IMMUNOCHEMICAL COMPARISONS OF SEED PROTEINS FROM POPULATIONS OF PINUS RADIATA (PINACEAE)

Antisera were prepared to seed proteins from five populations of Pinus radiata and to seed proteins from six other pine species. Differences between the P. radiata populations detected with these antisera were compared to differences in sizes of cones from the same populations. The strong correlation between antigenic differences and cone size differences provides evidence that in P. radiata, both seed proteins and cone size indicate quantitative genetic relationships among the populations. The data suggest that the three California mainland populations of P. radiata are more closely related to one another than to the insular populations, and that the insular populations are more closely related to each other than to the California populations, to P. attenuata, or to P. muricata.     

Archaeological evidence of cherimoya(Annona cherimolia Mill.) and Guanabana(Annona muricata L.) in ancient Peru

Archaeological Evidence of Cherimoya (Annona cherimolia Mill.)and Guanabana (Annona muricata L.)in Ancient Peru. Economic Botany 58(4):509-522, 2004. The results of this study confirm the presence of both guanabana and cherimoya in ancient Peru. Our evidence consists of linguistic data and botanical remains of plants that were found in archaeological contexts, as well as ceramic phytomorphic representations of the fruits.

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Evidencias arqueológicas de chirimoya (Annona Cherimolia Mill.) YGuanabana (Aannona muricata L.)en el Antiguo Perú

Résumé  Con el presente trabajo se demuestra, que tanto la guanábana como la chirimoya han sido conocidas y utilizadas en el antiguo Perú. Las evidencias consisten en datos linguistícos y restos botánicos de dichas plantas que han sido encontrados en contextos arqueológicos y representaciones en cerámica de sus frutos.

     

A novel reef coral symbiosis

Reef building corals form close associations with unicellular microalgae, fungi, bacteria and archaea, some of which are symbiotic and which together form the coral holobiont. Associations with multicellular eukaryotes such as polychaete worms, bivalves and sponges are not generally considered to be symbiotic as the host responds to their presence by forming physical barriers with an active growth edge in the exoskeleton isolating the invader and, at a subcellular level, activating innate immune responses such as melanin deposition. This study describes a novel symbiosis between a newly described hydrozoan (Zanclea margaritae sp. nov.) and the reef building coral Acropora muricata (=A. formosa), with the hydrozoan hydrorhiza ramifying throughout the coral tissues with no evidence of isolation or activation of the immune systems of the host. The hydrorhiza lacks a perisarc, which is typical of symbiotic species of this and related genera, including species that associate with other cnidarians such as octocorals. The symbiosis was observed at all sites investigated from two distant locations on the Great Barrier Reef, Australia, and appears to be host species specific, being found only in A. muricata and in none of 30 other species investigated at these sites. Not all colonies of A. muricata host the hydrozoans and both the prevalence within the coral population (mean = 66%) and density of emergent hydrozoan hydranths on the surface of the coral (mean = 4.3 cm⁻², but up to 52 cm⁻²) vary between sites. The form of the symbiosis in terms of the mutualism–parasitism continuum is not known, although the hydrozoan possesses large stenotele nematocysts, which may be important for defence from predators and protozoan pathogens. This finding expands the known A. muricata holobiont and the association must be taken into account in future when determining the corals’ abilities to defend against predators and withstand stress.     

Bioclimatic analysis of the distribution of damage to native plants in Tasmania by Phytophthora cinnamomi

Climatic profiles were generated by the computer program BIOCLIM for three sets of sites in native vegetation in Tasmania: (i) 308 sites at which Phytophthora cinnamomi was isolated from diseased plants Pc+ ive; (ii) 322 sites in healthy plant communities from which P. cinnamomi could not be recovered Pc?ive; and (iii) 801 sites representing the climatic range across Tasmania. A discriminatory analysis comparing the first and third sets indicated that seven of the 16 climatic indices available for analysis were good discriminators of the distribution of damage by P. cinnamomi. The analysis suggests that damage to native vegetation due to P. cinnamomi is unlikely on sites where annual mean temperature does not exceed 7.5°C or annual mean rainfall is < 600 mm. Two maps were produced to indicate those areas of Tasmania that have climates suited to damaging interaction between P. cinnamomi and native vegetation. The first was based on those sites that had annual mean temperature more than 7.5°C and annual mean rainfall less than 600 mm. The second included those sites that matched the values of the Pc+ ive set for all seven good discriminators. The two approaches produced similar results. Areas in which even the most favourable microsites are unlikely to support pathogenic activity by P. cinnamomi constitute less than 20% of the land area. Twelve substantial areas of native vegetation that occur in climates suited to infection by P. cinnamomi. but for which no record of the fungus exists, have been identified.     

Competitive effects of Rattus lutreolus presence on food resource use by Pseudomys gracilicaudatus

Abstract We examined faecal samples of the eastern chestnut mouse (Pseudomys gracilicaudatus) that were collected during a removal experiment conducted in a coastal heathland at Myall Lakes National Park to see whether removal of the swamp rat (Rattus lutreolus) had any effects on food resource use by P. gracilicaudatus. The results showed that, at the young successional stage of vegetation (1. 5 years since last fire), the diet of P. gracilicaudatus changed significantly after the number of R. lutreolus was significantly reduced on the experimental sites. Two months after the removal treatment was terminated there were no significant differences between the control and experimental sites. Factor analysis showed that seasonal change was significant for all three food factors on the control sites, whereas on experimental sites the change was significant only for factor 1. At the middle successional stage (3.5 years since last fire), P. gracilicaudatus showed relatively small seasonal changes on both control and experimental sites, and significant differences between the control and experimental sites did not occur until after the removal manipulation was completed, showing a delayed response. Comparisons of the young and the middle successional stages on both control and experimental sites showed that P. gracilicaudatus used proportionally different food when R. lutreolus was present, but consumed similar food when R. lutreolus was removed. These results suggest that R. lutreolus might have restricted the access of P. gracilicaudatus to better microhabitats, and hence to a better food supply. The ecological implication of these results is that the interpretation of observed population and community patterns must take into account the direct effects of species interactions.     

The effect of different pine hosts on the sampling of Rhizopogon spore banks in five Eastern Sierra Nevada forests

Our primary goal was to determine whether detection of Rhizopogon internal transcribed spacer (ITS) groups is affected by the pine species used in seedling bioassays. Our secondary goal was to investigate composition of Rhizopogon spore banks in the Eastern Sierra Nevada of California, a previously unsampled region. We used seedlings of Pinus contorta, Pinus jeffreyi, Pinus lambertiana, and Pinus muricata as bioassay plants and identified the Rhizopogon retrieved by internal transcribed spacer (ITS) sequence analysis. We found that each of the pine species retrieved all of the abundant Rhizopogon ITS groups, but there were significant differences among pines in the richness of Rhizopogon ITS groups recovered. Pinus muricata recovered all ITS groups found in this study and was significantly better than P. lambertiana. Rhizopogon communities from the five sampled sites contained six to eight ITS groups per site, with two unique sequence groups and a higher abundance of the Rhizopogon ellenae and Rhizopogon arctostaphyli groups than at previously sampled sites. These results show high cross-receptivity between Rhizopogon and pine species, and regional patterns in spore bank composition.     

Fatty acids,resin acids and phenols in Pinus muricata

Acetone-soluble extractives of “blue” and “green” strain Pinus muricata D. Don were found to consist of free and “combined” fatty acids, resin acids, and phenols. The composition of the extractives from the two strains was similar though “green” strain P. muricata contained more Δ^8(9),15 isopimaric acid than “blue” strain. This difference may be used to identify these muricata strains if the age of the wood precludes a monoterpene examination.     

Experimental tests of nest site competition in two Peromyscus species

The importance of interspecific competition for nest sites between the white-footed mouse (Peromyscus leucopus noveboracensis) and the cloudland deermouse (P. maniculatus nubiterrae) were investigated in the montane forests of southwestern Virginia over 3 years. Trials were conducted for both species using large, outdoor enclosures in order to examine: (i) nest site preference in isolation and (ii) nest site selection made in the presence of potential competitors. Both species demonstrated a strong preference for arboreal nest sites when tested without competitors present. After the introduction of a heterospecific intruder, P. leucopus often shifted to a non-arboreal nest while P. maniculatus continued to use arboreal nests. Intruding P. maniculatus displaced resident P. leucopus from P. leucopus' preferred nest sites in all 3 years while intruding P. leucopus never displaced P. maniculatus. Neither species was routinely displaced in conspecific trials. Resident P. maniculatus also excluded P. leucopus from access to preferred nesting sites in all three years while P. leucopus were only able to exclude P. maniculatus in the 3rd year. Both species exhibite relatively low frequencies of exclusion in conspecific trials with the exception of P. maniculatus which excluded high proportions of conspecific intruders in the second year. We suggest that the asymmetrical advantage enjoyed by P. maniculatus in nest site selection may result from both site-specific effects and a species-specific influence on P. leucopus. Nonetheless, the intensity of such influence varied between years, perhaps as a function of population density, and did not appear to drastically influence continued coexistence of these congeners.     

基于cpDNA和rDNA ITS片段分析西南地区青杨派杨树的系统发育与进化关系

西南地区青杨派杨树种质资源丰富,可为杨树遗传改良提供珍贵的基因资源,但树种之间形态学差异细微,该研究以山杨作为外类群,测定了西南地区及其他地区杨属青杨派17个种(杂种)共36份样本的3个叶绿体片段(atpF-atpH、trnL-F和matK)和核糖体ITS片段,并对其进行系统发育分析,以探讨西南地区青杨派树种的系统进化关系。结果表明:(1)在所有样本中,3个叶绿体片段atpF-atpH、trnL-F、matK的长度分别为605~634bp、957~1 010bp、819bp,3个片段拼接后的联合序列包含29个变异位点和15个信息位点;ITS片段对齐后的长度为646bp,变异位点19个,信息位点17个。(2)基于叶绿体联合序列和ITS片段的杨属青杨派树种的平均遗传距离分别为0.001 3和0.003 6。叶绿体联合片段的MP和Bayes系统树树型基本一致,青杨派树种可以划分为2组,第1组由青杨、三脉青杨、大青杨和辽杨构成;第2组中的小叶杨、小青杨、川杨、德钦杨、昌都杨、乡城杨、康定杨、西南杨、滇杨和藏川杨不能有效区分,且均与缘毛杨的遗传关系较近。(3)基于ITS的系统树与叶绿体联合片段构建的系统树差异不大,仅在于第2组中的小青杨与小叶杨、川杨等差异明显,与第1组中的树种紧密聚拢。     

Shoot regeneration in response to carbon source on internodal explants of Annona muricata L.

Adventitious shoot regeneration from internodal explants of mature plants of Annona muricata L. was obtained on Nitsch media. Meristems were induced with sorbitol as the sole carbon source supplemented with 2 mg l^–1 of benzylaminopurine and 0.5 mg l^–1 naphthaleneacetic acid. Adventitious shoots were developed only when the explants were transferred onto growth regulator-free media containing sucrose, galactose, or glucose. A hypothesis is proposed for the involvement of sorbitol in the induction and development of de novo shoots from internodal explants of mature trees of A. muricata.     

Improved measurement of dibenzo[a,l]pyrene-induced abasic sites by the aldehyde-reactive probe assay

Dibenzo[a,l]pyrene (DB[a,l]P) induces abundant amounts of depurinating adducts that spontaneously dissociate to form abasic sites in DNA. However, several previous studies that used the aldehyde-reactive probe (ARP) assay, could not verify abasic site formation by DB[a,l]P. Therefore, we examined whether a modification of the ARP assay would allow greater quantification of abasic sites. A previous study indicated that the abasic site quantification is improved by letting ARP trap the nascent abasic sites in cells, before extracting DNA for the assay. To test whether the addition of ARP to the DB[a,l]P–DNA adduct-forming reaction would improve abasic site quantification, we treated calf thymus DNA (0.625 mg/mL) with DB[a,l]P (80 μM) and 3-methylcholanthrene-treated rat liver microsomes with or without ARP (3 mM). The inclusion of ARP in the adduct-forming reaction resulted in significantly greater detection of abasic sites (62 lesions/10⁶ bp versus 3.7 lesions/10⁶ bp). DB[a,l]P also induces DNA strand breaks. The strand breaks may occur at abasic sites and by other mechanisms, such as oxidative damage. ARP/O-methoxyamine-abasic site conjugates are refractory to strand breakage, however, ARP or O-methoxyamine (3–10 mM) could only partially protect DB[a,l]P-induced DNA degradation, presumably by protecting the abasic sites, but not the other strand breaks. These results suggest that if DNA strand breakages occur at the abasic sites or at bases flanking them, and the fragments are lost during DNA extraction, abasic site estimation could be compromised. To obtain an independent line of evidence for abasic site formation in DB[a,l]P-treated cells, mouse Mβ16 fibroblasts were treated with DB[a,l]P and O-methoxyamine. O-Methoxyamine is known to potentiate cytotoxicity of abasic site-inducing chemicals by forming abasic site conjugates, which partially inhibits their repair. O-Methoxyamine was found to increase DB[a,l]P cytotoxicity in these cells, supporting the idea that DB[a,l]P formed abasic sites. In summary, the inclusion of ARP in the DB[a,l]P–DNA adduct-forming reaction traps and protects the nascent abasic sites, allowing an improved quantification of abasic sites.     

Soil CO2 efflux in uneven-aged managed forests: temporal patterns following harvest and effects of edaphic heterogeneity

Increased nutrient availability can have a large impact in Australian woodland ecosystems, many of which are very poor in nutrients, particularly phosphorus. A study was conducted in an urban Banksia woodland remnant in Perth, southwest Western Australia to test the hypothesis that the soil nutrient status in areas in good condition (GC), poor condition invaded by the perennial grass Ehrharta calycina (PCe), and poor condition invaded by the perennial herb Pelargonium capitatum (PCp), is reflected in the nutrient status of the native and introduced species. Leaf concentrations of P, K, N, Na, Ca, Mg, S, B, Cu, Fe, Mn and Zn of six native (Banksia attenuata, Banksia menziesii, Allocasuarina humilis, Melaleuca systena, Macrozamia fraseri and Conostylis aculeata) and four introduced species (Ehrharta calycina, Pelargonium capitatum, Gladiolus caryophyllaceus and Briza maxima), were measured. Soil pH, electrical conductivity, N (total), P (total), available P, K, S and organic C were assessed beneath all species on all sites. Significantly higher concentrations of soil P (total) and P (HCO₃) were found at PCe and PCp sites than GC sites, while PCp sites also had significantly higher soil concentrations for N (total) and S. Principal Components Analysis of the leaf analyses showed (a) individual species have characteristically different nutrient concentrations; (b) the introduced species Ehrharta calycina and Pelargonium capitatum clustered separately from each other and by vegetation condition. Leaf concentrations of P were significantly (P<0.05) higher, and K and Cu were significantly lower in PCe and PCp sites compared with those at GC sites. Introduced species leaf nutrient concentrations were significantly greater than native species for all nutrients except Mn which was significantly lower, with no differences for Mg and B. The results indicate a key role for P in the Banksia woodland, and we conclude that higher levels of available P at invaded sites are having a detrimental impact on the ecosystem. These results provide new knowledge to enhance conservation practices for the management of the key threatening process of invasion within a biodiversity hot spot. Section Editor: T. Kalapos     

How Phosphorus Availability Affects the Impact of Nitrogen Deposition on <Emphasis Type="Italic">Sphagnum</Emphasis> and Vascular Plants in Bogs

To elucidate the impact of high nitrogen (N) deposition on intact bog vegetation, as affected by phosphorus (P) availability, we conducted a 4-year fertilization experiment with N and P at six sites, one with moderate N deposition and five with high N deposition. During the growing season, N (40 kg ha^–1 ya^–1), P (3 kg ha^–1 y^–1), or a combination of both elements was applied to the vegetation. The fertilization effects turned out to be additive in nature. Adding P decreased the inorganic N concentration and increased the P concentration in the rhizosphere at two sites. Furthermore, P stimulated Sphagnum growth and Sphagnum net primary productivity (NPP) at two sites; it also seemed to encourage growth at two other sites including the moderate-deposition site. Vascular plant growth remained largely unaffected but was depressed at one high-deposition site. Adding N increased the concentration of inorganic N in the rhizosphere at the moderate-deposition site and at two of the three high-deposition sites; vascular plant growth and litter production were encouraged at three high-deposition sites. The addition of N depressed Sphagnum height increment at four high deposition sites and reduced Sphagnum NPP at two sites. Shading by vascular plants was of minor importance in explaining the negative effects of N on Sphagnum. We conclude that because P alleviates the negative impact N has on Sphagnum by enhancing its capability to assimilate the deposited N, P availability is a major factor determining the impact of N deposition on Sphagnum production and thus on carbon sequestration in bogs.     

啮齿动物对不同林木种子的搬运和取食微生境选择机制

不同植物种子依靠不同的方式实现扩散,啮齿动物对林木种子搬运后在取食点微生境和贮藏方式的选择存在偏好,研究其贮藏行为与微生境的关系是探究幼苗建成的关键。在秦岭中段火地塘林区,采用标签标记法,以锐齿槲栎、华山松和油松种子为材料,探究了小型啮齿动物对松栎混交林建群种种子扩散过程的影响。结果表明:1)油松种子原地取食率显著高于锐齿槲栎和华山松种子,且啮齿动物更倾向于搬运后取食(60%)和埋藏(4.33%)华山松种子,搬运后取食距离也为华山松最大(2.49 m);锐齿槲栎小种子被搬运后埋藏的距离最大(4.92 m)。2)除华山松种子外,其他类型种子被搬运后单个取食的比例均在85%以上;油松种子不存在埋藏点,而其他类型种子90%以上均以单个形式被埋藏。3)大部分种子被啮齿动物搬运后选择在裸地丢弃;锐齿槲栎大种子(87.5%)、小种子(78.57%)和华山松种子(53.33%)较大比例被啮齿动物埋藏在灌丛下方,埋藏在裸地的种子较少。4)大部分种子在灌丛下方被取食,仅华山松种子被啮齿动物搬运到洞穴取食;除油松种子被大量原地取食外,其他类型种子被搬运到取食点的种子比例基本呈现由微生境植被复杂到简单(灌丛—草丛—灌丛边缘—裸地)而逐渐减小的趋势。种子的营养价值及取食和搬运过程中啮齿动物付出的成本是影响种子命运的关键性因子,且啮齿动物对种子埋藏和取食地点的微生境存在较明显的选择性。     

Incidence of Prevotella intermedia and Prevotella nigrescens in Periodontal Health and Disease

The incidence of black-pigmented rods (BPRs), especially Prevotella intermedia and Prevotella nigrescens, in periodontal health and disease were examined. Furthermore, the degradative enzyme activities of P. intermedia were compared among the strains from periodontal health and disease. Microbiological specimens were collected from subgingival crevice or periodontal pocket by paper point. The BPRs were found in 71.1% of periodontally healthy subjects (n = 45), and in 47.1% of healthy sites (n = 34) and 87.8% of active sites (n = 41) among periodontally diseased patients. Porphyromonas gingivalis was detected only in active sites of periodontally diseased patients (17.8% of 180 strains). P. intermedia was the predominant BPR in both healthy and active sites (37.3 and 41.7%, respectively) of the patients. However, P. nigrescens was the predominant BPR (70.5% of 173 strains) in periodontally healthy subjects. The enzyme activities of esterase, esterase-lipase, acid-phosphatase and α-fucosidase of P. intermedia strains isolated from active sites in patients were significantly higher (P < 0.05) than those of healthy subjects. The results suggest that P. intermedia might increase the activity of degradative enzymes under a certain condition and support the progression of periodontitis.     

Cytological characterization of heterochromatin and rDNA inPinus radiata andP. taeda

Fluorochrome C-banding ofPinus radiata andP. taeda metaphase chromosomes showed many pericentromeric DAPI bands and interstitial CMA bands inP. radiata, and centromeric and interstitial CMA bands inP. taeda. Giemsa C-band patterns differed between the species with centromeric bands inP. radiata but no consistent bands inP. taeda. A karyotype ofP. radiata was developed based on banding patterns that distinguished all but two of the 12 pairs of chromosomes. In situ hybridization (ISH) using probes for high-copy ribosomal DNA (rDNA) showed 10 pairs of 18S–25S sites and two pairs of 5S sites in both species. Most of the sites were interstitial or centromeric.     

Geography of Pinus elliottii Engelm. and Pinus palustris Mill. leaf life-spans in the southeastern U.S.A.

Aim Past studies have investigated differences in leaf life‐spans between deciduous and evergreen species. Environmental controls such as light, temperature, and nutrient and moisture availability explain differences in leaf life‐spans between species. This study examined intraspecific leaf life‐spans across climate and nutrient gradients within the geographical range of Pinus palustris Engelm (longleaf pine) and Pinus elliottii Mill. (slash pine). Location Five study areas in the southeastern United States were selected along the north–south geographical range of Pinus elliottii and Pinus palustris. Methods Leaf life‐span was calculated based on stand inventories and annual litterfall totals for each site, and allometric relationships between d.b.h. and foliar biomass. Results Leaf life‐span of P. elliottii ranged from 1.28 to 1.95 years between sites. Leaf life‐span of P.palustris varied by nearly a factor of 5 between the study site with the lowest and highest value (0.58–2.49 years). anova indicated that leaf life‐spans of P. elliottii were not significantly different among sites. In contrast, anova indicated a significant difference for P. palustris leaf life‐spans among sites (P < 0.05). The Tukey multiple comparisons tests showed that 2 study areas were the only pair of P. palustris sites with a significant difference in leaf life‐spans. Main conclusions The geographical variation in leaf life‐spans between two species illustrates the different phenotypic responses to environmental controls. The variation in leaf life‐spans by individuals of P. palustris across a geographical range illustrated in this study suggests that P. palustris may exhibit a greater phenotypic plasticity than P. elliottii.     

Interspecific competition: A mechanism for rodent succession after fire in wet heathland

Abstract A competitive interaction between two species of sympatric native rodents was demonstrated experimentally in Myall Lakes National Park (NSW, Australia). The previously documented replacement of Pseudomys gracilicaudatus by Rattus lutreolus in areas of wet heath in this region implied that competition may be the mechanism facilitating this succession. We present experimental evidence to support this suggestion. Removal of the larger R. lutreolus caused a significant increase in abundance of P. gracilicaudatus on five experimental sites in comparison to five unmanipulated control sites. The sites used in this experiment were chosen from three ages of wet heath regenerating after fire. These three ages represent key stages in the replacement of P. gracilicaudatus by R. lutreolus and the occurrence of competition in each of these ages indicates that competition plays an important role in this succession. In the initial stages of the experiment when R. lutreolus were removed they were replaced by new R. lutreolus individuals. This has been interpreted as evidence of strong intraspecific competition. After removal of R. lutreolus, P. gracilicaudatus expanded its habitat range into microhabitats that had formerly been occupied by R. lutreolus and reduced its range in microhabitats previously occupied by P. gracilicaudatus. This leads us to believe that P. gracilicaudatus was occupying inferior microhabitat before the removal of R. lutreolus, which had excluded it from more preferable microhabitat.     

Decomposition and litter production in a northern bald cypress swamp

Abstract. Primary production as measured by annual mean litter fall in the Lower Cache near Perks, Illinois, was the lowest recorded for cypress swamps (2345.5 kg/ha/yr). This swamp is continuously flooded with a low input of phosphorus (< 0.24 mg 1). Rates of leaf litter decomposition were higher in the Lower Cache for Taxodium distichum than in swamps to the south of the region. The winter rates of leaf litter decomposition in the Lower Cache were slower than summer rates for Cephalanthus occidentalis, Echinochloa muricata, Polygonum pensylvanicum, Jussisaea repens, Taxodium distichum, and Eleocharis obtusa, but not for Typha latifolia. Because the 99% turnover rates for these species (0.69–5.10 years) often exceeds one year, undecomposed litter can be expected to accumulate or be exported from the system. Most leaves are shed in the autumn (October through December; 83.6%).     

Physical mapping of BglII, BamHI, EcoRI, HindIII and PstI Restriction fragments of bacteriophage P1 DNA

Summary A cleavage map of bacteriophage P1 DNA was established by reciprocal double digestion with various restriction endonucleases. The enzymes used and, in parenthesis, the number of their cleavage sites on the P1clts genome are: PstI (1), HindIII (3), BglII (11), BamHI (14) and EcoRI (26). The relative order of the PstI, HindIII and BglII sites, as well as the order of 13 out of the 14 BamHI sites and of 17 out of the 26 EcoRI sites was determined. The P1 genome was divided into 100 map units and the PstI site was arbitrarily chosen as reference point at map unit 20.DNA packaging into phage heads starts preferentially at map unit 92 and it proceeds towards higher map units. The two inverted repeat sequences of P1 DNA map about at units 30 and 34.