Picea Pungens Engelm Research Articles

Improvement of grafting procedures for the ornamental species: I. Picea pungens Engelm. var. glauca Regel

In order to get ornamental trees for landscaping, Colorado blue spuce ( Picea pungens Engelm. var. glauca Regel) scions were grafted on Norway spruce ( Picea abies (L. Karst.) rootstocks. An original double-side-veneer grafting method was applied in five experimental or basic variants. The plastic tapes and the ecological Ceraltin wax developed by the Research and Development of Bio-stimulators (CCDB) BIOS Cluj were tested. In addition, two controls in which the classic raffia and the traditional hot wax and the classic side-veneer-grafting method were used. The obtained results, expressed in percents, were transformed in arcsin square root of percent values, and then a two-way analysis of variance (ANOVA) was used. Highly significant ( p < 0.001) statistical differences were found between all grafting variants, including controls. The Duncan test proved that original double-side-veneer grafting method and the new developed materials, i.e. plastic tapes and the ecological Ceraltin wax have contributed in getting a better grafting success compared to the controls.Thus, the double-side-veneer grafting method and the two grafting materials are highly recommended to be used in getting grafted Colorado blue spuce ornamental trees.

Cambioxylophagous fauna developing on logging residues of blue spruce (Picea pungens Engelmann)

Cutting down 20- to 30-years-old trees of blue spruce (Picea pungens Engelm.) (October, May) and cross-cutting them to sections of different volume (0.5–75 dm3) under conditions of half-shade × open area resulted in a potential food offer for cambiophages. Ips amitinus (Eichh.) and Pityogenes chalcographus (L.) reached the higher frequency of occurrence on sections placed in the open area than in half-shade and on stems felled in the autumn season than in the spring season. Dryocoetes autographus (Ratz.) was markedly profiled on sections in half-shade with the gradual desiccation of phloem. P. chalcographus preferring open areas occurred on branches being accompanied by Cryphalus abietis (Ratz.), which attacked branches located in half-shade. On stems of sections from both autumn and spring felling, one generation of I. amitinus developed, however, on autumn sections, the 2&lt;sup&gt;nd&lt;/sup&gt; generation developed unsuccessfully on the original nutritive material. P. chalcographus completed the development of one generation on stems and branches from autumn felling. On the spring material, the invasion was delayed and a part of wintering larvae did not complete their development. Logging residues of P. pungens were available for the development of I. amitinus and P. chalcographus during one growing season only.

Recovery kinetics of winter stressed conifers: The effects of growth light environment, extent of the season, and species.

AbstractEvergreens undergo a dramatic reduction in their maximal photochemical efficiency (measured as Fv/Fm) during winter, which is largely due to increases in a sustained form of thermal energy dissipation. Upon removing winter-stressed leaves to room temperature and low light, Fv/Fm recovers over several days and can include both a rapid phase (reversing in minutes) and a slow phase (reversing over days). Both phases are associated with reversal of sustained energy dissipation. Preliminary examination of recovery of evergreens monitored in January in Minnesota showed an absence of the rapid component to recovery. Our goal was to monitor recovery kinetics of sun and shade evergreens in Minnesota throughout winter in order to assess whether the rapid phase of recovery exists early in the winter and converts to the slowly reversible form as winter progresses. Four species of conifers (sun and shade needles) were monitored during the winter of 2007/08: eastern white pine (_Pinus strobus_ L.), balsam fir [Abies balsamea (L.) P. Mill], Taxus cuspidata (L.) and blue spruce (Picea pungens Engelm.). Fv/Fm was measured on dark acclimated needles in the field, twigs were collected, brought indoors and maintained at room temperature and low light where Fv/Fm was monitored for six days.The results demonstrated that all species, and both sun and shade needles, showed a rapidly reversible component to recovery in early winter (November). In the sun needles this component was rarely present later in the season, while in the shade needles it was present (although only a small fraction of the total sustained energy dissipation) on most days monitored during winter. The slowly reversible component to sustained energy dissipation was present in both sun and shade needles of all species beginning in November. In all cases, shade needles recovered significantly faster than sun needles. There was a significant slowing of recovery (the slowly reversible component) as winter progressed in both sun and shade needles, and significant differences between species in their recovery response. The results indicate a relatively small contribution of the rapidly reversible component of sustained energy dissipation compared with earlier studies on evergreens growing in the milder winter conditions of Colorado. The results also provide evidence that the rapid component to recovery diminishes as the season progresses, particularly in needles growing in full sun where the slowly reversible component of sustained energy dissipation accounts for most or all of the observed sustained energy dissipation.

Intensity of free radical processes in the leaves of arboreal plants under act of industrial dust borne extracts

The influence of industrial pollutants on the intensity of lipid peroxidation in the assimilatory organs of arboreal plant was investigated. The differential changes of the probed indexes are set depending on the species. Information is got can testify to participation of lipid peroxidation products in forming of reactions-answers of arboreal plants on influence of industrial dust borne extract with content of heavy metals. Determination of level and rates of accumulation of Zn, Ni, Pb and Cd, in the leaves of arboreal plants in the conditions of different contamination level allowed to take species to two groups. To the first (phytoextraction potential exceeds a base-line level in 10 times) belong Populus bolleana Lauche, P. italica (Du Roi) Moench, Picea pungens Engelm and Sorbus aucuparia L. To the second (exceeds a base-line level from 5 to 10 times) belong Acer negundo L., Aesculus hippocastanum L., Betula pendula Roth and Tilia cordata Mill. The most substantial increase of peroxidation secondary product content (more than in 2.5 times) is peculiar for B. pendula, A. hippocastanum and P. pungens Engelm., that well conforms to the rates of heavy metals translocation, it has however species-specific character.

Chemical thinning in blue spruce (Picea pungens Engelm.) stands and its effects on cambioxylophagous fauna

Chemical thinning was applied in blue spruce (Picea pungens Engelm.) stands by the application of Roundup Klasik and Garlon 4 EC. The thinning efficacy of Garlon 4 EC was negligible, while that of Roundup Klasik reached nearly 100% when the full strength concentration was applied in quantities of 1 ml per 10 cm of stem girth using the method of drilling holes for the arboricide injection. Treated blue spruce trees died within 6 month after application. No difference was found in the response of silver and green varieties of blue spruce to the application of arboricides. Several species of cambioxylophages colonizing blue spruce were killed by Roundup. The economically insignificant Hylurgops palliatus (Gyll) was the most abundant negatively affected insect species found on the stem, followed by significant pests such as Ips amitinus (Eichh.) and Pityogenes chalcographus (L.). In these species, partial mortality of larvae was probably caused by the lowered quality of phloem. A significant mortality of Cryphalus abietis (Ratz.) was noted on branches.

Evaluating Root Crown Excavation as a Treatment for Deeply-Planted Landscape Trees

An experiment was conducted over a four-year period to evaluate root crown excavation (RCE) as a treatment for deeply-planted landscape trees. Tree growth, leaf chlorophyll, stress, and pest activity were monitored to determine plant response to RCE. Four of the sites, including shingle oak (Quercus imbricaria Michx.) street median strip trees, blue spruce (Picea pungens Engelm.) park trees, and honeylocust (Gleditsia triacanthos L. var. inermis (L.) Zab.) parking lot island and street trees failed to show any influence of RCE on tree growth and leaf chlorophyll. Two sites with maple (Acer spp.) park and street trees where RCE included removal of potential girdling roots resulted in a detrimental effect on twig extension and leaf chlorophyll. Measurements of chlorophyll on ash (Fraxinus spp.) park trees, and tree height and twig extension on lacebark elm (Ulmus parvifolia Jacq.) street trees, demonstrated a positive influence of RCE. The RCE treatment did not influence stress or pest activity at any of the experimental sites. Since tree disorders frequently require many years to develop it is speculated that a longer observation period may be necessary to see a greater impact of RCE on plant growth and health.

Mavi ladinin (Picea pungens Engelm.) Aşi ile Üretimi Üzerine Araştirmalar

Bu calismada, peyzaj uygulamalarinda cokca kullanilan ve ithal bir tur olan Picea pungens Hoopsii nin asi ile uretiminde, Avrupa ladini (Picea abies (L.) Karst.) ve dogu ladini (Picea orientalis (L.) Link.) fidanlarinin altlik olarak kullanimi arastirilmistir. Bu amacla 2+1 ve 2+0 yasindaki fidanlar altlik olarak kullanilmistir. Farkli asi teknigi olarak uygulanan yarma ve yanastirma asinin ve ayrica asi yerine macun surulup surulmemesinin de etkisi arastirilmistir. Arastirma sonuclarina gore asi basarisi; yarma asida %60, yanastirma asida da %55 olarak tespit edilmistir. Bununla birlikte, asi macununun asi basarisini arttirdigi belirlenmistir. En yuksek asi basarisi da %87 ile yarma asi tekniginin uygulandigi 2+1 yasli Avrupa ladini altliklarinin kullanildigi ve asi yerine asi macunu suruldugu denemelerde elde edilmistir

Cold-regulated proteins with potent antifreeze and cryoprotective activities in spruces ( Picea spp.)

Antifreeze proteins (AFPs) were obtained from intercellular spaces of spruce needles Picea abies (L.) Karst. and Picea pungens Engelm. by vacuum infiltration with ascorbic acid, followed by centrifugation to recover the infiltrate. As shown by sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE), apoplastic proteins are accumulated in these spruce species as a group of 5–9 polypeptide bands. These proteins have a molecular mass of 7–80 kDa. The spruce AFPs have the ability to modify the growth of ice and thermal hysteresis, TH, caused by these AFPs was close to 2.0 °C at a concentration of 400 μg/ml. The antifreeze activity of proteins from these winter-hardy coniferous species showed a positive correlation with the concentration of proteins after cold acclimation of needle tissues. Apoplastic proteins from winter spruce needles exhibited antifreeze activity, whereas no such activity was observed in extracts from summer needles. When we examined the possible role of spruce AFPs in cryoprotection, we found that lactate dehydrogenase, LDH, activity was higher after freezing in the presence of AFPs compared with bovine serum albumin. Amino-terminal sequence comparisons indicated that a 27-kDa protein from both P. abies and P. pungens was similar to some pathogenesis-related proteins namely chitinases, also from conifer species. These results show that spruces produce AFPs that are secreted into the apoplast of needles. The accumulation of AFPs in extracellular spaces caused by seasonal cold acclimation during winter indicates that these proteins may play a role in the acquisition of freezing tolerance of needle cells in coniferous species.

Nutrient Treatments Used on Field-harvested Colorado Spruce Trees to Maintain Postharvest Quality

Holding practices for balled and burlapped conifers may inadvertently impact nutrient availability and tree growth. The objective of this study was to examine the effectiveness of several nutrient treatments to maintain or enhance the growth and foliar nutrition of Colorado spruce (Picea pungens Engelm.) trees while they were in a mulch-holding bed. Sixty 1.5 to 1.8-m tall Colorado spruce trees with 61-cm (24 inch) diameter root balls were heeled into a holding bed of fresh pine bark mulch during 2002 and 2003. The treatments applied to the root balls were a control (pine bark without fertilizer), 114.2 g Osmocote (Scotts, Marysville, OH) 15N–3.9P–10K distributed over the top of the ball, one Ross Gro-Stake (Easy Gardener, Waco, TX) 10N–4.3P–8.3K Evergreen fertilizer spike (113 g) per ball, one-half cartridge (≈8.5 g) of Ross Root Feeder (Weatherly Consumer Products, Lexington, KY) 10N–5.2P–10K evergreen fertilizer injected into the root ball at four points, or a 1:1 biosolids-based compost:pine bark mixture (by volume). Trunk diameters and tree heights were measured and foliar samples for nutrient analyses were collected before applying these treatments and at the end of the growing season 20 or 17 weeks later. The 2003 trees were transplanted to a landscape site in 2004, and the height growth of their terminal leaders were measured at the end of the next two growing seasons. Overall, Colorado spruce trees appeared normal while they were held in the mulch beds the first season after nursery harvest. Changes in tree height and trunk diameter by the end of the first season after harvest were unaffected by the nutrient treatments. By fall of both years, needles from trees treated with the mixture of 1:1 compost:bark had the highest levels of foliar N, Mg, Ca, S, and B. Trees treated with the fertilizer spike in 2002 had similar levels of N and S in their needles compared with compost:bark-treated trees, whereas in 2003, spike-treated trees had the second highest levels of foliar N and S, and these levels were significantly higher than those of trees receiving the control or other fertilizer treatments with the exception of N in needles from fertilizer-injected trees in 2002. Plant-available N, however, was highest in the root balls of Osmocote- and fertilizer spike-treated trees only in 2003. Leaders on the 2003 trees that received the compost:bark or fertilizer spike treatments grew at least 70% or 36% taller, respectively, than those trees receiving the other treatments by the end of the second growing season in a managed landscape. Although all nutrient treatments failed to promote increases in tree heights and trunk diameters while the trees were held in a mulch bed for the first growing season after digging, the compost:bark mixture and, to some extent, the fertilizer spike improved foliar nutrition during this time.

Estimation of light interception properties of conifer shoots by an improved photographic method and a 3D model of shoot structure

The spherical mean of the shoot silhouette-to-total leaf area ratio (STAR) and the shoot transmission coefficient (c) are two key structural parameters in radiative transfer models for calculating canopy photosynthesis and leaf area index. The standard optical method for estimating these parameters might introduce errors in the estimates for species with flexible shoots and needles by changing shoot inclination relative to its inclination in situ. We devised and tested two methods to address this problem. First, we modified the standard optical method by designing an apparatus that allows shoots to be photographed in their original orientation. Second, we developed a faster, model-based approach to replace photography and tested the results against the established approach. We used shoots of three pine species, Pinus echinata Mill. (needle length ~50 mm), P. taeda L. (~150 mm) and P. palustris Mill. (~300 mm). Values of the parameters simulated by the model were similar to those measured from the photographs. In our data, STAR varied about twofold among the pine species and was ~40% higher in shade shoots than in sun shoots of P. taeda. The transmission coefficient for P. taeda shade shoots was also ~40% higher than that of sun shoots of all three species. We tested the versatility of the model by employing it on shoots of two other pine species (P. strobus L. and P. thumbergiana Parl.) as well as on shoots of Tsuga canadensis L. Carr. and Picea pungens Engelm. Regardless of shoot characteristics, the model generated values of shoot structural parameters similar to those estimated with the optical method. Although species-specific and vertical gradients in parameter values are best for modeling radiative transfer in conifer canopies, our results suggest that, in the absence of adequate data, STAR can be approximated as 0.16 for a wide range of shoot structures. For applications requiring angle-dependent parameterization, our new model facilitates rapid generation of these radiative transfer parameters.

The structure of genetic diversity in Engelmann spruce and a comparison with blue spruce

Genetic diversity and genetic structure in Engelmann spruce (Picea engelmannii Parry ex Engelm.) were interpreted with respect to the effects of glacial and interglacial displacement and compared with patterns in blue spruce (Picea pungens Engelm.), which occupies a range well south of the last glacial front. On average, Engelmann spruce populations were polymorphic at 80% of 24 isozyme loci, with 2.4 alleles per locus and expected heterozygosity of 0.255. The respective means for four populations of blue spruce were 42.7%, 1.6 alleles, and 0.138. Of total diversity, 14.7% was among populations in Engelmann spruce and 8.6% in blue spruce. In Engelmann spruce, numbers of alleles increased from south to north. Recent bottlenecks were indicated in the three southernmost populations of Engelmann spruce and in the northernmost population of blue spruce. Cluster analysis divided Engelmann spruce into a northern group and a Southwestern group; however, populations from Utah were distributed among both clusters. Genetic distance was correlated with geographic distance between northern populations but not between Southwestern populations, where drift predominated over gene flow. In two Engelmann spruce populations from Utah, multilocus outcrossing rates were 0.951 (±0.016) and 0.940 (±0.071). At Flys Peak, Arizona, the southernmost location of Engelmann spruce, outcrossing was also high, 0.899 (±0.017). Thus, inbreeding coefficients observed for parental (–0.104 to 0.047) and filial (0.011 to 0.026) generations were low. Although Engelmann spruce seemed genetically robust, the evidence of bottlenecks in the southern extreme of its range suggested future problems in an era of global warming.

(35) Foliar Mineral Nutrition of Colorado Spruce Trees after Digging Affects Shoot Growth in the Landscape

The goal of this study was to determine if nutrient treatments applied to Colorado spruce (Picea pungens Engelm.) trees while they were held in a mulch bed one season after digging affected subsequent shoot growth of the trees after they were planted in the landscape. Sixty 1.5- to 1.8-m-tall trees with 61-cm (24-inch) diameter root balls were heeled into a holding bed of fresh pine bark mulch. The nutrient treatments applied to the root balls were a control (pine bark without fertilizer), 114.2 g Osmocote 15–9–12 distributed over the top of the ball (label rate), one Ross Gro-Stake 10–10–10 Evergreen fertilizer spike per ball, one-half cartridge of Ross Root Feeder 10–12–12 evergreen fertilizer injected into the root ball at four points, or a 50:50 mixture (by volume) of Eko Compost mixed with pine bark. After one growing season in the mulch bed, the trees were transplanted to a landscape site. The height increases of the terminal leaders on all trees were determined for the next 2 years. Changes in tree height by the end of the growing season in the mulch bed were unaffected by the nutrient treatments. By fall, needles from trees treated with the mixture of 50:50 compost: bark had the highest levels of foliar N, Mg, Ca, S, Mn, and B. Trees treated with one fertilizer spike had the second-highest levels of foliar N and S. Leaders on trees that received the compost:bark or fertilizer spike treatments grew at least 70% or 36% taller, respectively, than those receiving the other treatments by the end of the second growing season in the landscape. The compost:bark mixture and to some extent the fertilizer spike improved tree foliar nutrition during the first growing season after digging, which later promoted tree height increases in the landscape.

Southwestern Dwarf Mistletoe, Arceuthobium vaginatum subsp. cryptopodum, Found Parasitizing Picea pungens in Colorado

Southwestern dwarf mistletoe (Arceuthobium vaginatum (Willd.) Presl subsp. cryptopodum (Engelm.) Hawksw. & Wiens, Viscaceae) severely parasitizes several species of pines (Pinus spp., family Pinaceae) in Colorado, Utah, Arizona, New Mexico, and northern Mexico, but it has not been reported to parasitize any species of spruce (Picea, family Pinaceae) (1). However, in June 2004, this dwarf mistletoe was observed parasitizing blue spruce (Picea pungens Engelm.) in the Black Forest north of Colorado Springs, CO (39°02.118'N, 104°36.028'W, elevation 2,250 m). The infected blue spruce was planted as an ornamental approximately 4 m from a 16-m-high ponderosa pine (Pinus ponderosa Douglas ex Lawson & C. Lawson) severely infected with southwestern dwarf mistletoe. Mature dwarf mistletoe shoots were produced on five infected branches of the blue spruce. These shoots were compared with a morphological description of southwestern dwarf mistletoe (1) and this was sufficient for a positive identification of the dwarf mistletoe. The other dwarf mistletoes reported to infect blue spruce are Arceuthobium microcarpum (Engelm.) Hawksw. & Wiens, A. americanum Nutt. ex Engelm., and A. douglasii Engelm.; these are all morphologically distinct from southwestern dwarf mistletoe (1). Three of the infected branches formed small (less than 0.3 m in diameter), nonsystemic witches' brooms. All of the infections on the 6-m-high blue spruce were higher than 1 m on the tree. Thus, it is likely that the spruce was infected after it was transplanted. Three other blue spruces were also located within 4 m of the infected ponderosa pine, but these trees were not infected. To our knowledge, this is the first report of southwestern dwarf mistletoe parasitizing blue spruce and the first report of this dwarf mistletoe on Picea spp. Voucher specimens have been deposited in the Deaver Herbarium, Northern Arizona University, Flagstaff (Accession No. 73959).

Examining Nutrient Treatments Used on Balled and Burlapped Colorado Spruce Trees to Maintain Postharvest Quality

The goal of this study was to examine the effectiveness of several nutrient treatments to maintain or enhance the growth and foliar nutrition of Colorado spruce (Picea pungens Engelm.) trees while they were in a mulch holding bed. Sixty 1.5 to 1.8 m tall Colorado spruce trees with 61 cm (24 inch) diameter root balls were heeled into a holding bed of fresh pine bark mulch. The treatments applied to the root balls were a control (pine bark without fertilizer), Osmocote 15-9-12 distributed over the top of the ball at 114.2 g (label rate) per root ball, one Ross Gro-Stake 10-10-10 Evergreen fertilizer spike per ball, one-half cartridge of Ross Root Feeder 10-12-12 evergreen fertilizer injected into the root ball at four points, or a 50:50 mixture (by volume) of Eko Compost mixed with pine bark. Trunk diameters and tree heights were measured and foliar samples for nutrient analyses were collected before applying these treatments and at the end of the growing season 17 weeks later. Overall, the Colorado spruce trees appeared quite normal throughout the study. Changes in tree height and trunk diameter by the end of the growing season were unaffected by the nutrient treatments. By fall, needles from trees treated with the mixture of 50:50 compost:bark had the highest levels of foliar N, Mg, Ca, S, MN and B. Trees treated with one fertilizer spike had the second highest levels of foliar N and S, and these levels were significantly higher than those of trees receiving the other fertilizer treatments. Even though all nutrient treatments failed to influence increases in tree heights and trunk diameters during the first growing season after digging, the compost:bark mixture and to some extent the fertilizer spike improved foliar nutrition during this time.

Western Dwarf Mistletoe Parasitizing Colorado Blue Spruce and Norway Spruce in California.

Western dwarf mistletoe (Arceuthobium campylopodum Engelm.), a common parasite of ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and Jeffrey pine (Pinus jeffreyi Grev. & Balf.), was found parasitizing planted Colorado blue spruce (Picea pungens Engelm.) and Norway spruce (Picea abies (L.) H. Karsten) in Upper Cuddy Valley, CA (Kern County, T. 9 N., R. 21 W., Sec. 25). One tree greater than 6 m in height of each spruce species was infected and both trees were within 12 m of a Jeffrey pine severely infected with western dwarf mistletoe. Five to 10 branches were infected on each tree and a few of these had abundant mistletoe shoot production, which allowed identification of the parasite. This is the first report of western dwarf mistletoe on Colorado blue spruce. Although this is the first report of natural infection of Norway spruce in California, this mistletoe/host combination has been reported by Weir from artificial inoculation (2) and collected by Russell in central Washington (1). We recommend that these spruce species not be planted within 15 m of pines infected with western dwarf mistletoe. Specimens of western dwarf mistletoe on Colorado blue spruce and Norway spruce were collected and deposited at the Deaver Herbarium, Northern Arizona University, Flagstaff.

Regeneration of planted conifers across climatic moisture gradients on the Canadian prairies: implications for distribution and climate change

The influence of dry climates on white spruce (Picea glauca (Moench) Voss)) regeneration was examined by conducting surveys of seedlings and small trees that had regenerated naturally at 100 farm shelterbelts and plantations in southern Saskatchewan, Canada. The sites surveyed were located along a climate moisture gradient extending from the relatively moist boreal forest, across the aspen parkland, to the semi‐arid prairie grasslands. Natural regeneration was greatest at sites in the boreal forest and northern aspen parkland, decreased in the southern aspen parkland, and was negligible in the grassland zone. Furthermore, the few seedlings found in the drier zones were usually in poor condition. Similar results were obtained for the introduced Colorado spruce (Picea pungens Engelm.) and Scots pine (Pinus sylvestris L.). It is concluded that the present climate of the southern parkland and grassland is too dry to permit natural regeneration of white spruce and other conifers. If increases in atmospheric CO2 levels lead to a drier future climate in the southern boreal forest of western Canada, the ability of conifers to regenerate naturally may be significantly reduced.

The effects of dry O3 , SO2 and NO2 on reconstituted epicuticular wax tubules.

Epicuticular wax tubules were reconstituted in vitro by recrystallizing nonacosan-10-ol from the soluble cuticular lipids of Picea pungens Engelm. on a glass support. Fumigation of these preparations for 100 h with dry O3 (1.8 %), SO2 (100%) or for 1500 h with NO2 (0.1 %) did not change their composition or crystal habit. Exposure of reconstituted wax tubules to 1 % of dry NO2 yielded planar crystals of nonacosan-10-one after 100 h. Further exposure (264 h) resulted in the complete degradation of aggregates and the formation of nonadecanoic and eicosanoic acids. The same oxidation steps and the accompanying changes of crystal shapes could be induced by fumigation of nonacosan-10-ol tubules with 100% of dry NO2 for 0.25-1 hand for 2 h, respectively. The oxidation of nonacosan-10-ol depended on the doses applied. At ambient concentrations, equivalent doses would accumulate only over thousands of years. Oxidative transformations alone can therefore not account for the in vivo degradation of wax tubules on conifer needles.

Biochemical changes during pollen germination measured in vivo by infrared spectroscopy

Biochemical changes during the germination of pine ( Pinus ponderosa Laws.), and spruce ( Picea pungens Engelm.) pollen grains were measured in vivo using Fourier transform infrared spectroscopy. Samples of dry, hydrated, and germinating pollen were analysed using cylindrical internal reflectance. Spectra were recorded at regular intervals up to the time of tube emergence. Germination was evaluated microscopically. The spectra revealed differences in exine structure/thickness and a significant difference in phytate content in pine and spruce pollen. Changes observed during germination included increased respiratory activity, changes in membrane lipid phase and amount, changes in protein amount and secondary structure, and changes reflecting the utilization of phytate and formation of cell walls. Infrared spectroscopy, in a short time and using a limited amount of sample, can provide biochemical insight to the process of pollen germination and has potential for the development of a more detailed analysis of pollen viability and vigor.

Defense Mechanisms of Conifers

Cell-free extracts from Pinus ponderosa Lawson (ponderosa pine) and Pinus sylvestris L. (Scotch pine) wood exhibited high levels of monoterpene synthase (cyclase) activity, whereas bark extracts of these species contained no detectable activity, and they inhibited cyclase activity when added to extracts from wood, unless polyvinylpyrrolidone was included in the preparation. The molecular mass of the polyvinylpyrrolidone added was of little consequence; however, polyvinylpolypyrrolidone (a cross-linked insoluble form of the polymer) was ineffective in protecting enzyme activity. Based on these observations, methods were developed for the efficient extraction and assay of monoterpene cyclase activity from conifer stem (wood and bark) tissue. The level of monoterpene cyclase activity for a given conifer species was shown to correlate closely with the monoterpene content of the oleoresin and with the degree of anatomical complexity of the specialized resin-secreting structures. Cyclase activity and monoterpene content were lowest in the stems of species containing only isolated resin cells, such as western red cedar (Thuja plicata D. Don). Increasing levels of cyclase activity and oleoresin monoterpenes were observed in advancing from species with multicellular resin blisters (true firs [Abies]) to those with organized resin passages, such as western larch (Larix occidentalis Nutt.), Colorado blue spruce (Picea pungens Engelm.) and Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco). The highest levels of cyclase activity and oleoresin monoterpenes were noted in Pinus species that contain the most highly developed resin duct systems. The relationship between biosynthetic capacity, as measured by cyclase activity, monoterpene content, and the degree of organization of the secretory structures for a given species, may reflect the total number of specialized resin-producing cells per unit mass of stem tissue.

Variation among Picea pungens Progenies grown in Ohio

Abstract Wide variation in foliage color, height, and form was found among progenies of blue spruce (Picea pungens Engelm.) grown in Ohio from seed collected from 32 provenances. Data were collected seven and 12 years after permanent field planting of 3-3 stock. Broad differences also occurred among 4 geographic regions, each made up of anywhere from 4 to 12 provenances. Trees from the region (Region 3) of southern Colorado, northern New Mexico, and northern Arizona averaged the fastest growth, bluest color, and most symmetrical form. Those trees from Utah and Wyoming (Region 2) most often had the slowest growth rate and least desirable form and color. The average performance of trees from northern Colorado (Region 1) and southern New Mexico and southern Arizona (Region 4) was generally intermediate between that of Region 2 and Region 3. Although regional differences were significant, great variability existed among provenances across the entire range of the species. Nurserymen desiring to grow blue spruce with improved growth rate, color, and form at a lower cost should consider collecting seed from those seed sources which have consistently proven themselves to be superior in this and other studies.