Development of long-shoot terminal buds of western white pine (Pinus monticola)

1977 ◽  
Vol 55 (10) ◽  
pp. 1308-1321 ◽  
Author(s):  
John N. Owens ◽  
Marje Molder

Long-shoot terminal bud (LSTB) development in western white pine (Pinus monticola Dougl.) was studied throughout the annual growth cycle to determine the phenology of LSTB development and the time of cone-bud differentiation. Development of LSTB began in early April and cataphylls were initiated from mid-August until early November. Cataphyll initiation was slow during May and June when shoots were elongating and then rapid just after shoot elongation was completed. Proximal cataphylls were sterile, whereas more distal cataphylls began to initiate axillary buds by late June or early July. Axillary buds were initiated first in the proximal portions of the LSTB and then acropetally in rapid succession. The last cataphylls to be initiated in the fall remained as sterile bud scales enclosing the LSTB apex. Axillary buds initiated sterile cataphylls which functioned as bud scales. The number varied with the type of axillary bud. Proximal axillary buds initiated few cataphylls and began to differentiate into dwarf shoots or pollen cones in August. The more distal axillary buds differentiated into dwarf shoots during September and October, The most distal axillary buds initiated many cataphylls during September and October but did not differentiate into seed-cone buds or lateral branch buds until after winter dormancy. Consequently, attempts to induce or enhance seed-cone production in P. monticola would probably be most successful in the spring when seed-cone buds differentiate. LSTB bearing seed cones were larger, had broader apices, and produced more cataphylls during the growing season than did LSTB bearing pollen cones. The phenology of LSTB development in soft pines and hard pines is discussed in relation to reports available on the association of cone crops and climatic conditions in several species of Pinus.

1984 ◽  
Vol 14 (4) ◽  
pp. 575-588 ◽  
Author(s):  
John N. Owens

Vegetative buds of mature Abiesgrandis (Dougl.) Lindl. (grand fir) were studied throughout the annual growth cycle. Vegetative buds became mitotically active in mid-March, bud burst occurred in mid-May, and shoot elongation continued until the end of June. Bud scales were initiated during shoot elongation. In mid-April axillary buds were initiated on elongating shoots. They were initiated subterminally in the axils of the first-formed bud scales and laterally in the axils of leaf primordia. Axillary buds followed the same developmental sequence as terminal buds. The end of bud-scale initiation was preceded by rapid apical enlargement and followed by a period of rapid leaf initiation. The rate of leaf initiation slowed in mid-August but continued until vegetative buds became dormant in mid-November. Seed cones are axillary on the upper surface of vigorous shoots in the upper region of the crown. Pollen cones are axillary on the lower surface of shoots below the seed cone bearing region of the crown. Bract and microsporophyll initiation began in early to mid-July, was rapid at first, until about two-thirds of the primordia were initiated, then slower until all primordia were initiated. All bracts and ovuliferous scales were initiated and seed-cone buds became dormant in early November. All microsporophylls were initiated by early September, microsporangial development began in mid-August, and pollen-cone buds became dormant in early November. The cyclic nature of cone production in Abies is discussed in relation to cone-bud initiation, cone maturation, and photosynthate utilization in developing shoots.


2006 ◽  
Vol 36 (5) ◽  
pp. 1059-1066 ◽  
Author(s):  
Isabelle Chuine ◽  
Gerald E Rehfeldt ◽  
Sally N Aitken

In this study we aimed to compare and explain the height growth performance of two contrasting pine species: lodgepole pine (Pinus contorta Dougl. ex. Loud) and western white pine(Pinus monticola Dougl. ex D. Don.). We compiled measurements of total height growth at different ages and shoot elongation phenology realized in several provenance test trials for 109 provenances of lodgepole pine and 54 provenances of western white pine. The response of shoot elongation to temperature was assessed using a phenological model fitted on provenance mean growth curves. Although total height growth followed the same geographic trends in both species, the response of shoot elongation to temperature was different between the two, with few (lodgepole pine) or no differences among provenances (western white pine) from diverse geographic regions. The temperature for which potential cell growth rate is 50% was 10.8 ± 0.13 °C (mean ± standard error) for western white pine compared to 5.26 ± 0.075 °C for lodgepole pine. Phenology did not explain growth performance differences among geographical regions in both species, which instead were explained by differences in the number of internodes set the preceding summer; provenances originating from stressful environments produced the fewest internodes, possibly due to reallocation of carbohydrates to stress resistance.


1965 ◽  
Vol 43 (12) ◽  
pp. 1553-1559 ◽  
Author(s):  
S. Eis ◽  
E. H. Garman ◽  
L. F. Ebell

Cone count records for a 28-year period on 80 Douglas fir, 14 grand fir, and 9 western white pine were statistically analyzed with the annual diameter increment to evaluate the relationship between cone and wood production. The width of annual rings was depressed only during the years of cone production, suggesting that carbohydrates used in cone development were supplied from current photosynthesis rather than from stored reserve. The initiation of reproductive buds did not appear to be dependent on the level of carbohydrates in a tree and the role of carbohydrates was probably only that of nutrition during cone development. Maturing cones did not exhibit any inhibitory effect on initiation of new flowering buds. Different species may require a different combination of climatic factors for initiation of flowering buds.


2001 ◽  
Vol 31 (10) ◽  
pp. 1731-1741 ◽  
Author(s):  
John N Owens ◽  
Glenda Catalano ◽  
Jordan S Bennett

The phenology of post-dormancy pollen cone, pollen, seed cone, and ovule development was determined for western white pine (Pinus monticola Dougl. ex D. Don) growing at a coastal and an interior seed orchard in British Columbia. Pollen cones were preformed and overwintered at the sporogenous cell stage before resuming development in early April. Meiosis occurred in May, and pollen was mature by late May or early June. Potential seed-cone buds resumed development in mid-April, and all bracts and ovuliferous scales were initiated before seed-cone buds burst. Comparable stages of development occurred about 2 weeks earlier at the coastal orchard. Numerical phenological stages were assigned to both pollen-cone and seed-cone development. Pollen-cone and seed-cone phenology were very dependent on temperature, whereas pollen release was dependent on both temperature and drying. Degree-days are a useful way to predict seed cone receptivity and to a lesser extent pollen shed at one site in successive years but not between sites. Receptivity and pollen release were fairly synchronized at both sites in both years of the study. The pollination mechanism is described and was similar to other pines studied in a similar manner. Seed cones were erect at receptivity and ovules inverted. Lipid microdrops were secreted on the micropylar arms to which the saccate pollen adhere. After several days of pollen collection on the arms and other cone surfaces, a pollination drop was secreted from the ovule, and if it was large it filled the space between the micropylar arms. Many large pollination drops were observed in cones at the coastal orchard, and the drops scavenged pollen from the arms and nearby cone surfaces. Few and small pollination drops were observed in cones at the interior orchard where low humidity may cause rapid evaporation of the drop. Water applied as a spray at the interior site increased the size of pollination drops or created artificial drops between the arms. At both sites water applied as a fine spray after pollen shed carried pollen from the hairs on the margins of the bracts and scales into the cone and to the ovules. The pollination mechanism in western white pine is well adapted to the wet humid coastal environment but not as well adapted to the dry interior.


2002 ◽  
Vol 32 (7) ◽  
pp. 1109-1125 ◽  
Author(s):  
Theresa B Jain ◽  
Russell T Graham ◽  
Penelope Morgan

Many studies have assessed tree development beneath canopies in forest ecosystems, but results are seldom placed within the context of broad-scale biophysical factors. Mapped landscape characteristics for three watersheds, located within the Coeur d'Alene River basin in northern Idaho, were integrated to create a spatial hierarchy reflecting biophysical factors that influence western white pine (Pinus monticola Dougl. ex D. Don) development under a range of canopy openings. The hierarchy included canopy opening, landtype, geological feature, and weathering. Interactions and individual-scale contributions were identified using stepwise log–linear regression. The resulting models explained 68% of the variation for estimating western white pine basal diameter and 64% for estimating height. Interactions among spatial scales explained up to 13% of this variation and better described vegetation response than any single spatial scale. A hierarchical approach based on biophysical attributes is an excellent method for studying plant and environment interactions.


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.


1999 ◽  
Vol 14 (1) ◽  
pp. 41-47 ◽  
Author(s):  
M. D. Meagher ◽  
R. S. Hunt

Abstract Survival, environmental damage, and juvenile height of 27 provenances of western white pine (Pinus monticola) in three plantation series were analyzed after 5 to 13 yr on site to assist in evaluating seed-transfer practices. Survival averaged 79.2% on nine sites in the "root-rot" series and 84.1% on six sites in the "provenance-test" series. Trends of survival on seed-source parameters differed between series, generally increasing with both elevation and latitude in the root-rot series, while generally decreasing with latitude in the provenance-test series. Analysis by seed zone (coast or interior) and plantation region (coast, southern interior, or northern interior) showed that coastal sources on interior sites caused much of these anomalies. Substantial environmental damage was found only on sites near to or beyond the species' northern limit. Differences in the trend of damage with source parameters were found between the test series: interior sources were damaged less than coastal sources on two root-rot sites, whereas interior sources were damaged more heavily than coastal sources on the provenance-test site exhibiting substantial damage. Damage increased with increasing provenance latitude and elevation in the root-rot series, while it dropped with increasing elevation in the "provenance-test" series. In general, taller seedlings in taller provenances were damaged. Coastal seed should not be used on interior sites, but transfer of seed from the BC interior to the BC coast seems safe. We recommend that the present limits for latitudinal transfer be doubled, except where late-spring-frost risk is high, and that elevational transfer of seeds for the interior zone be reduced by about half West. J. Appl. For. 14(1)41-47.


1985 ◽  
Vol 61 (6) ◽  
pp. 484-488 ◽  
Author(s):  
R. S. Hunt ◽  
J. F. Manville ◽  
E. von Rudloff ◽  
M. S. Lapp

Cluster analyses of relative terpene abundance in foliage of western white pine (Pinus monticola Dougl.) trees from throughout the Pacific Northwest geographic range of the species were produced. Terpene patterns were randomly distributed among populations; no geographic or site trends were evident. Although blister rust is devastating to stands, the gene pool is widely distributed and may well be preserved without establishing gene banks.About 40-50 trees selected at random would yield offspring with nearly all possible terpene patterns characteristic of the species and would thus constitute a broad genetic base. Therefore seed orchards do not necessarily need to be composed of many individuals, rather, they should contain highly selected individuals with multiple desirable traits including multiple blister rust resistance mechanisms. Key words: terpenes, dendrogram


1989 ◽  
Vol 19 (8) ◽  
pp. 1051-1058 ◽  
Author(s):  
John N. Owens ◽  
Anna M. Colangeli

Cone buds were induced on container-grown and field-grown western hemlock (Tsugaheterophylla (Raf.) Sarg.) clones during a 3-year period to study the effects of time and duration of gibberellin A4/7 treatment on cone induction, sexuality of cones, and to relate these results to bud and shoot development. The most effective treatment times preceded anatomical differentiation. The most abundant pollen cones and seed cones were produced when trees were sprayed with gibberellin A4/7 before vegetative bud burst and early shoot elongation. Two to three weekly gibberellin A4/7 applications starting at preswollen and swollen-bud stages were adequate for pollen-cone production. Pollen-cone production decreased when the applications were started at vegetative bud burst or during early shoot elongation. A minimum of three weekly applications were required for seed-cone production, and applications were equally effective when started at preswollen, swollen, and vegetative bud burst stages. Seed-cone production decreased when three weekly applications were started during early shoot elongation; however, this was overcome by increasing the number of applications.


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