The Waxy Grain Traits Of Genetic Analysis And Improvement Of GN1607

Waxy wheat,as a special germplasm resource,has attracted more and moreattention because of its starch's unique physico-rheological properties and its potential application in the food processing.Therefore,the papaer used the waxy wheat line?GN1607?was crossed and backcrossed with non-waxy wheat varieties?Guinong No.19 and Guinong No.30?respectively,to construct genetic populations of different generations.Based on the investigation and statistical of waxy grain traits of different hybrid generations,the genetic characteristic of waxy grain traits of varity?line?GN1607.Taking GN1607 as the object of genetic improvement,the F₂ population of the hybrid offspring was tested for the identification of resistance to striperust,powdery mildew and the agronomic traits;the waxy genotype of the progeny population was detected by relevant molecular markers and the different waxygenotype of amylose and soluble sugar content by corresponding GB,screening waxy individual plant materials with excellent agronomic traits.In order to providing atheoretical basis for waxy wheat germplasm innovation and promoting the industrial application of waxy wheat.The follow main research results were obtained:1.This paper used the waxy wheat variety?lines?GN1607 and non-waxy w heat varieties?Guinong No.19 and Guinong No.30?were reciprocal crosses and backcross respectively.The grains of the F₁ generation and the non-waxy paren ts both are non-waxy,In the reciprocal crosses of F₂ generation,the theoretical s eparation ratio of waxy and non-waxy grains were 1:63.When F₁ was crossed with the waxy parent or the non-waxy parent,the waxiness of the grain in the offspring population was separated,and the separation ratio of waxy and non-wa xy grains was 1:7.The results showed that the waxy grain trait of waxy wheat line?GN1607?was controlled by the nuclear genetic material and had no cyt oplasmic effect,which was consistent with the separation proportion of three ind ependent recessive genes,and the waxy grain trait was recessive.2.The investigation results of agronomic traits showed that in the F₂ popul ation constructed by waxy wheat line GN1607 and Guinong No.19,the variation range of the agronomic traits variation coefficient was 11.47-38.39%,and the a verage coefficient of variation was 20.51%.Among them,the agronomic trait wit h the largest coefficient of variation was the weight of grain per spike?38.39%?;the agronomic trait with the smallest coefficient of variation was the densi ty of spikelet?11.47%?.In the F₂ population constructed by waxy wheat line G N1607 and Guinong No.30,the variation range of the agronomic trait variation coefficient was 14.06%-40.53%,and the average coefficient of variation was 21.84%.Among them,the agronomic trait with the largest coefficient of variation w as spike weight?40.53%?;the agronomic trait with the smallest coefficient of v ariation was plant height?14.06%?.The correlation analysis showed that spike le ngth was positively correlated with spikelet number?correlation coefficient was0.672?,grain number per spike?0.617?,and grain weight per spike?0.476?.3.In the F₂ population of GN1607 and Guinong No.19,from nearly imm une to medium resistance to stripe rust accounted for 1.15%?4?,23.78%?83?and 38.97%?136?respectively;high and medium resistance to powdery mildew accounted for 12.03%?42?and 59.22%?61?respectively;37?10.6%?plants we re also resistant to stripe rust and powdery mildew.Among the F₂ populations c onstructed by waxy wheat line GN1607 and Guinong No.30,the high and medi um stripe resistance plants accounted for 6.27%?21?and 28.06%?94?,respectiv ely.Its F₂ populations were detected by relevant molecular markers,a total of 179 plants were carried Yr5 gene,and 242 plants contained Yr26 gene.Among th em,47,25 and 8 plants carried 2 resistant genes?Yr26+Yr5,Pm21+Yr26 and Pm21+Yr5?at the same time,and 4 plants contained 3 resistant genes?Pm21+Yr26+Yr5?at the same time.A total of 340 Wx gene normal types?A?B?D??were o btained;229 plants of single deletion type?aa B?D?or A?bb D?or A?B?dd?;108plants of double deletion type?A?bbdd or aa B?dd or aabb D??;7 plants of tota l deletion type?aabbdd?.4.The effects of different Wx gene types on agronomic traits,soluble sugar and amylose content and the ability of each gene to synthesize amylose were found.The results showed that:?1?The deletion of the Wx gene caused significant decrease in amylose content;the effects of different Wx gene types were:total loss type>double loss type>single loss type;in single loss type:Wx-B1a>Wx-D1a>Wx-A1a,indicated that Wx-B1a gene had the largest ability to synthesize amylose,followed by Wx-D1a and Wx-A1a;?2?There was no significant difference in spike length,plantheight,number of spikelets and other agronomic traits among the eight Wx genetypes,indicated that Wx gene would not affect the agronomic traits of wheat;?3?The soluble sugar content of the total deletion type was significantly higher than thenormal type,indicated that wx gene may have a gene dose effect on the soluble sugar content.5.13 plants with excellent agronomic traits such as spike length,spikelet number,grain number per spike and plant height were screened out;338 plants with resistance to stripe rust,103 plants with resistance to powdery mildew,37 plants with resistance to both powdery mildew and stripe rust;2 waxy plants with the excellent agronomic traits.