| Among the main grain ration of China and the world,wheat(Triticum aestivum L.)has a long history of cultivation.However,due to the more frequent wheat diseases in recent years,it has been a serious threat to China's food safety.Wheat sharp eyespot,wheat powdery mildew and wheat stripe rust,as the main diseases of wheat,restrict seriously the increase of wheat yield and the improvement of wheat quality.Secale cereale L(RR,2n = 14),a wild relative of Triticum aestivum L.,is the tertiary gene pool in wheat.It possesses many good characters which benefits the improvement of common wheat,such as big spikes,strong tillering,well developed root systems,high protein content and lysine content in grain,higher dietary fiber(DF)content.It also possesses many excellent genes related to drought resistance,salt tolerance,low temperature resistance,rust resistance(Yr9?Lr26?Sr31),powdery mildew resistance(Pm7?Pm8?Pm17?Pm20)and aphid resistance and so forth.To dig and utilize rye germplasm resources,46 derivatives was screened out from the hybrid progenies from wheat W770B and Mexico rye using colchicine treatment and chromosomal engineering.To clarify the genetic basis of these derivatives,the comprehensive application of evaluation of disease resistance(sharp eyespot,powdery mildew and stripe rust),cytological identification,Genomic in situ hybridization(GISH),molecular markers techniques(SCAR,SSR),biochemistry markers(A-PAGE?HmW-GS)and the investigation of the agronomic traits was used to provide available bridge materials for wheat breeding.The main results are as follows:1.Wheat-rye derived line 7-1 with resistance to sharp eyespot was screened out;wheat-rye derived lines 7-1 and 8-2-1 with immune resistance to powdery mildew were screened out using the strain E09 at seedling stage;wheat-rye derived line 8-2-1,showed at level 1 and expressed high resistance to stripe rust was screened out using mixed stripe rust strains(CYR31,CYR32)at its adult stage.Mexico rye showed resistance to sharp eyespot,powdery mildew and stripe rust,while W770B were susceptible to all above diseases,therefore we conjectured thar the resistance of 7-1 and 8-2-1 may be derived from from Mexico rye.2.The results of the cytological observation on 7-1 and 8-2-1 at both mitosis metaphaseIof theirs root tip cells and meiosis metaphaseIof theirs pollen mother cells,showed that 7-1 and 8-2-1 had 42 chromosomes(2n = 42 = 21?),respectively.The results of Genomic in situ hybridization using rye DNA as the probe showed that 7-1 and 8-2-1 were wheat-rye translocation lines.The analysis of SCAR markers showed that 7-1 and 8-2-1 possessed the IRS chromosome arms of rye.The analysis of SSR markers showed IBS chromosome arms of both 7-1 and 8-2-1 were replaced by IRS chromosome arms of Mexico rye.Gliadin analysis showed that 7-1 and 8-2-1 had secalin characteristic bands of IRS.Consequently,7-1 and 8-2-1 were confirmed as 1BL/1RS translocation lines.3.The results of SDS-PAGE showed that the subunit compositions of 7-1 were(1,7+9,2+12),8-2-1 were(Null,7+8,2+12).The crude protein(dry base),gluten content(wet base)and Zeleny sedimentation value were measured by near infrared cereal analyzer,DA7250.The results showed that 7-1(16.57%?35.00%?37.94 ml)met the index of strong gluten wheat,while 8-2-1(12.92%?26.94%?23.22 ml)achieved the index of weak gluten wheat.The investigation of the agronomic traits showed that 7-1 and 8-2-1 had long ears,large particles and excellent synthetic agronomic characters.The creation and identification of translocation lines 7-1 and 8-2-1 enriched wheat germplasm resources,laid a good material foundationIn for make full use of the excellent trait genes of rye and further genetic improvement of wheat. |
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