Study On The Techniques Of"Three High One Ensure"Cultivation And Its Mechanism Of High Yielding And Quality In Rice

As we know, rice is the most important food crop in China and even in the world. Increasing the rice yield per unit area and improving rice quality are necessary for safeguarding national food security and improving people’s living level. Nowaday China has bred a series of new rice varieties with a potential of super-high yield. Studying the cultivation technology matching with these varieties would have very important significance to exploit the potentialities of yield and quality of those varieties. The construction of population with flourishing growth at previous period, steady development at middle period and vigorous grain filling at later period is the essential requirement for high yielding and quality cultivation, especially for super-high-yield cultivation. Because of the climate and growth period of rice varieties, the rice in double cropping cultivation area usually has the characteristics with difficulty to have a flourishing growth at previous period, too many of ineffective tillers at middle period and early senescence at later period. So, super hybrid rice varieties were used as the study materials to study the effects and mechanism of special raising seedling fertilizer on improving the seedlings quality and the growth at previous period, formula, screening and application of rice tiller-inhibitor, the optimal regulation techniques of fertilizer and irrigation for controlling tiller and high yielding, the techniques of "three control" combination to control ineffective tillers, the cultivation model integration of "three high one ensure"(eg. SGYB) and its effects, the high yielding and quality mechimism SGYB cultivation model by the method of combining field experiment with lab analysis, around the core of "three high one ensure" namely high percent effective panicle, high seed setting rate, high grain plumpness and ensure of high quality, and on the basis of development of the special raising seedling fertilizer and the materials of tiller-inhibitor. The main research results are followings:(1) Special raising seedlings fertilizer improved the number of the tiller and the quality of the seedlings, increased the number of roots and the dry weight of aerial parts, improved the physiological activity and stress resistance of seedlings, and promoted the flourishing growth after transplanting so as to increase the grain yield. Moreover, the analysis of two-dimensional electrophoresis and mass spectrometry found that16differential expression proteins were identified. And the relative function analysis of those proteins indicated that the special raising seedlings fertilizer improved the amount of protein expression, subsequently improved the seedlings quality and flourishing growth after transplanting.(2) The formula of rice tiller-inhibitor which can control tillering, increase number of spikelets per panicle and grain yield had screened out by prescreening, screening and improving. Additionally, its application method was preliminarily worked out, namely:750kg/hm2tiller-inhibitor solution with the concentration of2g/kg will be sprayed at the critical leaf age of effective tiller or when the number of tillers is same to the planned number of panicles; or, split spraying by two times, half sprayed at the period stated above, and the other half sprayed after3-4d. Additionally,"rice compound tiller-inhibitor" had applied the national patent for invention (Bulletin No.:CN101444209). It would provide the technological support on tiller chemical control.(3) A rational fertilization management model of N, K fertilizer and an optimal irrigation model were worked out. The rational fertilization management model of N, K fertilizer was.base fertilizer: tillering fertilizer:panicle fertilizer:grain fertilizer=5:2:2:1. The optimal irrigation model was ahead of drying field and water-saving irrigation. Both this fertilization management model and the irrigation model were in favor of controlling ineffective tillers, improving percent effective panicles and grain yield.(4) Whatever measures of tiller control including chemical control, water control and fertilizer control could obviously reduce the number of ineffective tiller, and increase the percent of effective panicles and grain yield, and the chemical control was best in effect, followed by fertilizer control and water control. Furthermore, three kinds of tiller control method showed the synernies interaction at a certain extent, and the effects of combination with three tiller control methods were optimal.(5) The SGYB cultivation model of double cropping rice was integrated, and it had already obtained the national patent for invention (patent NO.:ZL200810136592.4). This model could promote the flourishing growth at previous period, decrease the number of ineffective tillers, increase the percent of effective panicle, seed setting rate and grain plumpness, and improve the grain yield and the rice quality, compared to conventional cultivation model.The rice under SGYB cultivation model possessed the following characteristics compared to conventional cultivation method:first, the LAI in the whole growth duration was higher, and the SPAD and Pn value in the whole growth duration were higher except in the period of ineffective tillering. Therefore, dry matter was more and the export ratio of dry matter in stem and sheath was higher, accordingly the proportion of dry matter transported to panicles was higher. The dry weight of roots was more and the activity of roots were stronger, so the rate and amount of absorption for nutrient in the whole growth duration were higher except from the N-n leaf stage to enlongation stage. Secondly, the grain filling rate was higher during grain filling period, the matter deposited in stem and sheath was more, the export rate was faster at previous period but slower at later period, the activity of APDGPase and Ssase in grains was stronger, the content of IAA、iPA、Z+ZR、GAs in grains was higher, but the content ABA was lower, and the senescence rate of leaves, roots and grains during grain filling period was lower. All these were the performances of the vigorous population characteristic during later period. Thirdly, the light transmittance between rows was higher but lower between hills, and the average light transmittance was also higher. The plant height and the length of basal stem internodes increased slightly but not significantly. The incidence of sheath blight was lower, and the ability of lodging resistance was stronger. Analysis found that the probable mechanisms of the high yielding and quality for SGYB method were promoting the flourishing growth after transplanting because of high seedlings quality cultivated with special raising seedlings fertilizer; controlling the ineffective tillering, improving root growth and panicle formation, increasing percent of effective panicle and matter amount in stem and sheath because of combinated with application of three tiller controlling measures; constructing population for high photosynthetic efficency, improving population ecological conditions, delaying organ senescence progress,increasing filling matter amount and promting seed filling during later period because of the high percent of effecfive panicle and the application of intergreted techniques.