水稻类穗颈瘟梨孢菌新种的生物学特性及不同水稻品种抗性分析

Biological characteristics of new Pyricularia species and resistance analysis of different rice varieties

稻瘟病菌引起的穗颈瘟严重影响水稻产量和质量。前期对江苏省稻区连续多年监测首次发现一类能引起类似穗颈瘟的梨孢菌新种Pyricularia sp.jiangsuensis,发生率高且在不同年份稳定存在。为了解该病原菌与稻瘟病菌之间的差异,本研究对该病原菌代表菌株P.sp.jiangsuensis 18-2与稻瘟病菌菌株P.oryzae Guy11在生长、产孢、各种胁迫及不同品种对两种病害的抗性等方面进行比较。结果表明,P.sp.jiangsuensis 18-2在PDA、CM和SDC三种培养基上的生长速度明显快于P.oryzae Guy11,但是P.sp.jiangsuensis 18-2的气生菌丝较为稀疏。在细胞壁胁迫因子和氧化压力下,P.sp.jiangsuensis 18-2对外源逆境的耐受性较P.oryzae Guy11更强,该病原菌更适应对外界胁迫的应答。进一步分析江苏省推广的主栽品种对类穗颈瘟的抗性,发现一些主栽品种对P.sp.jiangsuensis 18-2和P.oryzae Guy11引起的穗颈瘟存在抗性差异,鉴定筛选出品种镇稻448、盐粳15号、晶两优534和甬优2640对两者都表现良好的抗性,生产上应综合考虑选用对这两种病害抗性较好的品种。

Neck blast,caused by Pyricularia oryzae,seriously affect the yield and quality of rice.Previous results showed that a new species of Pyricularia,which was found by continuous monitoring in the rice fields in Jiangsu province,can cause neck blast-like with a high incidence and stable existence in different years.In order to understand the difference between the new pathogen and P.oryzae Guy11.The growth,sporulation,various stresses and resistance of different varieties to these two diseases were compared between the representative strain P.sp.jiangsuensis 18-2 and P.oryzae Guy11.The results showed that the growth of P.sp.jiangsuensis 18-2 on PDA,CM and SDC medium was significantly faster than that of P.oryzae Guy11,but the aerial mycelium of P.sp.jiangsuensis 18-2 was sparse.Under cell wall stress factor and oxidative stress,the tolerance of P.sp.jiangsuensis 18-2 to exogenous stress was significantly enhanced than that of P.oryzae Guy11,indicating that P.sp.jiangsuensis 18-2 was more adaptable to external stress response.Further analysis of the resistance of the main cultivars in Jiangsu province to panicle neck blast showed that some main cultivars had different resistance to panicle neck blast caused by P.sp.jiangsuensis 18-2 and P.oryzae Guy11.Varieties Zhendao 448,Yanjing 15,Jingliangyou 534 and Yongyou 2640 showed good resistance.In production,it is necessary to select the varieties with better resistance to these two diseases.