Characteristics Of Three Plant Types And Their Effects On Yield And Quality In Different Rice Varieties During Grain Filling Stage

Optimization of rice plant type is an important way to improve the efficiency of canopy interception.How to optimize the plant type through cultivation measures is of great significance to tap the high yield potential of super rice.Therefore,this study studied the plant type of different panicle varieties by the regulation of cultivation measures Three varieties were selected,which were Yongyou 2640(Extra Large Spike),Wuyunjing 24(Large Spike),Nanjing 9108(Middle Spike).This paper studied three types of canopy characteristics and photosynthetic characteristics and their yield and quality in different types of rice cultivars and the three types of canopy structures(grass cover,middle type,spike roof)were constructed by three kinds of nitrogen fertilizers,which will provide the theoretical basis and practical guidance for the high yield and quality of rice.The main results are as follows:1.For the same rice variety,the three types of plants showed the trend of grass cover>middle type>spike roof,But in terms of yield Increased,Yongyou 2640>Wuyunjing 24>Nanjing 9108,Respectively,increased by 10.1%,8.3%,5.6%.For spike roof,seed setting rate was the highest,but the number of grains per spike was minimum,grain weight per 1000 grains was the smallest,seriously restricting the yield increase.For middle type,Spike was large and the number of grains was most,but the number of panicles per hectare was not enough.For grass cover,The seed setting rate was low,but the number of spike per panicle,grain number per spike,Seed setting rate were low but the number of spike per hectare,the number of grains per spike,the grain weight were larger.As grass cover,the leaf area index and efficient leaf area index of the grass cover were high,and the leaf attenuation was slow,which provided sufficient source for the accumulation of dry matter.The net assimilation rate of the population was larger,the amount of dry matter accumulation and its proportion,population growth rate,photosynthesis potential were large.As spike roof,The transit、transit rate and contribution to grain of material transport were the highest among the three plant types,especially the three rice varieties with the contribution rate of 23.03%,32.25%and 28.46%respectively.For grass cover and middle type,the contribution rate,transit rate and contribution rate to grain were relatively high and moderate,but it was beneficial to the formation of high yield.On the single stem of the dry matter of the dynamic point of view,the middle of the various organs of dry matter quality is conducive to the formation of large spike.2.The three plant types of different panicle super rice varieties were similar,but there were significant differences among the three plant types.In the plant height and internode arrangement,The plant height of spike roof was relatively short,the top three internode were short and the percentage of the top internode was small,and the upper three leaves were short and relatively upright.For middle type,the plant height was higher,the length of the top three internode was longer,especially the top internode was the largest,and the top three leaves were longer and the drape was the highest.For grass cover,the plant height was relatively high,the length of the top three internode were longer,the length of the top internode was larger,the upper three leaves were longer and the drape is centered in the three plant types.In the distribution of leaf area on the canopy space,the leaf distribution of spike roof was pod type,and the maximum value of the stratified leaf area index was significantly lower than that of the other two plant types.The transmittance of the upper part of the canopy was largest.The distribution of the top cover of the grass cover was more concentrated,and the maximum value of the stratified leaf area index was the highest and the value was the largest.Since the point where leaf area index was the largest,leaf area index decreases rapidly,and the transmittance of the upper part of the canopy was centered,and the transmittance in the middle and lower layers was accelerated,and the light transmittance was lowest at the bottom.For middle type the distribution of leaf area in the space was relatively uniform,and the upper part of the canopy has the lowest light transmittance,but the light transmittance was reduced at ease in the whole space.3.For the same rice variety,The effect of three plant types on rice quality was significant,The processing quality of the whole milled rice,the appearance of quality and taste quality of spike roof were significantly higher than the middle type,The middle type ’s processing quality,appearance quality,taste quality were better than the grass roof.The chalky rice rate and chalkiness of the grass cover were significantly higher than those of the other two types,indicating that the grass roof could significantly reduce the appearance quality of rice.In addition,grass roof’s protein content of rice was significantly higher than that of middle type and spike roof,and the gel consistency and abatement value were significantly lower than that of middle type and spike roof,which indicated that the grass roof could significantly reduce the cooking and eating quality of rice.In general,there were significant correlations between the stem,leaf and ear of rice and the quality of rice.The quality of rice was as follows:the top three leaves and the top three internodes should not be too long,moderate length,leaf base angle and the drape should be small,leaves stand;spike length should not be too large,the number of grains per spike can not be too much,grain density can not be too compact.