Study On The Characteristics Of Yield Form And Quality Of Different Growth Period Types Japonica Rice

The experiments were tested in the experimental farms of Yangzhou university during 2003-2004, the soil type is the sandy loam, soil fertility medium, the following wheat, This experiment was carried out by using 104 japonica genotypes as materials under 4 nitrogen levels including zero(0kgN/666.7m2 ), low (10kgN/666.7m2 ), medium (15kgN/666.7m2 ), high (20kgN/666.7m2 ), The experiments have also studied the yield and quality of differences japonica rice, as well as the responses of the yield and quality of different growth period type japonica to the nitrogen, so as to analysis synthetically and filtrate the variety of high yield also excellent quality japonica rice. The main results were as follows:(1) Based on the whole growth period under medium N-level and Dingying`s Standard of classification of rice growth types, japonica rice used in the experiment can be classified into five types including early-maturing medium japonica, medium-maturing medium japonica, late-maturing medium japonica, early-maturing late japonica and medium-maturing late japonica. Calculate from the whole growth period ,the japonica rices were used could be safe to mature, the number of growth days of early-maturing medium japonica is 129.4, the medium-maturing medium japonica is 140.9, the late-maturing medium japonica is 149.3, early-maturing late japonica is 159.5 and medium-maturing late japonica is 171.2.With nitrogen levels to improve at the same time, there were significant differences in the whole growth period and the spans of total growth period of different varieties japonica were obviously prolonged, low-level treatments of N-fertilizer were prolonged averagely 1.8 days more than that of zero-level treatments, medium-level treatments were prolonged averagely 4.4 days, high-level treatments were prolonged averagely 6.8 days, range of lengthened growth period is shows a tendency to increase gradually with N-application increase. According to growth period structure , the employ nitrogen treatment is helps to promote the japonica rice to tassel contrasts with does not construct the nitrogen treatment, but construct the nitrogen level to improve, tassel-ripe days are lengthened gradually, so the tassel period was delayed instead. The degree of influence on amount of nitrogen to the growth period types is: medium-maturing late japonica>early-maturing late japonica>late-maturing medium japonica>medium-maturing medium japonica > early-maturing medium japonica.(2) Among different growth period types, the grain yield shows a tendency to increase with the extension of the growth period. Grain yield of the early-maturing medium japonica getting the lowest, and medium-maturing late japonica getting the most, the max is more than minimum by 68.6% in grain yield, the order of japonica rice grain yield is: medium-maturing late japonica > early-maturing late japonica >late-maturing medium japonica>medium-maturing medium japonica > early-maturing medium japonica. But the yield of some early-maturing varieties are higher than some late-maturing varieties, for example yueguang, yanjing204, wu99-2, huangjinqing, aiyou39, xudao3, huajing2, zhendao99, 69you8, nannong4030, wuyunjing8, nanjing39, yangfujing4928,yanyou1, yangjing9538,Ⅲyou98, yanyou2 and siyou418.With N-application increasing, the grain yield of the majority early-maturing medium japonica,medium-maturing medium japonica,late-maturing medium japonica,early-maturing late japonica shows a tendency to increase, the yield of medium-maturing late japonica shows increase first and then decrease. In medium N-application, the yield reaches most and drop in high N-application, fall in 2.1%. The yield of early-maturing medium japonica is the lowest and medium-maturing late japonica is the highest in all of N-fertilize treatments.(3) Among the different growth period types, the magnitude order of ear number per mu is medium-maturing medium japonica≈medium-maturing late japonica > late-maturing medium japonica >early-maturing medium japonica > early-maturing late japonica. The number of grain number per ear of early-maturing late japonica is the highest; is 194.1, the lowest number is 129.1 of early-maturing medium japonica. the magnitude order of grain number per ear is : early-maturing late japonica>medium-maturing late japonica>late-maturing medium japonica > medium-maturing medium japonica > early-maturing late japonica. With the growth period prolonging, seed setting rate of rice was first increase and then decrease. The magnitude order of seed setting rate of rice is late-maturing medium japonica>early-maturing late japonica>medium-maturing late japonica>medium-maturing medium japonica>early-maturing medium japonica. The number of 1000-grain weights increase according to growth period.Among N-fertilize treatments, ear number per mu is increased according to N-application levels. Grain number per ear of early-maturing medium japonica and medium-maturing medium japonica shows a tendency to increase with N-application, late-maturing medium japonica, medium-maturing late japonica and early-maturing late japonica shows first increase and then decrease. The number drop in high N-application treatment by 2.0%, 2.9%, 6.2%. The magnitude of seed setting rate of rice and 1000-grain weights were increase according to N-application.(4) With the growth period prolonging, milling quality shows increase tendency, the number of brown rice rate (BR), milled rice ratio (MR) and head rice ratio (HRR) of early-maturing medium japonica is the lowest and medium-maturing late japonica rice is the most. The later is higher than the former separately 2.3%, 5.7%, 21.1%. the sequence of milling quality is medium-maturing late japonica > early-maturing late japonica >late-maturing medium japonica>medium-maturing medium japonica> early-maturing medium japonica. Among the N-fertilize levels, BR, MR and HRR of early-maturing medium japonica rice, medium-maturing medium japonica rice, late-maturing medium japonica rice and early-maturing late japonica rice were increase according to N-application. Medium-maturing late japonica milling quality is first increase according to N-application and then decrease in high N-fertilize. The separately drop extent of BR, MR and HRR is 1%, 1.2% and 4.1%.Among the different growth periods types, the appearance quality shows as follow, the value of Chalk area(CA) is decrease according to growth period prolong, chalk rate(CR) and chalkiness(C) is first increase and then decrease. The sequence order is late-maturing medium japonica rice>medium-maturing medium japonica rice>early-maturing medium japonica rice>early-maturing late japonica rice>medium-maturing late japonica rice. Construct it among the N-fertilize levels, all varieties CR is raise with the N-application increase, CA and C were first raise and then decrease. The amylase content is first increase and then decrease among growth period types. The sequence order of amylase content is late-maturing medium japonica rice>early-maturing late japonica rice>medium-maturing late japonica rice>medium-maturing medium japonica rice>early-maturing medium japonica rice. Protein content is gradually decrease along with growth period prolong. Gel consistency is lengthened along with growth period prolong, but the difference is not significant among growth period types. Among the N-fertilize treatments, amylase content is decrease with N-application improves, protein content is increase and Gel consistency is lengthened.The starch viscosity characteristics among growth period types were show as follow: the breakdown is decreases with the growth period prolonging, setback shows increase and pasting temperature shows decrease. The breakdown is first decrease and then increases with the N-application improve, and reach the lowest value in the medium N-fertilize, the effected trend of setback is contrary to breakdown. The pasting temperature is increases with the N-application improve, but there were not significant differences in N-fertilize treatments.(5) Integrate analyze all varieties in the four N-fertilize treatments, the variety that steady shows high yield and quality is as follow: wu99-2 of early-maturing medium japonica rice; zhendao99 and huajing2 of medium-maturing medium japonica rice;yanyou1,Ⅲyou98, 69you8 and siyou418 of late-maturing medium japonica rice; 86you8 and 99-295 of early-maturing late japonica rice; changyou02-6, changyou1 and wuyu2105 of medium-maturing late japonica rice.