree form characteristics of jack pine (Pinus banksiana Lamb.) rooted cuttings propagated from proliferated dwarf shoots (PDS) were compared with seedlings in two field trials 8 years after establishment. Results indicated that jack pine rooted cuttings from PDS can grow as well as seedlings and maintain acceptable tree form. Rooted cuttings of progeny from the 22 top-ranking open-pollinated families in a seedling seed orchard of jack pine were 4.2% taller and 10% larger in diameter at breast height than commercial seedlings tested on the same sites, which indicates that rooted cuttings have potential in realizing genetic gains in jack pine tree improvement programs. Rooted cuttings increased the proportion of trees with normal branching characteristics and reduced the percentage of trees with excessive heavy branches in the Sault St. Marie trial, which had larger tree sizes. However, longer term monitoring (20 to 25 years) is needed to determine stability of jack pine rooted cuttings planted on sandy soil where wind throw may become a problem as tree size increases.


1994 ◽  
Vol 24 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Conor O'Reilly ◽  
J.N. Owens ◽  
J.T. Arnott ◽  
B.G. Dunsworth

Western hemlock (Tsugaheterophylla (Raf.) Sarg.) seedlings grown in two different container cavity sizes that received four different dormancy induction treatments, short (SD) or long days (LD), in combination with moisture stress (D) or no moisture stress (W), in the greenhouse, and lifted and placed in cold storage (November, January, or March) were planted on two adjacent coastal reforestation sites on Vancouver Island, British Columbia, and monitored for phenological responses during the first growing season. The SD seedlings flushed sooner and began bud development later than the LD seedlings, although the effect on flushing was small for those lifted in March. Moisture stress and SD together in the greenhouse reduced shoot elongation rates but had little impact on field bud development. Cold storage of seedlings lifted in November and January delayed flushing, reduced shoot elongation rates, and advanced bud development compared with the March-lifted stock. The influence of cavity size was generally small on most variables measured. Shoot elongation was slightly faster on the southeast site than on the northwest site, whereas bud development was more rapid on the northwest site. The effect of site on date of flushing varied with nursery treatment.


1992 ◽  
Vol 22 (1) ◽  
pp. 1-4 ◽  
Author(s):  
A. D. Barnes ◽  
W. D. Kelley

Uniconazol, applied in an aqueous solution to 3-year-old loblolly pine (Pinustaeda L.) at the soil–stem interface, decreased height growth by up to 55% after one growing season without phytotoxic effects. Results suggest that uniconazol may be useful in controlling height growth of seedlings and seed-orchard trees. The triazoles uniconazol, paclobutrazol, and BAS011106W were tested for effects on loblolly pine root growth. Root-applied uniconazol consistently increased root growth of 1-year-old seedlings. At 100 mg•L−1, uniconazol increased the number of new roots and survival by 47 and 19%, respectively. The increase in survival of uniconazol-treated seedlings was not statistically significant, but the tendency is encouraging.


2008 ◽  
Vol 57 (1-6) ◽  
pp. 276-282 ◽  
Author(s):  
Y. H. Weng ◽  
J. Kershaw ◽  
K. Tosh ◽  
G. Adams ◽  
M. S. Fullarton

AbstractDifferences in height-diameter (H-DBH) relationship were investigated using the Chapman-Richards function among jack pine seedlots planted in a realized genetic gain test in New Brunswick. Three seedlots representing the bulk mixed cone collection from the 1979 J.D. Irving’s first-generation seedling seed orchard (JDISSO) before rogueing (UNR), after the first time genetic rogueing (1STR) and after the second time genetic rogueing (2NDR), respectively, were planted in the test. Unimproved commercial seedlots (UC) were also included for comparison. Results indicate that an overall H-DBH relationship for all the seedlots was not appropriate. Seedlot pairwise comparisons in H-DBH relationships showed that, whereas most seedlot pairs were significantly different from each other, there was no significant difference between the UNR and UC and between the 1STR and 2NDR. Two models were developed with one targeting the UNR and UC (UNIMPROVED) and the other targeting the 1STR and 2NDR (IMPROVED). The difference between the UNIMPROVED and IMPROVED models was caused only by asymptote of the Chapman-Richards function. Applying the UNIMPROVED or IMPROVED model to predict height of the 1STR and 2NDR or the UNR and UC would result in an under-estimated or an over-estimated bias by 2 to 3% in height. In light of this study, seedlot differences in H-DBH relationships should be integrated into growth and yield models by a multiplier for height depending on genetic improvement levels.


1986 ◽  
Vol 16 (2) ◽  
pp. 211-221 ◽  
Author(s):  
J. N. Owens ◽  
J. E. Webber ◽  
S. D. Ross ◽  
R. P. Pharis

The anatomy, mitotic frequency, size, and total insoluble carbohydrate histochemistry was studied in axillary apices from 9- and 10-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) trees after cone induction treatments of root-pruning and (or) stem injections of a gibberellin A4 and A7 (GA4/7) mixture. Axillary buds were initiated at the time of root-pruning, but root-pruning treatment had no effect on axillary bud initiation. Axillary apices from control and gibberellin-treated trees were similar and followed the normal sequence of bud-scale initiation, differentiation, and leaf initiation (described previously) and no cone buds differentiated. Early development of axillary apices from root-pruned and root-pruned, gibberellin-treated trees was normal, but development became retarded near the time of vegetative bud flush. Retarded apices were small with low mitotic frequency and developed many features characteristics of latent apices. Retardation of axillary apices continued until mid-July when normal development resumed and apices differentiated into reproductive buds or vegetative buds, or became latent. The trees in which the greatest retardation of apical development occurred during lateral shoot elongation produced the most cone buds. These results are discussed in relation to hypotheses proposed to explain how cultural and gibberellin treatments affect cone induction in the Pinaceae.


1981 ◽  
Vol 11 (3) ◽  
pp. 580-585 ◽  
Author(s):  
Robert A. Cecich

Jack pine (Pinusbanksiana Lamb.) seeds were sown in October, January, and March, and the seedlings were cultured under accelerated growth conditions in a greenhouse. At biweekly intervals, from May 15 to August 15, they were transplanted to a nearby nursery and sprayed with GA4/7 or GA4/7 + NAA. The following spring a fourfold increase in flowering was noted in trees receiving either of the GA4/7 treatments. Trees in the March sowing did not flower. The data suggest that the increased flowering was caused by GA4/7-mediated differentiation of lateral long-branch primordia into ovulate strobili.


1988 ◽  
Vol 18 (1) ◽  
pp. 139-142 ◽  
Author(s):  
Rong H. Ho

Black spruce (Piceamariana (Mill.) B.S.P.) grafts growing in a seed orchard were sprayed with gibberellin A4/7, and grafts and trees in families growing in arboreta were sprayed with gibberellin A4/7 and (or) vitamin E from vegetative bud burst to the end of shoot elongation. Gibberellin A4/7 was very effective in promoting seed cones and 400 mg/L appeared optimal. Vitamin E at 1000 mg/L was not effective. Vegetative bud burst occurred in mid-May and shoot elongation ended in late June. Needle primordia were visible on the apices of newly formed buds at the end of June. Reproductive buds had fewer bud scales than vegetative buds. It appeared that potential reproductive buds terminated their bud scale initiation earlier. Gibberellin A4/7 application to promote seed-cone production should be carried out before bud-type differentiation. This coincides with the end of lateral shoot elongation.


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