Effect Of DEP1 On Canopy Structure, Yield And Quality Of Rice Population

In japonica rice breeding,the erect panicle structure is helpful to obtain higher yield.In molecular analysis,it was found that the dep1 allele was a multiple effect gene controlling the spike type,and the mechanism of increasing yield per plant by erect spike type was revealed.Compared with the yield per plant,the population yield of rice is particularly important.Therefore,in the rice breeding production,the research status of population structure on yield and quality has become more and more important.This study compared the plant type,canopy structure,material production,yield and quality of a curved panicle variety Sasanishiki(WT)and a vertical panicle mutant(crispr-dep1)edited by CRISPR / cas9 gene.The results are as follows:1.In CRISPR-dep1 plants,the angle of the flag leaf,the second leaf,the third leaf and the angle of the panicle were all less than those of WT at full heading and the ripeness stage.CRISPR-dep1 showed that the length of the flag leaf,the second leaf and the third leaf were significantly smaller than WT,while the width of upper three leaves significantly larger than WT.And the angle of the third leaf is more than the angle of the first leaf,the angle of the first leaf is more than that of the second leaf,and the width of the first leaf > the width of the second leaf > the width of the third leaf,and the length of the second leaf and the third leaf were longer than the length of the flag leaf.On the whole,CRISPR-dep1 plants showed lower plant height,shorter spike length,shorter plant type and wider leaves than wild type.Such plant type characteristics not only improved the lodging resistance of CRISPR-dep1 population,but also improved the light transmittance of the CRISPR-dep1 population.In addition,with the increase of density,the leaf angle of both plants decreased;with the increase of nitrogen application,the leaf angle of WT increased,while that of CRISPR-dep1 decreased.2.There were differences in the vertical distribution of photosynthetic radiation between WT and CRISPR-dep1 populations.At full heading stage,there was no significant difference in the vertical distribution of photosynthetic radiation between the two populations at different heights.But with the growth of the plant,the weight of the panicle increased,and the panicle type began to become curved.The difference of photosynthetic effective radiation between the two populations at different heights gradually became obvious,and the CRISPR-dep1 populations obtained the more light from the leaves under the spikes.In addition,comparedwith WT population,CRISPR-dep1 population had lower canopy CO2 concentration,higher temperature and lower humidity.This is conducive to the accumulation of photosynthetic products,promoting grain filling,and alleviating the impact of low temperature climate on crops in northern China.3.In different periods,the dry weight of CRISPR-dep1 was higher than that of WT,the dry weight of CRISPR-dep1 was lower than that of WT,and the biomass growth of CRISPR-dep1 was also higher than that of wt.it can be concluded that the economic yield of erect panicle type was always higher than that of curved panicle type.Among them,the dry weight of leaf and stem sheath of the two populations continued to decline,while the dry weight of panicle continued to increase,with the fastest growth rate 15 days after the full heading stage,and CRISPR-dep1 had a higher growth rate of dry weight in panicle than WT.The growth rate of dry weight during the full heading stage and 15 days after full heading.Compared with WT population,CRISPR-dep1 population had a higher proportion of biomass accumulation to the panicle.4.Under different cultivation methods,the yield of WT and CRISPR-dep1 population was various.On the whole,In general,the yield of CRISPR-dep1 population was higher than that of WT,and the high fertility can promote the yield of the two populations,while the high density can promote the yield of CRISPR-dep1 population,but the high density has a certain negative impact on the yield of WT population.CRISPR-dep1 had more effective panicles and grains per panicle than WT,but its seed setting rate and 1000 grain weight were lower than WT.Among them,the seed setting rate of primary branch of CRISPR-dep1 was higher than WT,while that of secondary branch was lower than WT.The number of effective panicles and the grain number of per panicle increased with the increase of fertility and density,and the high density had a positive effect on the number of effective panicles.It can be said that CRISPR-dep1 can increase the yield by increasing the number of plants per unit area,the number of effective panicles and the number of grains per panicle.Such characteristics are helpful to save land resources and realize the sustainable development of agriculture.5.This study showed that the effect of dep1 allele on the quality of rice grain had decreased,which was the result of the multi validity effect of dep1 gene.By reducing the ratio of length to width of grain,the dep1 allele improved the milled rice rate of CRISPR-dep1 to make the milling quality of CRISPR-dep1 be better.The chalkiness rate and chalkiness degreeof CRISPR-dep1 were significantly higher than those of WT,it caused that the appearance quality of CRISPR-dep1 decreased.At the same time,dep1 allele increased amylose and protein content,thus increased the hardness and viscosity scores of grains,resulting in the decrease of taste value.The nutritional quality was increase while the taste quality was decrease.