OBSERVATIONS ON APPLE STEM GROOVING VIRUS
Apple stem grooving virus nearly always occurs in combination with apple stem pitting virus. Both viruses induce wood symptoms in Virginia Crab apple and therefore the presence of stem grooving virus in this indicator cannot always be determined when stem pitting virus is present too. Single isolates of stem grooving virus, however, induced symptoms in Virginia Crab that can easily be distinguished from symptoms caused by stem pitting and from symptoms caused by a mixture of the two viruses. Virginia Crab and Chenopodiumquino a were both found to be sensitive to all of eleven single isolates studied, however, two isolates caused very mild symptoms in Virginia Crab. Both indicators were reliable to a high degree, but, in large scale routine tests C. q u i n o a had advantages for reasons of efficiency in time. Inocula prepared from over-ripe fruits appeared to be good virus sources for sap inoculation experiments. Stem grooving virus was seed-transmitted in C. quinoa as well as in Malus platycarpa. One stem grooving isolate probably caused leaf pattern symptoms on M. platycarpa. Aronia melanocarpa, A. prunifolia, Cotoneaster simonsii, C. acutifolia and C. dielsiana are reported as new hosts for apple stem grooving virus.
van der Meer, F.A. (1976). OBSERVATIONS ON APPLE STEM GROOVING VIRUS. Acta Hortic. 67, 293-304