Studies On Morphological And Physiological Characteristics Of Rice Cultivars With High Yield And Good Quality

In other to quantify the optimum range of characters,the studys on the growth and development of rice,physiological characters of the plants,and the accumulation and distribution of nutrition,using 13 cultivars of high grain yield and quality,were performed.The results are as follows:1.The cultivars are devided into 3 types:firstly,it is high yield cultivar,including Liaoyan188, Liaoyou20,Liaojing326;secondly.Secondly,it is high yield and good quality cultivar,including Liaojing294,Liaojing9,Shendao2,Shendao3,Shendao8,Shendao9.Thirdly,it is high quality cultivars, including aoyou316,shendao7,shennong315,shennong8718.2.For the variety with high yield and good quality,the range of yield is 9.32-9.66 ton per hecter, panicle number per square hundred-metre is 296.16-379.20,ripened grain number is 109.60-129.97, ripened grains rate is 85.55%-89.01%.The spiklets grains per panicle,ripened grains per panicle,and primary branche number could promote grains yield's increasing.In some extent,panicle number,spiklets per panicle,ripened grains per panicle and grains yield show significant quadratic curve,when panicle number per square hundred-metre reaches 325,spiklets per panicle reaches 150,ripened grains per panicle reaches 140,grains yield could reach 10000 kg.Ripened grains per panicle and spiklets per panicle are the main factors of grain yield.The percentage of ripened grains,grain weight of primary branches are higher than that of second branches.The percentage of ripened grains,grains weight of upper are higher than that of middle and bottom.Increasing the ripened grains of inferior grains could increase grain yield effectively.3.The difference of chalkiness characters is significant.The difference of eating value,protein content, gel consistency is distinct.The protein content and gel consistency of middle-yield cultivars are higher.For the variety with high yield and good quality,the range of brown rice rate is 81.13-82.22%,head rice rate is 65.77-67.22%,percentage of chalky kernel is 9.28-19.94%,chalkiness is 1.48-3.44,gel consistency is 17.50-17.76%,amylase content is 78.03-84.67cm.Rice cultivars with high brown rice rate,high milled rice rate,high chalkiness grain rate and chalkiness area,high eating value,and low protein have high grain yield. Met content,Leu content,Phe content and Lys content have significant negative effect on spileket grains per panicle,eating value,which is extremely significant positive on protein content.Adjusting panicle number,ripened grains per panicle,spikilet per panicle,grain weight could increase grain yield,milling, cooking and eating qualities,so it could coordinate high grain yield and quality.4.For the variety with high yield and good quality,the range of angle of panicle and culm is 41.52-54.4,angle of flag and culm is 14.19-20.37,angle of second leaf and culm is 12.71-15.39,primary rachis branches is 12.03-14.58,second rachis branches is 19.73-26.77,spiklet density is 7.72-8.89,spiklets per centimeter.It is negative relative relation of plant type characters,leaf characters and grain yield and quality.The grain yield,ripened grains per panicle,percentage of ripened grains,1000-grain weight, milling quality,appearance quality,cooking and eating quality of rice varieties will be lower,which is with larger angle of panicle and culm,larger angle of flag and culm,larger angle of second leaf and culm,larger angle of third leaf and culm.The 1000-grain weight,dry matter weight increases with longer and wider leaf, larger leaf area and LAI,leading to high grain yield.The chalkiness characters increase with larger leaf area and longer grains,and the eating value and amylase content are higher,the protein content,gel consistency and alkali apeeding value are lower. There is closed correlation of panicle characters and grain yield,or quality.There is more ripened grains per panicle and spilikets per panicle with more branches,spiklets density is larger,so grain yield is higher.The quality is worse with longer panicle.The cultivars with high branches number,ripened grains per panicle,spilkilets per panicle and spiklets density have high milling quality,high chalkiness,high eating value,high protain content,and gel consistency of which is lower.There is little difference of other quality characters.The grain yield,milling quality,chalkiness,eating value,protein content and gel consistency reach superior value,when panicle is 55-57°,primary branches is 12-13.5,secondary branches is about 34,spiklets density is 8.2-9.7 grains per cm.5.Leaf-cutting lowers the percentage of ripened grains and grain weight,especially influences greatly on the grains of late flowering.The order of the effect that leaves contributed to grain filling is the flag＞the second leave from the top＞other leaves.Cutting all leaves significantly increases empty grain percentage. Partially cutting leaf treatment have greater effect on percentage of shrunken grain.The accumulation matter weight shows in "logistic" curve,which is low before heading and then entered into advancing rapidly accumulation stage at 7-14 days after heading,the speed lowers at 21-28 days after heading.The accumulation amount of dry matter in various positions' grains is different, upper＞middle＞bottom,primary rachis branches＞second rachis branches.The filling rate shows different law,which of Liaoyou20 shows 'double-peak' curve,others 'single-peak' curve.The chlorollyll content reaches the highest 7-21 days after heading,then lowers.The leaf area and leaf area index show the same law:full heading stage＞filling stage＞booting stage＞ripening stage.Stomata conductance,stomata resistance,transpiration rate at full heading stage is high,leading to high net photosynthesis rate.There is closed correlation of leaf area index and grain yield,quality.In some extent increasing leaf area index could promoted grain yield and quality.The transporting matter weight of panicle is the highest,then that of leaves,that of culm is the lowest. Leaf is the main exporting organ to panicle,culm is also the exporting organ to panicle.There is some matter accumulation in the culm of Liaojing294,Shennong315,Shennong8718,Shendao7 at latter stage. The ratio of weight of culm or leaf,showed gradually decreasing trend,and that of panicle and yellow leaf is opposite.6.The accumulation weight of N,or P and K,at ripening stage is higher than full heading stage.Culm is the accumulation organ of K,The accumulation weight of K is higher than that of N,P.During filling stage all nutrients(except Cu) accumulated,and the accumulation weight of Mg is too high to the accumulation weight of N,or P.The accumulation weight order is Mg＞Mg＞Fe＞Cu.There is closed correlation between accumulation weight of N,P,K,Fe,Mn,and grain yield,quality.It is the way to improve grain yield and quality with increasing the nutrients.