Characterization of Fusarium population associated with wilt of jojoba in Israel

Fusarium wilt, caused by Fusarium oxysporum, is a major disease of jojoba, causing serious economic losses. This study was aimed at characterizing the Fusarium populations associated with jojoba in Israel. Fifty Fusarium isolates used in this study included 23 isolates from the 1990s (“past”) and 27 recently isolated (“recent”). All the isolates were characterized by arbitrarily primed (ap)-PCR and 16 representatives were additionally delineated using multilocus (tef1, rpb1, rpb2) phylogeny and evaluated for their pathogenic potential. Consequently, 88% of the isolates were identified and characterized to the F. oxysporum species complex. The remaining 12% grouped within the F. fujikuroi, F. solani, and F. redolens species complexes. Variations in the infection rate (16.7%–100%), disease symptoms (0.08–1.25, on a scale of 0–3), and fungal colonization index (0.67–2.17, on a scale of 0–4) were observed within the tested isolates, with no significant differences between the past and recent isolates. The representative isolates were assigned to 11 groups based on ap-PCR. Pathogenicity tests showed that isolates from Groups II, IV, and V were the most aggressive, whereas isolates from Groups III, VIII, and IX were the least aggressive. Among the tested isolates, F. oxysporum sensu lato was the most aggressive, followed by F. proliferatum, while F. nygamai was the least aggressive. This study demonstrates the complexity and genetic diversity of Fusarium wilt on jojoba in Israel, indicating possible multiple introductions of infected germplasm into the country.     

Common laboratory artifacts caused by inappropriate sample collection and transport: how to get the most out of a sample

Clinicians are frequently presented with laboratory test results that are not consistent with preconceived expectations for a given case. One important reason for such results is the occurrence of preanalytical errors. In this article preanalytical errors are discussed in 2 parts. The first part covers the steps of sample collection, preparation, and transportation, in which preanalytical errors often occur. This part would be most useful if read in full before collecting a sample. The second part of this article includes a systematic review of preanalytical errors divided according to individual analytes or parameters or, when appropriate, groups of analytes and parameters that represent the same biological system. This part will hopefully serve the clinician as a quick and user friendly guide for identification of possible pitfalls when presented with unexpected laboratory test results for a given case. This article is limited to errors that can affect the complete blood count, chemistry, and coagulation panels.