| Banana fusarium wilt(FW) bring a devastating disaster to the production of banana and t he only way to control the spread of banana FW is breeding disease-resistant varieties. At pres ent,there are some reports of screening resistant banana mutants to FW by using some method of bacteria toxin and chemical mutagen with tissue culture technology through which the bett er result is obtained.The germplasm resources of banana is very rich,which have payed more a ttention to the banana researchers especially for the banana with the chilling-resistant and dise ase-resistance.At present,the research and utilization of banana germplasm in our country wer e poor reported,of which research were mainly concentrated in banana genetic classification a nd evolution analysis.The research about markers associated with some important trait of ban ana and crossbreeding of banana were lagging, which cause to fail to make full use of wild res ources and severely impact on the reasonable use of banana germplasm resources and the bree ding for disease-resistant banana varieties.How to solve the problem of banana fusarium wilt, the most fundamental and effective m easure is to excavate the resistance genes and other excellent genes from the banana and integ rate the gene of the elite germplasm resources into banana varieties using marker-assisted bree ding technology to breed disease-resistant and high-quality varieties.It is difficult to build the separation groups in banana because most banana is triploid,the research about mapping the di sease resistant gene in banana are seldomly reported. In recent years many research are report ed that correlation analysis is a effective tool by which plant genotype are associate with phen otype.To overcome the problems above,this experiment turn to solve the FW problems of the banana production from three aspects.(1)The micro-cross section of banana plantlet(Musa AAA Cavendish, Brazil)was treated by Ethyl Methyl Sulphonate(EMS) for mutation induction,and follow to screen by the pressure of crude toxins of FOC with the aim to get the resistance to Panama disease.(2)The wild banana germplasm were screened for identification of resistance of FW.(3)30 bananas varieties which have trait with better resistance and susceptible to FOC race 1 and race 4,are selected for correlation analysis in order to find the mark associated with the resistant FW loci,and further unearth the elite alleles which correlated with resistance to FOC race 1 and race 4 respectively,provide valuable information for the breeding of banana.The main results were as follows:1、The banana chip regeneration system was established and the regeneration rate of this system was 69%.The semiletal concentration and time of EMS treartment was 200mmol and 30min respectively and the half lethal concentration of crude toxin was 36.17g/ml.We got 650 strains of toxin resistant Brazil banana mutants after through treating EMS and four consecutive screening by crude toxin.At last 25 resistant strains was available based on seedling identification and the field identification is in progress at present.2、The genetic relationship of the 32 banana germplasms of A group was analyzed by using structure software.The result showed that the 32 banana germplasms were divided into four groups,they were domestic plantain group,ABB group (Contains introduction of plantains subsets,dwarf banana group),AAA group and mix group.The genetic relationship between the domestic plantains and introducing plantains was bigger.The genomic diversity among the varieties of the dwarf banana and plantains groups were richer.Three times of structure analysis was used in the B group.Finally,the germplasms of B group were divided into four groups:ABB group、tetraploid、AA group and mix group.The results of this study show that the clustering analysis based on the model can be used as a genetic analysis.The results also showed that the selected different germplasm genetic diversity was rich and was suitable for correlation analysis.3、41 accessions of banana germplasms were evaluated in terms of resistance to FOC race 1.The results showed that 22 accessions of banana were moderately resistance to FOC race 1,14 susceptible and 5 highly susceptible;55 accessions of banana germplasms were evaluated in terms of resistance to FOC race 4,all of the 55 accessions,6 were found moderately resistance,18 susceptible and 31 highly susceptible,no highly resistant material. Resistance identification results showed that there were many disease-resistant resources in our collection of banana germplasm,which can provide materials for the excavation of the resistance gene later.4、The preliminary correlation analysis show as following.There were fifteen loci which were associated with resistance to FOC race 1 in preliminary genome scanning,among them four loci were significantly correlation(p<0.001),el-5、mw20-6、mw48-2 and mw49-3 were elite alleles corrected with resistance to FOC race l;seven loci were associated with the resistance to FOC race 4,only mw43-2 was significantly correlation,e48-6 and mw12-2 were elite alleles corrected with resistance to FOC race 4. |
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