| Tillering is a special branch in gramineae plants, such as rice (Oryza Sativa L.), wheat (Triticum L.), barley (Hordeum uhulgare L.) etc. As a key factor, tillering characters (including tiller morphology and tillering ability) are closely related with the genetic features and being to the center of attention. Of which study on tiller angle is especially important, for one thing it is well known that the angle between tiller and horizontal (tiller angle) not only influences photo-thermo condition competition, but also there is a close relation to the physiological ecology of rice, such as planting density, plant type, efficiency utilization of light and wind rate. For another, it has the important significance in constituting and shaping plant type and rice yield. Based on different tiller angles, they could be classified into scattering, constriction and compacting for tiller angle types. However, it is always dynamic for rice tiller angle and hard to measure exactly, and there are varies measure dates and principles, so not an agreement for the definition and types of rice tiller angle has been achieved at present. In recent years, there is a common awareness that the combination of plant type shaping and heterosis utilizing is super rice breeding objectives, by increasing tillering rate, yield and its components, a series of researches have been taken, including genetics, ecology, nourishment and auxin, which all contribution to theory and practice study of new rice type. As a carrier of rice high-yield genes, the new plant type material is virtual to rice high yield breeding. While studies on rice tiller angle stress on the certain growth stage, few reports have been found to research the mathematical relation between rice tiller angle and its yield in the whole growth, consider from niche and niche-fitness has yet not been documented. Niche is feature properties of species and it reflects the functional statues in a special habitat, methods and rules between species and their corresponding environment could also be understand.In other fields about crop, for example, cotton fiber in north Xinjiang, spring wheat, by topping on cotton population Ma Fuyu etc have analyzed the cotton fiber, Li Zizhen etc have investigated the relation between growing and yield for spring wheat according to the niche-fitness model and water and fertilizer control, both have got satisfied test results. In addition, niche theory has been widely applied into open coalmine land reclamation, the prevention and cure of plant disease and insect pests, vegetation community, desert vegetation recovery etc.In the early research, a rice genetic material, DI508has the characteristic of dynamic changing tiller angle (DCTA):semi-scattering at the tillering and turning to erect after shooting. In this paper, two rice materials were conducted. Besides DI508, there were two contrast materials, SS5O8:tiller semi-scattering in the whole growth and1T508:tiller erecting in the whole growth. Through niche-fitness model, setting nitrogen fertilizer and density tests respectively, niche-fitness of plant-type, nitrogen nutrition and density are analyzed. The main results are summarized as below:1. D1508has an advantage on plant-type nichc-fitness, mainly in the niche-fitness of plant height, leaf stage, No. of tiller per plant, length of stem, length of canopy, width of plant basal, space between two extreme tillers, space between two leaves tips, angle of primary tiller, top first leaf angle, top second leaf angle etc during four key growing developments are greater than those for SS508and IT508, which are weighted by No. of effective panicle, No. of seed setting, Weight of1000grains and grain yield. F values for DI508are dynamic in four key developmental stages and come to the top during panicle initiation stage.2. The contribution rate of nitrogen to dry biomass weight per plant of the above-ground during the growing stages for DI508is incremented obviously, while which for total soluble sugar content in leaf is decremented. In addition, the contribution rate of nitrogen to dry biomass weight per plant of the above-ground and to leaf area index both reach a maximum when treated with200kg/ha nitrogen fertilizer. However, there is a fluctuation for the contribution rate of nitrogen to total soluble sugar content in leaf, not just taking increment or decrement.3. With four different density treatments, F value for three rice materials with varies tiller angles is largely the same in early growth stage, which is30cmx25cm>30cmx20cm>25cmx20cm>30cm×15cm. From booting stage, there is a significant difference of F value for three plant-types.manifested as follows:the F value for DI508reaches the top by30cm×20cm density treatment and it is0.78(date not showed), while the minimum date is0.70(date not showed)and obtained by30cmx25cm density treatment. To IT508, F values are listed in order as:25cmx20cm>30cmx20cm>30cm×15cm>30cmx25cm; To SS508, F value by30cmx25cm density treatment are significantly greater than that by other three different density tests. Besides the F value of SS508in full heading stage is greater than that of DI508and IT508. For the three rice materials, F value in order as:DI508>IT508>SS508. |
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