1. It was the day after the circus(马戏团) came to our village that Yakub and I first saw the little horse. He looked terrible. Every rib (肋骨)showed clearly. His hair-was coming out in patches. His head hang down.
field attraction test of (7R,8S)-cis-7,8-epoxy-2- methyloctadec-17-ene (= 7R,8S-epo-2me-17ene-18Hy), a trace component of the sex pheromone gland of the Asian gypsy moth,(Lymantria dispar), traps that were baited with...field attraction test of (7R,8S)-cis-7,8-epoxy-2- methyloctadec-17-ene (= 7R,8S-epo-2me-17ene-18Hy), a trace component of the sex pheromone gland of the Asian gypsy moth,(Lymantria dispar), traps that were baited with the trace component attracted more L. dispar than traps baited with (7S,8R)-cis-7,8-epoxy-2-methyloctadec-17-ene (= 7S,8R-epo-2me-17ene-18Hy) and unbaited traps. However, traps baited with 7R,8S-epo-2me-17ene-18Hy were less attractive than traps baited with (+)-disparlure [=(7R,8S)-cis-7,8-epoxy-2-methyloctadecane], the sex pheromone of L. dispar. Combination tests with (?)-disparlure, 7R,8S-epo-2me-17ene-18Hy, and 7S,8R-epo-2me- 17ene-18Hy revealed that 7R,8S-epo-2me-17ene-18Hy acted synergistically with (?)-disparlure.展开更多
The dynamic activity of transposable elements(TEs)contributes to the vast diversity of genome size and architecture among plants.Here,we examined the genomic distribution and transposition activity of long terminal re...The dynamic activity of transposable elements(TEs)contributes to the vast diversity of genome size and architecture among plants.Here,we examined the genomic distribution and transposition activity of long terminal repeat retrotransposons(LTR-RTs)in Arabidopsis thaliana(Ath)and three of its relatives,Arabidopsis lyrata(Aly),Eutrema salsugineum(Esa),and Schrenkiella parvula(Spa),in Brassicaceae.Our analyses revealed the distinct evolutionary dynamics of Gypsy retrotransposons,which reflects the different patterns of genome size changes of the four species over the past million years.The rate of Gypsy transposition in Aly is approximately five times more rapid than that of Ath and Esa,suggesting an expanding Aly genome.Gypsy insertions in Esa are strictly confined to pericentromeric heterochromatin and associated with dramatic centromere expansion.In contrast,Gypsy insertions in Spa have been largely suppressed over the last million years,likely as a result of a combination of an inherent molecular mechanism of preferential DNA removal and purifying selection at Gypsy elements.Additionally,species-specific clades of Gypsy elements shaped the distinct genome architectures of Aly and Esa.展开更多
We optimized the extraction process of Lysurus mokusin(L.)Fr.insecticidal compound(LMIC)using response surface methodology with ultrasonic extraction(UE).The surface morphologies of maceration extract(ME)and UE residu...We optimized the extraction process of Lysurus mokusin(L.)Fr.insecticidal compound(LMIC)using response surface methodology with ultrasonic extraction(UE).The surface morphologies of maceration extract(ME)and UE residues were compared by scanning electron microscopy,and then the activity of LMIC on Lymantria dispar(Asian gypsy moths)larvae was determined.Results showed that the optimal condition of UE was followed by 80 min of extraction time,60%of ethanol concentration and 80 mL g^-1 of liquid–solid ratio.The surface morphologies of UE residue were looser and rougher than ME residue.The corrected mortalities of LMIC on L.dispar larvae was 59.77%.This result indicated that L.mokusin was a good candidate as pesticide for pest management.展开更多
The critical antioxidant catalase(CAT)breaks down hydrogen peroxide induced by environmental stresses.Here we cloned full length catalase cDNA from Lymantria dispar asiatic(LdCAT).Bioinformatic analyses showed that op...The critical antioxidant catalase(CAT)breaks down hydrogen peroxide induced by environmental stresses.Here we cloned full length catalase cDNA from Lymantria dispar asiatic(LdCAT).Bioinformatic analyses showed that open reading frames of LdCAT contains 1524 bp,encoding 507 amino acids with molecular weight of 126.99 kDa,theoretical pI of 5.00,aliphatic index of 29.92,grand average of hydropathicity of 0.764,and instability index(II)of 46.56.Protein BLAST and multiple sequence alignment indicated that LdCAT had high identity with CAT from other insects,especially lepidopterans.In a phylogenetic analysis,LdCAT was most similar to CAT from Spodoptera litura and S.exigua.Quantitative realtime polymerase chain reaction showed that LdCAT transcripts in all instar larvae and the five tissues tested,verifying the ubiquity of LdCAT in L.disapr.Moreover,LdCAT of third instar larvae was significantly upregulated after they fed on avermectin at sublethal and LC10 doses.The highest relative transcript levels were found 2 h after an avermectin spray at LC90,and in the cuticula,rather than heads,fat bodies,malpighian tubes,and midguts after a spray avermectin at a sublethal concentration.The expression level of LdCAT under pesticide stresses here suggested that CAT is an important antioxidant enzyme of L.disapr defensing against pesticide stress and may be a good target for controlling this pest.展开更多
Pre- and post-defoliation radial growth rates were used to examine the effects of silvicultural thinning and two consecutive years of gypsy moth (Lymantria dispar L.) defoliation on Quercus spp. wood volume production...Pre- and post-defoliation radial growth rates were used to examine the effects of silvicultural thinning and two consecutive years of gypsy moth (Lymantria dispar L.) defoliation on Quercus spp. wood volume production. In the first phase of the study, tree rings from 65 dissected stems, were used to develop polynomial models to estimate annual cumulative volume (m3) increment for the entire merchantable stem, as a function of dbh (tree diameter at 1.37 m above the ground). In Phase II of the study, 81 additional trees were sampled using only increment cores. Cumulative diameter increments from the cores were used in the polynomial models to compare tree volume growth changes during and after defoliation among the thinning treatments. Even though there was no significant difference in estimated volume lost during defoliation among treatments, post-defoliation growth was enhanced by thinning. Total volume reduction from defoliation ranged from 28,049 (±17,462) cm3 to 25,993 (±16,251) cm3 per tree. The stand receiving the thinning treatment with the lowest residual stocking produced significantly more volume (P = 0.002) after defoliation than the other treatments.展开更多
文摘1. It was the day after the circus(马戏团) came to our village that Yakub and I first saw the little horse. He looked terrible. Every rib (肋骨)showed clearly. His hair-was coming out in patches. His head hang down.
基金support of the "Cooperative Research Program for Agriculture Science and Technology Development(Project No.PJ01175601)" Rural Development Administration,Republic of Korea
文摘field attraction test of (7R,8S)-cis-7,8-epoxy-2- methyloctadec-17-ene (= 7R,8S-epo-2me-17ene-18Hy), a trace component of the sex pheromone gland of the Asian gypsy moth,(Lymantria dispar), traps that were baited with the trace component attracted more L. dispar than traps baited with (7S,8R)-cis-7,8-epoxy-2-methyloctadec-17-ene (= 7S,8R-epo-2me-17ene-18Hy) and unbaited traps. However, traps baited with 7R,8S-epo-2me-17ene-18Hy were less attractive than traps baited with (+)-disparlure [=(7R,8S)-cis-7,8-epoxy-2-methyloctadecane], the sex pheromone of L. dispar. Combination tests with (?)-disparlure, 7R,8S-epo-2me-17ene-18Hy, and 7S,8R-epo-2me- 17ene-18Hy revealed that 7R,8S-epo-2me-17ene-18Hy acted synergistically with (?)-disparlure.
基金the“Innovation Project for the Postdoctoral Researchers”in Chinathe“Open Research Fund Program”of Beijing Key Lab of Plant Resource Research and Development,Beijing Technology and Business University。
文摘The dynamic activity of transposable elements(TEs)contributes to the vast diversity of genome size and architecture among plants.Here,we examined the genomic distribution and transposition activity of long terminal repeat retrotransposons(LTR-RTs)in Arabidopsis thaliana(Ath)and three of its relatives,Arabidopsis lyrata(Aly),Eutrema salsugineum(Esa),and Schrenkiella parvula(Spa),in Brassicaceae.Our analyses revealed the distinct evolutionary dynamics of Gypsy retrotransposons,which reflects the different patterns of genome size changes of the four species over the past million years.The rate of Gypsy transposition in Aly is approximately five times more rapid than that of Ath and Esa,suggesting an expanding Aly genome.Gypsy insertions in Esa are strictly confined to pericentromeric heterochromatin and associated with dramatic centromere expansion.In contrast,Gypsy insertions in Spa have been largely suppressed over the last million years,likely as a result of a combination of an inherent molecular mechanism of preferential DNA removal and purifying selection at Gypsy elements.Additionally,species-specific clades of Gypsy elements shaped the distinct genome architectures of Aly and Esa.
基金The work was supported by the Central University Fundamental Research Funds Special Fund Project[2572016AA03,25720171118]Harbin Applied Technology Research and Development Project[2016RAXXJ035]the Central Financial Forest Science and Technology Promotion Demonstration Fund Project[JLT[2016]13].
文摘We optimized the extraction process of Lysurus mokusin(L.)Fr.insecticidal compound(LMIC)using response surface methodology with ultrasonic extraction(UE).The surface morphologies of maceration extract(ME)and UE residues were compared by scanning electron microscopy,and then the activity of LMIC on Lymantria dispar(Asian gypsy moths)larvae was determined.Results showed that the optimal condition of UE was followed by 80 min of extraction time,60%of ethanol concentration and 80 mL g^-1 of liquid–solid ratio.The surface morphologies of UE residue were looser and rougher than ME residue.The corrected mortalities of LMIC on L.dispar larvae was 59.77%.This result indicated that L.mokusin was a good candidate as pesticide for pest management.
文摘The critical antioxidant catalase(CAT)breaks down hydrogen peroxide induced by environmental stresses.Here we cloned full length catalase cDNA from Lymantria dispar asiatic(LdCAT).Bioinformatic analyses showed that open reading frames of LdCAT contains 1524 bp,encoding 507 amino acids with molecular weight of 126.99 kDa,theoretical pI of 5.00,aliphatic index of 29.92,grand average of hydropathicity of 0.764,and instability index(II)of 46.56.Protein BLAST and multiple sequence alignment indicated that LdCAT had high identity with CAT from other insects,especially lepidopterans.In a phylogenetic analysis,LdCAT was most similar to CAT from Spodoptera litura and S.exigua.Quantitative realtime polymerase chain reaction showed that LdCAT transcripts in all instar larvae and the five tissues tested,verifying the ubiquity of LdCAT in L.disapr.Moreover,LdCAT of third instar larvae was significantly upregulated after they fed on avermectin at sublethal and LC10 doses.The highest relative transcript levels were found 2 h after an avermectin spray at LC90,and in the cuticula,rather than heads,fat bodies,malpighian tubes,and midguts after a spray avermectin at a sublethal concentration.The expression level of LdCAT under pesticide stresses here suggested that CAT is an important antioxidant enzyme of L.disapr defensing against pesticide stress and may be a good target for controlling this pest.
文摘Pre- and post-defoliation radial growth rates were used to examine the effects of silvicultural thinning and two consecutive years of gypsy moth (Lymantria dispar L.) defoliation on Quercus spp. wood volume production. In the first phase of the study, tree rings from 65 dissected stems, were used to develop polynomial models to estimate annual cumulative volume (m3) increment for the entire merchantable stem, as a function of dbh (tree diameter at 1.37 m above the ground). In Phase II of the study, 81 additional trees were sampled using only increment cores. Cumulative diameter increments from the cores were used in the polynomial models to compare tree volume growth changes during and after defoliation among the thinning treatments. Even though there was no significant difference in estimated volume lost during defoliation among treatments, post-defoliation growth was enhanced by thinning. Total volume reduction from defoliation ranged from 28,049 (±17,462) cm3 to 25,993 (±16,251) cm3 per tree. The stand receiving the thinning treatment with the lowest residual stocking produced significantly more volume (P = 0.002) after defoliation than the other treatments.
