| Grain shape is an important economic character,which is closely related to the yield and quality.Indica rice,especially early indica rice,is characterized by long grain shape and long width ratio more big.The difference is determined by indica japonica attribute or affected by ecological environment.So far,no conclusion has been reached.In this paper,a recombinant inbred population of Shennong 265 and Shanghai Hui 99 hybrid constructs(RILs)as test materials,the effects of environmental factors on the population of recombinant inbred lines such as grain shape traits in indica japonica and its relationship with property,identification of different environments by regulating the expression of grain shape of QTL,and analyzes the relationship between the various regions grain shape and grain yield and quality traits.The main results are as follows:1.The regional difference of grain size in four area showed that the grain length of Shenzhen was significantly larger than that of Sichuan,Jiangsu and Shenyang,and the grain length of Sichuan was significantly larger than that of Shenyang and Jiangsu,and there was no significant difference in grain length between Shenyang and Jiangsu.The grain width of Shenyang was significantly greater than that of the other three regions,and the grain width in Sichuan was significantly greater than that of Jiangsu and Shenzhen;there was no significant difference between Jiangsu and Shenzhen.The length width ratio of Shenzhen is significantly larger than that of the other three regions.The aspect ratio of Shenyang is significantly less than that of the other three regions,and the aspect ratio of Sichuan is not significantly different from that of Jiangsu.The grain thickness of Shenyang and Shenzhen was significantly greater than that of Sichuan and Jiangsu.There is no significant difference between the grain thickness of Shenyang and Shenzhen and the 22 regions of the grain thickness of Sichuan and Jiangsu.2.using iMetos Agrometeorological station to collect and record the environmental factors of each strain of RILs from heading to maturity for 45 days in 4 regions.Relative to light and humidity,the temperature in 4 areas is more stable.The average temperature is Sichuan > Shenzhen > Jiangsu > Shenyang.During the whole monitoring period,the maximum temperature difference between night and night is Shenyang,and the diurnal temperature difference of Shenzhen has been at the lowest level.On the whole,the aspect ratio has a significant negative correlation with solar radiation,light intensity,illumination time,diurnal temperature difference and night humidity,and has a significant positive correlation with humidity in the day.In each area,most of the environmental factors have a significant relationship with the grain length.The relationship between the length width ratio and the environmental factors was not closely related,but the length width ratio of Sichuan was negatively correlated with the light time and the night humidity.3.according to the indica and japonica specific snp markers,RILs was divided into japonica type,indica japonica middle type and indica type three types,and the relationship between indica japonica properties and grain shape was studied.The length width ratio of Shenyang indica type was significantly greater than that of indica japonica middle type and japonica type.The grain width of Sichuan indica type was significantly smaller than that of indica japonica middle type and japonica type.The grain length and length to thickness ratio of Jiangsu indica type were significantly larger than those of middle type and japonica type.The grain width and grain thickness of the indica type in Shenzhen were significantly smaller than that of the intermediate type and the japonica type.On the whole,the frequency of the indica type in Shenyang was positively correlated with the ratio of length to width,but significantly or significantly negatively correlated with the grain width and width ratio.The indica frequency in Sichuan was negatively correlated with the grain width,and the indica frequency in Jiangsu was significantly correlated with the ratio of length to thickness.The indica frequency in Shenzhen had a significant negative correlation with grain width and grain thickness.This study showed that with the increase of the indica type frequency,the grain shape changed more and more elongated.The population size distribution of RILs was very small in Shenyang long grain lines,and significantly smaller than that in the other three regions.However,the long grain lines in Shenzhen were significantly higher than those in the other three regions,with short circles and very few,which had opposite trend with Shenyang.The distribution of three indica and japonica types in the long and long grains in the 4 regions is relatively balanced.4.under 4 environmental conditions,the grain shape traits were QTL.Including 26 long width ratios QTL,first,second,third,5,9,10,12 chromosomes,the LOD value is between 3.51 and 35.07,the additive effect value is-0.1 0.08,and the single contribution rate is 1.66% 35.58%.The 15 grain length QTL is located on the third,fifth,seventh,8 and 10 chromosomes.The LOD value is between 2.81 and 9.85.The additive effect value is-0.10 0.08,and the single contribution rate is 4.11%-18.85%.20,the QTL that controls grain width is located on chromosomes second,third,fifth,6,9 and 12.The LOD value is between 2.95 and 29.19,and the additive effect value is-0.03 0.11.The single contribution rate is 2.11%-39.02%.Among them,the qLW12 a locus was detected in 4 environments,and had great contribution to the phenotype.The stable expression of QTL with long to wide ratio could provide a theoretical basis for marker assisted breeding.5.the relationship between grain size and yield in different regions is: Shenyang grain width is positively correlated with 1000 grain weight,but negatively correlated with grain number per spike.The ratio of length to width and ratio of length to thickness is negatively correlated with 1000 grain weight.Grain width was positively correlated with 1000 grain weight,but negatively correlated with grain number per spike.There was a significant negative correlation between length width ratio and 1000 grain weight,while the width to thickness ratio had a significant positive correlation with 1000 grain weight in Sichuan.There was a significant positive correlation between grain width and 1000 grain weight in Shenzhen,and a significant positive correlation between grain length and grain number per spike.The correlation between grain shape and yield in Jiangsu did not reach a significant level.6.the relationship between grain shape and quality in different regions is: Shenyang grain length,aspect ratio,ratio of length to thickness are negatively correlated with processing and appearance quality,and grain width has a significant positive correlation with the quality of processing and appearance.There was a significant positive correlation between the length width ratio and the gel consistency and the alkali elimination value,and a significant negative correlation with the amylose content.There was a significant negative correlation between grain width and gel consistency.There is a significant negative correlation between the length width ratio and the head milled rice rate,chalkiness rate and chalkiness.The grain thickness is significantly positively correlated with amylose,brown rice rate,chalky grain rate and chalkiness,and is negatively correlated with gel consistency and alkali dissipation value in Sichuan.There is a significant negative correlation between Jiangsu length width ratio and chalky grain rate and chalkiness.Grain thickness is highly positively correlated with brown rice rate,chalkiness and amylose content.Shenzhen grain width and grain thickness have a significant positive correlation with the quality of processing and appearance. |
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