Sclerotium rolfsii Sacc. is a destructive soilborne fungal pathogen with a wide host range that includes peanuts. Biological control offers an interesting alternative to fungicides for sustainable management of soilbo...Sclerotium rolfsii Sacc. is a destructive soilborne fungal pathogen with a wide host range that includes peanuts. Biological control offers an interesting alternative to fungicides for sustainable management of soilborne diseases. The current investigation is aimed at evaluating one potential biocontrol agent Streptomyces sp. RP1 A-12 for growth promotion and the management of peanut stem rot disease caused by S. rolfsii under field conditions. Preliminary studies conducted under in vitro and the greenhouse conditions showed promising results against the stem rot pathogen. Further in vitro and pot experiments conducted to assess Streptomyces sp. RP1 A-12 for its growth promoting abilities using whole organisms have shown an increase in seed germination, root and shoot length. Other parameters like nodule number and plant biomass were also significantly increased over control treatments indicating that the test bioagent possesses growth promoting abilities along with disease suppression capabilities. Subsequently field studies were carried out for two consecutive rainy seasons. The bioagent was applied as whole organism and partially purified crude metabolites. Results indicate the bioagent reduced stem rot disease incidence by 64–67% and 22–49% respectively in two field trials conducted with notable increase in yield. Partially purified Streptomyces sp. RP1 A-12 metabolites exhibited an even greater effect in reducing the incidence and severity of stem rot compared to the pathogen inoculated control.展开更多
[Objectives]This study was conducted to improve the quality of straw returning to the field,enhance wheat disease resistance and ensure high and stable yield of wheat.[Methods]The effects of four returning modes on wh...[Objectives]This study was conducted to improve the quality of straw returning to the field,enhance wheat disease resistance and ensure high and stable yield of wheat.[Methods]The effects of four returning modes on wheat stem rot and yield were studied by observation and experiments.[Results]The incidence rate and disease index of stem rot and white head rate of wheat were significantly reduced and the yield was significantly increased by adopting the method of straw returning to the field with the separation of"returning and seeding".The incidence rate and disease index of stem rot and white head rate of wheat were higher than those of the CK and the yield was significantly reduced when adopting the straw returning method of direct sowing.Treatment T_(1)(after maize was harvested,fertilizers,a nutrient-loaded microbial agent and a soil conditioner were evenly spread on the surface of straw,which was then returned to the field using a straw returning machine twice,and then ploughing,soil preparation and wheat sowing were carried out)showed an incidence rate of wheat crown rot 54.8%lower than that of the CK and a white head rate 87.5%lower than that of the CK,and the yield was 2305 kg/hm^(2) higher than that of the CK.[Conclusions]Straw returning can increase soil organic matter content,reduce soil bulk density,enhance soil respiration,and improve wheat disease resistance and yield.展开更多
Southern stem rot,caused by Sclerotium rolfsii Sacc.,is a destructive soil fungal disease of peanut in China and other countries.To evaluate resistant germplasm,a total of 256 peanut accessions were investigated on th...Southern stem rot,caused by Sclerotium rolfsii Sacc.,is a destructive soil fungal disease of peanut in China and other countries.To evaluate resistant germplasm,a total of 256 peanut accessions were investigated on their resistance to southern stem rot in 3 environments by artificial inoculation.Variance analysis indicated that disease index was significantly influenced by environment,genotype and genotypeenvironment interactions.Peanut accessions of var.vulgaris type exhibited higher resistance to southern stem rot.Disease index was significantly negatively correlated with linoleic acid content,while positively correlated with oleic acid content.Six resistant accessions were identified,including Hua 28,Shandongzai,ICG 6326,Quanhua 7,Quanhua 9 and Guihua 836,with their disease indexes under 40 and mortality were less than 30%in the three environments.The identified resistant accessions showed the great potential to be applied in resistant peanut breeding,and would be good genetic resources for enhancing the resistance to southern stem rot.展开更多
The toxicities of several fungicides to Pythium ultimum were determined by the method of mycelia growth. The results showed that hymexazol, Ovraclostrobin＋ Metiram, copper calcium sulphate, Thiophamate-merhyl and Fam...The toxicities of several fungicides to Pythium ultimum were determined by the method of mycelia growth. The results showed that hymexazol, Ovraclostrobin＋ Metiram, copper calcium sulphate, Thiophamate-merhyl and Famoxadone＋Cymoxanil all showed good inhibitory effects, of which Hymexazol was the best one with the ECho of 2.631 2 mg/L, followed by Ovractostrobin＋Metiram, whose ECso was 5.303 3 mg/L, and the effects of other fungicides were relatively poor. In the field fungicide screening test, the combination of 70% hymexazol wettable powder and 70% Thiophamate-merhyl had the control efficiency of 95.57%, which was better than the other test combinations, and it was applicable in the field control of tomato basal stem rot.展开更多
Peanut stem rot caused by Sclerotium rolfsii is a soil-borne disease,and it has become the main disease of peanut in Yimeng mountainous area.S.rolfsii survives the winter as mycelia and sclerotia in soil and debris,be...Peanut stem rot caused by Sclerotium rolfsii is a soil-borne disease,and it has become the main disease of peanut in Yimeng mountainous area.S.rolfsii survives the winter as mycelia and sclerotia in soil and debris,becoming the primary source of infection in the following year.The disease resistance of peanut varieties,high temperature and humidity,and cultivation measures are the pathogenic factors affecting the occurrence of peanut stem rot.The disease can be effectively controlled by screening disease-resistant varieties and seed chemical treatment,improving soil by deep tillage and crop rotation,carrying out flowing water management of affected field,cutting off transmission routes,and strengthening seed dressing and triple spraying control.展开更多
Sclerotinia stem rot(SSR) caused by Sclerotinia sclerotiorum(Lib.) de Bary is one of the most devastating diseases of Brassica napus worldwide. Both SSR resistance and flowering time(FT) adaptation are major breeding ...Sclerotinia stem rot(SSR) caused by Sclerotinia sclerotiorum(Lib.) de Bary is one of the most devastating diseases of Brassica napus worldwide. Both SSR resistance and flowering time(FT) adaptation are major breeding goals in B. napus. However, early maturing rapeseed varieties, which are important for rice-rapeseed rotation in China, are often highly susceptible to SSR. Here, we found that SSR resistance was significantly negatively correlated with FT in a natural population containing 521 rapeseed inbred lines and a double haploid(DH) population with 150 individual lines, both of which had great variation in FT. Four chromosomal regions on A2, A6, C2, and C8 affecting both SSR resistance and FT were identified using quantitative trait loci(QTL) mapping after constructing a high-density genetic map based on single nucleotide polymorphism markers in the DH population.Furthermore, we aligned QTL for the two traits identified in the present and previous studies to the B. napus reference genome, and identified four colocalized QTL hotspots of SSR resistance and FT on A2(0–7.7 Mb), A3(0.8–7.5 Mb), C2(0–15.2 Mb), and C6(20.2–36.6 Mb). Our results revealed a genetic link between SSR resistance and FT in B.napus, which should facilitate the development of effective strategies in both early maturing and SSR resistance breeding and in map-based cloning of SSR resistance QTL.展开更多
The palm, Elaeis guineensis, has its origins in Africa but is planted on a commercial basis in several countries. Statistics for 2002 showed that in the lead for land mass under oil palm cultivation is Indonesia, at 3...The palm, Elaeis guineensis, has its origins in Africa but is planted on a commercial basis in several countries. Statistics for 2002 showed that in the lead for land mass under oil palm cultivation is Indonesia, at 3,769,000. ha, followed by Malaysia at 3,376,000. ha; however, the world’s leading producer of palm oil is still Malaysia, since the 1970’s. Both countries are predicted to produce 82.4% of the world’s palm oil production by the year 2005. However, the palm is susceptible to basal stem rot, a devastating disease which results in direct loss of field stands and to which no effective chemical control is yet available. Caused by Ganoderma boninense, infected palms appear symptomless, at the first sign of disease, at least 50% of the internal trunk tissue stem would have actually rotted. This study investigated the efficacy of Trichoderma harzianum (isolate FA 1132) as a biological control agent, using 6-month old oil palm seedlings as models and the experiment performed in a greenhouse at 29- 30 ℃. ambient conditions. The plants were artificially infected with G. boninense and a conidial suspension of 1×109-9×109 spores/mL was applied as a soil drench at 1L/plant every 2 weeks for 20 weeks. The parameters examined were efficacy of the biocontrol agent and the effect of Trichoderma- incorporated mulch in addition to the soil drench. Efficacy was assessed in terms disease severity index (DSI) where a higher percentage indicates a higher severity. Results showed that infection first sets in on untreated plants at week 12 and got worse progressively. The completely untreated plants were all infected and the DSI at 20 weeks after infection (wa.i.) was 92.5%. Plants given only a Trichoderma -infused food base supplement without conidial suspension gave a DSI of 70% whereas those given a conidial soil drench without supplemental food base gave a DSI of 85% at 20 w.a.i. Infected plants given a conidial treatment together with a food base supplement gave a DSI of 5% at 20 w.a.i. This investigation showed that there is potential in the use of T. harzianum (isolate FA 1132) as a biological control agent of basal stem rot and warrant further studies in its mass propagation for field trials.展开更多
[Objective]The paper was to effectively control stem base rot of sweet potato.[Method]Chemical prevention and control test against stem base rot of sweet potato were conducted for consecutive three years from 2016 to ...[Objective]The paper was to effectively control stem base rot of sweet potato.[Method]Chemical prevention and control test against stem base rot of sweet potato were conducted for consecutive three years from 2016 to 2018.[Result]The use of carbendazim or carbendazim+mancozeb,and carbendazim+embamycin had significant control effect on stem base rot of sweet potato.However,the applied concentration should be higher than the recommended concentration.Especially the concentration of 50%carbendazim WP should be no more than 300 times,and the prevention and control effect of 100 times dilution would be better.[Conclusion]The types and concentrations of prevention and control agents are determined in the test,which will provide certain basis for chemical prevention and control against stem base rot of sweet potato.展开更多
A mixture of six Georgia isolates of Phytophthora capsici (Leon.), the causal agent of phytophthora blight, were used for greenhouse mass screening of over 700 accessions of Capsicum annuum for both stem blight and fo...A mixture of six Georgia isolates of Phytophthora capsici (Leon.), the causal agent of phytophthora blight, were used for greenhouse mass screening of over 700 accessions of Capsicum annuum for both stem blight and foliar blight. From this screening, it was determined that resistance to both forms of the disease were relatively common in the germplasm, but resistance to one form of the disease was not strongly correlated to resistance to the other form. Ten accessions previously shown to possess root rot resistance were tested for resistance to stem rot and leaf blight, and were found to also be highly resistant to these forms of the disease. It appears that single accessions have resistance to foliar, stem and root rot caused by P. capsici, which may simplify breeding for resistance to all three forms of the disease.展开更多
基金Biotechnology Industry Research Assistance Council (BIRAC), a government of India enterprise, for providing financial support under Biotechnology Industry Partnership Programme (BIPP) (BT/BIPP0429/11/10)
文摘Sclerotium rolfsii Sacc. is a destructive soilborne fungal pathogen with a wide host range that includes peanuts. Biological control offers an interesting alternative to fungicides for sustainable management of soilborne diseases. The current investigation is aimed at evaluating one potential biocontrol agent Streptomyces sp. RP1 A-12 for growth promotion and the management of peanut stem rot disease caused by S. rolfsii under field conditions. Preliminary studies conducted under in vitro and the greenhouse conditions showed promising results against the stem rot pathogen. Further in vitro and pot experiments conducted to assess Streptomyces sp. RP1 A-12 for its growth promoting abilities using whole organisms have shown an increase in seed germination, root and shoot length. Other parameters like nodule number and plant biomass were also significantly increased over control treatments indicating that the test bioagent possesses growth promoting abilities along with disease suppression capabilities. Subsequently field studies were carried out for two consecutive rainy seasons. The bioagent was applied as whole organism and partially purified crude metabolites. Results indicate the bioagent reduced stem rot disease incidence by 64–67% and 22–49% respectively in two field trials conducted with notable increase in yield. Partially purified Streptomyces sp. RP1 A-12 metabolites exhibited an even greater effect in reducing the incidence and severity of stem rot compared to the pathogen inoculated control.
基金Supported by Shaanxi Provincial Innovation Capability Support Program(2019XY-03)Shaanxi Provincial Key R&D Program(2019ZDLNY01-05-02)+3 种基金Key R&D Project of Guangxi Zhuang Autonomous Region(GK AB19259016)Scientific and Technological Innovation Program of Shaanxi Academy of Forestry(SXLK2020-0218)Xi’an Science and Technology Program(20193051YF039N039)Xianyang Key R&D Program(2021DYF-GY-0008)。
文摘[Objectives]This study was conducted to improve the quality of straw returning to the field,enhance wheat disease resistance and ensure high and stable yield of wheat.[Methods]The effects of four returning modes on wheat stem rot and yield were studied by observation and experiments.[Results]The incidence rate and disease index of stem rot and white head rate of wheat were significantly reduced and the yield was significantly increased by adopting the method of straw returning to the field with the separation of"returning and seeding".The incidence rate and disease index of stem rot and white head rate of wheat were higher than those of the CK and the yield was significantly reduced when adopting the straw returning method of direct sowing.Treatment T_(1)(after maize was harvested,fertilizers,a nutrient-loaded microbial agent and a soil conditioner were evenly spread on the surface of straw,which was then returned to the field using a straw returning machine twice,and then ploughing,soil preparation and wheat sowing were carried out)showed an incidence rate of wheat crown rot 54.8%lower than that of the CK and a white head rate 87.5%lower than that of the CK,and the yield was 2305 kg/hm^(2) higher than that of the CK.[Conclusions]Straw returning can increase soil organic matter content,reduce soil bulk density,enhance soil respiration,and improve wheat disease resistance and yield.
基金This research was supported by National Natural Science Foundation of China(Grant No.31971981)and China Agriculturel Research System,(CARS-13).
文摘Southern stem rot,caused by Sclerotium rolfsii Sacc.,is a destructive soil fungal disease of peanut in China and other countries.To evaluate resistant germplasm,a total of 256 peanut accessions were investigated on their resistance to southern stem rot in 3 environments by artificial inoculation.Variance analysis indicated that disease index was significantly influenced by environment,genotype and genotypeenvironment interactions.Peanut accessions of var.vulgaris type exhibited higher resistance to southern stem rot.Disease index was significantly negatively correlated with linoleic acid content,while positively correlated with oleic acid content.Six resistant accessions were identified,including Hua 28,Shandongzai,ICG 6326,Quanhua 7,Quanhua 9 and Guihua 836,with their disease indexes under 40 and mortality were less than 30%in the three environments.The identified resistant accessions showed the great potential to be applied in resistant peanut breeding,and would be good genetic resources for enhancing the resistance to southern stem rot.
基金Supported by the Major agriculture application technology innovation project of Shandong Province"Establishment and demonstration of eco efficient and safe production technology model of protected vegetable"Major Scientific and Technological Innovation Project of Shandong Academy of Agricultural Sciences(No.2014CXZ07)+3 种基金the Agricultural Science and Technology Innovation Project of Shandong Academy of Agricultural Sciences(CXGC2016B11,CXGC2016A09)Special Fund for Agro-scientific Research in the Public Interest(201503112)the Major Project of National Agricultural Product Quality Safety Risk Assessment(GJFP2016013)~~
文摘The toxicities of several fungicides to Pythium ultimum were determined by the method of mycelia growth. The results showed that hymexazol, Ovraclostrobin＋ Metiram, copper calcium sulphate, Thiophamate-merhyl and Famoxadone＋Cymoxanil all showed good inhibitory effects, of which Hymexazol was the best one with the ECho of 2.631 2 mg/L, followed by Ovractostrobin＋Metiram, whose ECso was 5.303 3 mg/L, and the effects of other fungicides were relatively poor. In the field fungicide screening test, the combination of 70% hymexazol wettable powder and 70% Thiophamate-merhyl had the control efficiency of 95.57%, which was better than the other test combinations, and it was applicable in the field control of tomato basal stem rot.
基金Peanut Innovation Team Project of Shandong Agricultural Industry Research System(SDAIT-05-022)Special Fund Project of Agricultural Technology Extension of Shandong Province(SDTG-2016-08).
文摘Peanut stem rot caused by Sclerotium rolfsii is a soil-borne disease,and it has become the main disease of peanut in Yimeng mountainous area.S.rolfsii survives the winter as mycelia and sclerotia in soil and debris,becoming the primary source of infection in the following year.The disease resistance of peanut varieties,high temperature and humidity,and cultivation measures are the pathogenic factors affecting the occurrence of peanut stem rot.The disease can be effectively controlled by screening disease-resistant varieties and seed chemical treatment,improving soil by deep tillage and crop rotation,carrying out flowing water management of affected field,cutting off transmission routes,and strengthening seed dressing and triple spraying control.
基金supported by the National Natural Science Foundation of China(31671725,31601330,31330057)the National Key Basic Research Program of China(2015CB150201)+1 种基金Science&Technology Special Project of Guizhou Academy of Agricultural Sciences([2014] 014,[2017] 08)the China Postdoctoral Science Foundation(2015M581867,2016T90514)
文摘Sclerotinia stem rot(SSR) caused by Sclerotinia sclerotiorum(Lib.) de Bary is one of the most devastating diseases of Brassica napus worldwide. Both SSR resistance and flowering time(FT) adaptation are major breeding goals in B. napus. However, early maturing rapeseed varieties, which are important for rice-rapeseed rotation in China, are often highly susceptible to SSR. Here, we found that SSR resistance was significantly negatively correlated with FT in a natural population containing 521 rapeseed inbred lines and a double haploid(DH) population with 150 individual lines, both of which had great variation in FT. Four chromosomal regions on A2, A6, C2, and C8 affecting both SSR resistance and FT were identified using quantitative trait loci(QTL) mapping after constructing a high-density genetic map based on single nucleotide polymorphism markers in the DH population.Furthermore, we aligned QTL for the two traits identified in the present and previous studies to the B. napus reference genome, and identified four colocalized QTL hotspots of SSR resistance and FT on A2(0–7.7 Mb), A3(0.8–7.5 Mb), C2(0–15.2 Mb), and C6(20.2–36.6 Mb). Our results revealed a genetic link between SSR resistance and FT in B.napus, which should facilitate the development of effective strategies in both early maturing and SSR resistance breeding and in map-based cloning of SSR resistance QTL.
文摘The palm, Elaeis guineensis, has its origins in Africa but is planted on a commercial basis in several countries. Statistics for 2002 showed that in the lead for land mass under oil palm cultivation is Indonesia, at 3,769,000. ha, followed by Malaysia at 3,376,000. ha; however, the world’s leading producer of palm oil is still Malaysia, since the 1970’s. Both countries are predicted to produce 82.4% of the world’s palm oil production by the year 2005. However, the palm is susceptible to basal stem rot, a devastating disease which results in direct loss of field stands and to which no effective chemical control is yet available. Caused by Ganoderma boninense, infected palms appear symptomless, at the first sign of disease, at least 50% of the internal trunk tissue stem would have actually rotted. This study investigated the efficacy of Trichoderma harzianum (isolate FA 1132) as a biological control agent, using 6-month old oil palm seedlings as models and the experiment performed in a greenhouse at 29- 30 ℃. ambient conditions. The plants were artificially infected with G. boninense and a conidial suspension of 1×109-9×109 spores/mL was applied as a soil drench at 1L/plant every 2 weeks for 20 weeks. The parameters examined were efficacy of the biocontrol agent and the effect of Trichoderma- incorporated mulch in addition to the soil drench. Efficacy was assessed in terms disease severity index (DSI) where a higher percentage indicates a higher severity. Results showed that infection first sets in on untreated plants at week 12 and got worse progressively. The completely untreated plants were all infected and the DSI at 20 weeks after infection (wa.i.) was 92.5%. Plants given only a Trichoderma -infused food base supplement without conidial suspension gave a DSI of 70% whereas those given a conidial soil drench without supplemental food base gave a DSI of 85% at 20 w.a.i. Infected plants given a conidial treatment together with a food base supplement gave a DSI of 5% at 20 w.a.i. This investigation showed that there is potential in the use of T. harzianum (isolate FA 1132) as a biological control agent of basal stem rot and warrant further studies in its mass propagation for field trials.
基金Major Science and Technology Project for New Variety Breeding of Agriculture(Grain)in Zhejiang Province"Sweet Potato,Yam Germplasm Screening and New Variety Breeding"(2016C 02050-7-3)Key Agricultural Science and Technology Project of Taizhou City"Study on Pathogen Identification,Occurrence Regularity and Prevention and Control Technology of Sweet Potato Stem Base Rot(1701ny12)+2 种基金China Agricultural(Sweet Potato)Industry Research System“Fresh Sweet Potato Improvement"(CARS-10-C-17)Project of Guangzhou Comprehensive Test Station(CARS-10-B-4)2017 Special Project on Agricultural Development and Rural Work in Guangdong Province"Creation and Application of New Sweet Potato Varieties for High Quality and Resistance".
文摘[Objective]The paper was to effectively control stem base rot of sweet potato.[Method]Chemical prevention and control test against stem base rot of sweet potato were conducted for consecutive three years from 2016 to 2018.[Result]The use of carbendazim or carbendazim+mancozeb,and carbendazim+embamycin had significant control effect on stem base rot of sweet potato.However,the applied concentration should be higher than the recommended concentration.Especially the concentration of 50%carbendazim WP should be no more than 300 times,and the prevention and control effect of 100 times dilution would be better.[Conclusion]The types and concentrations of prevention and control agents are determined in the test,which will provide certain basis for chemical prevention and control against stem base rot of sweet potato.
文摘A mixture of six Georgia isolates of Phytophthora capsici (Leon.), the causal agent of phytophthora blight, were used for greenhouse mass screening of over 700 accessions of Capsicum annuum for both stem blight and foliar blight. From this screening, it was determined that resistance to both forms of the disease were relatively common in the germplasm, but resistance to one form of the disease was not strongly correlated to resistance to the other form. Ten accessions previously shown to possess root rot resistance were tested for resistance to stem rot and leaf blight, and were found to also be highly resistant to these forms of the disease. It appears that single accessions have resistance to foliar, stem and root rot caused by P. capsici, which may simplify breeding for resistance to all three forms of the disease.
