Pinus uncinata Ramond taxonomy based on needle characters

 11 needle characters of Pinus uncinata Ramond from the Spanish Pyrenees, P. mugo Turra from the Tatra Mountains, and P. sylvestris L. from N.E. Poland were analysed. It was shown that P. uncinata is much more closely related to P. mugo than to P. sylvestris. Nevertheless P. uncinata remains distinct from both in a number of the characters examined. The species differs from P. mugo especially in the length of the needles and in the distance between the vascular bundles. It differs from P. sylvestris in such characters as the number of resin canals, thickness of epidermis cells and the distance between the vascular bundles. Width of epidermis cells was similar in all taxa studied. Received May 31, 2000 Accepted February 13, 2001     

Abortive embryogenesis in hybrid swarm populations of <Emphasis Type="Italic">Pinus sylvestris</Emphasis> L. and <Emphasis Type="Italic">Pinus muga</Emphasis> Turra

Comparative study on fertilization process in Pinus sylvestris, Pinus mugo and in their putative hybrid swarm individuals was done involving pre-zygotic and post-zygotic stages. The amount of surviving ovules from open pollination reflecting the mode of interaction between pollen grains and nucellar tissue of an ovule averaged at 8.1 of sound ovules per conelet in Pinus sylvestris, 7.3 ovules in the hybrid swarm population and at 4.9 ovules in Pinus mugo. A strong correlation was observed between the number of surviving ovules and the proportion of germinating seeds in the compared species and hybrids. Normal course of embryogenesis in Pinus sylvestris and Pinus mugo contrasted with increased frequency of disturbances observed in the hybrid swarm individuals. The differential survival rates of the ovules and deviations from typical pattern of embryogenesis are discussed from the standpoint of cross-ability relationship between Pinus sylvestris and Pinus mugo.     

Biometrical variability of foliage and cone characters inCupressus bakeri (Cupressaceae)

Biometrical variability of foliage, cones, and seeds were analyzed in 8 native populations (throughout the range) of a relictual species,Cupressus bakeri Jeps. (Cupressaceae) from California and Oregon. The partition of variation within and among populations for this rare plant was investigated and the justification for subspecies status was reviewed. Morphological characters varied significantly, with more of the variation among populations than at the population level. Multivariate analyses indicated close affinities among populations on serpentine sites suggesting the presence of a serpentine race. However, the high degree of variation among populations did not permit their clear separation into the two subspecies described byWolf (1948). We conclude thatC. bakeri should be treated as a monotypic species.     

Pinus mugo (Pinaceae) in the Abruzzi Mountains: high morphological variation in isolated populations

Thirty-three individuals of Pinus mugo from the Abruzzian Apennines (Italy), the most isolated population of the species, were examined biometrically to verify the range of trait variation and compared with six other populations sampled in the north-eastern part of the species range. Ten needles and ten cones from each individual were measured and quantified on the basis of 31 traits. The interpopulation comparison revealed a close affinity of the Abruzzian population of P. mugo to three of the six other populations. The other three north-eastern populations, one from the Tatra Mountains and two from the Chornokhora Mountains, appeared to be different. This suggests that these populations originated from other Pleistocene centres of occurrence. The intrapopulation variation of the population from the Abruzzian Apennines is comparable with those of all six populations of P. mugo from the Sudety and Carpathian Mountains. These findings support the hypothesis that isolated but locally abundant plant populations do not necessarily show a reduction in variability resulting from isolation.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 147 , 309–316.     

Allozyme investigations on the genetic differentiation between closely related pines —Pinus sylvestris, P. mugo, P. uncinata, andP. uliginosa (Pinaceae)

In eight natural European populations of four closely related taxa of pines (Pinus sylvestris, P. mugo, P. uncinata, andP. uliginosa) starch-gel electrophoreses revealed altogether 58 alleles at 15 loci from nine enzyme systems. With Nei's genetic distance (D) the largest mean genetic distance (D = 0.171) was found betweenP. sylvestris andP. mugo, a distance corresponding to that between other closely related pine species. Mean genetic distances between the other taxa were less than half that value and characteristic for subspecies or varieties rather than for species. On the basis of our results we suggest that both,P. uliginosa andP. uncinata, could be the result of the ancient hybridization betweenP. sylvestris andP. mugo.     

The effect of ozone and season on the pool sizes of cyclitols in Scots pine (Pinus sylvestris)

Summary The effect of 100 and 200 g · m^-3 (50 and 100 ppb) ozone and ambient air on 4-year-old grafts of a Scots pine clone was tested in closedtop fumigation chambers. Ozone decreased the myo-inositol and inccreased the pinitol levels in the 1-year-old needles, whereas the effect in the current-year needles was less distinct. In neither case did ambient air lead to any detectable effects on these parameters compared with controls. However, there was a pronounced chamber effect in the levels of myo-inositol and pinitol compared with trees standing in the open field, where inositol was higher and pinitol lower. There is some evidence, based on visible symptoms as well as biochemical changes, that season is an important modifier of the effect of ozone on Scots pine.     

Two new spontaneous hybrids of American hard pines from Pinus sect. Trifoliae (Pinaceae) found in the unique Russian Sochi Arboretum

In the 1990s, an extraordinarily abundant live collection of the genus Pinus, including 49 species, 4 subspecies, and 7 interspecific hybrids, found in the Sochi Arboretum in Russia on the northeast coast of the Black Sea, was taxonomically revised. Among these taxa, two previously unknown interspecific hybrids of American hard pine species from P. sect. Trifoliae had arisen spontaneously in culture. These are described here as the new hybrid species Pinus × transamericana (P. muricata × P. rigida) and Pinus × critchfieldii (P. patula × P. taeda). All known natural or artificial interspecific hybrids within P. sect. Trifoliae are listed, and hybridization between American hard pine species is discussed. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Genetic relationships among Mexican white pines (Pinus, Pinaceae) based on RAPD markers

Genetic relationships among Mexican white pines have not been completely resolved by DNA sequencing analyses. The use of random amplified polymorphic DNA (RAPD) markers for the study of interspecific relationships has been questioned because of the possible lack of homology of co-migrating bands between species. However, several RAPD based studies on pines have provided sufficient information to discriminate between closely related taxa. Genetic relationships among four species of Mexican white pines (Pinus ayacahuite, Pinus strobiformis, Pinus lambertiana and Pinus chiapensis) were estimated based on RAPD markers. Sixty-nine primers generated 247 bands in pooled DNA samples from ten populations. In addition, four selected primers generated 27 bands in 176 individual DNA samples. Unweighted Pair Group Method with Arithmetic Average (UPGMA) dendrograms based on Jaccard similarity indices were constructed. The results suggest that the closest pine species analyzed were P. ayacahuite and P. strobiformis, followed by P. lambertiana. The most genetically distant species was P. chiapensis. Cluster analyses did not support P. strobiformis as a distinct species from P. ayacahuite.     

Long-term needle litterfall of a Scots pine Pinus sylvestris stand: relation to temperature factors

Summary Needle litterfall of a Scots pine was caught over 24 years (1962–1986) with litter-traps in a Scots pine stand in southeastern Finland. The age of the trees averaged 111 years in 1962. The stand was naturally recruited and only minor silvicultural treatments occurred during its history. Litterfall showed great year-to-year variation, the minimum being 18 g/m² (in 1968) and maximum 213 g/m² (in 1973). There was no overall trend in the amount of litterfall, and the age of the stand was thus not important in determining the needle fall. We used time domain time series analysis (ARIMA) and standard climatic data (temperature, precipitation) to investigate the relationship of litterfall to climatic factors. Mean July temperature was clearly correlated with needle litterfall. High temperature in July coincided with enhanced litterfall in the same and the next year. Litterfall enhanced litterfall in the same and the next year. Litterfall increased also after high temperatures during March–April, but only in the same year. In addition to these the litterfall had a 4-year self-dependency. This is approximately the same as the mean longevity of needles in the study area. Altogether the time series model we propose covers about 90% of the variance of the original time series.     

Food reserves of scots pine (Pinus sylvestris L.)

Summary Starch, soluble sugars, triacylglycerols, diacylglycerols and free fatty acids were measured in 30-year-old Scots pine (Pinus sylvestris L.) trees during an annual cycle in the sapwood (youngest ten xylem rings). The radial distribution of carbohydrates and lipids was studied in the trunkwood of 90 -to 150-year-old Scots pine trees collected at the end of the growing season. Determination of the compounds was performed using specific enzymatic assays, capillary gas chromatography and thin layer chromatography. The amounts of glucose, fructose, sucrose, and galactose/arabinose in the sapwood were slightly higher in winter than in summer. Raffinose/stachyose increased up to 5-fold during the cold period. At the beginning of the growing season starch amounts rose, and then decreased in summer and autumn. No concentration changes were observed in the total amounts of diacylglycerols and fatty acids throughout the year. Triacylglycerol levels were slightly higher in February than in summer and autumn. Relative frequencies of individual fatty acids were similar in all lipid fractions. Glucose, fructose, sucrose, starch and triacylglycerols disappeared almost entirely at the transition zone from sapwood to heartwood. In contrast, free fatty acids and galactose/arabinose rose in centripetal direction, and diacylglycerols remained constant across trunk cross-sections. The relative amounts of individual fatty acids changed markedly in the free fatty acid fraction and in the triacylglycerols when crossing the sapwood-heartwood boundary. Concentration changes of reserve materials are discussed in relation to season, mobilization and translocation processes, dormancy, frost resistance, and heartwood formation. The results are compared to those found in needles.     

Hybridisation processes in sympatric populations of pines Pinus sylvestris L., P. mugo Turra and P. uliginosa Neumann

Natural hybridisation was postulated between the closely related pine species Pinus sylvestris and the P. mugo complex, however no clear evidence on propagation of mature hybrids in nature has been documented so far. To test the hybridisation hypothesis we applied chloroplast DNA (cpDNA) markers and isozymes in the analyses of 300 individuals representing the variety of morphological forms in the sympatric populations of P. sylvestris, P. mugo and P. uliginosa at the peat bog complex in the Sudety Mts., Poland. Additionally, the haplotypes of paternally inherited cpDNA of 149 open pollinated progeny derived from seeds were compared to the haplotypes of parental trees to access the intensity and direction of contemporary hybridisation. The morphologically highly variable polycormic (multi-stemmed) hybrids between P. mugo and P. uliginosa were identified. The second group of hybrids was found among the monocormic (single-stemmed) P. sylvestris-like individuals carrying the cpDNA from P. mugo complex. Hybrids of P. sylvestris as a pollen donor and P. mugo or P. uliginosa as a mother were not found, either in the group of examined trees, or among the open pollinated progeny. The results indicate that numerous hybrids can exist in the sympatric population of the species studied and that gene flow can successfully proceed from P. mugo complex to P. sylvestris. Hybridisation and ecological selection seems to play a significant role in diversification and evolution of the investigated species.     

Pinus MUTOI (Pinaceae), a new species of permineralized seed cone from the upper Cretaceous of Hokkaido,Japan

Pinus mutoi is described as a new species on the basis of a permineralized seed cone from the Upper Cretaceous of Hokkaido, Japan. The cone is at least 20 cm long and up to 6 cm in diameter, consisting of a cone axis and numerous cone-scale complexes that are arranged helically around the axis. Two winged seeds are borne on the adaxial surface of each ovuliferous scale. Each complex receives a single trace from the vascular cylinder of the cone axis. In the scale base, all the resin canals occur abaxially to the vascular strand. The spatulate bract of the fossil is unique to the specimen among the cones of both living and fossil Pinus. The central umbo, broad sclerotic cortex of cone axis, and absence of serotinous features of the fossil cone suggest affinity with the subsection Sylvestres of the section Pinus, subgenus Pinus. This is the first record of permineralized preserved Pinus cone from the Cretaceous of Eastern Eurasia.     

Seasonal variation of neutral lipids in Pinus sylvestris L. sapwood and heartwood

Summary The lipid levels and fatty acid composition of three fractions (free fatty acids, triacylglycerols and sterol/triterpenoid esters) extracted from the sapwood and heartwood of three stems of Pinus sylvestris were determined to investigate both seasonal changes in sapwood and possible metabolic changes related to heartwood formation. Seasonal changes were observed only in the amount of the free fatty acids in the sapwood: the level of free fatty acids was greatest at the beginning and end of the growing season. In the January and March samples the amount of the free fatty acid fraction in the sapwood was very small. The amount of the other fractions remained at the same level throughout the study. Marked seasonal changes in the fatty acid composition occurred only in the free fatty acid fraction of the sapwood: the saturation grade increased during the winter.     

Phylogenetic relationships and taxonomy of subfamily Zygophylloideae (Zygophyllaceae) based on molecular and morphological data

Phylogenetic analysis of noncoding trnL plastid DNA sequences and morphological data for 43 species of Zygophylloideae, representing most of the morphological and geographical variation in the subfamily, indicates that the currently recognised genera Augea (monotypic, southern Africa), Tetraena (monotypic, China), and Fagonia (c. 30 species, widespread), are embedded in Zygophyllum (c. 150 species, widespread). A generic classification based on six monophyletic and morphologically distinctive entities is proposed: Roepera with c. 60 species in Australia and southern Africa, Zygophyllum with c. 50 species in Asia, Tetraena with c. 40 species in Africa and Asia, Augea with a single species in southern Africa, Melocarpum with two species in the Horn of Africa region, and Fagonia with c. 30 species in both the Old and the New World. Scanning electron microscopy studies of testa structure provided important characters for the delimitation of some genera. New combinations (61) are made in Roepera, a resurrected genus originally described from Australia, one new name is proposed in Zygophyllum, 35 new combinations are made in Tetraena, and two new combinations are made in Melocarpum (previously Zygophyllum sect. Melocarpum).     

Food reserves of Scots pine (Pinus sylvestris L.)

Summary The amounts of starch, soluble sugars, triacylglycerols, diacylglycerols and free fatty acids were studied in Scots pine (Pinus sylvestris L.) during an annual cycle in current-year needles and in 1-, 2- and 3-year-old needles collected shortly after bud break. Determination of the compounds was performed using specific enzymatic assays, capillary gas chromatography and thin layer chromatography. Newly emerging needles contained relatively large amounts of starch, but only trace amounts of fat. During autumn and winter, fat content rose, while starch content decreased; amounts of both these reserve materials were very high the next spring shortly before bud break and decreased again during shoot elongation. Concentration of intermediates in triacylglycerol biosynthesis (diacylglycerols and free fatty acids), were low in summer and high in winter. The same pattern was observed for fructose and glucose (the predominant soluble sugars), galactose/arabinose and raffinose/melibiose. In contrast, sucrose concentrations were highest in spring and in autumn. Mature needles of different ages collected in May showed significant differences only in their triacylglycerol and starch content. Concentration changes of reserve materials are discussed in relation to season, mobilization and translocation processes, dormancy, frost resistance and the possibility of carbohydrate-fat interconversions.     

Brassica taxonomy based on nuclear restriction fragment length polymorphisms (RFLPs)

Summary Preliminary analysis using nuclear RFLPs provided evidence that subspecies within Brassica rapa originated from two different centers. One center is in Europe, represented by turnip and turnip rape from which the oilseed sarson was derived. A second center is in South China containing a variety of Chinese vegetables of which pak choi and narinosa seem to be the most ancient forms. Based on RFLP data, the accessions of B. oleracea examined could be divided into three distinct groups, represented by thousand head kale, broccoli and cabbage. Thousand head kale and Chinese kale appear to be the primitive types. Observations of parallel variation among subspecies of both species are discussed.     

Review of the taxonomy of the Calanidae (Copepoda) and the limits to the genus Calanus

Conflicting systems of classifying the Calanidae (Brodsky, 1972; Bradford & Jillett, 1974) are analysed and a preferred system recommended. Brodsky's system, based on characters with assumed adaptive and functional significance is rejected as is his claim to have produced a phylogenetic scheme. Bradford & Jillett's system, based on a variety of characters, results in a coherent classification which aims to be neutral concerning phylogenetic relationships among genera. Species of Calanoides, Calanus, Nannocalanus, and Neocalanus are surveyed and the need for further taxonomic work is assessed.     

Taxonomic evaluations of the genusPinus (Pinaceae) based on electrophoretic data of salt soluble and insoluble seed storage proteins

Electrophoretic studies on seed storage proteins of various gymnosperm species showed that both salt soluble and insoluble protein fractions give taxonomic information. Among species of the genusPinus evident differences are found between the subgeneraHaploxylon (Strobus) andDiploxylon (Pinus). In sect.Strobus the two subsectt.Strobi andCembrae are readily distinguished fromP. bungeana (sect.Parrya) which appears to fall in an intermediate position between haploxyl and diploxyl pines. Among the species of subg.Diploxylon, mountain pines show very similar protein patterns in agreement with their recent speciation (Quaternary).     

The effects of flooding on the formation of ectomycorrhizae in Pinus sylvestris seedlings

Pinus sylvestris seedlings, grown in a vertical petri dish system, were inoculated with five different mycorrhizal fungi. Half of the root system in the petri dish was subjected to periodic flooding, and mycorrhizal colonization was studied. Thelephora terrestris, Laccaria laccata, and Hebeloma crustuliniforme were not sensitive to flooding, whereas Suillus flavidus and S. bovinus were highly sensitive. The latter failed to colonize the root even when flooded for only 2 min per day four times a week.