| Rice is one of the important food crops in the world.With the improvement of social progress and living standard,people pay attention not only to the quality of rice,but also to whether rice is rich in many functional nutrients.Functional rice can meet a variety of needs,in addition to the characteristics of general rice,but also have functional components,it can regulate the various functions of the human body.therefore,it is of great significance to carry out the excavation of functional nutritional quality QTL/ genes in rice to cultivate new rice varieties by molecular means.In this study,the contents of resistant starch,total flavonoids,glutenin,and ?-aminobutyric acid in rice were determined using 108 natural populations of cultivated rice.combined with 69 polymorphic SSR markers,the trait-marker association analysis was carried out through TASSEL3.0 GLM and MLM models based on population structure and relationship analysis.The high / low resistant starch varieties Longjin1 and D109 were used as test materials,respectively,in the early stage of rice filling,milk maturity,wax maturity and yellow maturity,to determine the content of resistant starch,and to verify some genes by transcriptome sequencing and q RT-PCR,so as to lay a foundation for the excavation and utilization of resistant starch synthesis related genes.The main findings are as follows:(1)Ten high-resistance starch varieties were selected by means of average value measured in the two years from 2017 to 2018.The representative varieties were Hypoglycemic Rice,P121,Longjin 1,Hua Mang,etc;Ten low-valley protein varieties,such as Longxiang Rice 1,Hongxian 4,Wanxuan 4,Rice Hua Xiang,etc;Ten varieties of high total flavonoids,such as Dongnong 425,Carmine Rice,Changbai 10,AC-1,etc;Ten varieties of high ?-aminobutyric acid,such as B137,Xiangmang Rice,Dark red Rice,etc.Among them,five varieties,AC-1,Carmine Rice,Hongxian 4,Long Rice 12 and Xiangmang Rice,have two or three excellent nutritional components.(2)Using the Tassel 3.0 GLM and MLM models,a total of 31 loci were detected that were significantly associated with 4 functional nutritional quality traits,cumulative 61 significant associations,and were distributed on all 12 chromosomes of which 13 loci were simultaneously detected in both models.Among them,there were 5,5,7 and 2 loci significantly associated with the contents of resistant starch,total flavonoids,glutenin and ?-aminobutyric acid,respectively.Eight loci were significantly associated with two or more traits.(3)The two models detected 13 loci at the same time and excavated 29 related excellent alleles as well as representative carrier materials.Among them,we found carrier materials carrying multiple excellent allele variants,such as Hypoglycemic Rice carrying 3,B137 carrying 2,Hua Mang carrying 3,Hongxian 4 carrying 5,AC-1 carrying 3,Carmine Rice carrying 6,P121 carrying 7 excellent alleles.(4)Using the selected high / low resistant starch content varieties Longjin 1 and D109 to determine resistant starch content and transcriptome sequencing at four stages: early filling stage ? milk maturity stage? wax maturity stage? yellow maturity stage,According to the m RNA sequencing results,241.59 Gb data were obtained,High / low resistance starch varieties had 1849 differential genes in the early stage of grouting? 3063 differential genes in milk ripening stage? 7179 differential genes at the wax ripening stage? and 1027 differential genes at the yellow ripening stage.The dynamic changes of differential genes were observed,and the number of differentially expressed genes in the early stage of grouting,the period of milk ripening and the period of wax ripening showed an increasing state,and the number of differentially expressed genes reached a peak in the period of wax ripening,while the number of differentially expressed genes in the period of yellow ripening tended to be stable,which was consistent with the change trend of resistant starch content.analysis of differentially expressed genes in different reproductive periods of different materials,the results showed that genes were specifically expressed in 4 reproductive periods,and the enriched GO entries had similarity,but the number of genes contained in each entry was significantly different,and most of the related genes were up-regulated in high resistant starch materials.(5)Eight differentially expressed genes were selected for quantitative verification by q RT-PCR,The quantitative results were basically consistent with the transcriptome sequencing results,showing that the transcriptome data are authentic and reliable. |
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