Rice spikelet rot disease(RSRD), caused by Fusarium proliferatum, is an emerging disease. So far, the effects of diseased rice floral organs as well as the primary infection sites and stages of this pathogen are not d...Rice spikelet rot disease(RSRD), caused by Fusarium proliferatum, is an emerging disease. So far, the effects of diseased rice floral organs as well as the primary infection sites and stages of this pathogen are not determined. We investigated changes in the floral organs, along with the infection processes of the pathogen in plants inoculated with F. proliferatum and labelled with a green fluorescent protein during different growth stages of rice. The results showed that RSRD is not a systemic infectious disease, which has negative effects on the fertility of the infected rice. F. proliferatum caused brown colored anthers, crinkled pistils and ovaries, pollen grain deformities and anther indehiscence. The number of pollen grains on the stigmas decreased significantly in the infected spikelets, and the anther dehiscence and seed-setting rate successively declined by 69% and 73%, respectively, as a result of the infection. The initial infection stage occurred at the pollen cell maturity stage, and the primary invasion sites were determined to be the anthers of rice. It was noted that the pathogen mainly damaged the pollen cells, and with the exception of the filaments, proceeded to colonize the pistils and endosperm.展开更多
Shifts in the realized niches of exotic species may play an important role in their invasion.Galinsoga quadriradiata has invaded China widely and occupied many climate zones that are different from its native range.We...Shifts in the realized niches of exotic species may play an important role in their invasion.Galinsoga quadriradiata has invaded China widely and occupied many climate zones that are different from its native range.We addressed the climatic niche shift of G.quadriradiata and evaluated how this could contribute to its invasion in China.We used the Maxent model to predict the potential distribution of G.quadriradiata using its native and invaded range occurrences and climatic variables.Principal component analysis was conducted to measure climatic niche shifts of G.quadriradiata during its invasion in China.The models revealed only 32.7%niche overlap between the native and invasive populations.The niche similarity of the two populations was significantly low(Schoener’s D=0.093,P<0.005),suggesting the occurrence of a niche shift.The envelop and center of the realized climatic niche in China has shifted to lower temperature and less precipitation compared to that in its native range.The majority of invaded areas in southern China are in the stabilizing zone,whereas the colonization and adaptation zones are predicted to be at the leading edge of G.quadriradiata invasion in northern China.This suggests that the regional distribution of G.quadriradiata may be in a quasi-equilibrium state,and that the species continues to invade environmentally suitable areas.Alterations in G.quadriradiata’s niche would help to explain why this species is so invasive in China.展开更多
基金supported by the National Key Research and Development Program of China(Grant Nos.2016YFD0200801,2017YFD0300409 and 2018YFD 020030405)National Natural Science Foundation of China(Grant No.31800133)+5 种基金Zhejiang Provincial Natural Science Foundation of China(Grant No.LQ18C140005)Agriculture,Rural Areas,and Farmers Six-Party Science and Technology Cooperation Projects of Zhejiang Province(Grant No.CTZB-F160728AWZ-SNY1-4)the Innovation Project of the Chinese Academy of Agricultural Sciences(CAAS)the Collaborative Innovation Project of the CAAS(Grant No.CAAS-XTCX2016012)the Core Research Budget of Nonprofit Governmental Research Insititute of China(Grant No.2014RG005-2)Zhejiang Key Research and Development Program of China(Grant No.2019C02018)
文摘Rice spikelet rot disease(RSRD), caused by Fusarium proliferatum, is an emerging disease. So far, the effects of diseased rice floral organs as well as the primary infection sites and stages of this pathogen are not determined. We investigated changes in the floral organs, along with the infection processes of the pathogen in plants inoculated with F. proliferatum and labelled with a green fluorescent protein during different growth stages of rice. The results showed that RSRD is not a systemic infectious disease, which has negative effects on the fertility of the infected rice. F. proliferatum caused brown colored anthers, crinkled pistils and ovaries, pollen grain deformities and anther indehiscence. The number of pollen grains on the stigmas decreased significantly in the infected spikelets, and the anther dehiscence and seed-setting rate successively declined by 69% and 73%, respectively, as a result of the infection. The initial infection stage occurred at the pollen cell maturity stage, and the primary invasion sites were determined to be the anthers of rice. It was noted that the pathogen mainly damaged the pollen cells, and with the exception of the filaments, proceeded to colonize the pistils and endosperm.
基金supported by the National Natural Science Foundation of China(32071520,31600445 and 31570425)the Natural Science Basic Research Plan in Shaanxi Province of China(2020JM-286)+2 种基金the Central University Innovation Team Project(GK202001006)the Fundamental Research Funds for the Central Universities(GK202103072 and 2020CSLY014)the Research Funds of Shaanxi Association for Science and Technology,and the Research Funds of Xi’an Association for Science and Technology(202113).
文摘Shifts in the realized niches of exotic species may play an important role in their invasion.Galinsoga quadriradiata has invaded China widely and occupied many climate zones that are different from its native range.We addressed the climatic niche shift of G.quadriradiata and evaluated how this could contribute to its invasion in China.We used the Maxent model to predict the potential distribution of G.quadriradiata using its native and invaded range occurrences and climatic variables.Principal component analysis was conducted to measure climatic niche shifts of G.quadriradiata during its invasion in China.The models revealed only 32.7%niche overlap between the native and invasive populations.The niche similarity of the two populations was significantly low(Schoener’s D=0.093,P<0.005),suggesting the occurrence of a niche shift.The envelop and center of the realized climatic niche in China has shifted to lower temperature and less precipitation compared to that in its native range.The majority of invaded areas in southern China are in the stabilizing zone,whereas the colonization and adaptation zones are predicted to be at the leading edge of G.quadriradiata invasion in northern China.This suggests that the regional distribution of G.quadriradiata may be in a quasi-equilibrium state,and that the species continues to invade environmentally suitable areas.Alterations in G.quadriradiata’s niche would help to explain why this species is so invasive in China.
