To confirm phytoplasma infection,samples of pomegranate(Punica granatum L.)plants showing symptoms of fasciation were collected from an orchard located in Tai’an,Shandong Province,China.A fragment of approximately 1....To confirm phytoplasma infection,samples of pomegranate(Punica granatum L.)plants showing symptoms of fasciation were collected from an orchard located in Tai’an,Shandong Province,China.A fragment of approximately 1.2 kb was amplified with universal primers targeting the phytoplasma 16S r RNA gene from symptomatic pomegranate plants,while no fragment was obtained from healthy plants.The phytoplasma associated with the disease was designated as pomegranate fasciation(Po F).Two representative phytoplasma 16S r DNA gene sequences(Po F-Ch01 and Po F-Ch02)had 100%nucleotide sequence identity.The 16S r DNA sequence of Po F-Ch01 and Po F-Ch02 showed the highest similarity(99.6%)to that of‘P.granatum’phytoplasma isolate AY-PG,which belong to 16Sr I-B.Further phylogenetic analysis showed that Po F-Ch01 and Po F-Ch02 belonged to a cluster of 16Sr I subgroup members.In silico RFLP analysis indicated that Po F-Ch01 shared the highest similarity coefficient of 0.97 with reference strains of 16Sr I-B,M and N.Actual RFLP analysis of both enzymes Bst U I and Bfa I confirmed that of the virtual RFLP analysis.Combining these results,we concluded that Po F was a member of the‘Candidatus Phytoplasma asteris’group(16Sr I),and has very close relationship with 16Sr I-B subgroup.展开更多
In flowering plants,the inflorescence meristem(IM)provides founder cells to form successive floral meristems,which are precursors of fruits and seeds.The activity and developmental progression of IM are thus critical ...In flowering plants,the inflorescence meristem(IM)provides founder cells to form successive floral meristems,which are precursors of fruits and seeds.The activity and developmental progression of IM are thus critical for yield production in seed crops.In some cereals,such as rice(Oryza sativa)and maize(Zea mays),the size of undifferentiated IM,which is located at the inflorescence apex,is positively associated with yield traits such as spikelet number.However,the relationship between IM size and yieldrelated spike traits remains unknown in the Triticeae tribe.Here we report that IM size has a negative correlation with yield traits in barley(Hordeum vulgare).Three FASCIATED EAR(FEA)orthologs,HvFEA2,HvFEA3,and HvFEA4,regulate IM size and spike morphogenesis and ultimately affect yield traits.Three HvFEAs genes are highly expressed in developing spikes,and all three loss-of-function mutants exhibit enlarged IM size,shortened spikes,and reduced spikelet number,which may lead to reduced grain yield.Natural variations identified in HvFEAs indicate selection events during barley domestication.We further reveal that HvFEA4,as a transcription factor,potentially targets multiple pathways during reproductive development,including transcriptional control,phytohormone signaling,and redox status.The roles of barley FEA genes in limiting IM size and promoting spikelet formation suggest the potential of increasing yield by manipulating IM activity.展开更多
This study addresses the hypothesis that stagnation of soybean yield on the farm can be improved by selection of a physiological trait favoring carbon assimilate partitioning to terminally placed pods versus genotypes...This study addresses the hypothesis that stagnation of soybean yield on the farm can be improved by selection of a physiological trait favoring carbon assimilate partitioning to terminally placed pods versus genotypes having axillary pods at close plant spacing.13C was fed to source-sink units comprising a leaf,axillary/terminal pods,and petioles at upper and lower positions of the stem axis in two soybean cultivars,namely Shakujo and Enrei,at different densities of populations.The cultivars differ significantly in architecture,Shakujo bearing a few hundreds of pods in close succession to one another in a terminally placed raceme,in contrast to Enrei having axillary racemes.Pod yield per plant was higher in Enrei than in Shakujo at low density,but Shakujo out-yielded Enrei at close spacing.Population density decreased yield per plant and altered the pattern of assimilate partitioning significantly within the plants for both varieties.At high density more assimilates moved to the upper parts at the cost of the lower parts.The terminally placed pods of Shakujo were advantaged to receive assimilates under density stress.No benefit was accrued to pod filling of Enrei,however,under this condition.展开更多
基金supported by National Natural Science Foundation of China (Grant No. 31401718 )the Foundation for Excellent Young Scientists of Shandong Province (Grant No. BS2013NY012 )+1 种基金Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. SRFDP, 20123702110013 BR0801 )
文摘To confirm phytoplasma infection,samples of pomegranate(Punica granatum L.)plants showing symptoms of fasciation were collected from an orchard located in Tai’an,Shandong Province,China.A fragment of approximately 1.2 kb was amplified with universal primers targeting the phytoplasma 16S r RNA gene from symptomatic pomegranate plants,while no fragment was obtained from healthy plants.The phytoplasma associated with the disease was designated as pomegranate fasciation(Po F).Two representative phytoplasma 16S r DNA gene sequences(Po F-Ch01 and Po F-Ch02)had 100%nucleotide sequence identity.The 16S r DNA sequence of Po F-Ch01 and Po F-Ch02 showed the highest similarity(99.6%)to that of‘P.granatum’phytoplasma isolate AY-PG,which belong to 16Sr I-B.Further phylogenetic analysis showed that Po F-Ch01 and Po F-Ch02 belonged to a cluster of 16Sr I subgroup members.In silico RFLP analysis indicated that Po F-Ch01 shared the highest similarity coefficient of 0.97 with reference strains of 16Sr I-B,M and N.Actual RFLP analysis of both enzymes Bst U I and Bfa I confirmed that of the virtual RFLP analysis.Combining these results,we concluded that Po F was a member of the‘Candidatus Phytoplasma asteris’group(16Sr I),and has very close relationship with 16Sr I-B subgroup.
基金financially supported by the Science and Research Grant of Southwest University of Science and Technology(19zx7146)the start-up grant from Nanjing Agricultural University(to Gang Li)+2 种基金the Australia–China Science and Research Fund Joint Research Centre grant(ACSRF48187)the Australian Research Council(DP170103352)the Waite Research Institute(WRI)of the University of Adelaide。
文摘In flowering plants,the inflorescence meristem(IM)provides founder cells to form successive floral meristems,which are precursors of fruits and seeds.The activity and developmental progression of IM are thus critical for yield production in seed crops.In some cereals,such as rice(Oryza sativa)and maize(Zea mays),the size of undifferentiated IM,which is located at the inflorescence apex,is positively associated with yield traits such as spikelet number.However,the relationship between IM size and yieldrelated spike traits remains unknown in the Triticeae tribe.Here we report that IM size has a negative correlation with yield traits in barley(Hordeum vulgare).Three FASCIATED EAR(FEA)orthologs,HvFEA2,HvFEA3,and HvFEA4,regulate IM size and spike morphogenesis and ultimately affect yield traits.Three HvFEAs genes are highly expressed in developing spikes,and all three loss-of-function mutants exhibit enlarged IM size,shortened spikes,and reduced spikelet number,which may lead to reduced grain yield.Natural variations identified in HvFEAs indicate selection events during barley domestication.We further reveal that HvFEA4,as a transcription factor,potentially targets multiple pathways during reproductive development,including transcriptional control,phytohormone signaling,and redox status.The roles of barley FEA genes in limiting IM size and promoting spikelet formation suggest the potential of increasing yield by manipulating IM activity.
文摘This study addresses the hypothesis that stagnation of soybean yield on the farm can be improved by selection of a physiological trait favoring carbon assimilate partitioning to terminally placed pods versus genotypes having axillary pods at close plant spacing.13C was fed to source-sink units comprising a leaf,axillary/terminal pods,and petioles at upper and lower positions of the stem axis in two soybean cultivars,namely Shakujo and Enrei,at different densities of populations.The cultivars differ significantly in architecture,Shakujo bearing a few hundreds of pods in close succession to one another in a terminally placed raceme,in contrast to Enrei having axillary racemes.Pod yield per plant was higher in Enrei than in Shakujo at low density,but Shakujo out-yielded Enrei at close spacing.Population density decreased yield per plant and altered the pattern of assimilate partitioning significantly within the plants for both varieties.At high density more assimilates moved to the upper parts at the cost of the lower parts.The terminally placed pods of Shakujo were advantaged to receive assimilates under density stress.No benefit was accrued to pod filling of Enrei,however,under this condition.
