Clonal Growth Of Tree Species Hippophae Rhamnoides L.ssp.sinensis In Response To Exogenous Plant Hormone

In order to maintain the stability of population, clonal plant can adjust to take full advantage of environment resource or avoid disadvantage resource with clonal growth when environment conditions change. The adjusting mechanism of clonal growth include to the external mechanism and the internal mechanism. Now day, the researches mainly focus on the external mechanism of herbage and woody herbage as the relationship between the supplying level of environment resource and the clonal growth characteristics and morphology characteristics. But there are not the reseaches about the internal mechanism (mainly hormones effect) and about tree species. Based on these, this program advanced that exogenous plant hormone (auxin in combination with cytokinin) was applied on the tree species Hippophae rhamnoides L. ssp. Sinensis. by adopting 3×3 regression design and drew the advantages from Latin layout. The ration connection between its growth increment, biomass amplitude, biomass distribution, clonal growth index and the hormone exogenous plant hormones level were observed and the accommodation mechanisms about population characteristics in response to quantity and ratio of exogenous plant hormones were discussed. So the results not only were used to explain the bionomic strategy and aboundance the ecological contents of clonal plant, also provide theoretical foundation to artificial control the clonal growth.(1) The show of growth increment (height, diameter, crown) and biomass amplitude (population, the above-ground, the underground portion) in response to exogenous plant hormones answered for the response surface equations and the response surface plots. For example: Y=17.179+0.26I+0.41F-0.0009I2-0.002F2+0.0003IF.It illuminated that hormones had obviously promoted growth of Hippophae rhamnoides L. ssp. Sinensis. Them increased first and then decreased with the increasing of amounts of hormones. When hormones exceed a certain amount of scope, excessive nutrients would become the limiting factor to plant growth. Later, while the amount of hormones continues to increase, the ability of growth would be restrained. The results of effect analysis indicated the effects of auxin in combination with cytokinin were better than single auxin or single cytokinin. Meanwhile, them each effect on different parts. Auxin promoted the high while cytokinin increase diameter and crown.(2) Biomass distribution can relevantly change with environment facts in order to use of environment resources and maintain growing actions. On the same way, biomass allocation of Hippophae rhamnoides L. ssp. Sinensis had same movement which biomass allocation of the above-ground (trunks, living branch, dead branch leaves) and clonal organs showed convex surface models (or convex parabola models), while biomass allocation of root and the underground portion showed concave surface models (or concave parabola models).This was the contrary law of biomass allocation between the aboveground and the underground, clonal organ and root or modules of resources obtaining and spacer actually suggest trade-offs between obtaining and storing of resources, growth and survival or clone and growth. Tt was to say, at disadvantage (low amount), the accumulation of underground biomass was increased in order to promote root growing to enhance the utilization rate of resource. On the contrary, population invested more biomass on the above-ground to extend area and strengthen the contention occupying the above ground resource at advantage environment (high amount).Then the resource allocation transferred to underground to strengthen the itself contention and mostly maintained own matter balance while the amount exceeded limit bound.(3) When tree speices Hippophae rhamnoides L. ssp. Sinensis was interfered by hormones, it could advance growth though adjusting not only biomass allocation also clonal growth ability (adjusting its ecological adapting strategy and propagate strategy) to maintain stability. Each clonal growth index show increased first and then decreased with the increasing of amounts of hormones which indicated that plants were regulating though phenotypic plasticity and growth pattern. The ability of clonal growth and ramets density increased with the increasing of amounts of hormones, so that ramets got shorter spacer from each other and distributed intensively in the habitat, which caused the foraging growth pattern tending to be phalanx type and a higher population fitness; on the other hand, when hormones exceeded a certain amount of scope, excessive hornmones would become the limiting factor to plant growth. Later, while the amount of hornmones continued to increase, the ability of clonal growth would be restrained. Then ramets density reduced so that ramets got longer spacer from each other and distributed sparsely in the habitat, which caused the foraging growth pattern tending to be guerrilla type and a lower population fitness. It was not difficult to infer that the ability of clonal growth and population fitness increased and then decreased with hormones transform from low to high, accompanied by transform in the foraging growth pattern, gradually transformed from guerrilla type to phalanx type and then from phalanx type to guerrilla type. So optimum ratios, op-curve equations and reasonable hormones range what were pointed out by experiment could provide good references at manufacture practice. It could save hormones amount and avoid unnecessary waste that producers spray hormones at reasonable range, moreover prevent todamage plants as excess amount and the greatest benefits could be achieved following op-curve in actual.