The dissipation of chlorpyrifos on pakchoi inside and outside greenhouse was studied. The decline curve of chlorpyrifos on pakchoi could be described as first-order kinetic. The experimental data showed that both the ...The dissipation of chlorpyrifos on pakchoi inside and outside greenhouse was studied. The decline curve of chlorpyrifos on pakchoi could be described as first-order kinetic. The experimental data showed that both the hermetic environment of greenhouse and season affected dissipation rates of chlorpyrifos on pakchoi. Chlorpyrifos declined faster outside greenhouse than inside greenhouse. Chlorpyrifos residues at pre-harvest time were below the maximum residue limits(MRLs) fixed in China, whereas the values inside greenhouse were higher than those outside greenhouse by almost 50%. The recommended pre-harvest time established under conditions of open field might not always fit to greenhouse production.展开更多
Two pot experiments with a completely random design and 4 replications were performed in a greenhouse to examine the response difference of 17 cultivars of pakchoi (Brassica chinensis L.) grown in a Cu-spiked and a cl...Two pot experiments with a completely random design and 4 replications were performed in a greenhouse to examine the response difference of 17 cultivars of pakchoi (Brassica chinensis L.) grown in a Cu-spiked and a clean soil to Cu. The response of pakchoi to Cu toxicity varied with the cultivars. The biomass in cultivars of Gaogengbai , Siyueman and Suzhouqing were sensitive to soil Cu pollution, but the cultivars of Heixinwu , Huoqingcai and HKcaixin were relatively tolerant. When the 17 cultiva…展开更多
Releases of manganese and iron ions from an albic soil (Albic-Udic Luvisol), a yellow-red soil (Hap-Udic Ferrisol) and a yellow-brown soil (Arp-Udic Luvisol) induced by calcium salt addition and their bioavailability ...Releases of manganese and iron ions from an albic soil (Albic-Udic Luvisol), a yellow-red soil (Hap-Udic Ferrisol) and a yellow-brown soil (Arp-Udic Luvisol) induced by calcium salt addition and their bioavailability to pepper (Capsicum frutescens L.) were studied in a pot experiment. Addition of Ca(NO3)2 decreased soil pH and increased both exchangeable and DTPA (diethylenetriamine pentaacetic acid)-extractable Mn and Fe in soils. Meanwhile, total Mn accumulation in the shoots of Capsicum frutescens L. on the salt-treated soils increased significantly (P ＜ 0.01) compared with the control, suggesting that salt addition to soil induced Mn toxicity in Capsicum frutescens L. Although exchangeable and DTPA-extractable Fe increased also in the salt-treated soils, Fe uptake by the shoots of Capsicum frutescens L. decreased. The effect of added salts in soils on dry matter weight of pepper varied with the soil characteristics, showing different buffer capacities of the soils for salt toxicity in an order of yellow-brown soil ＞ albic soil ＞ yellow-red soil. Fe/Mn ratio in shoots of Capsicum frutescens L. decreased with increasing salt addition for all the soils, which was ascribed to the antagonistic effect of Mn on Fe accumulation. The ratio of Fe/Mn in the tissue was a better indicator of the appearance of Mn toxicity symptoms than Mn concentration alone.展开更多
Effect of four commonly used pesticides, triadlmefon, jingganmycin, triazoplos andimidacloprid, on grain growth parameters was examined using a growth equation in thepresent paper. Two hundreds of spikes, not damaged ...Effect of four commonly used pesticides, triadlmefon, jingganmycin, triazoplos andimidacloprid, on grain growth parameters was examined using a growth equation in thepresent paper. Two hundreds of spikes, not damaged by pests were simultaneously markedper plot during the heading stage of rice. Rice plants were sprayed at 1 d after marking.Thereafter, 20 spikes were sampled at 4 d intervals and dried in an oven. Then, 10superior and inferior grains were picked from each spike, and brown rice was weighedafter shelling, respectively. First, second and third order derivates were deduced fromthe following grain growth formula:bt-aKwe1+=, where W was the weight of 100 grains brownrice at time t; K was maximum of grain growth; a and b were parameters of the formula. Theparameters were calculated as following:Where R0, △t, GT and Vmax were initial growth power, active growth stage, accumulativeweight of dried content during △t and maximum growth rate, respectively. The resultshowed that GT and K of superior grain following 22.5 and 45 ga.i.ha-1 of imidaclopridsprays were significantly reduced, and △t was significantly decreased for 112.5 and 225ga.i.ha-1 jingganmycin treatments. In addition, the high dose of imidacloprid signifi-cantly reduced the weight of 1000 rice grains by 9.77%. However, there was no significantdifference for the weight of 1000 grains between the high dose of jingganmycin and thecontrol, indicating that effective duration of jingganmycin on grain filling was shorterthan that of imidacloprid.展开更多
The phytophagous insect, Epiblema strenuana, is an effective biocontrol agent against Ambrosia and Parthenium, and was introduced to China in 1990 to control Ambrosia artemisiifolia. After a small scale release in Hun...The phytophagous insect, Epiblema strenuana, is an effective biocontrol agent against Ambrosia and Parthenium, and was introduced to China in 1990 to control Ambrosia artemisiifolia. After a small scale release in Hunan Province, E. strenuana established and begun to spread. Host specificity and feeding studies in Hunan have indicated that there are four host plants in China, A. artemisiifolia, A. trifida, Xanthium sibiricum and Parthenium hysterophorus. These plants are all weeds that need to be controlled. However, there are still some different views among scientists about the merits of this release because of potential effects on non-target species such as Helianthus annuus, and uncertainty about climatic suitability. To address these concerns, the CLIMEX system was used to predict the possibility of establishment of E. strenuana with A. artemisiifolia, A. trifida, and P. hysterophorus at 85 meteorological locations. Also, the probability of E. strenuana co-establishing with A. artemisiifolia, A. trifida or P. hysterophorus was evaluated quantitatively by bioclimatic risk index (BCRI) transferred from ecoclimate index (EI). Moreover, the hypothetical adaptation of E. strenuana to H. annuus as a host, were evaluated by bioclimate matching. These results help to predict the potential spread of A. artemisiifolia, A. trifida, P. hysterophorus and evaluate the merits of further releases of E. strenuana in China.展开更多
Gliocladium and Trichoderma are common fungi in agricultural soil. Several species of them were isolated and identified, great diversity was displayed in different agricultural soils of different crops, agricultural c...Gliocladium and Trichoderma are common fungi in agricultural soil. Several species of them were isolated and identified, great diversity was displayed in different agricultural soils of different crops, agricultural climate zones, different seasons, depths, different treated soybean cyst nematode soil, healthy and diseased crop soil. Among five crops soil samples, wheat and corn soil were found to possess the largest number of Gliocladium and Trichoderma separately. Gliocladium and Trichoderma of three major crops showed consistent changing patterns with seasonal variation. Corn soil displayed distinct vertical distribution of Trichoderma. There is a different distribution of the two fungi in diseased and healthy plant soil. Among the various isolated methods, diluted plate method is the best for isolating Gliocladium, and Trichoderma could be found in plant residue method and be tolerant to steam for two minutes. In the soybean cyst nematode soil mycobiota, the frequency of Gliocladium is higher than that of the others fungi, and Trichoderma may have the role of bioremediation in herbicide treated soil. Similarly, Gliocladium occurred frequently in different climate zones.展开更多
Aster albescens is a medicinal plant. The rust caused by Aecidium asterum is a new record in China and an importantdisease of A. albescens in Feng Tong-zhai national reservation area. The percentages of diseased plant...Aster albescens is a medicinal plant. The rust caused by Aecidium asterum is a new record in China and an importantdisease of A. albescens in Feng Tong-zhai national reservation area. The percentages of diseased plant and the diseasedleaf reach 100 and 28% respectively when the disease is serious. The disease results in leaf spot and leaf cast. Tuberculinapersicina is a natural hyperparasite of A. asterum and is firstly reported in the world. The hyperparasite attacks aecium ofA. asterum and hinderes the release of aeciospores. The symptom of the rust and the morphological characteristics of A.asterum is reported. The hyperparasitism of A. asterum and the morphological characteristics of the Tuberculina persicinaare also reported.展开更多
Five thousand and eight hundred publicly available expressed sequence tags (ESTs) of Phytophthora sojae were electronically searched and 415 simple sequence repeats (SSRs) were identified in 369 ESTs. The average den-...Five thousand and eight hundred publicly available expressed sequence tags (ESTs) of Phytophthora sojae were electronically searched and 415 simple sequence repeats (SSRs) were identified in 369 ESTs. The average den- sity of SSRs was one SSR per 8.9 kb of EST sequence screened. The most frequent repeats were trinucleotide re- peats (50.1%) and the least frequent were tetranucleotide repeats (8.2%). Forty primer pairs were designed and tested on 5 strains of P. sojae. Thirty-three primer pairs had suc- cessful PCR amplifications. Of the 33 functional primer pairs, 28 primer pairs produced characteristic SSR bands of the expected size, and 15 primer pairs (45.5%) detected poly- morphism among 5 tested strains of P. sojae. Based on the polymorphisms detected with 20 EST-SSR markers, the 5 tested strains of P. sojae were clustered into 3 groups. In this study, the SSR markers of P. sojae were developed for the first time. These markers could be useful for identification, genetic variation study, and molecular mapping of P. sojae and its relative species.展开更多
The extracts from 7 species of bamboo were tested for larvicidal activity against Culex pipiens pallens. At the tested concentration, the extracts of selected bamboo had different degree of toxic effects on the fourth...The extracts from 7 species of bamboo were tested for larvicidal activity against Culex pipiens pallens. At the tested concentration, the extracts of selected bamboo had different degree of toxic effects on the fourth instar larvae of Culex pipiens pallens. Among them,the extracts of Pleioblastus juxianensis, Brachystachyum albostriatum, Phyllostachys platyglossa and Pleioblastus amarus were found to be effective with LC50values at 24h of 30.65mg/L,53.94mg/L, 41.21 mg/L and 54.49 mg/L respectively, against Culex pipiens pallens larvae. The extract of Pleioblastus juxianensis by Soxhlet method showed stronger activity than the extract obtained by interval-shaking, the LC50 of which were 30.65 mg/L and 48.34 mg/L, respectively.The diethyl ether extract of Pleioblastus juxianensis exhibited better larvicidal activity than the methanol extract and the petroleum ether extract. The results would help to provide the basis for the study of environment acceptable pesticide for mosquito control, and also help to comprehensively utilize the source of bamboo.展开更多
Photoperiodic sensitivity for diapause induction of the green lacewing, Chrysoperla sinica (Tjeder) was examined at 22℃. The adult diapause of C. sinica was induced by short-day photoperiods, and the critical photope...Photoperiodic sensitivity for diapause induction of the green lacewing, Chrysoperla sinica (Tjeder) was examined at 22℃. The adult diapause of C. sinica was induced by short-day photoperiods, and the critical photoperiod for its induction was between 12.5L-11.5D and 13L-11D.Adults developed without diapause under long-day conditions, and entered diapause under short-day conditions. The adult stage was the uppermost sensitive stage for adult diapause induction, adults could go into diapause only when the emerging adults were under diapause-inducing short-day photoperiods. The short-day photoperiodic experience by transferring between 15L: 9D and 9L: 15D at preimaginal stages did not result in adult diapause under 15L: 9D photo regime, although some treatments extended the pre-oviposition period in adult stage. The results showed that the 3rd instar larvae and pre-pupae were more sensitive to the photoperiodic change from 15L: 9D to 9L: 15D photo regime than the other preimaginal stages.展开更多
Nineteen kinds of spiro enol ether analogues were screened with larvae of Pieris rapae for antifeedant activity. The results showed that the antifeedant activity of compounds No.20 and No.12 was higher than others. In...Nineteen kinds of spiro enol ether analogues were screened with larvae of Pieris rapae for antifeedant activity. The results showed that the antifeedant activity of compounds No.20 and No.12 was higher than others. In non-choice test, AFC50 values within 24 h of compounds No.20 and No.12 against 3rd instar larvae of P. rapae were 226.93ug/mL and 370.00ug/mL, and that in choice test against 4th larvae were 280.54 ug/mL and 398.88 ug/mL, respectively. Compd. No.20 could prolong the eggs hatch time and reduce the haemolymph content and the protein content in haemolymph of 4th instar larvae obviously. Compd. No.20 could protect tested leaves and control larvae of P. rapae effectively.展开更多
基金The National Natural Science Foundation of China(No. 20377036 30230250 and 30270880)+1 种基金 the Major State Basic Research Development Programme of China(No. 2002CB410806) the Natural Science Foundation of Zhejiang Province(No. 301050) and Hangzhou Committee of Science and Technology(No. 2002112A08)
文摘The dissipation of chlorpyrifos on pakchoi inside and outside greenhouse was studied. The decline curve of chlorpyrifos on pakchoi could be described as first-order kinetic. The experimental data showed that both the hermetic environment of greenhouse and season affected dissipation rates of chlorpyrifos on pakchoi. Chlorpyrifos declined faster outside greenhouse than inside greenhouse. Chlorpyrifos residues at pre-harvest time were below the maximum residue limits(MRLs) fixed in China, whereas the values inside greenhouse were higher than those outside greenhouse by almost 50%. The recommended pre-harvest time established under conditions of open field might not always fit to greenhouse production.
文摘Two pot experiments with a completely random design and 4 replications were performed in a greenhouse to examine the response difference of 17 cultivars of pakchoi (Brassica chinensis L.) grown in a Cu-spiked and a clean soil to Cu. The response of pakchoi to Cu toxicity varied with the cultivars. The biomass in cultivars of Gaogengbai , Siyueman and Suzhouqing were sensitive to soil Cu pollution, but the cultivars of Heixinwu , Huoqingcai and HKcaixin were relatively tolerant. When the 17 cultiva…
基金Project supported by the Natural Science Foundation of Anhui Province (No. 00023069) the Ecological Experiment Station of Red Soil, Chinese Academy of Sciences and the Knowledge Innovative Program of the Chinese Academy of Sciences (No. KZCX2-401).
文摘Releases of manganese and iron ions from an albic soil (Albic-Udic Luvisol), a yellow-red soil (Hap-Udic Ferrisol) and a yellow-brown soil (Arp-Udic Luvisol) induced by calcium salt addition and their bioavailability to pepper (Capsicum frutescens L.) were studied in a pot experiment. Addition of Ca(NO3)2 decreased soil pH and increased both exchangeable and DTPA (diethylenetriamine pentaacetic acid)-extractable Mn and Fe in soils. Meanwhile, total Mn accumulation in the shoots of Capsicum frutescens L. on the salt-treated soils increased significantly (P ＜ 0.01) compared with the control, suggesting that salt addition to soil induced Mn toxicity in Capsicum frutescens L. Although exchangeable and DTPA-extractable Fe increased also in the salt-treated soils, Fe uptake by the shoots of Capsicum frutescens L. decreased. The effect of added salts in soils on dry matter weight of pepper varied with the soil characteristics, showing different buffer capacities of the soils for salt toxicity in an order of yellow-brown soil ＞ albic soil ＞ yellow-red soil. Fe/Mn ratio in shoots of Capsicum frutescens L. decreased with increasing salt addition for all the soils, which was ascribed to the antagonistic effect of Mn on Fe accumulation. The ratio of Fe/Mn in the tissue was a better indicator of the appearance of Mn toxicity symptoms than Mn concentration alone.
基金supported by the National Natural Science Foundation of China(30070122).
文摘Effect of four commonly used pesticides, triadlmefon, jingganmycin, triazoplos andimidacloprid, on grain growth parameters was examined using a growth equation in thepresent paper. Two hundreds of spikes, not damaged by pests were simultaneously markedper plot during the heading stage of rice. Rice plants were sprayed at 1 d after marking.Thereafter, 20 spikes were sampled at 4 d intervals and dried in an oven. Then, 10superior and inferior grains were picked from each spike, and brown rice was weighedafter shelling, respectively. First, second and third order derivates were deduced fromthe following grain growth formula:bt-aKwe1+=, where W was the weight of 100 grains brownrice at time t; K was maximum of grain growth; a and b were parameters of the formula. Theparameters were calculated as following:Where R0, △t, GT and Vmax were initial growth power, active growth stage, accumulativeweight of dried content during △t and maximum growth rate, respectively. The resultshowed that GT and K of superior grain following 22.5 and 45 ga.i.ha-1 of imidaclopridsprays were significantly reduced, and △t was significantly decreased for 112.5 and 225ga.i.ha-1 jingganmycin treatments. In addition, the high dose of imidacloprid signifi-cantly reduced the weight of 1000 rice grains by 9.77%. However, there was no significantdifference for the weight of 1000 grains between the high dose of jingganmycin and thecontrol, indicating that effective duration of jingganmycin on grain filling was shorterthan that of imidacloprid.
基金supported by National Natural Science Foundation of China(39770510)National 10th“Five-year Plan”Key Research Program(2001BA611B-06-1-5).
文摘The phytophagous insect, Epiblema strenuana, is an effective biocontrol agent against Ambrosia and Parthenium, and was introduced to China in 1990 to control Ambrosia artemisiifolia. After a small scale release in Hunan Province, E. strenuana established and begun to spread. Host specificity and feeding studies in Hunan have indicated that there are four host plants in China, A. artemisiifolia, A. trifida, Xanthium sibiricum and Parthenium hysterophorus. These plants are all weeds that need to be controlled. However, there are still some different views among scientists about the merits of this release because of potential effects on non-target species such as Helianthus annuus, and uncertainty about climatic suitability. To address these concerns, the CLIMEX system was used to predict the possibility of establishment of E. strenuana with A. artemisiifolia, A. trifida, and P. hysterophorus at 85 meteorological locations. Also, the probability of E. strenuana co-establishing with A. artemisiifolia, A. trifida or P. hysterophorus was evaluated quantitatively by bioclimatic risk index (BCRI) transferred from ecoclimate index (EI). Moreover, the hypothetical adaptation of E. strenuana to H. annuus as a host, were evaluated by bioclimate matching. These results help to predict the potential spread of A. artemisiifolia, A. trifida, P. hysterophorus and evaluate the merits of further releases of E. strenuana in China.
文摘Gliocladium and Trichoderma are common fungi in agricultural soil. Several species of them were isolated and identified, great diversity was displayed in different agricultural soils of different crops, agricultural climate zones, different seasons, depths, different treated soybean cyst nematode soil, healthy and diseased crop soil. Among five crops soil samples, wheat and corn soil were found to possess the largest number of Gliocladium and Trichoderma separately. Gliocladium and Trichoderma of three major crops showed consistent changing patterns with seasonal variation. Corn soil displayed distinct vertical distribution of Trichoderma. There is a different distribution of the two fungi in diseased and healthy plant soil. Among the various isolated methods, diluted plate method is the best for isolating Gliocladium, and Trichoderma could be found in plant residue method and be tolerant to steam for two minutes. In the soybean cyst nematode soil mycobiota, the frequency of Gliocladium is higher than that of the others fungi, and Trichoderma may have the role of bioremediation in herbicide treated soil. Similarly, Gliocladium occurred frequently in different climate zones.
基金This study was supported by the Natural Science Foun-dation of Sichuan Province of China(2003C006).
文摘Aster albescens is a medicinal plant. The rust caused by Aecidium asterum is a new record in China and an importantdisease of A. albescens in Feng Tong-zhai national reservation area. The percentages of diseased plant and the diseasedleaf reach 100 and 28% respectively when the disease is serious. The disease results in leaf spot and leaf cast. Tuberculinapersicina is a natural hyperparasite of A. asterum and is firstly reported in the world. The hyperparasite attacks aecium ofA. asterum and hinderes the release of aeciospores. The symptom of the rust and the morphological characteristics of A.asterum is reported. The hyperparasitism of A. asterum and the morphological characteristics of the Tuberculina persicinaare also reported.
文摘Five thousand and eight hundred publicly available expressed sequence tags (ESTs) of Phytophthora sojae were electronically searched and 415 simple sequence repeats (SSRs) were identified in 369 ESTs. The average den- sity of SSRs was one SSR per 8.9 kb of EST sequence screened. The most frequent repeats were trinucleotide re- peats (50.1%) and the least frequent were tetranucleotide repeats (8.2%). Forty primer pairs were designed and tested on 5 strains of P. sojae. Thirty-three primer pairs had suc- cessful PCR amplifications. Of the 33 functional primer pairs, 28 primer pairs produced characteristic SSR bands of the expected size, and 15 primer pairs (45.5%) detected poly- morphism among 5 tested strains of P. sojae. Based on the polymorphisms detected with 20 EST-SSR markers, the 5 tested strains of P. sojae were clustered into 3 groups. In this study, the SSR markers of P. sojae were developed for the first time. These markers could be useful for identification, genetic variation study, and molecular mapping of P. sojae and its relative species.
文摘The extracts from 7 species of bamboo were tested for larvicidal activity against Culex pipiens pallens. At the tested concentration, the extracts of selected bamboo had different degree of toxic effects on the fourth instar larvae of Culex pipiens pallens. Among them,the extracts of Pleioblastus juxianensis, Brachystachyum albostriatum, Phyllostachys platyglossa and Pleioblastus amarus were found to be effective with LC50values at 24h of 30.65mg/L,53.94mg/L, 41.21 mg/L and 54.49 mg/L respectively, against Culex pipiens pallens larvae. The extract of Pleioblastus juxianensis by Soxhlet method showed stronger activity than the extract obtained by interval-shaking, the LC50 of which were 30.65 mg/L and 48.34 mg/L, respectively.The diethyl ether extract of Pleioblastus juxianensis exhibited better larvicidal activity than the methanol extract and the petroleum ether extract. The results would help to provide the basis for the study of environment acceptable pesticide for mosquito control, and also help to comprehensively utilize the source of bamboo.
文摘Photoperiodic sensitivity for diapause induction of the green lacewing, Chrysoperla sinica (Tjeder) was examined at 22℃. The adult diapause of C. sinica was induced by short-day photoperiods, and the critical photoperiod for its induction was between 12.5L-11.5D and 13L-11D.Adults developed without diapause under long-day conditions, and entered diapause under short-day conditions. The adult stage was the uppermost sensitive stage for adult diapause induction, adults could go into diapause only when the emerging adults were under diapause-inducing short-day photoperiods. The short-day photoperiodic experience by transferring between 15L: 9D and 9L: 15D at preimaginal stages did not result in adult diapause under 15L: 9D photo regime, although some treatments extended the pre-oviposition period in adult stage. The results showed that the 3rd instar larvae and pre-pupae were more sensitive to the photoperiodic change from 15L: 9D to 9L: 15D photo regime than the other preimaginal stages.
文摘Nineteen kinds of spiro enol ether analogues were screened with larvae of Pieris rapae for antifeedant activity. The results showed that the antifeedant activity of compounds No.20 and No.12 was higher than others. In non-choice test, AFC50 values within 24 h of compounds No.20 and No.12 against 3rd instar larvae of P. rapae were 226.93ug/mL and 370.00ug/mL, and that in choice test against 4th larvae were 280.54 ug/mL and 398.88 ug/mL, respectively. Compd. No.20 could prolong the eggs hatch time and reduce the haemolymph content and the protein content in haemolymph of 4th instar larvae obviously. Compd. No.20 could protect tested leaves and control larvae of P. rapae effectively.
