| Jerusalem artichoke plays an important role in food processing,forage,biomass energy and ecological restoration because of its large biomass and strong stress resistance.The relationship between yield and density of monocultures generally follows the"law of constant final yield".The study on the effect of density on the yield of Jerusalem artichoke organs has important guiding significance for the high-yield cultivation of Jerusalem artichoke.As the connection between individuals and populations,the study on the relationship between biomass and density is mostly focused on the aboveground parts of plants,and there is not sufficient understanding on the relationship between biomass and density at the organ level.Plant organ biomass allocation reflects plant in the process of growth,defense,survive the priority of functions,such as population density as an important one of the selection pressure of plants,changed the plant resources,the number of the individual has acquired the plant biomass allocation pattern density is in line with the prediction of"optimal partitioning theory"is still inconclusive.In this paper,we made use of Jerusalem artichoke as the research material to clarify its competition-density effect,biomass allocation pattern and yield-density relationship.The main research results are as follows:?1?With the increase of population density,the plant height,basal diameter,leaf area,number of leaves and nodes of Jerusalem artichoke were slightly smaller,while the node length and specific leaf area were gradually increased.The plant height of low density treatment?D1?increased by 73.4%was higher than that of high density treatment?D8?,the base diameter increased by 171.1%,leaf area increased by580.7%,the number of leaves increased by 249.9%,the number of sections increased by137.1%,the knot length decreased by 85.8%.?2?With the increase of population density,the various organ of Jerusalem artichoke biomass decreased,low density treatment?D1?of the stem and leaf,root and tuber biomass is high density treatment?D8?respectively 13.5 times,21.5 times,10.4times,15.6 times,the organ is power function relationship between biomass and density,organ by density control strength of sequence is leaf>stem>root tuber>.?3?Low density?D1?of the stem and leaf,root and tuber biomass allocation proportion of 46.9%,24.1%,7.4%and 21.7%,respectively,under the high density treatment?D8?of stem and leaf,root and tuber biomass allocation proportion of 50.6%,17.2%,10.4%and 21.8%respectively,with the increase of population density,the stem and root biomass allocation of Jerusalem artichoke increased,leaf and tuber biomass allocation decreased,stem biomass increase in the price of tuber biomass reduced stem biomass allocation and leaf biomass allocation does not exist between the trade-off.In the presence of intra-species competition,the biomass allocation pattern in Jerusalem artichoke organs does not completely have to be inconformity with the prediction of the optimal partitioning theory.?4?Compared with underground yield,the law of constant final yield is more applicable to aboveground yield of Jerusalem artichoke.The law of constant final yield of an organ only appears at certain harvest times.The maximum aboveground yield and tuber yield were obtained by the cultivation density of 49 plants·m-2,and the maximum aboveground yield was obtained by the harvest 140 days after the emergence of Jerusalem artichoke(24.7 t DM·ha-1),and the maximum tuber yield was obtained by the harvest 175 days after the emergence(30.1 t DM·ha-1).This study enriched the density-dependent theory,evaluated whether the biomass allocation model of Jerusalem artichoke under density-dependent conforms to the"optimal partitioning theory"and improved the research on the relationship between yield and density in underground organs,and determined the cultivation density when obtaining the maximum theoretical yield,providing theoretical support for high-yield cultivation of Jerusalem artichoke. |
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