Potato spindle tuber viroid eradicated in Western Australia
Potato spindle tuber viroid (PSTVd) was detected for the f irst time in an isolated hydroponic greenhouse tomato (Lycopersicon esculenturn) erop in the great southern region of Western Australia (WA). An urgent eradication plan was activated because of the highly contagious nature of the pathogen. The tomato erop on the infected property was destroyed and the greenhouses and surrounding area were decontaminated. Surveys of 15 other hydroponic tomato crops did not detect any other PSTVd infected tomato plants in WA.
Identification and eradication of potato spindle tuber viroid in dahlia in the Netherlands
In 2013, potato spindle tuber viroid (PSTVd) was identified in 17 lots of seven dahlia cultivars at a single company in the Netherlands. Analysis of the genotypes showed highest identities with a PSTVd genome from dahlias in Japan. The dahlia isolate could be transferred experimentally to tomato and potato. In tomato this resulted in mild chlorosis and stunting; in potato no symptoms appeared, nor in aerial parts, nor in tubers. The infections in dahlias were eradicated by destroying all infected lots at the infested company. No infections were found in lots of the same cultivars grown by other companies. Moreover, PSTVd was not detected in any of the lots of three other companies that had bought dahlia planting material of the infested company. In 2014, PSTVd was not found in a survey including all cultivars in which PSTVd had been identified in 2013. Therefore, it was concluded that PSTVd had been eradicated in dahlias in the Netherlands.
On the fractionation of β-lactoglobulin and α-lactalbumin
Abstract Existing methods for the preparation of α-lactalbumin and β-lactoglobulin are examined critically. It is proposed that the most satisfactory method for the preparation of the whey protein fraction from bovine milk is (NH 4 ) 2 SO 4 fractionation. A number of new gentle procedures for the fractionation of the whey proteins are compared with some existing methods. The distribution of total protein at various stages is determined by total Kjeldahl nitrogen and the kind of protein by starch-gel electrophoresis. The effect of variables, such as pH, salt concentration and temperature on the separation of α-lactalbumin and serum albumin from β-lactoglobulin is studied. Differences in the behavior ( e.g. solubility) of genetic variants of β-lactoglobulin are noted. The solubility of each of the major whey proteins, under similar conditions to those used in the fractionation, is compared with its solubility in the whey protein mixture. The understanding gained of factors important in the fractionation is used in recommending new procedures for α-lactalbumin and β-lactoglobulin isolation.