Malus pumila 'Spy 227' and Apple stem pitting virus: graft incompatibility and epinasty.

Apple stem pitting foveavirus (ASPV) is one of the most important and widespread virus infecting apples in the world. Of late, the virus has been found to be invariably associated with most of the apple plantations of Shimla district of Himachal Pradesh based on DAS-ELISA results. Bioassay of viruses in vegetatively propagated crops including apple is considered to be an essential component in indexing programmes for the production of virus free propagating material. Woody indicator Malus pumila 'Spy 227' was used for the detection of ASPV through double grafting method. Graft incompatibility and epinasty symptoms were observed on Malus pumila Spy 227 indicator plants. Further, molecular identification of the virus isolate was done by cloning and sequencing of the test isolate. Partial sequence analysis of the coat protein gene showed 89 % nucleotide identity in BLASTN analysis with ASPV isolate from China (Accession No. JF895517). This is the first record of ASPV producing Graft incompatibility on Spy 227 indicator plants.