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种质资源筛选是抗病育种的前提和基础。以已知抗病水平的5份鉴别品种为对照,对水稻5个类群和1个混合类群的299份品种进行了温室苗期纹枯病抗性鉴定,筛选抗纹枯病水稻新种质。在“雾室/mist-chamber”环境下以改进的带菌木质短棒为接种物、以基于“叶枕高”的“0~9”级病级指标为标准,可有效区分对照品种间的抗病水平。299份品种中未发现免疫和高抗品种,中抗以上品种比例仅为36.5%,多数品种为中感至高感水平。就水稻不同类群而言,AUS类群中中抗以上品种的分布频率最高,超过60%;其次为ARO类群,为54.6%;分布频率最低的为TRJ类群,仅为22.7%。结合各品种苗高及与抗病对照YSBR1间的病级差异,从299份品种中筛选到7份抗病新种质,其中1份的抗性显著高于YSBR1,接近高抗水平。本研究为水稻抗纹枯病遗传育种提供了新的抗源,同时为选择合适的类群间品种杂交以培育抗纹枯病新品种提供了理论依据。
Germplasm screening is the prerequisite and basis of disease-resistant breeding. Five cultivars with known disease resistance were used as control. The resistance to sheath blight of seedlings in 299 cultivars of 5 rice cultivars and 1 mixed population was identified and the new germplasm of resistance to Rhizoctonia cerealis was screened. Under the environment of “mist chamber / mist-chamber”, the improved inoculated wooden rod was used as the inoculum, based on the “0 ~ 9” grade index based on “leaf pillow height ” Differentiation between the control varieties of disease resistance levels. 299 varieties were not found in the immune and high resistance varieties, the proportion of above anti-Chinese varieties was only 36.5%, most of the varieties in the flu to a sense of high level. For different rice groups, the distribution frequency of above-resistance varieties was the highest in AUS groups, more than 60%; followed by ARO groups was 54.6%; and the lowest distribution frequency was TRJ groups, only 22.7%. Seven new germplasms were screened from 299 cultivars. One of them was significantly higher than YSBR1, which was close to high resistance level. This study provided a new source of resistance to rice sheath blight resistance breeding and provided a theoretical basis for the selection of suitable crossbreeds for cultivating new varieties of resistance to sheath blight.