Pear (Pyrus pyrifolia L.) has an S-RNase-based gametophytic self-incompatibility (SI) mechanism, and S-RNase has also been implicated in the rejection of self-pollen and genetically identical pollen. However, RNA degradation might be only the beginning of the SI response, not the end. Recent in vitro studies suggest that S-RNase triggers mitochondrial alteration and DNA degradation in the incom...

Please also refer to the excellent obituaries written by Miriam Poirier in Carcinogenesis and by Allan Conney in Cancer Research.

A loss and recovery of polysomes coincident with the temperature-dependent interruption and resumption of pear fruit (Pyrus communis, L.) senescence establishes a close correlation between the presence of protein-synthesizing machinery and the progression of senescence and ripening.

Black spot disease, which is caused by the Japanese pear pathotype of the filamentous fungus Alternaria alternata (Fries) Keissler, is one of the most harmful diseases in Japanese pear cultivation. We mapped a gene for susceptibility to black spot disease in the Japanese pear (Pyrus pyrifolia Nakai) cultivar 'Kinchaku' (Aki gene) at the top of linkage group 11, similar to the positions of the s...

Cultured pear (Pyrus communis L. cv Passe Crassane) cells were subjected to temperatures of 39, 42, and 45[deg]C. Heat-shock protein (hsp) synthesis was greater at 30[deg]C than at temperatures above 40[deg]C and continued for up to 8 h. Both cellular uptake of radiolabeled methionine and total protein synthesis were progressively lower as the temperature was increased. Polysome levels decrease...

Gametophytic self-incompatibility in Japanese pear (Pyrus pyrifolia Nakai) is controlled by the single, multi-allelic S-locus. Information about the S-genotypes is important for breeding and the selection of pollen donors for fruit production. Rapid and reliable S-genotype identification system is necessary for efficient breeding of new cultivars in Japanese pear. We designed S allele-specific ...

The Chinese pear psyllids, Cacopsylla spp., associated with Pyrus ussuriensis are reviewed. Three new species, C. accincta sp. n., C. burckhardti sp. n., and C. cinereosignata sp. n., are described. Cacopsylla liaoli (Yang & Li), C. qiuzili Li, C. maculatili Li and C. chinensis (Yang & Li) are redescribed. A key to the adults of the seven species and a key to nymphs of three species are given.

Shoot-tip cultures of Pyrus elaeagrifolia Pallas, an important gene source for drought and chlorosis resistance in pear rootstock breeding, were established from a wild mature tree originated from seed. Murashige and Skoog basal medium supplemented with different concentrations of benzyladenine (BA) singly or in combination with auxin was used in the study. In the initial culture, the highest p...

Marino, P., Schicchi, R., Barone, E., Raimondo F. M. & Domina G.: First results on the phenotypic analysis of wild and cultivated species of Pyrus in Sicily. — Fl. Medit. 23: 237-243. 2013. — ISSN: 1120-4052 printed, 2240-4538 online. Phenotypic analysis of Pyrus in Sicily using a set of 19 characters on 71 accessions belonging to 7 species is here reported. Results show a high level of morphol...