Pear decline is a very important phytoplasma disease that causes considerable quantitative and qualitative losses to this fruit crop. Due to economical importance of pear in Isfahan province, Iran, and the difficulty to determine the occurrence of the disease simply based on symptoms in orchards, a detection method for the phytoplasma causing disease in pears in the region was developed. Since ...

Polymerase chain reaction (PCR)-based detection strategies were adopted to examine the etiology and vectorship of pear decline in Taiwan (PDTW). 16S rDNA sequences were amplified from total DNAs prepared from PDTW-affected pear trees Pyrus serotina Rehd. cv. Hengshan and pear psyllid Cacopsylla chinensis using PCR. According to the sequence analyses, C. chinensis carried phytoplasmas of two 16S...

Apple proliferation (AP) and pear decline (PD) are the most severe diseases in pome fruit growing areas. AP-infected trees show typical symptoms such as witches’ broom, enlarged stipules, tasteless, and dwarf fruits. PD-infected pears show a progressive weakening, reduced terminal growth, smaller fruits, and die within weeks (quick decline) or years (slow decline). The diseases are caused by th...

Background and Aims: In spite of a long tradition of fruit-tree growing in all provinces of Iran, information on pear (Pyrus communis) tree viruses is scant. In order to identify of the nature of the virus like symptoms and decline in pear trees, we carried out a survey for the occurrence of four important viruses. Materials and Methods: Leaf samples of pear showing virus like symptoms wer...