Correspondence of environmental tolerances with leaf and branch attributes for six co-occurring species of broadleaf evergreen trees in northern California

 For the angiosperm dominants of northern California’s mixed evergreen forests, this study compares the display of photosynthetic tissue within leaves and along branches, and examines the correspondence between these morphological attributes and the known environmental tolerances of these species. Measurements were made on both sun and shade saplings of six species: Arbutus m e n z i e s i i (Ericaceae), C h r y s o l e p i s c h r y s o p h y l l a (Fagaceae), L i t h o c a r p u s d e n s i f l o r u s (Fagaceae), Quercus c h r y s o l e p i s (Fagaceae), Quercus w i s l i z e n i i (Fagaceae), and Umbellularia c a l i f o r n i c a (Lauraceae). All species had sclerophyllous leaves with thick epidermal walls, but species differed in leaf specific weight, thickness of mesophyll tissues and in the presence of a hypodermis, crystals, secretory idioblasts, epicuticular deposits, and trichomes. The leaves of Arbutus were 2 – 5 times larger than those of C h r y s o l e p i s, L i t h o c a r p u s and Umbellularia and 4 – 10 times larger than those of both Quercus species. Together with differences in branch architecture, these leaf traits divide the species into groups corresponding to environmental tolerances. Shade-tolerant C h r y s o l e p i s, L i t h o c a r p u s, and Umbellularia had longer leaf lifespans and less palisade tissue, leaf area, and crown mass per volume than the intermediate to intolerant Arbutus and Quercus. Having smaller leaves, Quercus branches had more branch mass per leaf area and per palisade volume than other species, whereas Arbutus had less than other species. These differences in display of photosynthetic tissue should contribute to greater growth for Quercus relative to the other species under high light and limited water, for Arbutus under high light and water availability, and for C h r y s o l e p i s, L i t h o c a r p u s, and Umbellularia under limiting light levels. Accepted: 22 March 1996     

Phylogenetic systematics of the Empis (Coptophlebia) hyalea-group (Insecta: Diptera: Empididae)

Six clades are inferred from a phylogenetic analysis including 42 species belonging to the Empis (Coptophlebia) hyalea‐group. These clades are named as follows: E. (C.) acris, E. (C.) aspina, E. (C.) atratata, E. (C.) hyalea, E. (C.) jacobsoni and E. (C.) nahaeoensis. The presence of two dorsal more or less developed epandrial projections is considered autapomorphic for the E. (C.) hyalea‐group in addition to two characters previously found to support the monophyly of this group (presence of an unsclerotized zone in the middle of labella and epandrium unpaired). Amongst the cladistically analysed species, 24 are newly described [ E. ( C. ) acris , E. ( C. ) aspina , E. ( C. ) cameronensis , E. ( C. ) duplex , E. ( C. ) incurva , E. ( C. ) inferiseta , E. ( C. ) kuaensis , E. ( C. ) lachaisei , E. ( C. ) lamellalta , E. ( C. ) lata , E. ( C. ) loici , E. ( C. ) longiseta , E. ( C. ) mengyangensis , E. ( C. ) menglunensis , E. ( C. ) missai , E. ( C. ) nimbaensis , E. ( C. ) padangensis , E. ( C. ) parvula , E. ( C. ) projecta , E. ( C. ) pseudonahaeoensis , E. ( C. ) submetallica , E. ( C. ) urumae , E. ( C. ) vitisalutatoris and E. ( C. ) woitapensis ], five are reviewed [E. (C.) hyalea Melander, E. (C.) jacobsoni De Meijere, E. (C.) ostentator Melander, E. (C.) sinensis Melander and E. (C.) thiasotes Melander] and 13 were recently described in two previous papers. Two additional species, E. (C.) abbrevinervis De Meijere and E. (C.) multipennata Melander, are also reviewed but not included in the cladistic analysis since they are only known from the female. A lectotype is designated for E. (C.) jacobsoni. A key is provided to the six clades of the E. (C.) hyalea‐group as well as to species of each clade. A catalogue of the E. (C.) hyalea‐group, including 72 species, is given. The taxonomic status of 25 additional species mainly described by Bezzi and Brunetti, from the Oriental and Australasian regions, is discussed. The E. (C.) hyalea‐group is firstly recorded from the Palaearctic Region and Australia. Finally, the distribution and the habitats of the species compared with their phylogeny suggest a possible relationship between the diversification of the group and forest fragmentations during the Quaternary. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society, 2005, 145 , 339–391.     

Taxonomic review of the genus Lymantria (Lepidoptera: Erebidae: Lymantriinae) in Korea

A taxonomic review of the Korean Lymantria Hübner, 1819 was conducted. A total of nine species of five subgenera with two unrecorded species are listed: Lymantria (Porthetria) dispar Linnaeus 1758, L. (P.) xylina Swinhoe 1903, L. (Lymantria) monacha (Linnaeus 1758), L. (L.) minomonis Matsumura 1933 (new to Korea), L. (L.) similis monachoides Schintlimeister 2004 (new to Korea), L. (L.) lucescens (Butler 1881), L. (Nyctria) mathura Moore 1865, L. (Collentria) fumida Butler 1877, and L. (Spinotria) bantaizana Matsumura 1933. Lymantria (Lymantria) minomonis and L. (L.) similis monachoides are newly added to the Korean fauna. Lymantria (L.) minomonis was found only on Bogildo Island of Jeollanam‐do in the southern part of Korea, and L. (L.) similis monachoides was collected in central Korea. Lymantria (Porthetria) xylina and L. (Collentria) fumida were not examined in this study, and it is considered that the previous records were due to misidentification or they are only distributed in the northern part of the Korean Peninsula. We provide diagnoses of two unrecorded species and adult habitus and genitalia photos of the Korean Lymantria species.     

Food attraction and population growth of fungivorous nematodes with different fungi

Food attraction of the fungivorous nematodes Aphelenchus avenae and Aphelenchoides spp. to seven fungal species (Pyrenochaeta lycopersici, Botrytis cinerea, Rhizoctonia solani strains AG 3 and AG 2‐1, Verticillium dahliae, Pochonia bulbillosa, Mortierella hyalina and Trichoderma harzianum) was determined on agar plates by counting the number of test nematodes present on the mycelium of each fungus 24 h after inoculation. Population growth of A. avenae and Aphelenchoides spp. on five of the seven fungi included in the attraction test (P. lycopersici, R. solani strain AG 3, V. dahliae, P. bulbillosa and T. harzianum) was also determined on agar plates by counting nematode numbers every week during a 6‐week period. A. avenae and Aphelenchoides spp. were attracted to all the fungi tested. A. avenae was preferentially attracted to V. dahliae (P < 0.0001), and Aphelenchoides spp. did not show any preference except for low attraction to R. solani. A. avenae and Aphelenchoides spp. reproduced on all fungal species tested. After 6 weeks of incubation, the highest number of nematodes was found on P. lycopersici and P. bulbillosa, while the lowest number occurred on R. solani for A. avenae and on T. harzianum for Aphelenchoides spp. The suitability of a fungus as a host was not clearly related to the attraction to that fungus.     

Mycorrhizae from Denali National Park and Preserve,Alaska

 Roots of 40 taxa of higher plants (Pteridophyta, Spermatophyta) from two alpine study sites in Denali National Park and Preserve in central Alaska were examined for their mycorrhizal colonization. We observed ectomycorrhizae on six species: Betula nana, Salix reticulata, Salix polaris, Salix arctica, Polygonum viviparum, and Dryas octopetala. Seven taxa, Cassiope tetragona, Empetrum nigrum, Ledum palustre subsp. decumbens, Ledum palustre subsp. groenlandicum, Loiseleuria procumbens, Vaccinium uliginosum and Vaccinium vitis–idaea (all Ericales), had ericoid mycorrhizae. One species, Arctostaphylos alpina, formed a typical arbutoid mycorrhiza. Two species (Sibbaldia procumbens and Aconitum delphinifolium) showed well-developed VA mycorrhizae, whereas three species of plants (Lycopodium clavatum, Silene acaulis and Oxytropis scammaniana) had vesicles, but no arbuscules. The roots of 11 other plants (Lycopodium clavatum, Lycopodium selago, Silene acaulis, Gentiana algida, Lupinus arcticus, Oxytropis scammaniana, Pedicularis langsdorffii, Pedicularis capitata, Pedicularis verticillata, Artemisia sp. and Carex bigelowii) had a variety of intracellular colonizations which are referred to as dark septate fungi. No mycorrhizae were found on 12 other plants: Equisetum arvense, Equisetum variegatum, Lycopodium alpinum, Polygonum bistorta, Saxifraga hieracifolia, Saxifraga hirculus, Astragalus alpinus, Pedicularis kanei, Petasites frigidus, Carex podocarpa, Carex microchaeta and Poa arctica. A possible ecological role of dark septate fungi is discussed. Accepted: 4 August 1995     

Phytochemical Study of Juglans regia L. Pericarps from Greece with a Chemotaxonomic Approach

Phytochemical research of different polarity extracts from green Juglans regia L. pericarps from Greece afforded 32 compounds: four pentacyclic triterpenes (1 – 4), three sesquiterpenes (5 – 7), four tetralones (8 – 11), two naphthoquinones (12 and 13), seven phenolic acids (14 – 20), one diarylheptanoid (21), one neo‐lignan (22), seven flavonoids (23 – 29), two phenylethanoids (30 and 31) and one hydrolysed tannin (32). Compounds 4 and 29 are isolated for the first time from the species, while compounds 3, 7, 20, 22, 23, 24, 25, 26, 28, 30 are reported for the first time in Juglandaceae. Chemotaxonomic significance of isolated compounds into Junglandaceae family is thoroughly discussed.     

Phylogeny and classification of Aedini (Diptera: Culicidae), based on morphological characters of all life stages

Higher‐level relationships within Aedini, the largest tribe of Culicidae, are explored using morphological characters of eggs, fourth‐instar larvae, pupae, and adult females and males. In total, 172 characters were examined for 119 exemplar species representing the existing 12 genera and 56 subgenera recognized within the tribe. The data for immature and adult stages were analysed separately and in combination using equal (EW) and implied weighting (IW). Since the classification of Aedini is based mainly on adult morphology, we first tested whether adult data alone would support the existing classification. Overall, the results of these analyses did not reflect the generic classification of the tribe. The tribe as a whole was portrayed as a polyphyletic assemblage of Aedes and Ochlerotatus within which eight (EW) or seven (IW) other genera were embedded. Strict consensus trees (SCTs) derived from analyses of the immature stages data were almost completely unresolved. Combining the adult and immature stages data resulted in fewer most parsimonious cladograms (MPCs) and a more resolved SCT than was found when either of the two data subsets was analysed separately. However, the recovered relationships were still unsatisfactory. Except for the additional recovery of Armigeres as a monophyletic genus, the groups recovered in the EW analysis of the combined data were those found in the EW analysis of adult data. The IW analysis of the total data yielded eight MPCs consisting of three sets of two mutually exclusive topologies that occurred in all possible combinations. We carefully studied the different hypotheses of character transformation responsible for each of the alternative patterns of relationship but were unable to select one of the eight MPCs as a preferred cladogram. Overall, the relationships within the SCT of the eight MPCs were a significant improvement over those found by equal weighting. Aedini and all existing genera except Ochlerotatus and Aedes were recovered as monophyletic. Ochlerotatus formed a polyphyletic assemblage basal to Aedes. This group included Haemagogus and Psorophora, and also Opifex in a sister‐group relationship with Oc. (Not.) chathamicus. Aedes was polyphyletic relative to seven other genera, Armigeres, Ayurakitia, Eretmapodites, Heizmannia, Udaya, Verrallina and Zeugnomyia. With the exception of Ae. (Aedimorphus), Oc. (Finlaya), Oc. (Ochlerotatus) and Oc. (Protomacleaya), all subgenera with two or more species included in the analysis were recovered as monophyletic. Rather than leave the generic classification of Aedini in its current chaotic state, we decided a reasonable and conservative compromise classification would be to recognize as genera those groups that are ‘weighting independent’, i.e. those that are common to the results of both the EW and IW analyses of the total data. The SCT of these combined analyses resulted in a topology of 29 clades, each comprising between two and nine taxa, and 30 taxa (including Mansonia) in an unresolved basal polytomy. In addition to ten genera (Armigeres, Ayurakitia, Eretmapodites, Haemagogus, Heizmannia, Opifex, Psorophora, Udaya, Verrallina and Zeugnomyia), generic status is proposed for the following: (i) 32 existing subgenera of Aedes and Ochlerotatus, including nine monobasic subgenera within the basal polytomy, i.e. Ae. (Belkinius), Ae. (Fredwardsius), Ae. (Indusius), Ae. (Isoaedes), Ae. (Leptosomatomyia), Oc. (Abraedes), Oc. (Aztecaedes), Oc. (Gymnometopa) and Oc. (Kompia); (ii) three small subgenera within the basal polytomy that are undoubtedly monophyletic, i.e. Ae. (Huaedes), Ae. (Skusea) and Oc. (Levua), and (iii) another 20 subgenera that fall within the resolved part of the SCT, i.e. Ae. (Aedes), Ae. (Alanstonea), Ae. (Albuginosus), Ae. (Bothaella), Ae. (Christophersiomyia), Ae. (Diceromyia), Ae. (Edwardsaedes), Ae. (Lorrainea), Ae. (Neomelaniconion), Ae. (Paraedes), Ae. (Pseudarmigeres), Ae. (Scutomyia), Ae. (Stegomyia), Oc. (Geoskusea), Oc. (Halaedes), Oc. (Howardina), Oc. (Kenknightia), Oc. (Mucidus), Oc. (Rhinoskusea) and Oc. (Zavortinkius). A clade consisting of Oc. (Fin.) kochi, Oc. (Fin.) poicilius and relatives is raised to generic rank as Finlaya, and Downsiomyia Vargas is reinstated from synonymy with Finlaya as the generic name for the clade comprising Oc. (Fin.) leonis, Oc. (Fin.) niveus and their relatives. Three other species of Finlaya?Oc. (Fin.) chrysolineatus, Oc. (Fin.) geniculatus and Oc. (Fin.) macfarlanei? fall within the basal polytomy and are treated as Oc. (Finlaya) incertae sedis. Ochlerotatus (Ochlerotatus) is divided into three lineages, two of which, Oc. (Och.) atropalpus and Oc. (Och.) muelleri, are part of the basal polytomy. The remaining seven taxa of Oc. (Ochlerotatus) analysed, including the type species, form a reasonably well‐supported group that is regarded as Ochlerotatus s.s. Ochlerotatus (Rusticoidus) is retained as a subgenus within Ochlerotatus s.s. Ochlerotatus (Nothoskusea) is recognized as a subgenus of Opifex based on two unique features that support their sister‐group relationship. A new genus, Tanakaius gen. nov. , is proposed for Oc. (Fin.) togoi and the related species Oc. (Fin.) savoryi. The taxonomic status and generic placement of all currently valid species of Aedini are listed in an appendix. © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society, 2004, 142 , 289?368.     

西藏蕨类植物新记录

报道了中国西藏自治区蕨类植物新记录2属,即粉叶蕨属(Pityrogramma)和肋毛蕨属(Ctenitis),以及新记录15种1变种——疏叶卷柏(Selaginella remotifolia)、粉叶蕨(Pityrogramma calomelanos)、云南网藤蕨(Lomagramma yunnanensis)、灰绿耳蕨(Polystichum scariosum)、高大复叶耳蕨(Arachniodes gigantea)、兆洪鳞毛蕨(Dryopteris wuzhaohongii)、亮鳞肋毛蕨(Ctenitis subglandulosa)、高山蹄盖蕨(Athyrium silvicola)、卵果双盖蕨(Diplazium ovatum)、肉刺双盖蕨(D.simile)、瘤羽假毛蕨(Pseudocyclosorus tuberculifer)、耳羽钩毛蕨(Cyclogramma auriculata)、尖嘴蕨(Lepisorus mucronatus)、黑鳞瓦韦(L.sordidus)、喙叶假瘤蕨(Selliguea rhynchophylla)和灰茎节肢蕨(Arthromeris himalayensis var.niphoboloides)。该文还对墨脱鳞盖蕨(Microlepia medogensis)的分类学处理提出了新的建议。凭证标本保存在上海辰山植物标本馆(CSH)。     

Detection of three virulence genes alt, ahp and aerA in Aeromonas hydrophila and their relationship with actual virulence to zebrafish

Aims: To evaluate the frequency of the aerolysin (aerA), cytotoxic enterotoxin (alt) and serine protease (ahp) genes in Aeromonas hydrophila isolates from different sources, and to determine the relationship between the presence of these genes and virulence of A. hydrophila in zebrafish. Methods and Results: Aeromonas hydrophila isolates from clinical cases (n = 40), from healthy fish (n = 22) and from water environment (n = 21) were analysed with respect to the prevalence of aerA, alt and ahp genes by PCR assay. These virulence factors occur among clinical isolates as well as among isolates from healthy fish and water environment. The majority (97·6%) of the strains examined carried one or more virulence genes. The isolates were divided into seven genetic profiles on the basis of PCR result: aerA⁺alt⁺ahp⁺ (62·7%), aerA⁺alt⁺ahp^? (13·3%), aerA⁺alt^?ahp⁺ (10·8%), aerA^?alt⁺ahp⁺ (4·8%), aerA^?alt^?ahp⁺ (3·6%), aerA⁺alt^?ahp^? (2·4%) and aerA^?alt^?ahp^? (2·4%). A higher frequency of genetic group aerA⁺alt⁺ahp⁺ was determined in the isolates from diseased animals compared to those from healthy fish or water environments. Virulence properties of 26 representative strains belonging to the seven genetic profiles were further characterized. Results demonstrated that as the present of virulence genes increased, the proteolytic, haemolytic and cytotoxic activities of extracellular products also increased. And the 50% lethal doses (LD₅₀s) of aerA⁺alt⁺ahp⁺ isolates (<10⁵) in zebrafish were lower when compared with the strains expressing one or combinations of two virulence genes (>10⁶). Conclusions: Virulence properties of A. hydrophila correlated well with the presence of virulence genes tested. aerA⁺alt⁺ahp⁺ was more frequent virulence genotype in A. hydrophila isolates from clinical diseases than from healthy fish and water environment, and the aerA⁺alt⁺ahp⁺ isolates were more virulent to zebrafish compared to the other six genetic profiles. Significant and Impact of the Study: The detection for aerA, alt and ahp can be used for virulence typing of A. hydrophila isolates.     

Demonstration and characterization of Ca2+ channel in tonoplast-free cells ofNitellopsis obtusa

Summary The presence of a Ca²⁺ channel in the plasmalemma of tonoplast-freeNitellopsis obtusa cells was demonstrated and its characteristics were studied using current- and voltage-clamp techniques. A long-lasting inward membrane current (I _m ), recorded using a step voltage clamp, consisted of a single component without time-dependent inactivation. Increasing either [Ca²⁺] _o or [Cl^–] _o 1) enhanced the maximum amplitude of inwardI _m ((I _m ) _p ) and 2) shifted the peak voltage ((V _m ) _p ) at(I _m ) _p to more positive values under ramp-shaped voltage clamping and 3) depolarized the peak value of action potentials. This behavior is consistent with predictions based on the Nernst equation for Ca²⁺ but not for Cl^–. DIDS (4,4-diisothiocyano-2,2-disulfonic acid stilbene) did not suppress(I _m ) _p in tonoplast-free cells, in contrast with its effect on normal cells. La³⁺ and nifedipine blocked(I _m ) _p irreversibly. On the other hand, Ca²⁺ channel agonist, BAY K 8644 irreversibly enhanced(I _m ) _p . Both Sr²⁺ influx and K⁺ efflux increased upon excitation. The charge carried by Sr²⁺ influx was compensated for by K⁺ efflux. It is concluded that only the Ca²⁺ channel is activated during plasmalemma excitation in tonoplast-free cells. In terms of the magnitude of(I _m ) _p , Sr²⁺ could replace Ca²⁺, but Mn²⁺, Mg²⁺ and Ba²⁺ could not. External pH affected(I _m ) _p and the membrane conductance (g _m ) at(I _m ) _p ((g _m ) _p ). Increasing the external ionic strength caused increases in both(I _m ) _p and(g _m ) _p , and shifted(V _m ) _p to positive values. At the same time, Sr²⁺ influx increased. Thus Ca²⁺ channel activation seems to be enhanced by increasing external ionic strength. The possible involvement of surface potential is discussed.     

The female-killing chromosome of the silkworm, Bombyx mori, was generated by translocation between the Z and W chromosomes

Bombyx mori is a female-heterogametic organism (female, ZW; male, ZZ) that appears to have a putative feminizing gene (Fem) on the W chromosome. The paternally transmitted mutant W chromosome, Df(p ^Sa + ^p W + ^od )Fem, derived from the translocation-carrying W chromosome (p ^Sa + ^p W + ^od ), is inert as femaleness determinant. Moreover, this Df(p ^Sa + ^p W + ^od )Fem chromosome has been thought to have a female-killing factor because no female larvae having the Df(p ^Sa + ^p W + ^od )Fem chromosome are produced. Initially, to investigate whether the Df(p ^Sa + ^p W + ^od )Fem chromosome contains any region of the W chromosome or not, we analyzed the presence or absence of 12 W-specific RAPD markers. The Df(p ^Sa + ^p W + ^od )Fem chromosome contained 3 of 12 W-specific RAPD markers. These results strongly indicate that the Df(p ^Sa + ^p W + ^od )Fem chromosome contains the region of the W chromosome. Moreover, by using phenotypic and molecular markers, we confirmed that the Df(p ^Sa + ^p W + ^od )Fem chromosome is connected with a partially deleted Z chromosome and that this fused chromosome behaves as a Z chromosome during male meiosis. Furthermore, we demonstrated that the ZZW-type triploid female having the Df(p ^Sa + ^p W + ^od )Fem chromosome is viable. Therefore, we concluded that the Df(p ^Sa + ^p W + ^od )Fem chromosome does not have a female-killing factor but that partial deletion of the Z chromosome causes the death of the ZW-type diploid female having the Df(p ^Sa + ^p W + ^od )Fem chromosome. Additionally, our results of detailed genetic analyses strongly indicate that the female-killing chromosome composed of the Df(p ^Sa + ^p W + ^od )Fem chromosome and deleted Z chromosome was generated by translocation between the Z chromosome and the translocation-carrying W chromosome, p ^Sa + ^p W + ^od .     

橡胶树橡胶生物合成调控相关基因表达丰度比较

蛋白质是构成生命系统的基本元件之一,是大部分生物学功能的执行者.蛋白质丰度与其生物学功能息息相关,其丰度受基因表达过程中各环节严格精密的调控.其中,蛋白质丰度与其相应mRNA丰度存在较强的相关性,蛋白质丰度差异的40％可由mRNA丰度来解释.茉莉酸信号途径调节巴西橡胶树中的天然橡胶生物合成,但相关基因彼此间的表达丰度差...     

Characterization of S tester lines in Brassica oleracea: polymorphism of restriction fragment length of SLG homologues and isoelectric points of S-locus glycoproteins

 Forty three S tester lines of Brassica oleracea were characterized using DNA and protein gel-blotting analyses. DNA gel-blot analysis of HindIII-digested genomic DNA with class-I and class-II SLG probes revealed that 40 lines could be classified as class-I S haplotypes while three lines could be classified as class-II S haplotypes. The band patterns in the S tester lines were highly polymorphic. Although the S tester lines typically showed two bands corresponding to SLG and SRK in the analysis with the class-I SLG probe, only one band was observed in the S ²⁴ homozygote. This band was identified as SRK, suggesting that this haplotype has no class-I SLG band. In the analysis using the class-II SLG probe, one plant yielded a different band pattern from the known class-II haplotypes, S ² , S ⁵ and S ¹⁵ . Unexpectedly, this plant was reciprocally cross-incompatible with the S ² haplotype. Therefore, it was designated as S ^2-b . We found an S ¹³ haplotype having a restriction fragment length polymorphism different from that of the S ¹³ homozygotes of the S tester line. These findings indicate that S homozygous lines with the same S specificity do not necessarily show the same band pattern in the DNA gel-blot analysis. Soluble stigma proteins of 32 S homozygotes were separated by isoelectric focusing and detected using anti-S ²² SLG antiserum. S haplotype-specific bands were detected in 27 S homozygotes but not in five S homozygotes, including the S ²⁴ homozygote. This is consistent with the observation that the S ²⁴ haplotype had no SLG band. Received: 13 July 1998 / Accepted: 29 September 1998     

Genetic complementation of rhizobial nod mutants with Frankia DNA: artifact or reality?

Two divergent reports have been published on the genetic complementation of rhizobial nod mutants using Frankia DNA. In 1991 putative Frankia cosmid library clones were reported to restore normal nodulation properties to Rhizobium leguminosarum biovar viciaenodD::Tn5, but no supporting sequence data were published. In 1992 a second group reported a failure to find any evidence of functional complementation of various rhizobial nod mutants by Frankia DNA (nodA, nodB and nodC). Complementation tests of nine Nod⁻ R. leguminosarum bv. viciae or Sinorhizobium meliloti Tn5 mutants (nodA ⁻ , nodB ⁻ , nodC ⁻ , nodD ⁻ , nodF  ⁻ , nodL ⁻ , nodH ⁻ ) were thus performed using a Frankia gene library in pLAFR3 to clarify this situation. Rhizobial transconjugants obtained by tri-parental matings were screened for restoration of the nodulation phenotype on their host plants, Vicia sativa subsp. nigra or Medicago sativa. Nodulation was observed on plants inoculated with transconjugants of the R. leguminosarum bv. viciaenodC::Tn5 mutant. The Nod⁺ rhizobial transconjugants were isolated and analysed. The Nod⁺ phenotype of these transconjugants was found to be due to Tn5 excision/transposition. No functional complementation was found with any of the mutants used, suggesting that rhizobial complementation of nod mutants with Frankia DNA is unlikely to occur. Received: 17 April 1998 / Accepted: 22 July 1998     

Community based natural resource management in Zimbabwe: the experience of CAMPFIRE

Communal Areas Management Programme for Indigenous Resources (CAMPFIRE) is a long-term programmatic approach to rural development that uses wildlife and other natural resources as a mechanism for promoting devolved rural institutions and improved governance and livelihoods. The cornerstone of CAMPFIRE is the right to manage, use, dispose of, and benefit from these resources. Between 1989 and 2006, CAMPFIRE income, mostly from high valued safari hunting, totalled nearly USD 30 million, of which 52 allocated to sub-district wards and villages for community projects and household benefits. Whilst a number of assumptions underlying the success of CAMPFIRE as an innovative model for CBNRM have yet to be met, CAMPFIRE confirms the concept that devolving responsibility and accountability for natural resource management can be highly effective for the collective and participatory management of such resources. Elephant numbers in CAMPFIRE areas have increased and buffalo numbers are either stable or decreased slightly during the life of the programme. However, offtake quotas for these two species have increased with a concomitant decline in trophy quality. Although the amount of wildlife habitat diminished after 1980, following the commencement of CAMPFIRE the rate of habitat loss slowed down and in some specific instances was even reversed. More recently there has been increased pressure on habitats and other natural resources as a consequence of deteriora

a

30 million, of which 52% was allocated to sub-district wards and villages for community projects and household benefits. Whilst a number of assumptions underlying the success of CAMPFIRE as an innovative model for CBNRM have yet to be met, CAMPFIRE confirms the concept that devolving responsibility and accountability for natural resource management can be highly effective for the collective and participatory management of such resources. Elephant numbers in CAMPFIRE areas have increased and buffalo numbers are either stable or decreased slightly during the life of the programme. However, offtake quotas for these two species have increased with a concomitant decline in trophy quality. Although the amount of wildlife habitat diminished after 1980, following the commencement of CAMPFIRE the rate of habitat loss slowed down and in some specific instances was even reversed. More recently there has been increased pressure on habitats and other natural resources as a consequence of deteriorating socio-economic conditions in the country. Where devolution has been successful, promising results have been achieved and the recent acceptance and implementation of direct payments to communities is probably the most significant development since 2000. That this has happened can be attributed to CAMPFIRE enabling communities to maximize their roles within the existing set of rules, and by so doing, allowing these rules to be challenged. Donor (73%) and government (27%) investments into the programme amounted to 35 million during the period 1989 to 2003. Since 2003 however, donor funding has been reduced to <$600,000 over the past 5 years.     

A comparison of five distance‐based methods for spatial pattern analysis

Abstract. The behaviour of five statistics (extensions of Pielou's, Clark and Evansapos;, Pollard's, Johnson & Zimmer's, and Eberhardt's statistics, which are denoted as P_i, C_e, P_o, J_z and E_b respectively) that involve the distance from a random point to its jth nearest neighbour were examined against several alternative patterns (lattice‐based regular, inhomogeneous random, and Poisson cluster patterns) through Monte Carlo simulation to test their powers to detect patterns. The powers of all the five statistics increase as distance order j increases against inhomogeneous random pattern. They decrease for P_i and C_e and increase for P_o, J_z, and E_b against regular and Poisson cluster patterns. P_o, J_z, and E_b can reach high powers with the third or higher order distances in most cases. However, P_o is recommended because no extra information is needed, it can reach a high power with the second or third distance even though the sample size is not large in most cases, and the test can be performed with an approximate χ² distribution associated with it. When a regular pattern is expected, J_z is recommended because it is more sensitive to lattice‐based regular pattern than P_o and E_b, especially for the first distance. However, simulation tests should be used because the speed of convergence of J_z to normal distribution is very slow.     

Genetics of tolerance to iron chlorosis in rice

Genetics of tolerance to iron chlorosis was investigated in eight crosses involving parents distinctly different in their level of tolerance. The segregating populations with parents and F₁s were screened under actual stress conditions in the field. Also, selected crosses were studied for Fe³⁺ uptake capacity. Tolerance/moderate tolerance to Fe chlorosis was dominant over susceptibility and it was controlled by two sets of nonallelic genes with complementary interaction. Gene Ic ₁ has been found to be basic and in complementation with Ic ₃ it confers tolerance. Likewise, Ic ₂ with Ic ₄ confers tolerance. The basic genes Ic ₁ and Ic ₂ are nonallelic and, in the absence of their respective complementary genes Ic ₃ and ₄ , ineffective, which results in susceptibility. Of tolerant cultivars, ARC 10372 and Cauvery have been tentatively assigned the genotype of Ic ₁ , Ic ₂ , Ic ₃ , Ic ₄ , and moderately tolerant IET 7613, Prasanna and Akashi Ic ₁ , ₂ Ic ₃ Ic ₄ . The susceptible ARC 5723 has been assigned Ic ₁ , ₂ , Ic ₃ , Ic ₄ , and IET 9829, Ic ₁ , ₂ Ic ₃ Ic ₄ . IET 7614 is susceptible, due to the presence of inhibitory genes I-Ic ₁ , I-Ic ₂ together with ic ₁ pt>, ic ₂ , Ic ₃ , Ic ₄ . Further, the gene Pc for purple coleoptile shows linkage with one of the complementary genes with a crossover value of 15.26%, while the gene(s) for seedling height Ts with Ic ₁ with a crossover value of 1.7%. It is possible that the gene(s) for iron chlorosis tolerance might belong to the second linkage group, where genes for purple leaf were located.