Phytophthora capsici: A Soilborne Pathogen Dangerous on Grafted Tomato (Solanum lycopersicum × S. hirsutum) in Italy.

During an extensive survey carried out in Piedmont (northern Italy) aimed at identifying the emerging soilborne diseases affecting tomato in commercial fields where alternatives to methyl bromide have been implemented in response to national and international regulations, sudden collapse of tomato plants, cv. Tomahawk, grafted on cv. Beaufort, were repeatedly observed in a commercial plastic tunnel operation. Affected plants suddenly collapsed 60 days after transplant during the month of May 2010. Symptoms included chlorosis, stunting, and severe root and crown rot, leading to sudden collapse of approximately 25% of the plants within 60 days of transplant. Symptomatic tissues from the root and collar of infected plants were surface disinfested for 1 min in a 1% NaOCl solution, rinsed for 5 min in water, and submerged in selective medium based on corn meal agar. A Phytophthora-like organism (2) with characteristic coenocytic hyphae was consistently isolated and transferred to V8 agar. The sporangia were spherical to ovoid, papillate, and 40 to 77 × 23 to 34 (average 55.1 × 30.3) µm. Oospores were globose and 22.2 to 30.8 µm. The internal transcribed spacer (ITS) region of rDNA of a single isolate was amplified using the primers ITS1/ITS4 and sequenced. BLAST analysis (1) of the 750-bp segment showed a 100% homology with the sequence of Phytophthora capsici JN382543.1. The nucleotide sequence has been assigned the GenBank Accession No. JX090306. Pathogenicity tests were performed on healthy 30-day-old tomato plants cv. Beaufort by using one strain of P. capsici grown for 15 days at 22 to 25°C on a mixture of 2:1 wheat/hemp kernels, and then 1 g per L of the inoculum was mixed into a substrate based on peat blonde/peat black (15:85 v/v). Two plants were transplanted into 3-L pots, with five replicates. Ten non-inoculated plants represented the control treatment; the trial was repeated once. All plants were kept in a greenhouse at temperatures ranging from 22 to 25°C. Inoculated plants became chlorotic 7 days after inoculation and root and crown rot developed 30 days after inoculation. Control plants remained symptomless. P. capsici consistently was reisolated from inoculated plants. In Italy, the presence of P. nicotianae on hybrids of Solanum lycopersicum × S. hirsutum is known (3), while, to the best of our knowledge, this is the first report of P. capsici on the hybrid S. lycopersicum × S. hirsutum in Italy. The economic importance of the disease can increase due to the expanding use of grafted tomato plants. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997 (2) D. C. Erwin and O. K. Ribeiro. Phytophthora Diseases Worldwide. APS Press, St Paul, MN, 1996. (3) A. Garibaldi and M. L. Gullino. Acta Hortic. 833:35, 2010. (4) H. M. Masago et al. Phytopathology 67:425, 1977.

Attempts to control Fusarium root rot of bean by seed dressing.

In summer 2006, a root rot caused by Fusarium oxysporum was observed in commercial farms on common bean (Phaseolus vulgaris) on the cv Billò and Borlotto. A study was undertaken in order to evaluate the efficacy of different biological control agents applied as seed dressing. In the presence of a medium-high disease incidence, among the biocontrol agents tested, Trichoderma harzianum T 22, Bacillus subtilis QST 713, followed by Pseudomonas chlororaphis, provided generally the best control. Their efficacy was also consistent in the different trials. Also the mixture of T. harzianum + T. viride provide a good disease control. Streptomyces griseoviridis and the 3 strains of Fusarim oxysporum, although less effective, provided a partial control of the disease. The fungicide mancozeb provided only a partial disease control.

Constant postoperative monitoring of cardiac output after correction of congenital heart defects.

A new method has been developed that permits constant postoperative monitoring of mean and phasic cardiac output in patients after correction of congenital heart defects. A miniature ultrasound probe is attached to the adventitia of the ascending aorta at the conclusion of the operative procedure. This is connected to the monitoring equipment by means of polyurethane-covered wires that exit the chest wall through a small stab wound. The probe can easily be removed by gentle traction when the patient's condition is stable. The technique was developed, validated, and refined in extensive animal studies, and this report describes the first series of 20 consecutive human implants, performed between August 1984 and September 1985, in which the absolute cardiac output determination obtained with the ultrasound probe at the time of its application was correlated with cardiac output as measured with a standard electromagnetic flow probe. Fourteen male and six female patients (mean age 5.5 years) were studied. Operations performed included eight atrial septal defect repairs, four procedures for tetralogy of Fallot, three ventricular septal defect repairs, three stenotic valve corrections, and two Senning operations. One operative death occurred, but no complications were related to probe application or removal. The average cardiac output in the 20 patients as measured with the ultrasound probe was 2.2 +/- 1.1 L/min (range 0.67 to 5.27 L/min). This is nearly identical to the results noted with the electromagnetic flow probe, where the mean cardiac output was 2.3 +/- 1.2 L/min (range 0.7 to 6 L/min). Regression analysis revealed a high linear correlation (r = 0.9) between the two techniques. A monitor can display the cardiac output trend with 1 minute updates, which greatly enhance management of intravenous drug therapy and volume administration. In conclusion, this new extraluminal removable probe allows virtually continuous monitoring of the postoperative cardiac output after correction of congenital heart defects and should become a standard technique in the postoperative care of these patients.

Continuous measurement of pulmonary blood flow using a retractable pulsed Doppler probe.

The feasibility of measuring pulmonary blood flow (PAQ) continuously using a removable, extraluminal 20 MHz pulsed Doppler probe, which has been used successfully to measure aortic blood flow, was assessed in seven anesthetized mongrel dogs. Simultaneous recordings were made from the Doppler probe (range-gated 5-6 mm from the anterior wall of the main pulmonary artery) and an electromagnetic flow probe (encircling the aorta) over cardiac outputs (CO) ranging from 0.2 to 5.5 L/min. Assuming a flat velocity profile and a fixed cross-sectional area, PAQ was initially calculated as the product of area and mean velocity. Regression analyses (PAQ = a + b X CO) indicated good intraanimal linear correlations in six animals (r greater than or equal to 0.84) and no correlation in one animal (r = 0.003); however, PAQ was consistently higher than CO and interanimal variability was marked, as suggested by large deviations in mean intercept and slope values (a = 1.67 +/- 1.09 L/min and b = 0.70 +/- 0.33). Results improved (r greater than or equal to 0.79 in all animals, a = 0.47 +/- 0.52 L/min, and b = 0.77 +/- 0.21) when the method to estimate PAQ was altered to assume that the starting cross-sectional area was the area that would make baseline PAQ and CO agree, and that the area during each subsequent CO level changed as a function of pulmonary artery pressure and an estimate of pulmonary artery compliance. Results of this study imply that it will be more difficult to use this Doppler probe to monitor CO from the pulmonary artery than it was from the aorta due to the elliptical, more compliant pulmonary vessel walls and the irregular pulmonary artery velocity profile.