Studies On Comprehensive Productivity Of Mechanical Transplanted Different Genotypes Of Rice In Taihu Region

The field experiments were conducted in Changshu institute of agriculture science, Jiangsu Province at Taihu region in2012—2013. The soil was clay loam and the fertility was medium, the former crop was wheat.4types (Super hybrid indica(SHIR), Indica japonica hybrid japonica rice(IJHJR), Japonica japonica hybrid japonica rice(JJHJR), Super conventional japonica rice(SCJR)) of20rice varieties were taken as material, which were recently launched, planted widespread and appropriatly in Taihu Region. The growth stage, yield, number of stems, dry matter production, photosynthetic characters and rice quality of the4different types of varieties were studied. The main results were as follows:1. Different typed-cultivars had the highly significant or significant difference in yield. The IJHJR got the highest yield. The order of the yield from high to low was IJHJR(12.13t·hm-2)> JJHJR(11.3t·hm-2)> SCJR(10.63t·hm-2)> SHIR(10.01t·hm-2). The grain yield and its components was similarity between two years.The level of grain yield was depend largely on the number of total spikelets.The days of main growth stage and duration of different typed-cultivars showed as follows: the whole growing period of japonica rice was longer than indica rice. The days form sowing to jointing of super conventional japonica rice was extend more.While the days form jointing to maturity of hybrid japonica rice was extend more.2. In the whole development process, the stem number of japonica rice was smooth and steady. The stem number of indica rice was smooth and steady during earlier stage, but at the middle and later periods showed big rise and fall.The dry matter production and its ratio to total of different typed-cultivars showed as follows:In earlier stage, Super hybrid indica rice is higher than japonica rice and hybrid japonica rice is higher than conventional japonica rice. In the middle stage, The dry matter production of Indica japonica hybrid japonica rice is highest. But the ratio to total of indica hybrid rice is highest. In the late growth stage, super hybrid indica rice is lower than japonica rice and conventional japonica rice was lower than those of japonica hybrid rice. Meanwhile, the dry matter production in this phase is the biggest differences of different typed-cultivars.In earlier stage, the LAI of indica hybrid rice was rising fairly rapidly, but it was declined sharply at the late stage. The trends form heading to maturity period was that japonica rice is greater than indica, hybrid japonica rice is greater than Conventional japonica rice. Especially, the LAI of japonica rice at the maturity period was above3.O.It shows that the japonica rice have higher photosynthetic productivity at the late growth stage.The difference of the SPAD which is in the top three leaves at the late growth stage was showed as follow:IJHJR> JJHJR> SCJR> SHIR. The downward trends of SPAD showed super hybrid indica falling fast, hybrid japonica rice down slowly, and conventional japonica rice in between.3. Milling quality, appearance quality, cooking and eating quality of japonica rice were better than indica rice highly significant. Brown rice rate, milled rice rate, and head rice rate were very significantly higher than indica rice; the chalky grain rate, the amylase content, protein content were significantly or very significantly lower than indica rice; The gel consistency was very significantly longer than indica rice.The peak viscosity and breakdown of japonica rice were very significantly higher than indica rice, and conventional japonica rice was very significantly higher than hybrid japonica rice. The setback and pasting temperature of japonica rice were very significantly lower than indica rice, and conventional japonica rice was very significantly lower than hybrid japonica rice. There is no significantly difference between Two types japonica hybrid rice except the value of hot viscosity.