Use of Entomopathogenic Nematodes for Control of Grape Phylloxera (Homoptera: Phylloxeridae): A Laboratory Evaluation

The effectiveness of 2 species of entomopathogenic nematodes was examined in the laboratory against the root-form of grape phylloxera Daktulosphaira vitifolia (Fitch). Our basic unit of measurement was survival of grape phylloxera established on root pieces of the cultivated grape Vitis vinifera L. variety ‘Cabernet Sauvignon' in the presence or absence of nematodes. In petri dish trials, the Oswego strain of Heterorhabditis bacteriophora Poinar reduced survival of attached grape phylloxera by up to 80% relative to the control treatment, whereas Steinernema glaseri Steiner (isolate 326) had no measurable impact and was not used in further experiments. Hb Oswego significantly reduced survival of grape phylloxera on root pieces placed in small cups filled with soil, but only when soil moisture was high (>13% water content wt:wt) and when high densities of infective nematodes were used (>15,000/g soil). Grape phylloxera exposed to Hb Oswego often turned a brick-red color, indicating successful infection. However, we did not detect any evidence that Hb Oswego could successfully reproduce within the bodies of grape phylloxera hosts. Therefore, although Hb Oswego can exert significant mortality in the laboratory, their use in the field in an augmentative release program may be constrained by the need to use high densities, their dependence on moist soils, and their inability to propagate themselves within grape phylloxera host

EST contig-based SSR linkage maps for Malus × domestica cv Royal Gala and an apple scab resistant accession of M. sieversii , the progenitor species of domestic apple

Malus sieversii is a progenitor species of domestic apple M.×domestica. Using population "GMAL 4595” of 188 individuals derived from a cross of Royal Gala×PI 613988 (apple scab resistant, M. sieversii), 287 SSR (simple sequence repeats) loci were mapped. Of these SSRs, 80 are published anchors and 207 are newly developed EST (expressed sequence tag) contig-based SSRs, representing 1,630 Malus EST accessions in GenBank. Putative gene functions of these EST contigs are diverse, including regulating plant growth, development and response to environmental stresses. Among the 80 published SSRs, 18 are PI 613988 specific, 38 are common and 24 are Royal Gala specific. Out of the 207 newly developed EST contig-based SSRs, 79 are PI 613988 specific, 45 are common and 83 are Royal Gala specific. These results led to the construction of a M. sieversii map (1,387.0cM) of 180 SSR markers and a Royal Gala map (1,283.4cM) of 190 SSR markers. Mapping of scab resistance was independently conducted in two subsets of population "GMAL 4595” that were inoculated with Ventura inaequalis races (1) and (2), respectively. In combination with the two major resistance reactions Chl (chlorotic lesions) and SN (stellate necrosis) to each race, four subsets of resistance data, i.e., Chl/race (1), SN/race (1), Chl/race (2) and SN/race (2), were constituted and analyzed, leading to four resistance loci mapped to the linkage group 2 of PI 613988; SNR1 (stellate necrosis resistance to race (1)) and SNR2 are tightly linked in a region of known scab resistance genes, and ChlR1 (Chlorotic lesion resistance to race (1)) and ChlR2 are also linked tightly but in a region without known scab resistance genes. The utility of the two linkage maps, the new EST contig-based markers and M. sieversii as sources of apple scab resistance are discusse

Variation in host and pathogen in the Neonectria/Malus interaction; toward an understanding of the genetic basis of resistance to European canker

Apple canker caused by the phytopathogenic fungus Neonectria ditissima is an economically important disease, which has spread in recent years to almost all pome-producing regions of the world. N. ditissima is able to cross-infect a wide range of apple varieties and causes branch and trunk lesions, known as cankers. Most modern apple varieties are susceptible and in extreme cases suffer from high mortality (up to 50%) in the early phase of orchard establishment. There is no known race structure of the pathogen and the global level of genetic diversity of the pathogen population is unknown. Resistance breeding is underway in many global breeding programmes, but nevertheless, a total resistance to canker has not yet been demonstrated. Here we present preliminary data from a survey of the phylogenetic relationships between global isolates of N. ditissima which reveals only slight evidence for population structure. In addition we report the results of four rapid screening tests to assess the response to N. ditissima in different apple scion and rootstock varieties, which reveals abundant variation in resistance responses in both cultivar and rootstock material. Further seedling tests show that the segregation patterns of resistance and susceptibility vary widely between crosses. We discuss inconsistencies in test performance with field observations and discuss future research opportunities in this area

New Insight into the History of Domesticated Apple: Secondary Contribution of the European Wild Apple to the Genome of Cultivated Varieties

The apple is the most common and culturally important fruit crop of temperate areas. The elucidation of its origin and domestication history is therefore of great interest. The wild Central Asian species Malus sieversii has previously been identified as the main contributor to the genome of the cultivated apple (Malus domestica), on the basis of morphological, molecular, and historical evidence. The possible contribution of other wild species present along the Silk Route running from Asia to Western Europe remains a matter of debate, particularly with respect to the contribution of the European wild apple. We used microsatellite markers and an unprecedented large sampling of five Malus species throughout Eurasia (839 accessions from China to Spain) to show that multiple species have contributed to the genetic makeup of domesticated apples. The wild European crabapple M. sylvestris, in particular, was a major secondary contributor. Bidirectional gene flow between the domesticated apple and the European crabapple resulted in the current M. domestica being genetically more closely related to this species than to its Central Asian progenitor, M. sieversii. We found no evidence of a domestication bottleneck or clonal population structure in apples, despite the use of vegetative propagation by grafting. We show that the evolution of domesticated apples occurred over a long time period and involved more than one wild species. Our results support the view that self-incompatibility, a long lifespan, and cultural practices such as selection from open-pollinated seeds have facilitated introgression from wild relatives and the maintenance of genetic variation during domestication. This combination of processes may account for the diversification of several long-lived perennial crops, yielding domestication patterns different from those observed for annual species

The Performance-Perceptual Test (PPT) and its relationship to aided reported handicap and hearing aid satisfaction

Objective: Results of objective clinical tests (e.g., measures of speech understanding in noise) often conflict with subjective reports of hearing aid benefit and satisfaction. The Performance-Perceptual Test (PPT) is an outcome measure in which objective and subjective evaluations are made by using the same test materials, testing format, and unit of measurement (signal-to-noise ratio, S/N), permitting a direct comparison between measured and perceived ability to hear. Two variables are measured: a Performance Speech Reception Threshold in Noise (SRTN) for 50% correct performance and a Perceptual SRTN, which is the S/N at which listeners perceive that they can understand the speech material. A third variable is computed: the Performance-Perceptual Discrepancy (PPDIS); it is the difference between the Performance and Perceptual SRTNs and measures the extent to which listeners "misjudge" their hearing ability. Saunders et al. in 2004 examined the relation between PPT scores and unaided hearing handicap. In this publication, the relations between the PPT, residual aided handicap, and hearing aid satisfaction are described.Design: Ninety-four individuals between the ages of 47 and 86 yr participated. All had symmetrical sensorineural hearing loss and had worn binaural hearing aids for at least 6 wk before participating. All subjects underwent routine audiological examination and completed the PPT, the Hearing Handicap Inventory for the Elderly/Adults (HHIE/A), and the Satisfaction for Amplification in Daily Life questionnaire. Sixty-five subjects attended one research visit for participation in this study, and 29 attended a second visit to complete the PPT a second time.Results: Performance and Perceptual SRTN and PPDIS scores were normally distributed and showed excellent test-retest reliability. Aided SRTNs were significantly better than unaided SRTNs; aided and unaided PPDIS values did not differ. Stepwise multiple linear regression showed that the PPDIS, the Performance SRTN, and age were significant predictors of scores on the HHIE/A such that greater reported handicap is associated with underestimating hearing ability, poorer aided ability to understand speech in noise, and being younger. Scores on the Satisfaction with Amplification in Daily Life were not well explained by the PPT, age, or audiometric thresholds. When individuals were grouped by their HHIE/A scores, it was seen that individuals who report more handicap than expected based on their audiometric thresholds, have a more negative PPDIS, i.e., underestimate their hearing ability, relative to individuals who report expected handicap, who in turn have a more negative PPDIS than individuals who report less handicap than expected. No such patterns were apparent for the Performance SRTN.Conclusions: The study showed the PPT to be a reliable outcome measure that can provide more information than a performance measure and/or a questionnaire measure alone, in that the PPDIS can provide the clinician with an explanation for discrepant objective and subjective reports of hearing difficulties. The finding that self-reported handicap is affected independently by both actual ability to hear and the (mis)perception of ability to hear underscores the difficulty clinicians encounter when trying to interpret outcomes questionnaires. We suggest that this variable should be measured and taken into account when interpreting questionnaires and counseling patients.</p

Hearing-aid counseling:comparison of single-session informational counseling with single-session performance-perceptual counseling

Objective: Hearing-aid counseling can improve outcome but programs are often too resource-intensive to be clinically practical. Here we examined the effectiveness of single-session informational counseling with single-session performance-perceptual counseling.Design: Two forms of counseling were compared: informational counseling (IC) and performance-perceptual counseling (PPC). IC focused on discussing communication strategies and tips for hearing-aid use. PPC addressed the discrepancy between measured and perceived ability to understand speech. Outcomes were measured eight-to-ten weeks post-counseling using quantitative and qualitative measures: Hearing handicap inventory, abbreviated profile of hearing aid benefit, psychosocial impact of assistive devices scale (PIADS), international outcome inventory for hearing aids, and a semi-structured exit interview.Study sample: Seventy-four hearing aid-users with symmetrical sensorineural hearing loss participated.Results: Scores on the hearing questionnaires showed no change following either form of counseling. Scores on the PIADS improved for participants as a whole, and the semi-structured interview revealed increased hearing-aid use, better understanding and acceptance of hearing loss, increased use of communication strategies, and improved ability to explain hearing difficulties to others.Conclusions: A single session of hearing-aid counseling can improve hearing-aid use and satisfaction. Open-ended interview and/or quality of life measures are more sensitive to these benefits than hearing questionnaires.</p

The Attitudes towards Loss of Hearing Questionnaire (ALHQ): a comparison of paper and electronic formats.

The purpose of the study was to determine whether scores obtained on the ALHQ when completed in electronic format are the same as when completed in paper format. Four groups of 25 individuals participated. Each completed the ALHQ on two occasions in either its paper version, its electronic version, or both. The variance in ALHQ scores from the first to second administrations was compared across test groups. Data showed that the two forms of the questionnaire yielded equivalent scores but that completion in different modes on both occasions resulted in more variability in scores than completion in the same mode on both occasions. It is concluded that when comparing questionnaire data across administrations, the same response format should be used. Electronic completion took longer than paper completion, but it is concluded that the numerous advantages of electronic administration outweigh the disadvantages of additional completion time