| The wild relatives of wheat contain many valuable genes without in wheat. The transfers of alien genes from related species and genera into common wheat, and the identification and utilization of alien genetic chromatin in wheat, will enrich the foundation of wheat breeding and provide new approaches for wheat improvement. Psathyrostachys huashanica Keng(2n=2x=14,NsNs) is the vital wild germplasm resources for cultivated wheat, Which is characterized by early maturity and special resistantance under stresses.In this paper, 109 derivative offspring from hybridizing between Triticum aestivum L cv. 7182 and P.huashanica were characterized using cytology, genomic in situ hybridization (GISH), protein electrophoresis and DNA molecular markers technology to detection the alien genetic chromatin. The investigations of homoeologous grouping of P.huashanica chromosomes were conducted on the basis of tracing transferred genetic stability of alien chromosomes in the wheat background. Moreover, a large-spike and fertile florets wheat germplasm, B46, was obtained from the offspring of the hybridizing between Triticum aestivum L cv. 7182 and P.huashanica. Main results are as follows:(1)The cytological observation showed 53 plants with chromosome constitution of 2n=42, 26 plants with chromosome constitution of 2n=43, 30 plants with chromosome constitution of 2n=44. The mitotic and meiotic GISH analysis of 30 plants( 2n=44), indicated that 11 plants were wheat-P. huashanica disomic addition lines, 19 plants were wheat-P. huashanica double monosomic addition lines . It has been proven that exotic chromosome pairs could be steadily transmitted into the descendants.(2)Seventy-eight pairs of EST-SSR primers from seven homoeologous groups of Triticeae were screened specific markers for P.huashanica chromosomes and revealed the homoeologous relationship between P.huashanica chromosomes of wheat-P. huashanica disomic addition lines and chromosomes of common wheat .The result showed that 12 pairs of primers can be preliminary used as P. huashanica chromosomes specific molecular markers. The homoeologous relationship between common wheat and P.huashanica chromosomes of wheat-P. huashanica disomic addition lines was analyzed by means of PCR and gliadin bands analysis showed that P.huashanica chromosomes of 11 wheat-P. huashanica disomic addition lines were grouped into homoeologous group 1, 2, 4, 5, 6and 7. The added chromosomes in disomic addition line 5 were grouped into homoeologous group 1; addition line 6 and 9 were grouped into homoeologous group 2; addition line 7 and 11 were grouped into homoeologous group 5; addition line 2 were grouped into homoeologous group 6; addition line 8 were grouped into homoeologous group 7, respectively. While chromosomal rearrangement of homoeologous group 2 and homoeologous group 4 was detected in the addition line 4, the chromosomal rearrangement between homoeologous group 4 and homoeologous group 7 was identified in the addition line 10.(3) Exploration on the genetic material of large-spike and fertile florets wheat germplasm B46, which was obtained by selection the offspring of hybridizing, back-crossing and self-crossing between Triticum aestivum L cv. 7182 and P.huashanica by means of combined morphological observation, cytological analysis and genomic in situ hybridization (GISH) analysis after years of backcross and selfing. The result shows that B46 is a large-spike and fertile florets wheat with12cm ear length, 23 spikelets per spike and 6 florets per spikelet. There are 44 chromosomes in the root tip cell of B46 and the GISH analyses revealed that B46 contains a pair of homologous P.huashanica chromosomes. Ultimately, B46 was a wheat-P.huashanica hybridization disomic addition line, and of comprehensive agronomy traits, which can be utilized as good resource for cultivating wheat varieties of high yield.These reseach will be crucial to exploit the advantageous genes of the endangered species P. huashanica, improve and enrich conventional germplasm in further study. |
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