Indefication And Inheritance Of B Genome Chromosome Addition Line In B.napus

This research identified chromosome number in ovary and root tip cell ofthe descendant from the crops of inter-specific Brassica napus×Brassicacarinata, as well as analyzed the chromosome behavior of pollen mother cell(PMC) meiosis by applying plant cytology method. The goal is to screen B-genomechromosome addition line of Brassica napus. The genetic analysis of theadditional chromosomes of Brassica napus-carinata disomic additionline "9211096" obtained was carried out.The main results from present research were summarized as follow:1. Optimization of the condition of root-tip culture. When seeds culturedat 27℃, the time required to obtain an ideal root-tip would be short. And whena root-rip was treated in the solution of 0.002M 8-hydroxyquinoline at 23℃for 3.5～4 hours, you may obtain a root-tip with The cell living goodappearance of chromosome within the nucleus at the time of division.2. A multi-chromosome addition line of B genome in Brassica napus 04-8089was screened and indentified out of the offsprings of an interspecific cropbetween B. napus and B. carinata, number of chromosome in somatic cell (ovaryor root-tip) was 2n=45. The configretion of chromosome at metaphoreâ… (Mâ… ) ofpollen mother cells (PMCs) meiosis was (19～20)â…¡+(5～7)â… . several laggedchromosomes were observed. The chromosome bridge was formed at MⅠ～Mâ…¡period.Chromosome number in each of the diad was veried in a segregation mannerof 19:26, 20:25, 21:24 and 22:23.3. A phenomena of mixoploidy of the alien additional chromosome B. napuschromosome was detected from the observation. The processdure of meiosis ofthe hybrid PMCs between 04-8089 In the research of the meiosis of hybrid PMCsbetween 04-8089 and euploid parent thereof, the discretion of alien additionalchromosome did not synchronize with basal chromosome derived, separating andassortment independently as a mass. As a result, it formed a diad at Mâ…¡withunequal chromosome nember in each of the two pole.4. The observation of chromosome number in somatic cell and the agronomictraits of F1 and F2 derived from hybrid between 92I1096 and euploid B. napuswere conducted and the results indicated that chromosome number in cell ofhybrid F1 is 2n=39. Out of 91 plants of F2 population observed, 8 were 2n=40,24of 2n=39, 59 of 2n=38. Additional chromosome transmission rate was 61.54% fromF1 to F2. If a plant carrying the additional chromosome, the plant performs late-maturing and shorter in plant height. Initially believed, this twoadditional chromosomes in 92I1096 were involved in the genes controllinglate-maturing and short stalk characters.5. Two SRAP marker, me19-em51₈₀₀and me24-em56₃₆₀ were identified related to theadditional chromosome in 92I1096 which could be used as SRAP marker forscreening a plant carrying the additional chromosomes in the offspring of92I1096.