Genetic Analysis And Improvement Of Ear Branching Characters Of GZ95-6 Branch Wheat

Ear branch wheat is a variation type of common wheat.There are branches and ear axes on the main ear axis node,and there are many spikelets on the branch axis,so the number of grains per ear is more,which has potential use value for improving the yield of wheat.At the same time,the KGW of spike branch wheat is generally low,mature later,resistance and quality are poor,so it is difficult to use it directly in wheat breeding.Genetic improvement of spike branch wheat is helpful to create excellent germplasm resources.In this study,the genetic populations of GZ95-6,ZY96-3 and Guizhou purple wheat No.1 were constructed to analyze the characteristics of ear branching.The cross of ZY96-3,Guizhou purple wheat No.1,Guinong No.19 and Guinong No.30 was used to identify the different hybrid progenies in the field.The KGW,grain shape,plumpness and resistance were detected by molecular marker In order to provide reference for the selection of wheat varieties with multiple spikelets and high yield,we improved the characters of sex and grain color.The main results are as follows:1.GZ95-6 was significantly different from ZY96-3 and Guizhou purple wheat No.1in ear branching characters.F₁ plants were normal ears,indicating that ear branching characters were controlled by recessive genes.The ear branch character of F₂population began to separate,and the ratio of branch to normal ear type was close to1:15,which was consistent with 1:15 by?2test.In F₃ population,the branch related characters are generally in the normal distribution,among which the number of branches,branch length and branch index are in the continuous normal distribution,and the variation is in the continuous characteristic,which indicates that the branch character of ear belongs to the quality number character controlled by two pairs of main effect+micro effect genes.2.To analyze the correlation between the ear branches of the hybrid progenies of GZ95-6 and ZY 96-3,in F2,the GN and SL?0.62?,the SN?0.37?were significantly positively correlated;in F3,the BN and BL?0.24?,the BSP?0.34?,the GN?0.16?,the KGW?0.14?were significantly positively correlated,and the BGN and BN?0.56?,the BL were significantly positively correlated?0.42?,BSP?0.43?,GN and SL?0.49?,SN?0.23?were significantly positively correlated.The correlation analysis showed that the branches of branch wheat were longer and there were more spikelets,which effectively increased the number of grains per spike.The analysis results of ear branch related characters of Hybrid Progenies of GZ95-6 and Guizhou purple wheat No.1 were basically the same as the above results.3.The field identification of GZ95-6 showed that the number of grains per spike was more,79 grains on average,but it was susceptible to stripe rust,white powder and leaf rust,with poor resistance.The KGW was only 26.97g,and the grains were smaller:GL was 7.06mm,GWI was 2.82mm,GD was 4.33mm,and SR was 71.80%.If we want to use it in wheat breeding,it is necessary to improve its KGW,grain shape,plumpness,resistance and other related properties.4.The SR and KGW of ZY96-3 were improved by crossing with GZ95-6.Among the F₂ population,184 ear branching plants were screened out.The SR and KGW of these ear branching plants were greatly improved,the average KGW was significantly increased to 30.74g,the average SR was increased to 83.49%,the GL was 7.26mm,the GWI was 2.90mm,and the GD was 4.47mm.Among the 85 plants with more than65 grains per ear,79 plants with TaCwi-Ala gene were detected by molecular markers.Among the F₃ population,195 plants with branches per ear were screened,with an average SR of 93.61%.The average KGW of the plants with branches per ear was47.02g,the largest was 56.74g,with a GL of 13.86mm,a GWI of 6.32mm and a GD of 8.99mm.94 plants with 65 grains per ear,140 plants with TaCwi-Ala gene were detected by molecular markers.In F₃ population,four stable ear branch wheat lines were also screened,among which 27 individual plants were selected from line 5,11were higher than the mean value of 70 grains,the highest was 133 grains,14 were higher than the mean value of 31.78g,the highest was 42.30g,45 individual plants were selected from line 6,18 were higher than the mean value of 64 grains,the highest was 137 grains,25 were higher than the mean value of 33.04g,the highest was 51.79g.The significant analysis of agronomic characters showed that the number of spikelets and the number of grains per ear of the hybrid progeny showed a significant advantage by crossing ZY96-3,and the SR and KGW of the hybrid progeny were also greatly improved.5.The grain color of Guizhou purple wheat No.1 was improved by crossing with GZ95-6.Among the 195 plants of F₃ branch population,the average KGW was increased to 31.69g,the GL was 8.15mm,the grain width was 3.76mm,the grain thickness was 5.3mm,the KGW was more than 40g,41 plants,the number of grains per ear was more than 65,23 plants,and the SR was increased to 85.29%.Molecular detection showed that 52 plants with TaSus2-2BH gene contained grain weight,14 of which were purple.At present,these 14 plants have been planted to obtain preliminary stable F₄ lines.6.The disease resistance?resistance to stripe rust,white powder and leaf rust?and comprehensive characters were improved by crossing Guinong No.19 and Guinong No.30 with GZ95-6.According to the field resistance identification,84 individual plants of F₂ generation of 200 branch populations were identified as resistant to stripe rust and 73 individual plants were identified as resistant to powdery mildew.Among them,78 strains of Yr Gn6 gene,65 strains of Pm21 gene and 25 strains of Yr Gn6+Pm21 gene were detected by molecular detection.At the same time,the grain size was improved after hybridization with guinongmai 19,with GL of 7.47mm,grain width of3.35mm The grain thickness was 4.91mm,the KGW was increased from 26.97g to45.11g,which was higher than 53 plants of GZ95-6,among which 32 plants were above 45g.At the same time,the cross with Guinong No.30 improved the stripe rust,white powder,leaf rust and comprehensive agronomic characters of branch wheat GZ95-6.Through the field resistance identification,73 plants were resistant to stripe rust and 75 to Powdery Mildew in 187 branch populations of F₂ generation after crossing with Guinong No.30.65 plants with Yr Gn6 gene,70 plants with Pm21 gene and 72 plants with Lr37 gene were detected by molecular detection,among which 10plants with Yr Gn6+Pm21+Lr37 gene were also detected.The KGW significantly increased by 22.83g to 49.8g,16 plants with GL of 7.59mm,GWI of 3.40mm,GD of5mm and GWI of more than 45g?To sum up,the ear branching characters of GZ95-6 belong to the quality quantitative characters controlled by two major+minor genes.ZY96-3,Guinong No.19,Guinong No.30 and Guizhou purple wheat No.1 were used to improve the correlation of them.The highest KGW was 64.91g,and some of them contained TaCwi-Ala or TaSus2-2BH genes.The grain length,width and thickness were 13.86,6.32 and 8.99mm,the SR was 93.61%,and the maximum number of grains per ear was 137.Ten plants containing the disease resistant gene Yr Gn6+Pm21+Lr37 were screened by molecular markers,and 14 initially stable purple kernel branched wheat lines were obtained.These excellent single plants or lines selected from the hybrid progenies provide excellent breeding materials for the breeding of multi spike wheat varieties and characteristic wheat breeding.