The chromosome constitution of hybrids and chromation patterns of Agropyro-nelelongatum(Host)Neviski in F5 somatic hybrid lines Ⅱ -1-3 and l-1-9 between Triticum aesti-vum L.and A.elongatum were analyzed.Based on the statistic data of pollen omther cells,F5 l-1-9 and Ⅱ-1-3 had 20—21 bivalents with a frequency of 84.66% and 85.28%,of which,89.83% and 89.57% were ring bivalents.The result indicated that both hybrid lines were basically stable in the chromosome constitution and behavior.RAPD analysis showed that the two hybrids contained biparental and integrated DNA.GISH(Genome in situ hybridization)revealed that in the form of small chromosome segments,A.elongatum chromatin was scattered on 4—6 wheat chromo-somes near by the region of centromere and telomere in the two hybrid lines.SSR analysis in-dicated that A.elongatum DAN segments were distributed on the 2A,5B,6B and 2D wheat chromosomes in the hybrids,which was in accordance with the GISH results that small-segments intercalated poly-site.
WANG Jing,XIANG Fengning,XIA Guangmin & CHEN Huimin School of Life Sciences,Shandong University,Jinan 250100,China
Plant somatic hybridization has progressed steadily over the past 35 years. Many hybrid plants have been generated from fusion combinations of different phylogenetic species, some of which have been utilized in crop breeding programs. Among them, asymmetric hybrid, which usually contains a fraction of alien genome, has received more attention because of its importance in crop improvement. However, few studies have dealt with the heredity of the genome of somatic hybrid for a long time, which has limited the progress of this approach. Over recent ten years, along with the development of an effective cytogenetical tool ＂in situ hybridization （ISH）＂, asymmetric fusion of common wheat （Triticum aestivum L.） with different grasses or cereals has been greatly developed. Genetics, genomes, functional genes and agricultt, ral traits of wheat asymmetric hybrids have been subject to systematic investigations using gene cloning, genomic in situ hybridization （GISH） and molecular makers. The future goal is to fully elucidate the functional relationships among improved agronomic traits, the genes and underlying molecular mechanisms, and the genome dynamics of somatic introgression lines. This will accelerate the development of elite germplasms via somatic hybridization and the application of these materials in the molecular improvement of crop plants.
