| The field experiments were conducted in the experimental farm of agricultural college of Yangzhou university during2009-2010using Nanjing44and Yongyou8as material. The experiments were investigated from the point of population starting by setting four population starting structures, with a rational population structure of conventional cultivation for CK. The effects on yield, plant population quality, photosynthetic characters and rice quality were studied under different bowl seedling planting pattern and basic seedling. The main results are as follows:1. The treatment of three foramens reached the highest yield level between the two varieties (Nanjing4411095.57kg ha-1, Yongyou812367.52kg ha-1), significantly. Comparing with CK, more spikelets per panicle and population spikelets were observed in the model of three foramens, with less panicles per unit area and roughly the same level of filled-grain percentage and1000grain weight. In the model of three foramens treatment in comparison with CK, the population of stems and tillers achieved the expected number punctually at the critical leaf-age for productive tillers, and reached the peak with an appropriate value, then decreased gently. Plants of three foramens treatment developed approximately the same population LAI dynamics as dynamic of stems and tillers, and its maximal LAI appeared at the heading stage (Nanjing447.8, Yongyou88.6) and remained a level of3.5-4.0at the maturity stage. As for the population photosynthesis potential and the dry matter accumulation, the model of three foramens treatment showed lower values than CK during the early stages (from transplantation to jointing stage), and during the middle stages (from jointing to heading) it was roughly the same with CK, showing no statistical significance, and for the later stages, it was significantly higher in growth and development (from heading to maturity). There was no significant difference in filling rate of sink between three foramens treatment and CK, but the amount of actual filling of sink was significantly more than CK. Three foramens treatment had rational population starting structure and developed smoothy, so it increased yield significantly.2. There were differences in photosynthetic characters of two cultivars in different treats. Along with the increase of transplanting seedlings per hill, light transparence rate dropt at booting stage and heading stage and also the light transparence rate of the other four treatments were higher than CK. After heading, the net photosynthetic rate of three foramens treatment was the highest, and five foramens treatment was the lowest, and two foramens treatment and four foramens treatment were slightly higher than CK. However, the net photosynthetic rate of CK dropt the quickest in late stage. Along with the increase of transplanting seedlings per hill, SPAD values after heading of the top three leaves assumed the tendency increased first and then decreased and only the SPAD values of five foramens treatment were lower than CK. The larger the density, the quicker the SPAD value dropt in late stage.3. There was no significant difference between three foramens treatment and CK in rice quality. Along with the increase of transplanting seedlings per hill, there was variation in rice quality. The brown rice rate, the milled rice rate and the head milled rice rate dropt, the chalkiness rate and chalkiness degree rose, the protein content was lower, the amylose content increased, but the variation of coefficient of the main grain quality characteristics was different. The peak viscosity, hot viscosity, breakdown, final viscosity and the pasting temperature of the RVA profiles assumed the tendency increased first and then decreased along with the increase of density, while the setback and peak time rose. The variation of coefficient of the RVA profiles was different. The final viscosity and the pasting temperature was uneasily effected by density. |
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