Screening of broad-spectrum resistant resources against rice bacterial leaf streak

ObjectiveRice lines with broad-spectrum resistance toward several kinds of pathogenic bacteria of Xan-thomans oryzae pv. Oryzicola at multiple growth stages were selected in order to provide source for rice bacterial leaf streak resistance breeding. MethodA total of 1100 rice lines with rich genetic background were offered as selective objects. Highly susceptible cultivar Jingang 30 was used as control. Inoculation was carried out on five strong pathogenic bacteria. Acupuncture method was used in resistance identification using multiple pathogenic strains at various growth stages. Re-sultFourteen disease-resistant materials were obtained through preliminary screening , accounting for 1.27% of the total materials. Nine materials over mediately resistant were obtained via secondary screening , accounting for 0.82% of the total materials. Besides, three of them(RL6,RL9 and RL14) were resistant to a number of bacterial leaf streaks at three growth stages. In particular, RL6 presented broad-spectrum resistance to multi-strains with high resistance levels. Six of them (RL2、RL4、RL5、RL8、RL11 and RL12) were resistant to single strain at single growth period. ConclusionThe obtained three materials are broad-spectrum resistant to rice bacterial leaf streak at multiple growth periods , which can be served as an important source for cultivating disease-resistant rice varieties. RL6 maintains high broad-spectrum resistance at all growth stages, which can be used as a prior resistance source for breeding rice varieties. While the six materials obtained with resistance at particular growth stages can be used as alternative resistance sources.