Genetic separation of chalkiness by hybrid rice of Huanghuazhan and CS197

The present study focused on the segregation of the percentage of grains with chalkiness(PGWC),using Huanghuazhan as the female parent and CS197 as the male parent to construct the hybrid rice F2 population.Molecular markers were used for genotype analysis among the extremely low and extremely high PGWC individuals from the F2 population.The results revealed that the genotypes of 10 extremely low PGWC individuals were 80.00%and 3.33%,which is identical to Huanghuazhan and CS197,respectively.The heterozygotes accounted for 16.67%.On the contrary,the genotypes of 10 extremely high PGWC individuals were 37.78%and 32.22%,which is identical to Huanghuazhan and CS197,respectively.The heterozygotes accounted for 30.00%.The extremely low and extremely high PGWC individuals had high coincidence with the corresponding F2:3 family lines in phenotype and genotype.Scanning electron microscopy(SEM)images showed that the shape and spacing of starch granules in the extreme low and high PGWC individuals corresponded to Huanghuazhan and CS197,respectively.Correlation analysis showed that the F2 individuals showed a normal distribution trending towards Huanghuazhan.The broad heritability sense was 26.31%,and the narrow heritability sense was 17.21%.The results of cluster analysis showed that the range of PGWC variations of group III based on phenotype varied from 5.66%to 50.00%with an average of 25.46%,and group II results based on genotype varied from 14.34%to 60.67%with an average of 32.33%.Groups II and III shared 28 identical individuals.

Genetic Evaluation of Starch Synthesis-Related Genes and Starch Quality Traits in Special Rice Resources

The genetic diversity of 36 rice landraces and 43 breeding materials in the upper reaches of the Yangtze River in China was studied by intragenic molecular markers of 26 starch synthesis-related loci.And research on quality traits such as the amylose content(AC),gel consistency(GC)and alkali spreading value(ASV)to analyze genetic differences in quality traits.The results showed that the number of alleles,average gene diversity and polymorphism information content values of landraces were higher than those of breeding materials.The genetic similarity coefficient(GS)of 79 rice materials ranged from 0.392 to 1,with an average of 0.757.There were significant variations in the quality traits of rice landraces and breeding materials,and the high-quality compliance rates were low,only 6.3%of the varieties have an amylose content that reached grade 1.The results of cluster analysis and population structure analysis are generally consistent;that is,the two resource types are closely related and cannot be clustered independently.This study can provide a basis for genetic improvement of rice starch quality.Make full use of the quality genetic diversity of landraces in modern breeding work,further broaden the genetic base of rice and improve rice quality.