Alternate bearing influences annual nutrient consumption and the total nutrient content of mature pistachio trees

The influence of alternate bearing on nutrient utilization and total tree nutrient content was investigated in mature pistachio (Pistacia vera L. cv Kerman trees). Removal of N, P and Zn in fruit and abscised leaves of cropping (‘on’) trees averaged 5, 6, and 2 times, respectively, the removal in abscised leaflets of the non-fruiting, ‘off’ year trees. One hundred and thirty-five kg N, 131 kg K, 86 kg Ca, 39 kg Mg and 18 kg P per hectare were removed in fruits and abscised leaves in ‘on’ year trees. Tree nutrient contents and, presumably, the size of nutrient storage pools in dormant trees varied between ‘on’ and ‘off’ years. There was 22% and 14% more N and P, respectively, in dormant trees following ‘off’ than ‘on’ years. The greater N and P accumulation in ‘off’ year trees is depleted in support of the large fruit demand for N and P during ‘on’ years. In contrast to N and P, there was greater K and Ca accumulation in perennial tree parts during ‘on’ years than during ‘off’ years. The greater K accumulation in perennial tree parts and approximately 30% greater removal of K in annual organs during ‘on’ than ‘off’ years suggests that K uptake could be 4 times higher in ‘on’ year trees than in (non-cropping), ‘off’ year trees.     

Evolution of early determinate tomato cultivars during the last three decades as a result of research conducted at Warsaw Agricultural University

Earliness is a crucial factor of tomato field production in Poland. A. Michalska and B. Kubicki (1978) conducted the first investigations on tomato earliness at the Department of Plant Genetics and Breeding. The main conclusions from these studies indicated that it was possible to obtain varieties earlier than ‘New Yorker’ as a result of transgression. The two new varieties (‘Alfa’ and ‘Akord F₁’) proved to be two weeks earlier than ‘New Yorker’. However, earliness was correlated with smaller fruit weight (30–40 g). At the next stage of experiment some improvement was achieved both in the size of fruit (45 g for ‘Beta’ up to 70 g for ‘Alka’) as well as colour intensity and good flavour. With the next few years fruit weight was still increased (up to 100 g for ‘Maskarena’) and a higher level of firmness was obtained (mid firm fruits for ‘Maskarena’ and ‘Delta’). At present, the Polish Research Centre for Cultivar Testing recommends our varieties ‘Betalux’, ‘Promyk’ and ‘Delta’ as standards.     

The estimation of productivity and yield of linseed (<Emphasis Type="Italic">Linum usitatissimum</Emphasis> L.) using the growth analysis

In three year field experiments (2001 – 2003) the growth, yield and productivity of 8 flax cultivars were compared. Cultivars ‘AC Linora’, ‘Flanders’, ‘Linola™ 947’, ‘Norlin’ and ‘Omega’ were obtained from Canada, ‘Barbara’ and ‘Hungarian Gold’ from Hungary and ‘Opal’ from Poland. Apart from the estimation of the yield of aboveground parts dry matter and seed yield the determinations of the primary index value of growth analysis were done and on their basis the indices LAI, LAD, RGR, CGR and HI were calculated. The obtained yield results of the examined flax cultivars show significant genotypic — environmental relationships pertaining to the dynamics of dry matter accumulation and the amount of seed yield. Meteorological conditions in the successive years significantly influenced the particular phases of growth and development of cultivars and the factor which increased the amount of dry matter was the air temperature during the period of plant emergence — budding. During the vegetative season with a large amount of rainfall the average seed yield was about 40 % lower than compared with a year of average precipitation and a warm second part of the second period of flax vegetation. Among the analyzed cultivars a stable yield in all the years was characteristic for cultivars ‘Flanders’, ‘Barbara’ and ‘AC Linora’ (that cultivar, however, during a wet year yielded at a low level). The assimilation leaf surface of the linseed quickly increased during the period from budding to flowering and the accumulation of dry matter of the aboveground parts lasted up to the green maturity. In the successive years of the experiment there were observed significant (linear or logarithmic regressions) relationship between the yield of dry matter and the indices of growth analysis. The biggest values of the CGR indicator were observed for the period from budding to flowering. The maintaining of a high CGR value after plant flowering in the year with a favourable course of climatic parameters was beneficial for a better yield of all flax cultivars. The low values of the RGR index after flowering of cultivar ‘Hungarian Gold’ and ‘Opal’ strictly corresponded to their low yield of seed and straw biomass.     

The climate of the Younger Dryas as a boundary for Einkorn domestication

The domestication of the Neolithic founder crops of the Near East has recently been a topic of debate particularly with respect to how rapidly the domestication of these crops occurred. One school of thought maintains that these processes lasted several thousand years (‘protracted model’ with ‘gathering’, ‘cultivation’ and ‘domestication’ as three stages of a continuum, each taking up to several thousand years), while another favors the view that domestication occurred much more quickly, over several hundred years at most (‘rapid transition’). Our study focuses on one of these crops, 1-grained domesticated Einkorn wheat, incorporating data from geology, vegetation history, and climate. In the Karacadağ region of southeastern Turkey, where 1-grained Einkorn wheat was domesticated, the climate was severe (i.e. cold and dry) during the Younger Dryas. The climate of the Younger Dryas acted as boundary during which a) conditions were not suitable for ‘cultivation’, and b) Einkorn would have retreated to refugia exhibiting more suitable moisture-bearing soils that would have made ‘gathering’ difficult. Around 11600 cal. b.p., the Younger Dryas ended and a very rapid climatic amelioration commenced at the beginning of the Early Holocene, enabling grasses to spread throughout the region. A ritual PPNA/PPNB site (G?bekli Tepe) and associated PPNB settlements such as Nevali ?ori and ?ay?nü were established at this time. In the settlements of Nevali ?ori and Cafer H?yük, the oldest domesticated Einkorn was found in the earliest archaeological layers. This confirms that the inhabitants made use of domesticated 1-grained Einkorn from the very beginning of settlement activity, although they continued to practice a mixed lifestyle as hunter-gatherers and farmers. For ?ay?nü the issue is more complex, but here domesticated Einkorn also appears around the same time. In summary, by 10400 cal. b.p. domesticated 1-grained Einkorn was present in large quantities at a variety of sites. This would give a maximum window of time lasting approximately 1,200 years and is therefore not in agreement with the ‘protracted’ model but would be consistent with a ‘rapid transition’. It is improbable that the ‘cultivation’ of wild Einkorn was practiced in the Karacadağ region, since wild Einkorn was plentiful during the favorable growing conditions following the Younger Dryas, making it more likely that ‘gathering’ would have been practiced. Because Einkorn has not been found in early settlements in the southern Levant, this crop cannot have been ‘gathered’ and ‘cultivated’ there but instead was ‘domesticated’ independently and solely in southeastern Turkey. Therefore, the YD acts as a boundary, providing a maximum time frame for 1-grained Einkorn domestication.     

Foucault’s ‘Metabody’

The paper treats several ontological questions about certain nineteenth-century and contemporary medical and scientific conceptualizations of hereditary relation. In particular, it considers the account of mid-nineteenth century psychiatric thought given by Foucault in Psychiatric Power: Lectures at the Collège de France, 1973–1974 and Abnormal: Lectures at the Collège de France, 1974–1975. There, Foucault argues that a fantastical conceptual prop, the ‘metabody,’ as he terms it, was implicitly supposed by that period’s psychiatric medicine as a putative ground for psychiatric pathology. After presenting the heart of Foucault’s thought on the ‘metabody,’ the paper investigates the possibility that a contemporary version of a ‘metabody’ may operate today as a conceptual analog of the nineteenth-century psychiatric theory and practice that Foucault began to expose in the texts examined here. It speculates that we might identify a contemporary genetic version of a ‘metabody’ in a particular current conception of the gene as replicator, an item marked by an ambiguous temporal ontology.     

Photosynthesis parameters and activities of enzymes of oxidative stress in two young ‘Chemlali’ and ‘Chetoui’ olive trees under water deficit

The effects of water deficit on photochemical parameters and activities of superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase were investigated in two olive cultivars differing in drought tolerance — ‘Chemlali’ and ‘Chetoui’. After 30 days without irrigation, leaf water potential fell to −5.5 MPa that was accompanied by a marked decrease in net photosynthesis in ‘Chetoui’ olive cultivar. Maximal efficiency of PSII photochemistry (F_v/F_m) decreased slightly in ‘Chemlali’ (28 %) and substantially in ‘Chétoui’ (47 %). Both cultivars showed a similar decline (about 25 %) in the photochemical quenching coefficient, but only the drought-sensitive olive cultivar exhibited an enhancement (31 %) of non-photochemical fluorescence quenching under water deficit conditions. The quantum yield of electron transport decreased in both olive cultivars. ‘Chemlali’ showed a higher protection against oxidative stress, as judged from the lower levels of the malondialdehyde production. Catalase activity was higher in ‘Chetoui’. Glutathione reductase activity was increased similarly in both olive cultivars under water stress. Ascorbate peroxidase activity was enhanced in ‘Chemlali’ under water stress, but was unaffected in ‘Chetoui’. While, superoxide dismutase activity was inhibited in both cultivars under water stress, but higher activity was detected in ‘Chemlali’. Thus, the ability to increase ascorbate peroxidase and a higher superoxide dismutase activity might be an important attribute linked to the drought tolerance in ‘Chemlali’ olive cultivar.     

Response of antioxidant activity to excess copper in two cultivars of <Emphasis Type="Italic">Brassica campestris</Emphasis> ssp. <Emphasis Type="Italic">chinensis</Emphasis> Makino

Changes in ascorbic acid content and antioxidant enzyme activities were investigated in non-heading Chinese cabbage (Brassica campestris ssp. chinensis Makino) leaves of ‘Wutacai’ and ‘Erqing’ exposed to excess copper (Cu). Cu treatment reduced the fresh weight of shoot and root by 57% and 46% in ‘Wutacai’, and 60 and 54% in ‘Erqing’, respectively. The accumulation of copper in leaves was higher in ‘Wutacai’ than that in ‘Erqing’. Compared to the control, ascorbic acid (AsA) contents were significantly decreased after copper treatment in both cultivars, while they were higher in ‘Wutacai’ than in ‘Erqing’, which may explain the higher copper-tolerance of ‘Wutacai’ with higher copper accumulation. The higher AsA contents of ‘Wutacai’ resulted from their lower activities of degrading enzymes, such as ascorbate oxydase (AAO) and ascorbate peroxidase (APX), as well as the increasing activity of dehydroascorbate reductase (DHAR) after copper treatment compared with ‘Erqing’. Copper stimulated superoxide dismutase (SOD) activity in both cultivars, but for catalase (CAT), there was little difference between both cultivars. Peroxidases (POD) activity was decreased after copper treatment in ‘Erqing’, while in ‘Wutacai’, it was significantly increased at 14 days, and POD activity was higher in ‘Wutacai’ than that in ‘Erqing’ at 21 and 28 days. Therefore, the induced increasing activity of POD in ‘Wutacai’ also played an important role in its copper tolerance.     

Induction of embryogenic mango cultures as affected by genotype,explanting, 2,4-D and embryogenic nurse culture

The nucellus was removed from immature seeds of 4 mango genotypes, andcultured under different induction conditions. The mango genotypes includedpolyembryonic ‘Hindi’ and ‘Nam Doc Mai’ and monoembryonic ‘Lippens’ and’Tommy Atkins‘. Nucellar explants were cultured on modified B5 basal mediumunder the following inductive conditions: 1) 4.52 μM 2,4-D; 2) nogrowth regulator (control); 3) 4.52 μM 2,4-D + embryogenic ‘Parris‘nurse culture; 4) no growth regulator + embryogenic ‘Parris’ nurse culture.Induction of embryogenic competence was mediated by 4 factors: genotype,explanting, 2,4-D and the presence of a highly embryogenic nurse culture,although there was considerable difference in genotype response. ‘Hindi’ hadthe greatest embryogenic potential, followed by ‘Lippens’, ‘Tommy Atkins‘and ‘Nam Doc Mai’, respectively. Induction of embryogenic cultures of allgenotypes at low frequency occurred as a result of explanting excisednucellus onto control medium. The most effective treatment for inducingembryogenic cultures was 2,4-D + embryogenic ‘Parris’ nurse culture with’Hindi’, ‘Lippens’ and ‘Nam doc Mai’, with the exception of ‘Tommy Atkins’,in which the treatment with 2,4-D alone was most effective. This revised version was published online in June 2006 with corrections to the Cover Date.     

Enrichment of anaerobic nitrate-dependent methanotrophic ‘ Candidatus Methanoperedens nitroreducens’ archaea from an Italian paddy field soil

Paddy fields are a significant source of methane and contribute up to 20% of total methane emissions from wetland ecosystems. These inundated, anoxic soils featuring abundant nitrogen compounds and methane are an ideal niche for nitrate-dependent anaerobic methanotrophs. After 2 years of enrichment with a continuous supply of methane and nitrate as the sole electron donor and acceptor, a stable enrichment dominated by ‘Candidatus Methanoperedens nitroreducens’ archaea and ‘Candidatus Methylomirabilis oxyfera’ NC10 phylum bacteria was achieved. In this community, the methanotrophic archaea supplied the NC10 phylum bacteria with the necessary nitrite through nitrate reduction coupled to methane oxidation. The results of qPCR quantification of 16S ribosomal RNA (rRNA) gene copies, analysis of metagenomic 16S rRNA reads, and fluorescence in situ hybridization (FISH) correlated well and showed that after 2 years, ‘Candidatus Methanoperedens nitroreducens’ had the highest abundance of (2.2 ± 0.4 × 108) 16S rRNA copies per milliliter and constituted approximately 22% of the total microbial community. Phylogenetic analysis showed that the 16S rRNA genes of the dominant microorganisms clustered with previously described ‘Candidatus Methanoperedens nitroreducens ANME2D’ (96% identity) and ‘Candidatus Methylomirabilis oxyfera’ (99% identity) strains. The pooled metagenomic sequences resulted in a high-quality draft genome assembly of ‘Candidatus Methanoperedens nitroreducens Vercelli’ that contained all key functional genes for the reverse methanogenesis pathway and nitrate reduction. The diagnostic mcrA gene was 96% similar to ‘Candidatus Methanoperedens nitroreducens ANME2D’ (WP_048089615.1) at the protein level. The ‘Candidatus Methylomirabilis oxyfera’ draft genome contained the marker genes pmoCAB, mdh, and nirS and putative NO dismutase genes. Whole-reactor anaerobic activity measurements with methane and nitrate revealed an average methane oxidation rate of 0.012 mmol/h/L, with cell-specific methane oxidation rates up to 0.57 fmol/cell/day for ‘Candidatus Methanoperedens nitroreducens’. In summary, this study describes the first enrichment and draft genome of methanotrophic archaea from paddy field soil, where these organisms can contribute significantly to the mitigation of methane emissions.     

Impact of sulfur on density of <Emphasis Type="Italic">Tetranychus pacificus</Emphasis> (Acari: Tetranychidae) and <Emphasis Type="Italic">Galendromus occidentalis</Emphasis> (Acari: Phytoseiidae) in a central California vineyard

Sulfur is the oldest and most widely used fungicide in the vineyards of California, where it is used for control of powdery mildew (Uncinula necator [Schw.] Burr). For decades, sulfur use has been associated with outbreaks of Tetranychus pacificus McGregor (Acari: Tetranychidae) on cultivated grapes in the San Joaquin Valley. I undertook large-scale field studies to test this association, to evaluate the impact of sulfur on Galendromus occidentalis (Nesbit) (Acari: Phytoseiidae), a major predator of T. pacificus, and to determine if timing of sulfur applications with respect to grape bloom has an impact on T. pacificus density. The studies took place in a 32 ha vineyard in Fresno County, and all fungicide applications were made with commercial-scale equipment. In 1998 a ‘high sulfur’ treatment, a combination of wettable sulfur and sulfur dust, was compared to ‘low sulfur,’ in which demethylation inhibitor (DMI) fungicides partially substituted for sulfur. In 1999 treatments were ‘sulfur,’ ‘DMI,’ ‘sulfur pre-bloom’ (here sulfur was applied prior to grape bloom, in late May, and then DMIs were applied until mid-season) and ‘sulfur post-bloom’ (the reverse of ‘sulfur pre-bloom’). In each year, the T. pacificus population increase came after the end of fungicide applications, and results clearly show a relationship between sulfur use and T. pacificus density. In 1998, mean T. pacificus density was 2.7 times higher and mean G. occidentalis density 2.5 times higher in ‘high sulfur’ compared to ‘low sulfur.’ In 1999, the highest T. pacificus counts were in the ‘sulfur’ and ‘sulfur pre-bloom’ treatments, 4.8 times higher than ‘sulfur post-bloom’ and 2 times higher than ‘DMIs.’ Density of G. occidentalis was 2.3 times as high in ‘sulfur’ or ‘sulfur pre-bloom’ than ‘DMIs.’ The predator/prey ratio was not significantly different among treatments in 1998, but in 1999 it was highest in the ‘sulfur pre-bloom’ treatment. In 1999, density of Homeopronematus anconai (Baker) (Acari: Tydeidae) was 2.7 times higher in ‘sulfur pre-bloom’ compared to ‘sulfur,’ and higher by 2.7 times in ‘DMI’ compared to ‘sulfur post-bloom,’ suggesting a negative effect of sulfur on this tydeid. These results do not support the hypotheses that the cause of the increase in T. pacificus density is due to negative effects of sulfur on phytoseiids or tydeids. Rather, it appears that a plant-based explanation is likely, first, because of the differences in pre-bloom versus post-bloom sulfuring, and second, because of the long lag time between the end of the sulfur applications and the corresponding increase in spider mite density.     

Long-term study of somatic embryogenesis from anthers and ovaries of 12 grapevine (<Emphasis Type="Italic">Vitis</Emphasis> sp.) genotypes

Summary Anthers and ovaries of six grapevine cultivars (three Vitis vinifera L., two V × Labruscana L. H. Bailey, and one complex hybrid) were extracted from flower buds over 2 yr and cultured on three media reported to promote somatic embryogenesis in Vitis tissues. The highest percent embryogenesis from the hybrid ‘Chancellor’ and V. vinifera ‘Chardonnay’, ‘Merlot’, and ‘Pinot Noir’ occurred on medium C [Nitsch and Nitsch, 1969, basal medium with 3.0% (w/v) sucrose, 0.01% (w/v) inositol. 0.3% (w/v) Phytagel, 2.5 μM 2.4-dichlorophenoxyacetic acid, 2.5μM β-naphthoxyacetic acid, 5.0μM N-(2-chloro-4-pyridyl)-N′-phenylurea, and 0.05% (w/v) glutamine]. Regardless of the media, the labrusca cultivars ‘Concord’ and ‘Niagara’ produced soft non-embryogenic callus that was sometimes mixed with well-developed somatic embryos. Nine vinifera genotypes were further tested for several different years on medium C. Embryogenic cultures suitable for transformation were obtained from all genotypes in more than 1 yr. The average percent embryogenesis from ovaries was 7-fold higher than from anthers. There was significant annual variation in percent embryogenesis, demonstrating the need for media comparisons to be replicated for more than one season. Suspension cultures suitable for use in genetic transformation were initiated from ‘Chardonnay’, ‘Merlot,’ and ‘Pinot Noir’ pro-embryogenic masses. ‘Chardonnay’ suspension cultures plated and grown under conditions developed for recovery of plants after biolistic transformation yielded approximately 500 non-transformed embryos per plate after 4 mo. of culture, with 68.6% of the embryos converting to plants. This is the first reported protocol for embryogenesis from ‘Concord,’ ‘Cabernet Franc,’ and ‘Pinot Noir’ grapevines.     

QTL analysis of resistance to sharka disease in the apricot (Prunus armeniaca L.) ‘Polonais’ × ‘Stark Early Orange’ F1 progeny

Different hypotheses on the genetic control of the resistance to the plum pox virus (PPV) have been reported in apricot, but there was a lack of agreement about the number of loci involved. In recent years, apricot genetic maps have been constructed from progenies derived from ‘Stark Early Orange’ or ‘Goldrich’, two main sources of resistance, three of these including the mapping of the PPV resistance loci. As the location of the locus was not precisely established, we mapped the PPV resistance loci using interval mapping (IM), composite interval mapping (CIM), and the Kruskal–Wallis non-parametric test in the F₁ progeny derived from a cross between the susceptible cv. ‘Polonais’ and ’Stark Early Orange’. Four genomic regions were identified as being involved in PPV resistance. One of these mapped to the upper region of linkage group 1 of ‘Stark Early Orange’, and accounted for 56% of the phenotypic variation. Its location was similar to the one previously identified in ‘Goldrich’ and Prunus davidiana. In addition, a gene strongly associated to these major quantitative trait loci (QTL) was found to be related to PPV infection. Two putative QTLs were detected on linkage groups 3 of ‘Polonais’ and 5 of both ‘Polonais’ and ‘Stark Early Orange’ with both parametric and non-parametric methods at logarithm of odds (LOD) scores slightly above the detection threshold. The last QTL was only detected in the early stage of the infection. PPV resistance is, thus, controlled by a major dominant factor located on linkage group 1. The hypothesis of recessive factors with lower effect is discussed.     

Assaying for Pollen Drift from Transgenic ‘Rainbow’ to Nontransgenic ‘Kapoho’ Papaya under Commercial and Experimental Field Conditions in Hawaii

In 1992, papaya ringspot virus (PRSV) was discovered in the Puna district of Hawaii island where 95% of the state of Hawaii’s papaya was being grown. By 1998 production in Puna had decreased 50% from 1992 levels. A PRSV-resistant transgenic papaya ‘Rainbow’ containing the coat protein gene of PRSV was released commercially in Hawaii in 1998, and saved the papaya industry from further devastation. In the ensuing years since the release of the transgenic papaya, a number of farmers grew hermaphrodite nontransgenic ‘Kapoho’ papaya in close proximity to plantings of hermaphrodite transgenic ‘Rainbow’ papaya. These plantings provided a unique opportunity to assay for transgenic-pollen drift under commercial conditions. Between 2004 and 2010, assays for the GUS (beta-glucuronidase) transgene in embryos were done to study transgenic-pollen drift in commercial ‘Kapoho’ plantings and in replicated field plots. Very low pollen drift (0.8%) was detected in fruit of ‘Kapoho’ trees in the border row of one plantation when 90 embryos were assayed per fruit, while no pollen drift was detected in four other commercial plantings in which eight embryos were tested per fruit. Pollen drift averaged 1.3% of tested embryos in field plots where individual hermaphrodite ‘Kapoho’ trees were adjacent to two or four ‘Rainbow’ trees. In contrast, 67.4% of tested embryos were GUS positive in similarly located female ‘Kapoho’ trees. The very low transgene flow to close-by ‘Kapoho’ plantings is likely due to the fact that hermaphrodite trees are used commercially in Hawaii and that these trees are largely self-pollinated before the stigma is exposed to external pollen.     

Anthurium roots for micropropagation and Agrobacterium tumefaciens-mediated gene transfer

Growth of Blechnum spicant gametophytes was optimal in MS liquid medium, a 16-h photoperiod, and it was unaffected by variation of the pH between 4.7 and 8.7. Antheridia were observed during all developmental stages of the gametophyte: filamentous, spatulate or cordate and their formation was induced by compounds excreted into the culture medium by mature gametophytes. This antheridiogen activity was found in the fractions corresponding to free and apolar esters of gibberellins. IBA at 5 μM and 50 μM, and BA at 50 μM inhibited antheridiogen. Exogenous application of GA₃ allowed spore germination but strongly inhibited gametophyte development; the two dimensional state was not reached. This revised version was published online in June 2006 with corrections to the Cover Date.     

Delimitation of a QTL region controlling cold tolerance at booting stage of a cultivar, ‘Lijiangxintuanheigu’, in rice, <Emphasis Type="Italic">Oryza sativa</Emphasis> L.

Low temperature at the booting stage of rice causes male sterility resulting in severe yield loss. Cold tolerance has long been an important objective in rice breeding. We identified a quantitative trait locus (QTL) for cold tolerance on the long arm of chromosome 3 from the cold-tolerant breeding line ‘Ukei 840’ by using F₂ and BC₁F₂ populations from crosses between ‘Ukei 840’ and ‘Hitomebore’. The cold tolerance of ‘Ukei 840’ is derived from the Chinese cultivar ‘Lijiangxintuanheigu’. The effect of this QTL on cold tolerance was confirmed by developing ‘Hitomebore’ chromosome segment substitution lines having ‘Lijiangxintuanheigu’ alleles on chromosome 3. By producing recombinants in chromosome 3, the QTL region for cold tolerance was delimited to the region of about 1.2-Mb region between RM3719 and RM7000. All lines heterozygous for the QTL showed seed fertilities as low as that of ‘Hitomebore’, suggesting that the ‘Lijiangxintuanheigu’ allele for cold tolerance in the QTL region is recessive. Determination of a 1.2-Mb nucleotide sequence of ‘Ukei 840’ and comparison with the published genomic sequence of ‘Nipponbare’ showed 254 SNPs, of which 11 were in coding regions of genes, seven in five genes being non-synonymous. SNPs were detected in the 5-kb upstream regions of 89 genes, but no differences of gene expression levels were detected between alleles of these genes. Although further delimitation is required to identify the gene responsible for cold tolerance of ‘Lijiangxintuanheigu’, SNP markers developed here will be useful for marker-assisted selection in a breeding program using ‘Lijiangxintuanheigu’ as a donor of cold tolerance.     

Effect of low doses of gamma irradiation on in vitro growth of grapevine

Shoot tips and single node explants of two rootstocks (R.99 and 3309) and two varieties (‘Helwani’ and ‘Cabernet Franc’) of grapevine cultured on DSD1 media for a period of 60 days, were irradiated with 0, 2, 5 and 7 Gy doses of gamma irradiation. Shoot length of ‘Helwani’ and ‘Cabernet Franc’ was increased by 7 Gy irradiation. The 5 Gy dose increased the number of roots in plants of the two rootstocks and ‘Helwani’. Root length of ‘Helwani’ and ‘Cabernet Franc’ at the 2 and 7 Gy doses were significantly higher than those of the non-irradiated control. A similar effect was noticed on R.99 rootstock subjected to 5 Gy. Five Gy also increased the dry weight of the R.99 rootstock, whereas 2 and 7 Gy had a similar effect on ‘Helwani’ and ‘Cabernet Franc’. Number of leaves of plants exposed to 5 and 7 Gy was increased when compared with the non-irradiated control. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effects of 1-aminocyclopropane-1-carboxylic acid,aminoethoxyvinylglycine, methylglyoxal bis-(guanylhydrazone) and dicyclohexylammonium sulfate on induction of embryogenic competence of mango nucellar explants

The effects of aminoethoxyvinylglycine (AVG),1-aminocyclopropane- 1 -carboxylic acid (ACC), dicycyclohexylammonium sulfate (DCHA) and methylglyoxal bis-(guanylhydrazone) (MGBG) on induction of embryogenic competence from the nucellus of two mango genotypes, ‘Tutehau’ (polyembryonic) and ‘Tommy Atkins’ (monoembryonic), were compared. Induction of embryogenic competence in the explanted nucellus of ‘Tommy Atkins’ was more sensitive to AVG and DCHA than ‘Tutehau’. MGBG had no effect on induction of embryogenic competence of either genotype, and ACC suppressed somatic embryogenesis with both cultivars. Ethylene biosynthesis was greater from explanted ‘Tommy Atkins’ cultures. Reducing ethylene biosynthesis with AVG marginally increased the number of embryogenic cultures of ‘Tutehau’, but completely inhibited somatic embryogenesis in ‘Tommy Atkins’ cultures. Ethylene biosynthesis was stimulated by ACC in nonembryogenic cultures of both genotypes and in ‘Tommy Atkins’ embryogenic cultures, in which ethylene biosynthesis was ca 7 X greater than in ‘Tutegau’ embryogenic cultures. The greater sensitivity of ‘Tommy Atkins’ to the ethylene antagonist, AVG, may be due to its greater sensitivity to disturbance of ethylene biosynthesis and spermidine synthesis. This revised version was published online in June 2006 with corrections to the Cover Date.     

Characterization,Ecological Status and Type-specific Reference Conditions of Surface Water Bodies in Wallonia (Belgium) using Biocenotic Metrics based on Benthic Invertebrate Communities

The river types in Wallonia (Belgium) were defined according to the system B of the European Water Framework Directive (WFD) taking into account obligatory and optional factors synthesized in three criteria: ‘size’, ‘slope’ and ‘natural region’. Under the hypothesis that benthic invertebrate assemblages would be specialized according to river type, a set of 627 faunal samples originating from an 11-year sampling period was tested to characterize river types with faunal assemblages. A multivariate approach led to gather 23 river types into seven groups exhibiting similar faunal assemblages. Using biocenotic metrics based on benthic invertebrate assemblages (e.g., the French standard IBGN), type-specific reference conditions and ecological status class limits were defined for each ‘natural’ river type group. Ecological potential was defined for heavily modified and for artificial (i.e., man-made canals) types. An ‘ecological status’ evaluation strategy was therefore developed and applied in the southern – and more natural – part of Wallonia, where many reference sites were available. In the northern part of Wallonia (i.e., the ‘Loess region’) where no high quality site was available, the expert judgement took a larger part in the definition of the reference conditions and of the ecological status class limits, in addition to the calculations. Two independent distribution gradients of taxa assemblages resulted from multivariate ordination: a first ‘saprobity axis’, as the taxa-sensitivity to organic contamination was increasing from ‘very resistant’ taxa (mainly located in the ‘Loess region’) to ‘sensitive’ and ‘very sensitive’ taxa (from the river types belonging to the Condroz, the Famenne, the Arden and the Jurassic regions) and a second axis characterizing the Meuse-specific faunal assemblage, gathering exotic species and typical limnophilous taxa of large heavily modified rivers. The ecological status monitoring management system developed in this study – i.e., the definition of faunal river type groups, related reference conditions and ecological status class limits – represents a proposal to be integrated in the ecological status assessment of biological elements for the implementation of the WFD and was tested in Wallonia. For the period 2000–2002 involving 349 different sites, the element ‘benthic invertebrate fauna’ was in that way classified ‘high status’ for 31.5% of sites, ‘good status’ for 31.5% and below ‘good status’ for 37% of sites. The best ecological status (i.e., 100% ‘high’ and ‘good’ status) was found in river type ‘Arden’s xenotrophic brooks with strong slope’ and in river types 8large rivers with medium slope’. The worst status was found in river types ‘Loess brooks and rivers with medium slope’.     

Selecting dwarf apple (Malus × domestica Borkh.) trees in vitro: multiple cytokinin tolerance expressed among three strains of ‘McIntosh’ that differ in their growth habit under field conditions

Microcuttings of three strains of ‘McIntosh’ apple that varied in their growth habit under field conditions were tested for their tolerance to three cytokinins (BA, kinetin, and 2iP) and one cytokinin-like compound (TDZ) in vitro. The three strains were ‘McIntosh’ (standard), ‘Macspur’ (intermediate) and ‘Wijcik’ (dwarf). For each cytokinin ‘Wijcik’ was more tolerant of high cytokinin levels than either ‘Macspur‘, which showed an intermediate tolerance, or ‘McIntosh’ which did not tolerate (died) high levels of cytokinins. These results show that ‘Wijcik’ exhibits multiple cytokinin tolerance in vitro. The relationship between growth habit and BA tolerance has been reported earlier. The present study demonstrates that cytokinins can be used to differentiate among growth types in apple. This revised version was published online in June 2006 with corrections to the Cover Date.     

Assessing the Sensitivity of Seabed Species and Biotopes – The Marine Life Information Network (MarLIN)

Science-based approaches to support the conservation of marine biodiversity have been developed in recent years. They include measures of ‘rarity’, ‘diversity’, ‘importance’, biological indicators of water ‘quality’ and measures of ‘sensitivity’. Identifying the sensitivity of species and biotopes, the main topic of this contribution, relies on accessing and interpreting available scientific data in a structured way and then making use of information technology to disseminate suitably presented information to decision makers. The Marine Life Information Network (MarLIN) has achieved that research for a range of environmentally critical species and biotopes over the past four years and has published the reviews on the MarLIN Web site (www.marlin.ac.uk). Now, by linking the sensitivity database and databases of survey information, sensitivity mapping approaches using GIS are being developed. The methods used to assess sensitivity are described and the approach is advocated for wider application in Europe.