Plant body ideal for high-density planting and use thereof (toyota jidosha) gas laws worksheet pdf

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It has been known that in general, when the number of individuals planted per unit area (hereinafter, referred to as “planting density”) increases, the weight of a plant individual decreases. Meanwhile, it is also known that when the planting density is increased, both yield and total biomass quantity per unit area increase. For example, in the case of Glycine max, cultivation at a high planting density is effective for increasing the yield of Glycine max. Accordingly, a method of cultivation at a high planting density is prevailing in the field of agriculture.

Cultivation at a high planting density for the purpose of increasing yield leads to an increase in biomass quantity per unit area. However, such cultivation accelerates competition between individuals at an earlier stage of growth. This results in rank growth and consequently causes the yield to level off. In other words, as the planting density increases, the biomass quantity per plant individual decreases. Accordingly, the biomass quantity per unit area levels off in due course. Non-Patent Literature 1 discloses that an increase in planting density leads to a decrease in weight of an individual, and a relationship between the weight “W” of an individual and the number “N” of plants per area (planting density) is expressed by the following:

Further, the following techniques are well known: (i) a technique for increasing a ratio of a biomass quantity of harvests to a total biomass quantity of plants (Patent Literature 1); and a technique for sufficiently increasing biomass quantity of plants per unit area (Patent Literature 2).

As described above, each plant has an optimal planting density for biomass productivity per unit area. Then, even if plants are planted at a planting density higher than the optimal planting density, the biomass productivity per unit area of the plants does not improve. Accordingly, in order to improve the biomass productivity per unit area, it is necessary to extend the upper limit of yield in cultivation at a high planting density. Further, it is also known that an increase in yield obtained by cultivation at a high planting density varies depending on varieties of plants. Accordingly, there is a demand for breeding of a plant variety suitable for cultivation at a high planting density, as means for increasing the yield.

The present invention provides a method and a tool each for producing plant biomass by means of cultivation at a high planting density, and use of the method and the tool. The present invention provides a technique for increasing yield more than ever before in cultivation at a high planting density, by changing the slope of the graph disclosed in Non-Patent Literature 1.

A method for producing plant biomass in accordance with the present invention includes the step of cultivating a plant body in which an MYB30 signaling pathway is activated, the plant body being cultivated under a high-density planting condition.

The method in accordance with the present invention is arranged preferably such that the plant body is a transformed plant obtained by transformation with an exogenous gene which contains an MYB30-related gene. In one embodiment, the MYB30-related gene may be operably connected to a promoter which regulates expression timing. In this case, the promoter is preferably arranged to initiate expression of the MYB30-related gene immediately prior to a flower bud formation stage of a non-transformed plant.

Preferably, the method in accordance with the present invention further includes the step of collecting biomass after cultivation of the plant body. For example, the method may further include the step of collecting biomass after fruiting of the plant body. For another example, the method may further include the step of collecting biomass prior to the flower bud formation stage.

A kit in accordance with the present invention includes an exogenous gene which contains an MYB30-related gene, for improving productivity per unit area of a plant under a high-density planting condition. The kit in accordance with the present invention may further include a reagent for determining the presence or absence of disease resistance which results from activation of an MYB30 signaling pathway.

In the exogenous gene, the MYB30-related gene may be operably connected to a promoter which regulates protein expression timing, and the MYB30-related gene is preferably a gene encoding a protein functionally equivalent to a protein selected from the group consisting of AtMYB30, BAK1 and PLA2α.