Identification Of Resistance To Charcoal Rot And The Clone Of Resistance Gene Analogs In Sesame

Sesame (Sesamum indicum L.) belongs to Pedaliaceae Sesamum cultivated widely in subtropics and temperate zones. Sesame is the oldest oilseed crop, rich in edible proteins, vitamins, fatty acids as well as amino acids. Sesame charcoal rot caused by Macrophomina phaseolina (Tassi) Goid is one of the severest fungal diseases. This pathogen has an extensive host range, a strong resistance to adverse conditions in addition to the emerging of fungicide resistant strains, which has an adverse impact on yield, quality and mechanization. In recent years, environment pollution, pesticide residues besides ecological problem are high frequency due to the increasing dosages of fungicide. All these require pathologists to search for environmentally-friendly measures to control sesame charcoal rot, It is proved that use of crop resistance is an economical, safe and valid mean to control crop diseases through long-term practice of crop disease control.One of the research purposes was to select resistant resources for the resistance breeding and production application through identifing sesame resistance to Macrophomina phaseolina (Tassi) Goid in seeding stage and adult. The other purpose was to isolate resistance gene analogs to lay the foundation for the clone of resistance gene or be applicable to molecular mark assisted breeding. The main research conclusions are as follows:1. Five strains were isolated from sesame charcoal rot plants which came from different regions in Henan province. They all were confirmed as Macrophomina phaseolina (Tassi) Goid according to surveying the morphology of colony, re-inoculation and identification as well as molecular detection;2. The best sterile technique by comparing the different sterilants effect was that 2% NaCIO process sesame seeds for twenty minites, after that sterile water washed three times;3. This study evaluated twenteen sesame varieties seeding resistance to five Macrophomina phaseolina (Tassi) Goid strains though fungus cake approach, Yuzhishiyi as the control variety. The result demonstrated that the resistance of ZZM0905 and ZZM1205 were stable and high. They were resistant to five dififferent strains. Others had different resistance response style to different strains;4. This study evaluated seventy-four sesame varieties adult resistance to Macrophomina phaseolina (Tassi) Goid through naturally infected method in field disease nursery, the number of immune, high resistant, resistant, susceptible varieties was six, thirteen, twenty-six, twenty-nine respectively. There was no high susceptible variety; ZZM0905 is resistant in seeding and adult.5. One hundred and twenty-eight sequences were isolated from twenty-six resistant variaties and four susceptible variaties genomic DNA. Sequence analysis indicated that forty-two sequences from sesame were non-TIR-NBS-LRR style RGAs.