The cultivation of Panax plants is hindered by replanting problems, which may be caused by plantdriven changes in the soil microbial community. Inoculation with microbial antagonists may efficiently alleviate replanti...The cultivation of Panax plants is hindered by replanting problems, which may be caused by plantdriven changes in the soil microbial community. Inoculation with microbial antagonists may efficiently alleviate replanting issues. Through high-throughput sequencing, this study revealed that bacterial diversity decreased,whereas fungal diversity increased, in the rhizosphere soils of adult ginseng plants at the root growth stage under different ages. Few microbial community, such as Luteolibacter, Cytophagaceae, Luteibacter, Sphingomonas,Sphingomonadaceae, and Zygomycota, were observed; the relative abundance of microorganisms, namely,Brevundimonas, Enterobacteriaceae, Pandoraea, Cantharellales, Dendryphion, Fusarium, and Chytridiomycota,increased in the soils of adult ginseng plants compared with those in the soils of 2-year-old seedlings. Bacillus subtilis 50-1, a microbial antagonist against the pathogenic Fusarium oxysporum, was isolated through a dual culture technique. These bacteria acted with a biocontrol efficacy of 67.8%. The ginseng death rate and Fusarium abundance decreased by 63.3% and 46.1%, respectively, after inoculation with B. subtilis 50-1. Data revealed that microecological degradation could result from ginseng-driven changes in rhizospheric microbial communities;these changes are associated with the different ages and developmental stages of ginseng plants. Biocontrol using microbial antagonists alleviated the replanting problem.展开更多
Apple replant disease（ARD） causes the inhibition of root system development, stunts tree growth and so on. To further investigate the effects of ARD on apple fruits, a 25-year-old apple orchard was remediated to est...Apple replant disease（ARD） causes the inhibition of root system development, stunts tree growth and so on. To further investigate the effects of ARD on apple fruits, a 25-year-old apple orchard was remediated to establish a replant orchard between November 2008 and March 2009. A rotational cropping orchard was established on an adjacent wheat field. The cultivar and rootstock-scion combination used in the newly established orchards was Royal Gala/M26/Malus hupehensis Rehd. Ripe fruits were collected in mid-August 2011 and mid-August 2012, meanwhile, the following indices were measured： yield per plant; fruit weight; the fruit shape index; the contents of anthocyanin, carotenoid and chlorophyll; the soluble sugar content in the flesh; titratable acid; the sugar-acid ratio; firmness; and aroma components; apple plant ground diameter, plant height increment and the total length of the current-year shoots. The results showed that compared to rotational cropping, continuous cropping yielded statistically significant reductions in fruit weight and yield per plant of 39.8 and 76.5%, respectively. However, there were no changes in the fruit shape index. The anthocyanin and carotenoid contents decreased by 81.7 and 37.7%, respectively, while the chlorophyll content increased by 251.0%. All of these differences in content were statistically significant. The soluble sugar levels and sugar-acid ratio decreased by 25.4 and 60.9%, respectively, but the titratable acid levels and fruit firmness increased by 90.9 and 42.8%, respectively. Ten of the most important esters contributing to the apple aroma were analyzed, and the following changes were observed： hexyl acetate, butyl acetate, hexyl butyrate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate, amyl acetate, butyl butyrate, 2-methyl-butyl butyrate, hexyl propionate and hexyl hexanoate decreased by 25.5, 78.4, 89.1, 55.5, 79.5, 77.2, 86.8, 69.9, 61.2, and 68.1%, respectively. The contents of three other aroma components,（E）-2-hexenal, hexanal and 1-hexanol, signi展开更多
The herbaceous peony(Paeonia lactiflora Pall.)has high ornamental value.Replanting problems occur when seedlings are replanted into previous holes.We studied the root system and soil environment of the'Dongjingnvl...The herbaceous peony(Paeonia lactiflora Pall.)has high ornamental value.Replanting problems occur when seedlings are replanted into previous holes.We studied the root system and soil environment of the'Dongjingnvlang'variety under a continuous planting regime of one,four,and seven years,and a replanting regime of one and four years.Under the condition of continuous planting,with the increase of number of years,pH,ammonium nitrogen,and nitrate nitrogen decreased in the rhizosphere and non-rhizosphere soils,whereas organic matter,available phosphorus and potassium,enzyme activities,and the number of bacteria,fungi,and actinomycetes increased.Under the condition of replanting,with the increase of number of years,fungi and actinomycetes in both soils increased,while pH,organic matter,nutrients,enzyme activities,and bacterial number decreased.pH,organic matter,nutrient content,enzyme activity and the number of bacterial were lower in soil replanted for four years,whereas the abundance of fungi and actinomycetes was higher,altering the soil from“bacterial high-fertility”to“fungal low-fertility”with increasing years of replanting.The activity of antioxidant enzymes and MDA content in roots of peony in replanting were higher than those in continuous planting,while the content of osmotic regulatory substances in replanting was lower than that in continuous planting.The results showed that there were no obvious adverse factors in soil during seven years of continuous planting,and herbaceous peony could maintain normal growth and development.However,soils after four years of replanting were not suitable for herbaceous peony growth.Benzoic acid increased with years of replanting,which potentially caused replanting problems.This study provides a theoretical basis for understanding the mechanism of replanting problems in the herbaceous peony.展开更多
基金supported by grants from the National Science Foundation of China(81603238)
文摘The cultivation of Panax plants is hindered by replanting problems, which may be caused by plantdriven changes in the soil microbial community. Inoculation with microbial antagonists may efficiently alleviate replanting issues. Through high-throughput sequencing, this study revealed that bacterial diversity decreased,whereas fungal diversity increased, in the rhizosphere soils of adult ginseng plants at the root growth stage under different ages. Few microbial community, such as Luteolibacter, Cytophagaceae, Luteibacter, Sphingomonas,Sphingomonadaceae, and Zygomycota, were observed; the relative abundance of microorganisms, namely,Brevundimonas, Enterobacteriaceae, Pandoraea, Cantharellales, Dendryphion, Fusarium, and Chytridiomycota,increased in the soils of adult ginseng plants compared with those in the soils of 2-year-old seedlings. Bacillus subtilis 50-1, a microbial antagonist against the pathogenic Fusarium oxysporum, was isolated through a dual culture technique. These bacteria acted with a biocontrol efficacy of 67.8%. The ginseng death rate and Fusarium abundance decreased by 63.3% and 46.1%, respectively, after inoculation with B. subtilis 50-1. Data revealed that microecological degradation could result from ginseng-driven changes in rhizospheric microbial communities;these changes are associated with the different ages and developmental stages of ginseng plants. Biocontrol using microbial antagonists alleviated the replanting problem.
基金supported by the Earmarked Fund for National Modern Agro-industry Technology Research System (CARS-28), Chinathe Key Innovation Project for Agricultural Application Technology of Shandong Province, ChinaYangtze River Scholar and Innovative Team Development Plan of the Ministry of Education, China (IRT1155)
文摘Apple replant disease（ARD） causes the inhibition of root system development, stunts tree growth and so on. To further investigate the effects of ARD on apple fruits, a 25-year-old apple orchard was remediated to establish a replant orchard between November 2008 and March 2009. A rotational cropping orchard was established on an adjacent wheat field. The cultivar and rootstock-scion combination used in the newly established orchards was Royal Gala/M26/Malus hupehensis Rehd. Ripe fruits were collected in mid-August 2011 and mid-August 2012, meanwhile, the following indices were measured： yield per plant; fruit weight; the fruit shape index; the contents of anthocyanin, carotenoid and chlorophyll; the soluble sugar content in the flesh; titratable acid; the sugar-acid ratio; firmness; and aroma components; apple plant ground diameter, plant height increment and the total length of the current-year shoots. The results showed that compared to rotational cropping, continuous cropping yielded statistically significant reductions in fruit weight and yield per plant of 39.8 and 76.5%, respectively. However, there were no changes in the fruit shape index. The anthocyanin and carotenoid contents decreased by 81.7 and 37.7%, respectively, while the chlorophyll content increased by 251.0%. All of these differences in content were statistically significant. The soluble sugar levels and sugar-acid ratio decreased by 25.4 and 60.9%, respectively, but the titratable acid levels and fruit firmness increased by 90.9 and 42.8%, respectively. Ten of the most important esters contributing to the apple aroma were analyzed, and the following changes were observed： hexyl acetate, butyl acetate, hexyl butyrate, acetate-2-methyl butyl, 2-methyl-hexyl butyrate, amyl acetate, butyl butyrate, 2-methyl-butyl butyrate, hexyl propionate and hexyl hexanoate decreased by 25.5, 78.4, 89.1, 55.5, 79.5, 77.2, 86.8, 69.9, 61.2, and 68.1%, respectively. The contents of three other aroma components,（E）-2-hexenal, hexanal and 1-hexanol, signi
基金supported by grants from the National Natural Science Foundation of China(Grant No.31670663).
文摘The herbaceous peony(Paeonia lactiflora Pall.)has high ornamental value.Replanting problems occur when seedlings are replanted into previous holes.We studied the root system and soil environment of the'Dongjingnvlang'variety under a continuous planting regime of one,four,and seven years,and a replanting regime of one and four years.Under the condition of continuous planting,with the increase of number of years,pH,ammonium nitrogen,and nitrate nitrogen decreased in the rhizosphere and non-rhizosphere soils,whereas organic matter,available phosphorus and potassium,enzyme activities,and the number of bacteria,fungi,and actinomycetes increased.Under the condition of replanting,with the increase of number of years,fungi and actinomycetes in both soils increased,while pH,organic matter,nutrients,enzyme activities,and bacterial number decreased.pH,organic matter,nutrient content,enzyme activity and the number of bacterial were lower in soil replanted for four years,whereas the abundance of fungi and actinomycetes was higher,altering the soil from“bacterial high-fertility”to“fungal low-fertility”with increasing years of replanting.The activity of antioxidant enzymes and MDA content in roots of peony in replanting were higher than those in continuous planting,while the content of osmotic regulatory substances in replanting was lower than that in continuous planting.The results showed that there were no obvious adverse factors in soil during seven years of continuous planting,and herbaceous peony could maintain normal growth and development.However,soils after four years of replanting were not suitable for herbaceous peony growth.Benzoic acid increased with years of replanting,which potentially caused replanting problems.This study provides a theoretical basis for understanding the mechanism of replanting problems in the herbaceous peony.
