Development And Identification Of Wheat-thinopyrum Elongatum3E Chromosome Translocations

Wheat is the second crop and plays an important significance to the country’s food stability and economic development in china. The increasing population and the improvment of people’s living standards of our country, and genetic resources of wheat is becoming more and more narrow, this requires us to conduct genetic improvement in wheat in order to improve its yield and quality. Thinopyrum elongatum(Th.elongatum) carrying many excellent traits, tranfer the excellent genes from Th.elongatum into wheat is an important means of genetic improvement in wheat. The main objective of this study was to screen common wheat’Chinese spring’-Th.elongatum3E chromosome translocations from the hybrid progeny of’Chinese spring’-Th.elongatum chromosome3E disomic addition lines(CS-3E) and’Chinese spring’-Ae.cylindryca gametocidal chromosome2C disomic addition lines(CS-2C), and characterized by analysis of agronomic characters, cytology, molecular markers, genomic in situ hybridization and SSR. The results of this study are showed as follows:1. The seed of F1and BC1F1of CS-3E and CS-2C hybrids progeny is larger and abdominsl groove is deeper than parents, but not full and the surface is rough. The different phenomena are showed in the size, full level and abdominsl groove of the F2generation seeds. The seed of translocation lines are big and long, but its not full and abdominsl groove is deep compared with CS-3E.The heading of F1and translocation lines are significantly later than the CS-3E, with the maturity is corresponding late also. In addition, the translocation lines plants are straight and hard, its glume packet seeds tight and hard. The glume hardness of F1plants is between the two parents. The heading of F2and BC1F1plants have a larger range of fluctuation and its glume hardness is different.The spike-type of translocation lines is between two parents, and it have two types of awned and awnless plants. The spikes appeared to aberration of compactoid, multi-small flowers and bend awn in F2, F3and BC1F1.2. Compared with CS-3E, the plant height, spike length, number of tillers, number of spikelets and seed-setting rate of F1plants is not significant difference, but the number of florets are lower then CS-3E and significant difference. The spike length, number of tillers, number of spikelets of F2plants are not significant difference to CS- 3E, but the plant height and seed-setting rate are lower then CS-3E and significant difference. The plant height, spike length, number of spikelets and seed-setting rate of BC1F1plants are not significant difference to CS-3E, but the number of tillers is significantly higher than CS-3E, the number of florets is significantly lower than CS-3E. Compared with the CS-3E, the spike length, number of tillers and number of florets of translocation lines are not significant difference, but its plant height, number of spikelets and seed-setting rate are lower then CS-3E and significant difference, and the seed-setting rate is extremely significant difference.3. The chromosome number of F2and BC1F1plants somatic cell variated from38to45, and some chromosome aberrations such as ring chromosome, dicentromeric chromosome, telosome were observed in F2and BC1F1plants. The chromosome number of F4is mostly42and43, chromosome aberrations are observed rarely. Observed the PMCs metaphase of F2plants, we found many abnormal phenomena such as unpaired univalents chromosome fragment, chromosome bridge and lagging chromosome.4. Th.elongatum3E alien chromatin in CS-3E, F1, F2and F4plants was detected by primer EP3, EP4, which is the specific PCR marker of Th.elongatum. The frequency of the F1, F2and F4plants carrying3E chromatin was100%,36.73%, and83.87%, respectively. The materials of translocation lines were identified by specific Th.elongatum chromosom3E EST-SSR marker Xedm8and Xedm96, specific band of chromosom3E short arm is amplified by Xedm96, and it is show that the twenty-one translocation lines are wheat-Th.elongatum3E chromosome short arm translocation lines5. Eighteen heterozygous translocation lines were identified from the F2and F4generations by genomic in situ hybridization, and three homozygous translocation lines were identified from the F4generations. Combined with SSR results, eighteen wheat-Th.elongatum3E heterozygous short arm translocation lines and three homozygous short arm translocation lines were screened in this study. In addition, the root tip cell of F2generation plants A-8, A-35, B-11, B-22and B-106carrying a chromosome segment of3E. The root tip cell of plant A-9and B-78carrying two chromosome segments of3E.