Differential Response Of Early And Intermediate Flowering Strawberry Cultivars To Nursery Late-Season Nitrogen Applications And Digging Date

The response of ‘Ventana’, an early flowering cultivar, and ‘Camarosa’, an intermediate flowering cultivar, to nursery late-season nitrogen (N) applications and digging date were studied in strawberry (Fragaria x ananassa Duch). Two experiments were conducted. In the first experiment, runner plants dug on September 20 and October 11 from a high-latitude nursery in California, were established in growth chambers set at 25°/15ºC day/night temperature, 12-h photoperiod, and grown for 90 days. Compared to the first experiment, in the second experiment plants received extra N (foliar-applied) in the nursery in late summer, and runner plants were not grown in GC but in open field (Irvine, California). In the second experiment, runner plants were dug on Sept 20 and Oct 2. In both experiments, plants dug in September were exposed to ~100 chilling units (CU: hours ≤7.2°C) and plants dug in October were exposed to ~300 CU. As a result, October-dug plants had greater crown and root dry weight, and greater concentration of starch and total nonstructural carbohydrates (TNC) in leaves, crowns and roots, compared to September-dug plants. In control plants, from September to October, root TNC concentration increased in ‘Camarosa’ from ~6% to ~11%, and in ‘Ventana’ from ~14% to ~21%, and leaf N concentration ranged from 1.47 to 1.81% in ‘Camarosa’, and from 1.60 to 1.96% in ‘Ventana’. Late summer N applications increased plant N concentration and early-season yields. Late-summer nursery N applications reduced dead leaf biomass (DLB) and dead leaf area (DLA) in both cultivars, although ‘Ventana’ had lower DLB and DLA than ‘Camarosa’. ‘Ventana’ had a greater leaf number and flowered earlier, and had greater early fruit production than ‘Camarosa’. The genetic earliness of ‘Ventana’ would be correlated with the potential of the plant for accumulation of higher initial levels of leaf N and root TNC, and for having greater leaf longevity, compared to ‘Camarosa’.EEA FamailláFil: Kirschbaum, Daniel Santiago. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; ArgentinaFil: Larson, Kirk D. University of California Davis. Department of Plant Sciences; Estados UnidosFil: Weinbaum, Steven A. University of California Davis. Department of Plant Sciences; Estados UnidosFil: DeJong, Theodore M. University of California Davis. Department of Plant Sciences; Estados Unido

Accumulation Pattern Of Total Nonstructural Carbohydrate In Strawberry Runner Plants And Its Influence On Plant Growth And Fruit Production

The pattern of total nonstructural carbohydrate (TNC) accumulation in strawberry (Fragaria ananassa Duch.) nursery runner plants, cv. ‘Camarosa’, was determined for three growing seasons. Plant growth and fruit production patterns were also evaluated. The experiments were carried out on plants propagated in high latitude (41°50' N) and high elevation (1292 m) nurseries in Siskiyou County, California. Plants were sampled beginning in late summer through early autumn and analyzed for dry mass (DM) and TNC. Plants from different digging dates were established in growth chambers (GC) at UC Davis or fruit evaluation plots in Irvine, California. In the nursery, TNC concentration in storage tissues increased steadily from the second week of September to the third week of October, and crown and root TNC concentration was positively correlated with the accumulation of chilling units (hours ≤7.2°C). The root TNC concentration consistently increased from 6 to 10% DM from mid-September to the first week of October. Transplant growth and fruiting pattern were affected by digging date. Overall, the roots were more sensitive to chilling in terms of TNC accumulation, than the crowns. Therefore, roots would be the appropriate organ for assessing TNC status and potential digging dates of strawberry nursery runner plants early in the fall.EEA FamailláFil: Kirschbaum, Daniel Santiago. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; ArgentinaFil: Larson, Kirk D. University of California Davis. Department of Plant Sciences; Estados UnidosFil: Weinbaum, Steven A. University of California Davis. Department of Plant Sciences; Estados UnidosFil: DeJong, Theodore M. University of California Davis. Department of Plant Sciences; Estados Unido

Late-season nitrogen applications in high-latitude strawberry nurseries improve transplant production pattern in warm regions

The influence of late-season nitrogen (N) applications on the fruiting pattern of strawberry runner plants of ‘Camarosa’ was determined over three growing seasons. Experiments were carried out in high-latitude nurseries in northern California and fruit production trials were established in southern California. A total of 80 kg/ha of foliar nitrogen was delivered in three applications to the nursery in late summer. Late-season foliar nitrogen applications: (1) increased early yields (+22% on average) as well as the number of early marketable fruit, (2) did not affect total season yields, fruit size, appearance and firmness and (3) resulted in greater N concentration in leaves, crowns and roots. Runner plants with leaf N concentration within the sufficiency range (1.9 - 2.8% of dry mass) produced the highest early yields. Total nonstructural carbohydrate concentrations decreased in most of the N-treated plants. Apparently, nursery late-season foliar nitrogen applications enhance N mobilization to crown and root, stimulate plant activity during the period of flower differentiation after planting, accelerating flower development and contributing to the advancement of fruit production.EEA FamailláFil: Kirschbaum, Daniel Santiago. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; ArgentinaFil: Larson, Kirk D. University of California Davis. Department of Plant Sciences; Estados UnidosFil: Weinbaum, Steven A. University of California Davis. Department of Plant Sciences; Estados UnidosFil: DeJong, Theodore M. University of California Davis. Department of Plant Sciences; Estados Unido

Impact of Prison Status on HIV-Related Risk Behaviors

Baseline data were collected to evaluate the effectiveness of interventions on completion of the hepatitis A and B vaccine series among 664 sheltered and street-based homeless adults who were: (a) homeless; (b) recently (<1 year) discharged from prison; (c) discharged 1 year or more; and (d) never incarcerated. Group differences at baseline were assessed for socio–demographic characteristics, drug and alcohol use, sexual activity, mental health and public assistance. More than one-third of homeless persons (38%) reported prison time and 16% of the sample had been recently discharged from prison. Almost half of persons who were discharged from prison at least 1 year ago reported daily use of drugs and alcohol over the past 6 months compared to about 1 in 5 among those who were recently released from prison. As risk for HCV and HIV co-infection continues among homeless ex-offenders, HIV/HCV prevention efforts are needed for this population

First record of Glycaspis brimblecombei (Moore) (Homoptera: Psyllidae) in North America: initial observations and predator associations of a potentially serious new pest of eucalyptus in California

Volume: 75Start Page: 55End Page: 5

Podocytes require the engagement of cell surface heparan sulfate proteoglycans for adhesion to extracellular matrices.

Item does not contain fulltextPodocytes adhere to the glomerular basement membrane by cell surface receptors. Since in other cells these adhesions are enhanced by cell surface proteoglycans, we examined the contribution of these molecules and their glycosaminoglycan side chains to podocyte adhesion by developing immortalized podocyte cell lines with (control) or without (mutant) heparan sulfate glycosaminoglycan chains. In adhesion assays control podocytes attached, spread, and migrated more efficiently compared with mutants, indicating a requirement for heparan sulfate chains in these processes. The proteoglycan syndecan-4 is known to have direct effects on cell attachment, spreading, and cytoskeletal organization. We found it localized to focal adhesions in control podocytes coincident with stress fiber formation. In mutant cells, syndecan-4 was associated with smaller focal contacts and cortical actin organization. Analysis by flow cytometry showed that mutant cells had twice the amount of surface syndecan-4 of control cells. Protein kinase Calpha, a signaling molecule bound to and activated by syndecan-4, showed a fourfold increase in membrane localization-activation than that seen in control cells. In vivo, the loss of heparan sulfate glycosaminoglycans in PEXTKO mice led to a loss of glomerular syndecan-4. Overall, our study provides further evidence for a dynamic role of cell surface heparan sulfate glycosaminoglycans in podocyte activity.1 december 201