水稻胡麻斑类似病危害转Bt稻“克螟稻”初报

 于田间转Bt稻“克螟稻”稻叶上观测到一种病斑，病斑中心和周围均呈褐色，长椭圆形与稻胡麻斑病类似，平板上分离到的病原菌菌丝呈灰褐色，菌丝有多个隔膜，分生孢子梗成丛，但在PDA培养基上，产生的分生孢子特征与稻胡麻斑病不吻合。从为害级别和严重度上分析克螟稻对胡麻斑类似病的感病程度远远超过其亲本秀水11。克螟稻叶片间发病速率增长迅速，而秀水11叶片间发病速率增长缓慢。

Preliminary Study on Rice Brown Spot Mimic Lesion Virulence on Bt Gene Transformed Rice Kemingdao

A diseased spot had been observed on leaves of Bt gene transformed rice Kemingdao in paddy field. The lesion was similar to the rice brown spot, however, the fungus had not been identified as Cochiliobolus miyabeanus according to the characteristics of spores produced on PDA media. Three indices, i.e. severity, maximum injure degree and injure degree were used to evaluate the virulence of rice brown spot mimic lesion on Bt gene transformed rice Kemingdao 1 (KMD 1), Kemingdao 2 (KMD 2), as well as their original parent Xiushui 11. The results indicated that KMD was much more susceptible than Xiushu 11. Comparison with the virulence among top leaf to the 5th leaf, a significant difference indicated that the lesion occurred sequentially from the bottom to the top, and damaged KMD more seriously than their parent Xiushui 11.