Thermo tolerance in Brassica: refined rapid screening method to identify thermo tolerant genotypes in Brassica
Brassica being a crop of arid and semi arid region, its sowing depends upon rain. Due to early rains, many times the farmers have to sow the crop early in the season on the conserved moisture. High temperature at that time causes seedling mortality. This necessitates thermotolerant genotypes. The present paper deals with simple, rapid and refined methodology suitable for screening exhaustive germplasm. Sowing is done in plastic trays containing soil. Each tray can accommodate 3-4 rows, and each row has 6-7 spots depending upon the dimensions of the tray. Four seeds are sown on each spot. Sowing is done in three trays as replicates.Seeds are allowed to germinate inside the seed germinator at optimum temperature and humidity. Five days old seedlings are exposed to threshold high temperature. Time taken to 50％ seedling mortality is used as the criteria to assess thermotolerance.Longer the time taken to 50 ％ mortality, more a variety will be tolerant to high temperature. The main advantages of this method are:Ⅰ. The chances of error are the least, as the large numbers of genotypes being tested are in a single lot having similar microclimatic conditions.Ⅱ. Method is rapid as the thermotolerance of large number ofgenotypes can be tested in a few hours.Ⅲ. As the testing is done in natural soil, this method is similar to natural soil conditions rather than using petri plate/fitter paper methods, which are purely laboratory methods.Ⅳ. Time taken to seedling mortality is better testing tool than percent seedlingmorality.Ⅴ. Verification of the above-proposed method was done by testing thermo tolerance of many species of Brassica and whose tolerance/susceptibility is already established.
Brassica Thermotolerance Screening Techniques Heat stress
Rajesh Sharma M.L.Chhabra Ashok Dhawan Kamal Dhawan Dhiraj Singh
Department of Plant Breeding (Oilseeds section), Chaudhary Charan Singt, Haryana Agricultural University, Hisar-125 004
国际会议
第十二届国际油菜大会( The 12th International Rapeseed Congress)
武汉
英文
430-432
2007-03-26（万方平台首次上网日期，不代表论文的发表时间）