Screening And Identification Of Trititrigia Germplasms

Thinoprum were perennial wild herbs with rich genetic basis. Thinoprum were determined to have many useful agronomical traits for wheat improvement, such as tolerance to salt, drought,cold, stripe rust, leaf rust, yellow rust and powdery mildew, while they showed close genetic relationship with common wheat. Thinoprum were valuable genetic resources for genetic improvement of cultivar wheat. In the present study, identified and screened by methods of morphology, cytology and molecular biology, ascertained Trititrigia alien chromosome lines from progenies between Triticum aestivum and Th.intermedium,Th.ponticum.The main results were as follows:1. Shannong303 had luxuriant growth and large spikes with multiple florets and grains.Identification and analysis of the germplasm of Shannong303 by cytological method showed that its root tip cell has 42 chromosomes and its chromosome contifiguration of PMC MI has21 bivalents, which indicated that it was cytological stable. GISH was conducted using genomic DNA from Th.intermedium as the probe found that Shannong303 had no fluorescence hybridization signal. Double colour fluorescence in situ hybridization(FISH)with the probe of pTa535 and pSc119.2 was used to analyze the genome constitution of Shannong 303. The results indicated that the 5A, 2B, 6B, 7B and 1D chromosomes of Shannong303 were different from those of Yannong15. By methods of molecular marker and sequencing of SSR primers Xcau12 and Xbarc125 PCR products, Yannong15, Shannong303 and Th. intermedium were detected obtaining that Shannong303 and Th.intermedium were both amplified the same DNA fragmentation, but Yannong15 were amplified other one,repectively. In conclusion, it made clear that Shannong303 was a wheat-Th.intermedium introgression.2. Cytological identification found that the number of Shannong31504 RTC chromosome was 2n=42 and its chromosome contifiguration of PMC MI was 22 bivalents,which indicated that it was a disomic alien addition line; Shannong 31504-1 and 31504-3 had 42 chromosomes and 21 bivalents in its RTC, PMC, respectively, which showed that they wereboth metirials of cytology stability. GISH was proceed using St-genomic DNA from Pseudoregnaria strigosa as the probe concluding that the two alien chromosomes of Shannong31504 belonged to St genome, however, Shannong31504-1 and 31504-3 had no fluorescence hybridization signal. FISH with the probe of pTa535 and pSc119.2 was used to establish the genome constitution of Shannong 31504-1 and 31504-3. The results indicated that their 6B and 1D chromosomes were both different from those of Lumai5, which revealed that they were wheat- Th.ponticum introgressions.3.Through artificial inoculation, 192 wheat-Th.Ponticum germplasms descended from Shannong 87074 were evaluated and screened for resistance to powdery mildew and yellow rust, of which 21 germplasms had better resistance. By methods of morphology and cytogenetics, ascertained that 21 germplasms were genetic stable. GISH was conducted for 21 germplasms of wheat-Th.ponticum germplasms found that all of them had no fluorescence hybridization signal. FISH with the probes of pTa535 and pSc119.2, found that fluorescence signals on 1D, 6B and 5D chromosomes of wheat-Th. ponticum germplasm 20131115 were different from those of Lumai5 and Jinan13. It showed that 20131115 was wheat-Th.ponticum introgression.