Analysis Of Grain Shape Gene Pyramid Effect Based On Single Segment Substitution Lines In Rice

Rice(Oryza sativa L.)is one of the most important food crops in the world.With the population growth and people’s demand for rice quality,breeding for high-yield and high-quality rice varieties have become one of the main targets of rice breeding.However,the results of the pyramiding of quality genes are often restricted by the inter-gene epistasis.In this study,rice single-segment substitution lines were used as materials to construct epithelial effects between grain-shaped genes by constructing grain shape gene-pyramiding lines and analyzing grain-shaped mutations to reveal the genetic patterns of these genes,which are high-yield and high-quality rice.Molecular pyramiding breeding provides theoretical basis and material basis.The main findings are as follows:1.A total of 74 multi-segment pyramided materials were obtained,of which 36 homozygous pyramided lines were used for the grain shape investigation.2.Seven single-segment substitution lines have significant additive effects,two are high-yield and high-quality genes(q LGY3 and gs3),two are high-quality genes(GW7 and gw8),one is high-yield genes(GS2).3.A batch of high-yield and high-quality pyramided lines were selected,and the pyramided lines such as GS2/GW7,GS2/GS5,gs3/gw8/GW7,gs3/GL3.1/GW5/GW7/gw8,etc.,can be used for specific target pyramiding breeding.4.Grain shape epistasis is common.Most of the epistasis is characterized by reduced grain shape.Only the epistasis of GLW7/GW5 and GLW7/GW7 increases the grain length,and the epistasis of gs3,gw8 and other genes narrows the grain width;GW5 and The epigeneity of other genes increases the 1000-grain weight.This study further confirmed the grain-shaped genes of nine single-segment substitution lines,and obtained some pyramided lines of grain-shaped genes by marker-assisted.The effect analysis of the pyramided line estimated the additive and epistatic effects of the grain-shaped genes.The genetic interaction mechanism of grain-shaped genes was revealed,which provided the theoretical basis and material components for the subsequent rice-shaped molecular pyramiding breeding.