| Japonica rice has characteristics of good rice quality and high commodity rate and it plays an important role in ensuring grain security of our country.Our country has many japonica rice varieties,but fewer varieties with large popularization area and wide adaptability,which has a direct relationship with the wide distribution of japonica rice,big climate difference and poor ecological adaptability of cultivars.In this study,12 japonica new strains and 1 control variety were planted in 7 experimental sites in 4 provinces of Tianjin,Beijing,Hebei and Shandong,respectively.The yield,yield components and rice quality characters of different materials were investigated in different experimental sites,and the stability of yield and quality characters in different regions were analyzed,as well as the influence of different characters on the cultivated environment.The meteorological data of each test site were collected to analyze the relationship between temperature and light conditions and rice yield and quality characters,and to further analyze the relationship between protein,starch and starch characteristics and rice quality characters,so as to provide a scientific basis for improving the ecological adaptability of rice varieties and exploring the factors affecting rice quality.1.The yield and yield stability of 13 rice materials were analyzed.Two of the 12 japonica strains had better yield than the control varieties,and the coefficient of variation was similar to the control with better high yield and stable yield.Four strains had similar yield to the control varieties,and the coefficient of variation was less than 10% among the seven test sites,and had better ecological adaptability,which was expected to be widely suitable varieties to be widely promoted.Effective panicle number and grain number per panicle may be the important factors affecting the yield difference of rice in different ecological zones.The mean coefficients of variation of effective panicle number and grain number per panicle of each rice material were26.31% and 28.06%,which were much higher than the seed setting rate(8.10%)and 1000-grain weight(6.17%),indicating that effective panicle number and grain number per panicle were easily affected by the cultural environment.The seed setting rate and 1000-grain weight were mainly affected by rice genotypes.2.The processing quality of 12 new japonica rice strains was not obviously better than that of control varieties.However,the appearance quality of most strains was better than that of control varieties,indicating that breeding units paid more attention to the selection of rice appearance quality.The stability of quality traits of 13 rice materials was analyzed.The processing quality of rice materials in different regions had little difference.The mean coefficients of variation of brown rice rate,mished rice rate and whole mished rice rate were1.08%,4.04% and 8.19%,respectively.The variation coefficients of chalkiness and chalkiness were 56.26% and 59.06%.These results indicated that the appearance quality of rice was easily affected by environmental differences in different regions,while the processing quality was stable in different regions.The protein content of the 12 new strains was higher than that of the control varieties,but the amylose content was lower overall,and only one strain was better than the control,indicating that the influence of protein on the taste may be greater,and the coefficient of variation of protein was greater than that of amylose,indicating that protein is more susceptible to the influence of cultural environment,and it is feasible to improve the taste quality through reasonable cultivation measures.The texture properties of 12 rice strains were worse than that of the control,most of the rice hardness was greater than that of the control,the viscosity of 2 rice strains was greater than that of the control,and the balance of 2 rice strains was better than that of the control.he relationship between agronomic traits and quality traits of rice was analyzed.The results showed that the varieties(lines)with short ear in this study had better appearance quality and processing quality,and the yield was significantly positively correlated with the balance and taste value of rice,indicating that the improvement of yield and quality was not contradictory.3.Meteorological data of different experiments were collected to analyze the relationship between temperature and light conditions and rice yield and quality.There are obvious differences in the planting and growth period of rice in different areas,and the two places with the biggest difference have an average difference of 28 days in the whole growth period of rice.Affected by the difference of temperature and light between regions,there are great differences in rice yield and quality between different areas,and the overall yield shows Shunyi > Tanghai >Funing > Ninghe > Jinnan > Kenli > Baodi.In terms of yield composition,Funing has the largest number of effective panicles,but the least number of grains per panicle.Baodi field has the best number of grains per panicle,but the worst number of effective panicles.In this study,with the increase of average daily temperature,the rice yield and effective panicle number showed a decreasing trend,while the seed setting rate showed an increasing trend.With the increase of effective accumulated temperature,the effective panicle number showed a decreasing trend,and the grain number per panicle showed an increasing trend.Sunshine hours showed a significant positive correlation with the yield,effective panicle number and grain number per panicle.The rice material processing quality of Kenli was better,while the appearance quality of Tanghai was better.The protein content of the rice material of Kenli was higher than that of other areas,while the amylopectin content was lower than that of other areas.The food taste value of the rice material of Funing was higher.The correlation analysis between temperature and light conditions and each quality character showed that,with the increase of daily temperature,the processing quality of rice showed a trend of decrease,while the appearance quality showed a trend of increase,and the increase of temperature promoted the accumulation of protein in rice and reduced the accumulation of amylose,and the increase of effective accumulated temperature had a trend of decrease in taste value,while the temperature and light conditions had no significant correlation with the texture characteristics of rice.4.The relationship between rice protein and rice quality characters was analyzed.The results of this study showed that with the increase of protein content,the processing quality and appearance quality of rice were improved,the viscosity and elasticity of rice were increased,and the balance and taste value of rice were decreased.There were certain differences in the relationship between different protein components and rice quality,and the alcohol soluble protein was negatively correlated with the processing quality,while the gluten content was positively correlated with the processing quality.All protein components were negatively correlated with chalkiness and chalkiness,globulin and glycolin were significantly positively correlated with hardness of rice,gluten was significantly positively correlated with viscosity and elasticity of rice,and gluten was significantly negatively correlated with balance of rice5.There was no significant difference in the starch effector maps of rice planted in different regions,and all of them were consistent with A-type diffraction maps.The peak locations were mainly 13°-25°,and obvious diffraction peaks were observed at 15°,17°,18° and 23°.The diffraction intensities of 17° and 18° were the strongest,followed by those of 23° and 15°.However,the starch crystallinity of rice planted in different regions was different.The grain planted in Jinnan had better crystallinity,while the grain planted in Shunyi had lower crystallinity.The relationship between starch characteristics and rice quality of rice grown in different regions was analyzed.The crystallinity of starch was significantly negatively correlated with the appearance quality,the viscosity and elasticity of rice were significantly positively correlated with the dilatancy of starch was positively correlated with the processing quality of rice,and the chalkiness and chalkiness were significantly negatively correlated with the production of chalkiness,which indicated that the production of chalkiness would inhibit the expansion of rice starch during the hydrothermal process.The water solubility was negatively correlated with the processing quality.The increase of amylose content decreased the processing quality and appearance quality of rice,which decreased the viscosity and elasticity of rice and inhibited the expansion of starch. |
