Spatial Analysis of the Canopy of Kiwifruit Vines as it Relates to the Physical, Chemical and Postharvest Attributes of the Fruit

The position of individual fruit on kiwifruit vines (Actinidiadeliciosa var. deliciosa) grown on a horizontal trellis (pergola)and on a T-bar trellis was determined using a theodolite. Thephysical, chemical, and postharvest attributes of the fruitwere related to their position on the vine during development. Fruit from the pergola vines were more numerous, of lesser weight,with lower concentrations of most mineral nutrients, but greaterconcentrations of soluble solids, and similar flesh firmnessafter 12 weeks of storage at 0 °C, than fruit from the T-barvines. The position on the vine accounted for most of the variationin the attributes of the fruit. Differences between fruit ona single lateral accounted for 43-56% of the variation. Variationbetween vines was relatively small (< 4% of the total variance). The heavier fruit were located at the apical ends of the laterals,while greater concentrations of soluble solids were associatedwith fruit located closer to the cordon. The larger fruit fromthe pergola vines developed from the early opening flowers.A similar relationship existed initially for the T-bar vines,but a reduction in growth of fruit from the early opening flowers8 weeks after anthesis resulted in a more even distributionof fruit size at harvest. The strongest relationship between mineral composition and postharvestattributes of the fruit was with soluble solids concentration(29-46% of the variance). The relationship with flesh firmnesswas weak (r = -0·14 to -0·32). Individual elementscould not be considered in isolation but rather in groups ofelements. Nitrogen was grouped strongly with phosphorus, sulphur,potassium, and copper, while calcium was linked with a secondgroup which included manganese and zinc. These two groups werenegatively related to one another. The greatest proportion of fruit with superior characteristicswas located in the denser parts of the canopy. Fruit with lessdesirable attributes were from the extremities of the canopywhere the leaf area index was low.Copyright 1994, 1999 AcademicPress Actinidia deliciosa, kiwifruit, fruit position, fruit quality, within-vine variation     

Variable reproductive output among clones of Spartina alterniflora (Poaceae) invading San Francisco Bay,California: the influence of herbivory,pollination, and establishment site

Spartina alterniflora has recently been introduced to San Francisco Bay, California, and is rapidly invading open mud flats, growing in circular patches that we found to be individual genetic clones. We collected spikelet samples from more than 200 clones and observed germination rates ranging from 0% to 59%, indicating substantial variation in reproductive output among clones. Several experiments were performed to explore the cause of variation. Pollination manipulations showed that S. alterniflora is outcrossing, but pollen supplements did not increase spikelet germination rates. Exclusion of the only insect herbivore (a phloem feeder, Prokelisia marginata) from developing inflorescences increased the proportion of spikelets containing seed, but failed to increase germinations per spikelet. Spikelets from Willapa Bay, Washington, grown free of insect herbivores, had germination rates similar to San Francisco Bay. These results suggest herbivory is not limiting reproductive output of S. alterniflora. Spikelet viability was not related to clone size; however, clones located lower in the intertidal or far up a drainage slough averaged fewer germinations per spikelet, suggesting clones in areas with lower genet density may have lower spikelet viabilities. Spikelet samples from different sections of clones growing across wide environmental ranges had similar rates of germination, suggesting some genetic influence on spikelet viability. Differential reproductive output among clones and the novel selective environment of San Francisco Bay are expected to cause gene frequency changes in this rapidly expanding population.     

Peptide crystal growth via sulfonate salt formation: The structure of bis-glycylglycine-1,5-naphthalenedisulfonate hydrate

Summary Continuing a line of investigations on methods for formation and growth of high-quality crystals of peptides, the glycylglycine sequence has been crystallized by evaporation methods as a salt with 1,5-naphthalenedisulfonic acid. The structure of the peptide is highly extended, and is conformationally quite similar to the structures which have been characterized for other zwitterionic and salt forms of this sequence. Thus, crystallization as a salt with this sulfonic acid has imposed no undue influence upon the molecular conformation. These results offer further indication that the preparation of peptide sulfonate salts, particularly with arene templates, may have broad general utility for crystallization of interesting sequences which until now have not been approachable in their zwitterionic forms.     

Dietary circumvention of acorn tannins by blue jays

Blue jays consume large quantities of acorns to fuel energy-demanding caching flights in the fall. Yet blue jays possess no known physiological adaptation to counter the negative effects of a high tannin diet on protein digestion. Dietary experiments were conducted to determine if blue jays could subsist on an acorn-only diet, and if they could not, to determine whether supplements of acorn weevil larvae (Curculio), present inside acorns, enabled them to maintain their mass. Comparative tannin assays also were conducted on Lepidobalanus (low tannin; white oak) and Erythrobalanus (high tannin; pin oak) acorns using radial diffusion assay. Captive jays consumed considerable acorn material, yet were unable to maintain mass on ad lib. acorn-only diets or on an acorn +1.5 g larvae/day supplement. There were no significant differences in mass loss between high and low tannin diets. In contrast, blue jays were able to stabilize mass on a diet of acorns +5.0 g larvae supplement/day. These results suggest that acorn weevil larvae, or perhaps other insects, counteract the effects of acorn tannins in the jay diet allowing jays to subsist largely on acorns during the fall caching season. Oak demographic processes may be partly regulated by a tri-trophic relationship among plant, insect and bird. Acorn weevil larvae, considered damaging to oak populations, may actually facilitate oak recruitment and population vagility in the long-term.     

Interpreting the role of phosphorus and growth rate in enhanced fungal induction of sesquiterpenes from Hyoscyamus muticus root cultures

The effect of thiamine limitation in combination with fungal elicitation on sesquiterpene (solavetivone) production was studied in Agrobacterium-transformed hairy-root cultures of Hyoscyamus muticus as a potential means of manipulating the growth rate independent of phosphorus availability. Limiting the initial supply of thiamine did not affect the growth of these cultures compared to growth at the control level of thiamine (0.01 g/l). There was also no enhancement in sesquiterpene production when thiamine supply was limited. Serial culturing in thiamine-free media suggests that these root cultures are not strictly auxotrophic for thiamine, in contrast to previously published results for untransformed root culture. The effect of phosphate limitation combined with elicitation on the production of solavetivone was examined at constant media volume to provide a constant elicitor concentration and to eliminate feedback-inhibition effects. Limiting the initial supply of phosphate to elicited cultures resulted in a twofold increase in solavetivone production as compared to the elicitation at control media phosphate levels (1.1mm). Because growth was attenuated, production per unit cell mass increased 11-fold compared to the control. The effect of phosphate limitation on solavetivone production at constant cell mass and elicitor per root mass was studied. Limiting the initial supply of phosphate to elicited cultures under these conditions did not result in enhanced production of solavetivone. The initially observed enhanced production of solavetivone at limiting initial phosphate concentrations is therefore due to factors other than the growth rate or phosphate involvement in secondary metabolism. Correspondence to: W. R. Curtis     

Structure of the intergenic spacer region from the ribosomal RNA gene family of white spruce (Picea glauca)

Five genomic clones containing ribosomal DNA repeats from the gymnosperm white spruce (Picea glauca) have been isolated and characterized by restriction enzyme analysis. No nucleotide variation or length variation was detected within the region encoding the ribosomal RNAs. Four clones which contained the intergenic spacer (IGS) region from different rDNA repeats were further characterized to reveal the sub-repeat structure within the IGS. The sub-repeats were unusually long, ranging from 540 to 990 bp but in all other respects the structure of the IGS was very similar to the organization of the IGS from wheat, Drosophila and Xenopus.     

Linkage analysis of idiopathic generalized epilepsy (IGE) and marker loci on chromosome 6p in families of patients with juvenile myoclonic epilepsy: no evidence for an epilepsy locus in the HLA region.

Evidence for a locus (EJM1) in the HLA region of chromosome 6p predisposing to idiopathic generalized epilepsy (IGE) in the families of patients with juvenile myoclonic epilepsy (JME) has been obtained in two previous studies of separately ascertained groups of kindreds. Linkage analysis has been undertaken in a third set of 25 families including a patient with JME and at least one first-degree relative with IGE. Family members were typed for eight polymorphic loci on chromosome 6p: F13A, D6S89, D6S109, D6S105, D6S10, C4B, DQA1/A2, and TCTE1. Pairwise and multipoint linkage analysis was carried out assuming autosomal dominant and autosomal recessive inheritance and age-dependent high or low penetrance. No significant evidence in favor of linkage was obtained at any locus. Multipoint linkage analysis generated significant exclusion data (lod score < -2.0) at HLA and for a region 10-30 cM telomeric to HLA, the extent of which varied with the level of penetrance assumed. These observations indicate that genetic heterogeneity exists within this epilepsy phenotype.