Since several Asian pear species are considered to be potential source of fire blight resistance, we crossed “Doyenné du Comice”, the susceptible European cultivar, with four Asian pear species. The aim of the ...Since several Asian pear species are considered to be potential source of fire blight resistance, we crossed “Doyenné du Comice”, the susceptible European cultivar, with four Asian pear species. The aim of the study was to establish the level of resistance of each genotype and the mode of transmission of fire blight resistance to each F1 full-sib progeny. The best sources of resistance were P. ussuriensis 18 and P. ussuriensis var. ovoidea 8 ranked to resistant and highly resistant, respectively. Although pear resistance to fire blight is suggested to be polygenic, distribution of phenotypes in “Doyenné du Comice” × P. ussuriensis var. ovoidea 8 hybrid family suggests the possibility of monogenic inheritance with the dominance of resistance derived from P. ussuriensis var. ovoidea 8. Polygenic inheritance of pear resistance to fire blight was identified in cross combinations of “Doyenné du Comice” with P. pyrifolia 6, and contributed by the major gene, with P. ussuriensis 18 and P. calleryana 12. Transgressive segregation was observed within the progenies of susceptible, moderately susceptible and resistant parents.展开更多
Bacterial-fungal interactions are widespread in nature.We observed that pear orchards affected by Cytospora pyri(formerly Valsa pyri)were often accompanied with Erwinia amylovora.However,the relationship of the two pa...Bacterial-fungal interactions are widespread in nature.We observed that pear orchards affected by Cytospora pyri(formerly Valsa pyri)were often accompanied with Erwinia amylovora.However,the relationship of the two pathogens was unclear.The objective of this study was to determine whether the synergistic effect exists between E.amylovora and C.pyri.We first analyzed the coexistence frequencies of E.amylovora and C.pyri in pear trees.Virulence of the two pathogens,growth,physical interactions,amylovoran production,and expression of genes for amylovoran biosynthesis were conducted.Our results showed that E.amylovora and C.pyri could coexist on the same lesion and caused much more severe disease.We also found that E.amylovora could physically attach to C.pyri and the expression of amylovoran biosynthesis genes were up-regulated with fungal metabolite treatment.These results indicate that E.amylovora and C.pyri can cooperatively interact,which provides C.pyri with an opportunity to promote bacterial dispersal and production of virulence factor in E.amylovora.展开更多
文摘Since several Asian pear species are considered to be potential source of fire blight resistance, we crossed “Doyenné du Comice”, the susceptible European cultivar, with four Asian pear species. The aim of the study was to establish the level of resistance of each genotype and the mode of transmission of fire blight resistance to each F1 full-sib progeny. The best sources of resistance were P. ussuriensis 18 and P. ussuriensis var. ovoidea 8 ranked to resistant and highly resistant, respectively. Although pear resistance to fire blight is suggested to be polygenic, distribution of phenotypes in “Doyenné du Comice” × P. ussuriensis var. ovoidea 8 hybrid family suggests the possibility of monogenic inheritance with the dominance of resistance derived from P. ussuriensis var. ovoidea 8. Polygenic inheritance of pear resistance to fire blight was identified in cross combinations of “Doyenné du Comice” with P. pyrifolia 6, and contributed by the major gene, with P. ussuriensis 18 and P. calleryana 12. Transgressive segregation was observed within the progenies of susceptible, moderately susceptible and resistant parents.
基金supported by the Major Science and Technology Projects in Xinjiang,China(2023A02006).
文摘Bacterial-fungal interactions are widespread in nature.We observed that pear orchards affected by Cytospora pyri(formerly Valsa pyri)were often accompanied with Erwinia amylovora.However,the relationship of the two pathogens was unclear.The objective of this study was to determine whether the synergistic effect exists between E.amylovora and C.pyri.We first analyzed the coexistence frequencies of E.amylovora and C.pyri in pear trees.Virulence of the two pathogens,growth,physical interactions,amylovoran production,and expression of genes for amylovoran biosynthesis were conducted.Our results showed that E.amylovora and C.pyri could coexist on the same lesion and caused much more severe disease.We also found that E.amylovora could physically attach to C.pyri and the expression of amylovoran biosynthesis genes were up-regulated with fungal metabolite treatment.These results indicate that E.amylovora and C.pyri can cooperatively interact,which provides C.pyri with an opportunity to promote bacterial dispersal and production of virulence factor in E.amylovora.
