水稻黑条矮缩病抗性评价方法及抗性资源筛选

水稻黑条矮缩病是水稻主要病毒病害之一。目前由于缺乏规模、高效的黑条矮缩病抗性鉴定体系,制约了抗黑条矮缩病水稻资源的发掘,限制了抗黑条矮缩病的育种进程和基础研究。本研究通过分析水稻黑条矮缩病田间鉴定所需灰飞虱的有效接种密度、带毒率及播期等,提出水稻黑条矮缩病田间鉴定有效接种的灰飞虱密度在800万头hm–2左右较为合理,而带毒率应不低于5%。并进一步对现有黑条矮缩病人工接种鉴定的循回期、接种虫量、接种时间及虫龄等进行了优化。利用上述鉴定体系,2010年对来源于20个国家的共1240份水稻种质进行黑条矮缩病田间鉴定,初步获得发病率低于10%的品种34个;2011、2012连续两年对该34个品种进行多年多点重复抗性鉴定,发现来自东南亚地区的3个品种Kanyakumari 29、Madurai 25和Vietnam 160连续3年发病率均低于10%,表现较高的黑条矮缩病的抗性。进一步分期播种鉴定的结果表明,Kanyakumari29在3个播期、3个鉴定点的发病率均低于12%,而Madurai 25和Vietnam 160发病率均低于9%。此外,在人工接种条件下Kanyakumari 29、Madurai 25和Vietnam 160的发病率均低于9%。因此,多年多点田间鉴定和人工室内接种鉴定的结果均表明,Kanyakumari 29、Madurai 25和Vietnam 160稳定、高抗黑条矮缩病。综上所述,本研究建立的田间鉴定与室内鉴定相结合的黑条矮缩病鉴定体系准确、可靠,可用于黑条矮缩病的大规模鉴定,该体系的建立及高抗黑条矮缩病水稻资源的发掘为水稻抗黑条矮缩病基因的鉴定及育种利用提供了重要的方法和材料基础。

An Evaluation System for Rice Black-Streaked Dwarf Virus Disease and Screening for Resistant Rice Germplasm

Rice black-streaked dwarf virus disease (RBSDVD) is one of the most serious viral diseases. The absence of efficient resistance evaluation system for RBSDVD restricts the excavation of the resistance resource, thereby the resistance breeding and basal researches are limited. Here, we proposed that the appropriate density of small brown planthopper (SBPH) should be 8 million ha^-1 and the rate of RBSDV-carrying SBPH should be over 5% for RBSDVD evaluation in field condition. Further, we optimized the artificial inoculation evaluation system including circulative period, number of SBPH per plant, infestation time and age of SBPH. We evaluated 1240 varieties from 21 countries for RBSDV resistance by natural inoculation in 2010, 34 cultivars had the disease incidence less than 10%. The 34 cultivars were further evaluated by natural inoculation in three different locations in 2011 and 2012, respectively. Finally, only three varieties, Kanyakumari 29, Madurai 25, and Vietnam 160, which all came from Southeast Asia, had the consistent disease incidence less than 10% in different locations and years. To verify the resistance of the three varieties against RBSDVD, we carried out the interval sowing inoculation experiment in the three different locations in 2012. In the interval sowing experiment, the disease incidence of Kanyakumari 29 was less than 12%, whereas Madurai 25 and Vietnam 160 less than 9%. In addition, in the artificial field inoculation and artificial room inoculation experiments, the disease incidence of the three varieties was less than 9%. The above natural and artificial inoculation experiments showed that Kanyakumari 29, Madurai 25, and Vietnam 160 performed stable and high RBSDVD resistance. Taken together, the RBSDVD evaluation system combining field with artificial infestation identifications used in this study is accurate and reliable. This system could be used to widely screen RBSDVD resistance resources. The construction of RBSDVD evaluation system and the RBSDVD resistance resources identified in this study will provide the useful tools and materials for the identification of RBSDVD resistance gene(s) and development of RBSDVD resistance varieties.