Effects Of Reduction Of Nitrogen Fertilizer On Plant Type Characters, Yield And Grain Quality Traits Of Crossbred Progeny Of Liaojing 5 And Akita Komachi

The recombined inbred line(RIL)population derived from the cross of Liaojing 5,the most representative panicle rice variety in Northeast China,and Akita Komachi(curve panicle type),a famous good quality rice variety in Japan,were used as the test materials.To provide a theoretical basis for timproving breeding and cultivation measures of high-yield,lodging-resistance and high-quality rice varieties under the environment of nitrogen fertilizer reduction.The change rules of plant type traits,panicle traits and lodging resistance traits of the RIL populations in different fertilization patterns were analyzed,and further more,the relationship between these characters and yield or rice quality traits was analyzed.The results showed that in different fertilization patterns,the plant type traits,panicle traits,lodging resistance traits,yield,and quality traits of the RIL populations were all separated and recombined.Individuals with different plant traits,yields,and quality traits can be selected through crossbreeding of Chinese and Japanese rice varieties.In the strains with reduced nitrogen fertilizer application,the plant height became shorter;the leaves(sword leaves,top 2 leaves,and top 3 leaves)became shorter and wider;the number of panicles decreased,the seed setting rate,1000-grain weight,and economic coefficient increased,and the biological yield and economic yield decreased.The height of the center of gravity decreased,and the bending moment and lodging index decreased.The higher yield lines have larger sword leaf base angles,top 2 leaf base angles,longer leaf lengths,and more primary branch numbers;Good-quality rice plants with higher plant height,smaller panicle currature and leaf-base angle,narrower leaf width and longer head length;Plants with stronger lodging resistance have lower plant height,lower height of center of gravity,smaller panicle currature,wider and shorter leaves,shorter spike length,lower yield,higher economic coefficient,and lower taste value.Rice plant height,panicle length,leaf length of upper three leaves and draping degree of sword leaf,and high yield and high taste value strains were significantly higher than those of low yield and low taste value strains.In the high-fertilizer pattern,the high-yield and high-taste-value plants have higher plant height,larger panicle curvature,larger leaf base angle,longer and narrower leaves,longer spike length,and higher primary and secondary seed setting rates.;In the low-fertilizer pattern,the plant type characteristics of the high-yield and high-taste-value strains had higher plant height,narrower leaf length,and higher primary seedling number.The high-yield and stable-producing strains have larger sword leaf angles,narrower leaf widths,and larger lodging index in the first section of the base.