The burrowing nematode （Radopholus similis） is one of the main quarantine pests in China, and the risk of invasion posed by this nematode is becoming more and more serious with regard to the international trade bein...The burrowing nematode （Radopholus similis） is one of the main quarantine pests in China, and the risk of invasion posed by this nematode is becoming more and more serious with regard to the international trade being intensified day by day. It is urgent to analyse the potential geographic distribution of R. similis in China. Genetic algorithm for rule-set prediction modeling system （GARP） and maximum entropy （MAXENT）, the two niche models which have been widely used to predict the potential geographic distribution of alien species, were used to predict the distribution of R. similis in China. We also presented a model comparison of the results by both threshold-dependent and threshold-independent evaluations. It has been shown that the two niche models could be used to predict the potential distribution of R. similis reliably. The potential distribution of R. similis should be constricted within the south of China, such as Hainan, Guangdong, Guangxi, Fujian, Yunnan provinces, and Taiwan of China. The MAXENT gives a better prediction than that of GARP. R. similis can be introduced to China by flowers and nursery stock＇s international shipping. The predicted results indicate that R. similis can occur in south coastal area of China and Yunnan Province, which are the main flower and nursery stock＇s import-export areas in China. Consequently, a strong quarantine program is needed at the ports of such areas to prevent the pest from being introduced to China.展开更多
Potassium(K),an important nutrient element,can improve the stress resistance/tolerance of crops.The application of K in resisting plant-parasitic nematodes shows that the K treatment can reduce the occurrence of nemat...Potassium(K),an important nutrient element,can improve the stress resistance/tolerance of crops.The application of K in resisting plant-parasitic nematodes shows that the K treatment can reduce the occurrence of nematode diseases and increase crop yield.However,data on K_(2)SO_(4)induced rice resistance against the root-knot nematode Meloidogyne graminicola are still lacking.In this work,K_(2)SO_(4)treatment reduced galls and nematodes in rice plants and delayed the development of nematodes.Rather than affecting the attractiveness of roots to nematodes and the morphological phenotype of giant cells at feeding sites,such an effect is achieved by rapidly priming hydrogen peroxide(H_(2)O_(2))accumulation and increasing callose deposition.Meanwhile,galls and nematodes in rice roots were more in the potassium channel OsAKT11 and transporter OsHAK5 gene-deficient plants than in wild-type,while the K_(2)SO_(4)-induced resistance showed weaker in the defective plants.In addition,during the process of nematode infection,the expression of jasmonic acid(JA)/ethylene(ET)/brassinolide(BR)signaling pathway-related genes and pathogenesis-related(PR)genes OsPR1 a/OsPR1 b was up-regulated in rice after K_(2)SO_(4)treatment.In conclusion,K_(2)SO_(4)induced rice resistance against M.graminicola.The mechanism of inducing resistance was to prime the basal defense and required the participation of the K^(+)channel and transporter in rice.These laid a foundation for further study on the mechanism of rice defense against nematodes and the rational use of potassium fertilizer on improving rice resistance against nematodes in the field.展开更多
文摘The burrowing nematode （Radopholus similis） is one of the main quarantine pests in China, and the risk of invasion posed by this nematode is becoming more and more serious with regard to the international trade being intensified day by day. It is urgent to analyse the potential geographic distribution of R. similis in China. Genetic algorithm for rule-set prediction modeling system （GARP） and maximum entropy （MAXENT）, the two niche models which have been widely used to predict the potential geographic distribution of alien species, were used to predict the distribution of R. similis in China. We also presented a model comparison of the results by both threshold-dependent and threshold-independent evaluations. It has been shown that the two niche models could be used to predict the potential distribution of R. similis reliably. The potential distribution of R. similis should be constricted within the south of China, such as Hainan, Guangdong, Guangxi, Fujian, Yunnan provinces, and Taiwan of China. The MAXENT gives a better prediction than that of GARP. R. similis can be introduced to China by flowers and nursery stock＇s international shipping. The predicted results indicate that R. similis can occur in south coastal area of China and Yunnan Province, which are the main flower and nursery stock＇s import-export areas in China. Consequently, a strong quarantine program is needed at the ports of such areas to prevent the pest from being introduced to China.
基金supported by the Natural Science Foundation of China(32172382,31801716,and 31571986)the National Key Research and Development Program of China(2021YFC2600404)the Scientific Research Project of Hunan Provincial Department of Education of China(19B259)。
文摘Potassium(K),an important nutrient element,can improve the stress resistance/tolerance of crops.The application of K in resisting plant-parasitic nematodes shows that the K treatment can reduce the occurrence of nematode diseases and increase crop yield.However,data on K_(2)SO_(4)induced rice resistance against the root-knot nematode Meloidogyne graminicola are still lacking.In this work,K_(2)SO_(4)treatment reduced galls and nematodes in rice plants and delayed the development of nematodes.Rather than affecting the attractiveness of roots to nematodes and the morphological phenotype of giant cells at feeding sites,such an effect is achieved by rapidly priming hydrogen peroxide(H_(2)O_(2))accumulation and increasing callose deposition.Meanwhile,galls and nematodes in rice roots were more in the potassium channel OsAKT11 and transporter OsHAK5 gene-deficient plants than in wild-type,while the K_(2)SO_(4)-induced resistance showed weaker in the defective plants.In addition,during the process of nematode infection,the expression of jasmonic acid(JA)/ethylene(ET)/brassinolide(BR)signaling pathway-related genes and pathogenesis-related(PR)genes OsPR1 a/OsPR1 b was up-regulated in rice after K_(2)SO_(4)treatment.In conclusion,K_(2)SO_(4)induced rice resistance against M.graminicola.The mechanism of inducing resistance was to prime the basal defense and required the participation of the K^(+)channel and transporter in rice.These laid a foundation for further study on the mechanism of rice defense against nematodes and the rational use of potassium fertilizer on improving rice resistance against nematodes in the field.
