[Objective] This study was conducted to determine the toxicity of 26 fungicides against Oidium heveae and the synergistic effects of their binary mixtures.[Method] The sensitivity of O.heveae to 26 fungicides was dete...[Objective] This study was conducted to determine the toxicity of 26 fungicides against Oidium heveae and the synergistic effects of their binary mixtures.[Method] The sensitivity of O.heveae to 26 fungicides was determined in vitro and in vivo by calculating EC50 values.Horsfall＇s toxicity rate was preliminarily employed to predict the type of joint action of 180 two-way mixtures,based on which the interaction level of the potentially synergistic mixtures was validated by Sun and Johnson＇s co-toxicity coefficient.[Result] Triflumizole,pyraoxystrobin,flufenoxystrobin,epoxiconazole,pyrametostrobin,flusilazole,pyraclostrobin and tetraconazole were the most potent inhibitors of both spore germination and mycelial growth.An ‘in vitro-in vivo＇ integrated strategy is proposed for screening the inhibitors of O.heveae,according to the fact that data obtained in germination experiment are able to reflect to some extent the effectiveness of fungicide confirmed by pot experiment.Results achieved by Horsfall＇s were in line with that validated by Sun and Johnson＇s,the Horsfall＇s seems to be a convenient means to assess rapidly the potential interaction type and level of fungicides in a binary mixture.Nineteen mixtures interact synergistically：epoxiconazole ＋ pyraclostrobin at the mixing ratio of 6：4,8：2;tetraconazole ＋ flufenoxystrobin at 1：9,2：8,3：7 and 4：6;triadimefon ＋ flufenoxystrobin at 9：1;triflumizole ＋ flufenoxystrobin at 8：2;flusilazole ＋pyrametostrobin at 7：3,8：2 and 9：1;tetraconazole ＋ pyrametostrobin at 6：4;triadimefon ＋ pyrametostrobin at 5：5,8：2;triflumizole ＋ pyrametostrobin at 7：3,8：2;tetraconazole ＋ pyraoxystrobin at 9：1;triflumizole ＋ pyraoxystrobin at 8：2,9：1.[Conclusion] The single fungicides and their binary mixtures are expected to serve as the alternatives to triadimefon and the alternate use of them could delay the buildup of resistant O.heveae isolate.展开更多
[Objective] The paper was to explore the herbicidal effects of Periconia heveae culture filtrate on Mikania micrantha. [Method] Through indoor bioassay method, the inhibition effects of culture filtrates of seven spec...[Objective] The paper was to explore the herbicidal effects of Periconia heveae culture filtrate on Mikania micrantha. [Method] Through indoor bioassay method, the inhibition effects of culture filtrates of seven species of plant disease fungi on seed germination and seedling growth of M. micrantha were studied, and the security of P. heveae culture filtrate on pepper （Capsicum annuum） and tomato （Solanum lycopersicum） was also evaluated. [Result] The culture filtrates of P. heveae had strong inhibition effects on seed germination and the growth of root, shoot and seedling of M. micrantha, and the inhibition rates were 72.7%, 93.0%, 32.4%, and 54.6% （fresh weight）, respectively. Security tests showed that culture filtrates of P. heveae were safe to seed germination and root and shoot growth of tomato, and the growth rate had no significant difference with control, but they inhibited seed germination of pepper. [Conclusion] As potential biological herbicide, the culture filtrate and metabolites of P. heveae is worthy of further development. .展开更多
The relationship between the effect of exogenous jasmonic acid (JA) on the induction of secondary laticifer differentiation and the distribution of JA in the seedling of Hevea brasiliensis Mull. Arg. was investigated ...The relationship between the effect of exogenous jasmonic acid (JA) on the induction of secondary laticifer differentiation and the distribution of JA in the seedling of Hevea brasiliensis Mull. Arg. was investigated with the aid of experimental morphological and radioisotope technique. Most radioactivity of H-3-JA sustained in treated site within one hour while no radioactivity was detected in new shoot and the radioactivity in upper leaf was much less than that in the parts below the treated site, suggesting that JA was mainly transported downwards in the shoot of H brasiliensis. Mechanical wounding hindered the entrance of exogenous JA remarkably while held back the entered JA to the regions around wounded site. The effect of exogenous JA and mechanical wounding on the induction of the secondary laticifer differentiation was limited to treated site where high level of JA was expected. Mechanical wounding reduced the effect of exogenous JA on the differentiation of secondary laticifer, which could be ascribed to the hindrance of mechanical wounding to the entrance of exogenous JA. It was concluded from the combined data that a high accumulation of JA was required for inducing the secondary laticifer differentiation in H. brasiliensis.展开更多
[Objective]The aim was to study on the characteristics of soil organic carbon and nitrogen in rubber （Hevea brasiliensis Muell-Arg） plantations at different age stages in the western region of Hainan Island,so as to...[Objective]The aim was to study on the characteristics of soil organic carbon and nitrogen in rubber （Hevea brasiliensis Muell-Arg） plantations at different age stages in the western region of Hainan Island,so as to evaluate the ecological benefits of rubber plantations and provide basic data for studying the effect of tropical land utilization/cover change on the global carbon and nitrogen cycle. [Method]The situs was in Danzhou city,western region of Hainan Island,and the samples were four kinds of rubber plantations soil at different ages and one kind of control check （pepper,Piper nigrum L.） soil. In this research,four quadrats were set up in each sample,and the size of each was 20 cm×20 cm. Four specimens were gathered from four layers of 0-15,15-30,30-45,45-60,and the average of them was the last analysis result of each sample. Soil density was measured by cutting ring method,soil containing and hygroscopic water was detected by oven drying method,soil organic carbon （SOC） was measured by low temperature heated outside potassium dichromate oxidation-colorimetry method,and soil total nitrogen （STN） was detected by semimicro Kjeldahl method. [Result]SOC contents of different layers in rubber plantations soil at different age stages （including the CK pepper soil,the same as below） varied little,and the content of SOC in surface layer （0-15 cm） was higher,while the underlayer （45-60 cm） was lower than the average value; there was significant difference in SOC content among different kinds of soil,and the content was of 6.03-7.78 g/kg,tapping young trees （7 years） CK pepper mature age trees （30 years） prophase of young trees （2 years） tapping trees （16 years）; there was no significant difference in SOC storage among different kinds of soil,and the storage was of 61.33-74.29 t/hm2,mature age trees （30 years） tapping young trees （7 years） prophase of young trees （2 years） CK pepper tapping trees （16 years）; there was significant difference in STN content among rubber plantations soil at different age stages,the content was of 410.86-664.14 mg/kg2,CK pepper tapping young trees （7 years） prophase of young trees （2 years） mature age trees （30 years） tapping trees （16 years）,and STN content of tapping trees （16 years） soil was extremely lowest; there was significant difference in C/N ratio among different kinds of soil,the ratio was of 10.94-14.47,and the ratio of tapping trees （16 years） mature age trees （30 years） tapping young trees （7 years） CK pepper prophase of young trees （2 years）. [Conclusion]There wasn＇t unhealthy effect of rubber trees planted in tropical area on the content and storage of SOC,the content of STN and the ratio of C/N. there was no significant difference between rubber plantations and CK pepper soil,and the effects of rubber plantation on soil carbon-nitrogen was similar to that of other tropical crops （such as pepper）.展开更多
1876年,英国皇家植物园邱园（The Royal Botanic Gardens,Kew,简称邱园）将三叶橡胶（Hevea brasiliensis）幼苗送至英国在南亚、东南亚的殖民地试种,这些幼苗是邱园用从南美洲引种获得的种子繁殖出来的。橡胶在东南亚试种获得成功后,...1876年,英国皇家植物园邱园（The Royal Botanic Gardens,Kew,简称邱园）将三叶橡胶（Hevea brasiliensis）幼苗送至英国在南亚、东南亚的殖民地试种,这些幼苗是邱园用从南美洲引种获得的种子繁殖出来的。橡胶在东南亚试种获得成功后,发展成为庞大的橡胶产业,对全世界的工业、农业、交通运输、经济、社会乃至政治产生了极大的影响,也使得橡胶成为一种＂改变世界历史进程＂的植物。展开更多
Abundant microfibrillar protein inclusions were present in the lutoids of the primary laticifers in Hevea brasiliensis Mull. Arg. Two forms of the inclusions could be distinguished under the electron microscope, each ...Abundant microfibrillar protein inclusions were present in the lutoids of the primary laticifers in Hevea brasiliensis Mull. Arg. Two forms of the inclusions could be distinguished under the electron microscope, each in separate lutoids. As revealed by SDS-PAGE, the 59.5 kD and 63.5 kD proteins were the major components of the microfibrillar protein purified by isoeleettic point precipitation. Western-blotting analysis indicated that they were immunorelated with the 67 kD protein accumulated in the protein-storing cells. The 59.5 kD and 63.5 kD proteins were abundant in the uppermost part, the stem of new shoot and sustained their abundance during the growth and development of new shoot while their contents decreased remarkably in the lower parts of the trunk, accompanying by the accumulation of 3-5 kinds of proteins with low molecular weights. This fluctuating pattern suggested that the degradation of the 59.5 kD and 63.5 kD proteins had nothing to do with the new shoot growth and may be closely related to the primary laticifer differentiation. The 67 kD protein could not be detected in the young stem of new shoot when its leaves were broze-colored while the protein started to be accumulated in the stem, when the leaves of new shoot had matured, behaving like a typical vegetative storage protein.展开更多
In this study, the rubber tree clone PR107 was selected as test material,and its yields and physiological features under micro-tapping with different concentrations of ethylene were compared. The results showed that t...In this study, the rubber tree clone PR107 was selected as test material,and its yields and physiological features under micro-tapping with different concentrations of ethylene were compared. The results showed that there was no significant correlation between rubber yield and ethylene concentration applied by microtapping on PR107. Too high level of ethylene was not conducive to improvement of rubber yield. When the ethylene concentration for micro-tapping was higher than60%, physical deficiencies appeared in rubber tree PR107, the dry rubber content was reduced, and the yield was unstable. Instead, when the ethylene concentration was lower than 40%, the physiological features of PR107 were steady, the dry rubber content was stable, and the yield was relatively high.展开更多
[Objective] The aim was to look for an effective way of decreasing explants contamination in the root tissue culture of Hevea brasiliensis.[Method] In order to study root tissue culture of H.brasiliensis,new roots fro...[Objective] The aim was to look for an effective way of decreasing explants contamination in the root tissue culture of Hevea brasiliensis.[Method] In order to study root tissue culture of H.brasiliensis,new roots from forest section after treatment for one month were as explants,and 1 g/L carbendazim,75% ethanol,0.1% mercuric chloride and Yipeilong with different concentrations were used as disinfectants for roots disinfection.[Result] Before conventional disinfection,root explants were treated by 1 g/L carbendazim for 2.5 h,and disinfected by 75% ethanol for 30 s and 0.1% HgCl2 for 6 min,then cultured on the callus induction medium supplemented with 0.1% Yipeilong.The results showed that the contamination rate of explants decreased to 44.59%,and 25.60% explants survived after cultured for 30 d.[Conclusion] The study could provide theoretical foundation for the decrease of explant contamination in the root tissue culture of H.brasiliensis.展开更多
[Objective] ＂Tapping panel dryness （TPD）＂, a syndrome known as tapping incision blocked partly or entirely during latex exploiting, has become the most important factor causing great losses for rubber production. ...[Objective] ＂Tapping panel dryness （TPD）＂, a syndrome known as tapping incision blocked partly or entirely during latex exploiting, has become the most important factor causing great losses for rubber production. Aiming to elucidate the molecular mechanism of tapping panel dryness occurrence, this study carried out molecular cloning and bioinformatical analysis of a mRPL21 cDNA sequence, a gene associated with TPD. [Method] In a preliminary study, an expressed sequence tag （EST） encoding a deduced protein homologous to mitochondrial 50S ribosomal protein L21 （mRPL21）, which showed to be down-regulated in the latex of TPD-affected rubber trees, was isolated by suppression subtractive hybridization （SSH）. After ESTs assembling and RT-PCR validation, an 853 bp cDNA sequence with an open reading frame （ORF） was cloned, which was named as HbmRPL21 under GenBank accession number of HM230670. [Result] Bioinformatical analysis suggests that HbmRPL21 encodes a deduced polypeptide of 271 amino acids with a theoretical molecular weight （Mw） of 30.52 kDa and isolectric point （pI） of 8.40, and HbmRPL21 is a mitochondrion-targeted protein with a conserved domain of Ribosomal_L21p involving translation. Homology analysis reveals high amino acid sequence identity of mRPL21 from plants, while diversity of that between plant and animal kingdom. [Conclusion] This study laid the basis for further revealing the biological functions of mRPL21 in TPD-affected rubber trees.展开更多
To understand the mechanism of benzothiadiazole (BTH)-induced susceptible rubber clone resistance to powdery mildew on gene level, a differentially expressed cDNA library was constructed by suppression subtractive hyb...To understand the mechanism of benzothiadiazole (BTH)-induced susceptible rubber clone resistance to powdery mildew on gene level, a differentially expressed cDNA library was constructed by suppression subtractive hybridization (SSH) with rubber Reyan 7-33-97 clone. The constructed cDNA library was high integrity through detection of the critical processes of SSH, such as efficiency of adaptor connection, subtraction and conversion, as well as the type of recombinant genes. The positive rate was 99% after identification with random 400 white spots. The size of the cDNA clone inserted fragments was various but most in 400 bp - 1000 bp. There were 23 cDNA sequences matching the function of energy and basic metabolism, signal transduction, membrane and transport, secondary metabolism and so on after detection of the 42 positive clone sequences selected randomly from the cDNA library and comparison on nucleic acid sequences in Genbank. 7 ESTs were logged in Genbank and accession numbers were GW873071 and GW874604- GW874610. The results implicated that BTH could effectively induced rubber tree resistance to powdery mildew through increasing expresses of defense-related genes in leaves of rubber tree susceptible clone. It should provide a new approach for rubber disease management.展开更多
基金financed by the ministry of science and technology of P.R.China
文摘[Objective] This study was conducted to determine the toxicity of 26 fungicides against Oidium heveae and the synergistic effects of their binary mixtures.[Method] The sensitivity of O.heveae to 26 fungicides was determined in vitro and in vivo by calculating EC50 values.Horsfall＇s toxicity rate was preliminarily employed to predict the type of joint action of 180 two-way mixtures,based on which the interaction level of the potentially synergistic mixtures was validated by Sun and Johnson＇s co-toxicity coefficient.[Result] Triflumizole,pyraoxystrobin,flufenoxystrobin,epoxiconazole,pyrametostrobin,flusilazole,pyraclostrobin and tetraconazole were the most potent inhibitors of both spore germination and mycelial growth.An ‘in vitro-in vivo＇ integrated strategy is proposed for screening the inhibitors of O.heveae,according to the fact that data obtained in germination experiment are able to reflect to some extent the effectiveness of fungicide confirmed by pot experiment.Results achieved by Horsfall＇s were in line with that validated by Sun and Johnson＇s,the Horsfall＇s seems to be a convenient means to assess rapidly the potential interaction type and level of fungicides in a binary mixture.Nineteen mixtures interact synergistically：epoxiconazole ＋ pyraclostrobin at the mixing ratio of 6：4,8：2;tetraconazole ＋ flufenoxystrobin at 1：9,2：8,3：7 and 4：6;triadimefon ＋ flufenoxystrobin at 9：1;triflumizole ＋ flufenoxystrobin at 8：2;flusilazole ＋pyrametostrobin at 7：3,8：2 and 9：1;tetraconazole ＋ pyrametostrobin at 6：4;triadimefon ＋ pyrametostrobin at 5：5,8：2;triflumizole ＋ pyrametostrobin at 7：3,8：2;tetraconazole ＋ pyraoxystrobin at 9：1;triflumizole ＋ pyraoxystrobin at 8：2,9：1.[Conclusion] The single fungicides and their binary mixtures are expected to serve as the alternatives to triadimefon and the alternate use of them could delay the buildup of resistant O.heveae isolate.
基金Supported by Research Special Project of Public Industry(Agriculture)(201103027)Control of Invasive Alien Species of MOA & International Cooperation Project of MOST(2011DFB30040)+1 种基金Key Project of Science andTechnology of Hainan Province(080149)Basic Scientific Research Expenses for Central Scientific Research Institutes in Environment and Plant Protection Institute,Chinese Academy of Tropical Agricultural Sciences(2009hzs1J018)
文摘[Objective] The paper was to explore the herbicidal effects of Periconia heveae culture filtrate on Mikania micrantha. [Method] Through indoor bioassay method, the inhibition effects of culture filtrates of seven species of plant disease fungi on seed germination and seedling growth of M. micrantha were studied, and the security of P. heveae culture filtrate on pepper （Capsicum annuum） and tomato （Solanum lycopersicum） was also evaluated. [Result] The culture filtrates of P. heveae had strong inhibition effects on seed germination and the growth of root, shoot and seedling of M. micrantha, and the inhibition rates were 72.7%, 93.0%, 32.4%, and 54.6% （fresh weight）, respectively. Security tests showed that culture filtrates of P. heveae were safe to seed germination and root and shoot growth of tomato, and the growth rate had no significant difference with control, but they inhibited seed germination of pepper. [Conclusion] As potential biological herbicide, the culture filtrate and metabolites of P. heveae is worthy of further development. .
文摘The relationship between the effect of exogenous jasmonic acid (JA) on the induction of secondary laticifer differentiation and the distribution of JA in the seedling of Hevea brasiliensis Mull. Arg. was investigated with the aid of experimental morphological and radioisotope technique. Most radioactivity of H-3-JA sustained in treated site within one hour while no radioactivity was detected in new shoot and the radioactivity in upper leaf was much less than that in the parts below the treated site, suggesting that JA was mainly transported downwards in the shoot of H brasiliensis. Mechanical wounding hindered the entrance of exogenous JA remarkably while held back the entered JA to the regions around wounded site. The effect of exogenous JA and mechanical wounding on the induction of the secondary laticifer differentiation was limited to treated site where high level of JA was expected. Mechanical wounding reduced the effect of exogenous JA on the differentiation of secondary laticifer, which could be ascribed to the hindrance of mechanical wounding to the entrance of exogenous JA. It was concluded from the combined data that a high accumulation of JA was required for inducing the secondary laticifer differentiation in H. brasiliensis.
基金Supported by the Project of the Basic Research Operation Cost of State Level Research Institutes "Long-term Location Investigation of Basic Data for Rubber Production " ( XJSYWFZX-2008-14 and XJSYWFZX-2007-2)the Project Natural Sciences Fund of Hainan Province (807045)~~
文摘[Objective]The aim was to study on the characteristics of soil organic carbon and nitrogen in rubber （Hevea brasiliensis Muell-Arg） plantations at different age stages in the western region of Hainan Island,so as to evaluate the ecological benefits of rubber plantations and provide basic data for studying the effect of tropical land utilization/cover change on the global carbon and nitrogen cycle. [Method]The situs was in Danzhou city,western region of Hainan Island,and the samples were four kinds of rubber plantations soil at different ages and one kind of control check （pepper,Piper nigrum L.） soil. In this research,four quadrats were set up in each sample,and the size of each was 20 cm×20 cm. Four specimens were gathered from four layers of 0-15,15-30,30-45,45-60,and the average of them was the last analysis result of each sample. Soil density was measured by cutting ring method,soil containing and hygroscopic water was detected by oven drying method,soil organic carbon （SOC） was measured by low temperature heated outside potassium dichromate oxidation-colorimetry method,and soil total nitrogen （STN） was detected by semimicro Kjeldahl method. [Result]SOC contents of different layers in rubber plantations soil at different age stages （including the CK pepper soil,the same as below） varied little,and the content of SOC in surface layer （0-15 cm） was higher,while the underlayer （45-60 cm） was lower than the average value; there was significant difference in SOC content among different kinds of soil,and the content was of 6.03-7.78 g/kg,tapping young trees （7 years） CK pepper mature age trees （30 years） prophase of young trees （2 years） tapping trees （16 years）; there was no significant difference in SOC storage among different kinds of soil,and the storage was of 61.33-74.29 t/hm2,mature age trees （30 years） tapping young trees （7 years） prophase of young trees （2 years） CK pepper tapping trees （16 years）; there was significant difference in STN content among rubber plantations soil at different age stages,the content was of 410.86-664.14 mg/kg2,CK pepper tapping young trees （7 years） prophase of young trees （2 years） mature age trees （30 years） tapping trees （16 years）,and STN content of tapping trees （16 years） soil was extremely lowest; there was significant difference in C/N ratio among different kinds of soil,the ratio was of 10.94-14.47,and the ratio of tapping trees （16 years） mature age trees （30 years） tapping young trees （7 years） CK pepper prophase of young trees （2 years）. [Conclusion]There wasn＇t unhealthy effect of rubber trees planted in tropical area on the content and storage of SOC,the content of STN and the ratio of C/N. there was no significant difference between rubber plantations and CK pepper soil,and the effects of rubber plantation on soil carbon-nitrogen was similar to that of other tropical crops （such as pepper）.
文摘1876年,英国皇家植物园邱园（The Royal Botanic Gardens,Kew,简称邱园）将三叶橡胶（Hevea brasiliensis）幼苗送至英国在南亚、东南亚的殖民地试种,这些幼苗是邱园用从南美洲引种获得的种子繁殖出来的。橡胶在东南亚试种获得成功后,发展成为庞大的橡胶产业,对全世界的工业、农业、交通运输、经济、社会乃至政治产生了极大的影响,也使得橡胶成为一种＂改变世界历史进程＂的植物。
文摘Abundant microfibrillar protein inclusions were present in the lutoids of the primary laticifers in Hevea brasiliensis Mull. Arg. Two forms of the inclusions could be distinguished under the electron microscope, each in separate lutoids. As revealed by SDS-PAGE, the 59.5 kD and 63.5 kD proteins were the major components of the microfibrillar protein purified by isoeleettic point precipitation. Western-blotting analysis indicated that they were immunorelated with the 67 kD protein accumulated in the protein-storing cells. The 59.5 kD and 63.5 kD proteins were abundant in the uppermost part, the stem of new shoot and sustained their abundance during the growth and development of new shoot while their contents decreased remarkably in the lower parts of the trunk, accompanying by the accumulation of 3-5 kinds of proteins with low molecular weights. This fluctuating pattern suggested that the degradation of the 59.5 kD and 63.5 kD proteins had nothing to do with the new shoot growth and may be closely related to the primary laticifer differentiation. The 67 kD protein could not be detected in the young stem of new shoot when its leaves were broze-colored while the protein started to be accumulated in the stem, when the leaves of new shoot had matured, behaving like a typical vegetative storage protein.
基金Supported by Project of National Natural Rubber Industry Technology System of China(CARS-34-GW7)Project of Agricultural Technology Extension and System Construction for Tropical Crops(13RZNJ-43)Fundamental Research Funds of Rubber Research Institute,Chinese Academy of Tropical Agricultural Sciences(1630022013023)~~
文摘In this study, the rubber tree clone PR107 was selected as test material,and its yields and physiological features under micro-tapping with different concentrations of ethylene were compared. The results showed that there was no significant correlation between rubber yield and ethylene concentration applied by microtapping on PR107. Too high level of ethylene was not conducive to improvement of rubber yield. When the ethylene concentration for micro-tapping was higher than60%, physical deficiencies appeared in rubber tree PR107, the dry rubber content was reduced, and the yield was unstable. Instead, when the ethylene concentration was lower than 40%, the physiological features of PR107 were steady, the dry rubber content was stable, and the yield was relatively high.
基金Supported by Natural Science Foundation of Hainan Province(30821)Basic Scientific Research Business Fees of Chinese Academy of Tropical Agricultural Sciences(XJSYWFZX2008-02)~~
文摘[Objective] The aim was to look for an effective way of decreasing explants contamination in the root tissue culture of Hevea brasiliensis.[Method] In order to study root tissue culture of H.brasiliensis,new roots from forest section after treatment for one month were as explants,and 1 g/L carbendazim,75% ethanol,0.1% mercuric chloride and Yipeilong with different concentrations were used as disinfectants for roots disinfection.[Result] Before conventional disinfection,root explants were treated by 1 g/L carbendazim for 2.5 h,and disinfected by 75% ethanol for 30 s and 0.1% HgCl2 for 6 min,then cultured on the callus induction medium supplemented with 0.1% Yipeilong.The results showed that the contamination rate of explants decreased to 44.59%,and 25.60% explants survived after cultured for 30 d.[Conclusion] The study could provide theoretical foundation for the decrease of explant contamination in the root tissue culture of H.brasiliensis.
基金Supported by the Fundamental Research Funds for Rubber Research Institute, CATAS (1630022011014)Key Science and Technology Project of Hainan Province (90107)+1 种基金Basic Scientific Research Operational Fund for Central-level Public-interest Research Institutes (YWFZX2010-9)Special Fund for Science and Technology Research of Public Welfare Trades ( nyhyzx07-033-1)~~
文摘[Objective] ＂Tapping panel dryness （TPD）＂, a syndrome known as tapping incision blocked partly or entirely during latex exploiting, has become the most important factor causing great losses for rubber production. Aiming to elucidate the molecular mechanism of tapping panel dryness occurrence, this study carried out molecular cloning and bioinformatical analysis of a mRPL21 cDNA sequence, a gene associated with TPD. [Method] In a preliminary study, an expressed sequence tag （EST） encoding a deduced protein homologous to mitochondrial 50S ribosomal protein L21 （mRPL21）, which showed to be down-regulated in the latex of TPD-affected rubber trees, was isolated by suppression subtractive hybridization （SSH）. After ESTs assembling and RT-PCR validation, an 853 bp cDNA sequence with an open reading frame （ORF） was cloned, which was named as HbmRPL21 under GenBank accession number of HM230670. [Result] Bioinformatical analysis suggests that HbmRPL21 encodes a deduced polypeptide of 271 amino acids with a theoretical molecular weight （Mw） of 30.52 kDa and isolectric point （pI） of 8.40, and HbmRPL21 is a mitochondrion-targeted protein with a conserved domain of Ribosomal_L21p involving translation. Homology analysis reveals high amino acid sequence identity of mRPL21 from plants, while diversity of that between plant and animal kingdom. [Conclusion] This study laid the basis for further revealing the biological functions of mRPL21 in TPD-affected rubber trees.
文摘To understand the mechanism of benzothiadiazole (BTH)-induced susceptible rubber clone resistance to powdery mildew on gene level, a differentially expressed cDNA library was constructed by suppression subtractive hybridization (SSH) with rubber Reyan 7-33-97 clone. The constructed cDNA library was high integrity through detection of the critical processes of SSH, such as efficiency of adaptor connection, subtraction and conversion, as well as the type of recombinant genes. The positive rate was 99% after identification with random 400 white spots. The size of the cDNA clone inserted fragments was various but most in 400 bp - 1000 bp. There were 23 cDNA sequences matching the function of energy and basic metabolism, signal transduction, membrane and transport, secondary metabolism and so on after detection of the 42 positive clone sequences selected randomly from the cDNA library and comparison on nucleic acid sequences in Genbank. 7 ESTs were logged in Genbank and accession numbers were GW873071 and GW874604- GW874610. The results implicated that BTH could effectively induced rubber tree resistance to powdery mildew through increasing expresses of defense-related genes in leaves of rubber tree susceptible clone. It should provide a new approach for rubber disease management.
