The Population Characteristics Of The Productive Ability Evolution On Single Cropping Late Japonica Rice

Test go on in the experimental farm of Yangzhou University during the year 2008-2009,the pervious stubble is wheat. Fifty early-maturing late japonica rice types which appropriate to the local temperture and light reasources on the N level of 262.5 kg ha-1 were reasurched the difference of yield and its components, matter production, nutrient element uptake, plant type with different yield types. This test will provide the theory basis and the technical references for those reasch about rice high yield and super high yield,stable yields over large areas and even the genetic improvement of high yield rice by using the methods of clustering analysis. The main result of study is as follows:1.The 50 rice types were classify into five grades which named A,B,C,DandE from lower yield to higher yield by by using the methods of clustering analysis. The amplitudes of all the five grades were:7422~ 8278 kg/hm2, 8545.5 ~8989.5kg/hm2 , 9223.5 ~ 9373.5 kg/hm2, 9585~ 10087.5 kg/hm2 and 10267.5~11047.5 kg/hm2,the average of the five yield types were 7927.5 kg/hm2,8749.5 kg/hm2,9276 kg/hm2,9856.5 kg/hm2 and 10542 kg/hm2. The yields of different single cropping late Japonica rice yield types are statistical different.The effective panicles number,grains per panicle,spikelet number and 1000-grain weight of different yield types of single cropping late Japonica rice show increases with the increase of yield, Analysis of correlation revealed that the spikelet number is the main reason for the formation of grain yield. The yield of the E type which is the highest yield type stage significantly or very significantly correlated with the panicles number,grains per panicle,spikelet number and seed setting rate,it can be concluded that reasonable collocation of all the yield's components can help us to obtain the high yield on rice.2.The dry matter accumulation at jointing stage,heading stage and maturity stage of different yield type increase with the increasing of yield, but their grown rate became smaller. The result of correlation analysis shows that the dry matter accumulation of heading have a linear correlation with yields of the five yield type of single cropping late Japonica rices.The analysis on the phasic dry matter accumulation, the date increase with the increading of yield at the three processdures which include before jointing stage,from jointing stage to heading stage and form heading stage to maturity stage,the dry matter accumlation from heading stage to maturity stage significantly or very significantly correlated with yield.The rate of the dry matter accumulation from heading stage to maturity stage curve in whole growth period bacame higher with the yield increasing quckily, and the rate of the stage which before jointing became smaller , the rate of jointing stage to heading shage have not obvious difference.3.The accumulation of the N,P,K increases with the increasing of yield on all the five yield types in single cropping Japonica rice, and the content of the three elements in the five yield types decreases at the same time.The content of the jointing stage and the heading stage,the accumuiation of the stage before jointing and the stage from heading to maturity,the rate of the N accumulation from heading to matuyity curve in whole growth period and Nitrogen Use Efficiency increase with the increading of yield as a whole, but the content of the stage of maturity decreases with the increasing of yield.The content of P element at the three main stages and the accumulation of P element at the three stage which include beform joniting,from joiting to heading and from maturity increase with the increasing of yield.There are not significant difference with the content of K element at all the main stage,but they increase with the increasing of yield as a whole,the accumulation of K element at the main three stage also increase at the same condition. The rate of the accumulation of K element from heading to maturity curve in whole growth on the high yield rices is higher then the rices whose yield are lower, the famer's rate at the stage of before jointing. It can be conclude that more accumulation of k element in later developmental stage will steengthen the culm strength, increase the power of lodging, all this seems very favorable in obtaining a high yield.4.The difference of five yield types in single cropping Japonica rice can be cincluded that the top three leaves of low yield rice are longer and narrorer then the high yield rice, ratio of length and width are biger. There is no significant difference with the plant height of all the rice, the heighe at heading stage is 100cm to 123 cm, the maturity's is a litter higher then the heading stage, 115cm to 128cm. But, we also can find that the E yield type's height whose yield is highest is not the highest, the heading stage's height is about 120cm, and the maturity stage's is about 125cm, all this seems very favorable in obtaining a high yield.Single cropping Japonica rice's appearance of plant type tend to be medium Panicle type,truncated Panicle and leaf type,medium the whole shape with the increasing of yield.