水稻稻瘟病抗性基因的研究

水稻稻瘟病是由子囊菌Magnaporthe grisea(无性世代为Phyricularia grisea)引起的广泛性灾害。选育抗稻瘟病品种是防治稻瘟病行之有效的方法之一。通过总结稻瘟病菌与水稻之间的相互作用机理,DNA分子标记的开发与应用,稻瘟病抗性基因定位、克隆与分离及其功能表达等相关方面的研究进展,展望了水稻稻瘟病抗性基因的研究方向。     

宁夏水稻种质资源主要抗稻瘟病基因的鉴定和评价

针对宁夏地区水稻抗稻瘟病主要基因尚不清楚的现状，采用已克隆抗稻瘟病基因的功能标记对143份宁夏水稻种质资源进行抗稻瘟病基因的分子扫描。同时，利用宁夏地区致病性强且致病力频率高的10个稻瘟病菌菌株混合悬浮液进行人工接种与自然诱发相结合的方法鉴定其抗病性。进而开展稻瘟病抗性性状与抗性基因的关联分析。结果表明：在宁夏水稻种质资源中表现主要的抗病基因有Pikm、Pi9、Pi2、Pi5和Pid2。在此基础上，对主要抗病基因在宁夏水稻品种中的应用进行评价，发现Pikm、Pi9、Pi5、和Pid2基因在宁夏水稻种质资源中的分布频率比较低，分别为0.56、0.35、0.30、和0.11。所以这些基因是今后改良宁夏水稻稻瘟病抗性的主要抗病基因。     

Current progress on genetic interactions of rice with rice blast and sheath blight fungi

Analysis of genetic interactions between rice and its pathogenic fungi Magnaporthe oryzae and Rhizoctonia solani should lead to a better understanding of molecular mechanisms of host resistance, and the improvement of strategies to manage rice blast and sheath blight diseases. Currently, dozens of rice resistance (R) genes against specific races of the blast fungus have been described. Among them, ten were molecularly characterized and some were widely used for breeding for genetic resistance. The Pi-ta gene was one of the best characterized rice R genes. Following the elucidation of its molecular structure, interaction, distribution, and evolution, user friendly DNA markers were developed from portions of the cloned genes to facilitate the incorporations of the Pi-ta mediated resistance into improved rice varieties using marker assisted selection (MAS). However, rice blast is still a major threat for stable rice production because of race change mutations occurring in rice fields, which often overcome added resistance based on single R genes, and these virulent races of M. oryzae pose a continued challenge for blast control. For sheath blight, progress has been made on the exploration of novel sources of resistance from wild rice relatives and indica rice cultivars. A major quantitative trait locus (QTL), named qSB9-2, was recently verified in several mapping populations with different phenotyping methods, including greenhouse methods. The ability to identify qSB9-2 using greenhouse methods should accelerate the efforts on the qSB9-2 fine mapping and positional cloning.     

黑龙江省水稻稻瘟病研究现状及抗病育种

对黑龙江省水稻稻瘟病的研究进展情况进行综述,着重在稻瘟病优势生理小种的变化动态、抗性基因、无毒基因、抗病品种研究等方面进行了总结,并简要提出了黑龙江省稻瘟病研究及抗病育种的未来发展方向。     

水稻病害生防细菌的筛选及其生物活性测定

从健康水稻植株体表筛选对稻瘟病等水稻主要病害有益的生防细菌 ,在室内分离到对稻瘟病等病菌菌丝具有很强抑制能力的细菌菌落 2 7株 ,经室外试验测定 ,有 9个细菌菌落对稻瘟病、纹枯病等具有一定的防治作用。其中 ,G_0 5的防治效果最佳 ,叶瘟、穗颈瘟防效分别为 5 0 8%和 4 4 7% ,纹枯病的防效达到 4 6 1% ,是一个非常有应用前景的菌株     

海南省部分水稻品种对稻瘟病菌22个株系的抗瘟性鉴定

为有效利用抗瘟品种控制稻瘟病的大发生,掌握水稻品种的抗瘟性。本研究采用五叶期水稻离体叶片研究了36个水稻品种对22个株系稻瘟病菌的抗性,有21个水稻品种表现抗病,其它15个品种感病。在此基础上对其中有代表性的4个水稻品种进行了抗瘟生化机制的初步研究。生化测定结果表明,接种RB22菌株后,各抗感品种中各种生化因子大部分具有明显差异,且具有一定的规律性。该结果对于培育新的抗瘟水稻品种、布局水稻不同抗瘟基因型品种和治理稻瘟病的流行具有一定意义。     

Functional Characterization of a NEM1-Like Gene in Magnaporthe oryzae

Magnaporthe oryzae, a filamentous ascomycete fungus, is well known as the causal agent of rice blast. With the technology of suppression subtractive hybridization (SSH), it was previously found that MGG_06001 (or named MoNEMl), a gene of M. oryzae homologous to the NEMl (nuclear envelope morphology protein 1) gene of baker's yeast (Saccharomyces cerevisiae), is differentially expressed between the mature appressium and the conidium and mycelium. This study aimed to characterize the function of MoNEMl gene by knocking it out using the method of target gene replacement. The AMoneml mutants exhibited reduced mycelial growth and conidiation. However, disruption of MoNEMl gene does not affect the pathogenicity of M. oryzae on barley and rice.     

24.1%肟菌.异噻胺种子处理悬浮剂对稻瘟病和恶苗病的田间防效

水稻稻瘟病和恶苗病是水稻上危害严重的真菌病害,化学防治是主要防治措施之一。为探明24.1%肟菌.异噻胺种子处理悬浮剂(FS)对稻瘟病和恶苗病的防治效果,采用干稻种拌种并晾干后播种的处理方式进行了田间药效试验。结果表明,24.1%肟菌.异噻胺FS 15 mL/kg和25 mL/kg种子对沪软1212苗瘟、叶瘟和穗瘟的防效分别为87.19%、77.64%、45.20%和93.75%、84.75%、58.92%,对沪软1212在苗期、分蘖期和抽穗期的恶苗病防效分别为83.44%、83.89%、84.35%和85.89%、88.26%、88.12%,各处理对水稻种子萌发和成苗安全。24.1%肟菌.异噻胺FS推荐剂量拌种对苗瘟、叶瘟和恶苗病防效较好,对水稻生长安全;研究结果可为稻瘟病和恶苗病综合防治提供理论依据。     

稻瘟病圃中水稻品系的抗瘟性评价与育种利用

在20世纪80年代抗病育种的基础上,从1994-2003年采用人工辅助接种、自然发病的方法对12151份次水稻材料在病圃中的稻瘟病抗性进行了监测。结果表明,10年共计有4933份次叶瘟表现抗病,7103份次表现为感病,分别占总份次的40.60％和58.46％;有4071份次颈瘟表现抗病,7965份次表现为感病,分别占总份次的33.50％和65.55％。有9034份次的材料叶瘟颈瘟表现一致,占总份次的74.35％,其中叶瘟感病颈瘟也感病的材料份次是叶瘟抗病颈瘟也抗病材料的两倍;叶瘟颈瘟表现不一致的材料有3002份次,占总份次的24.71％,其中叶瘟感病而颈瘟抗病的材料份次多于叶瘟抗病而颈瘟感病的材料份次。利用早期筛选的抗源,选育了抗病优良籼型杂交稻恢复系6326、蜀恢162、蜀恢527等。对稻瘟病抗病育种和抗病品种的合理利用等问题也进行了讨论。     

源宝占抗稻瘟病遗传分析及基因定位

稻瘟病是水稻三大病害之一,严重威胁着粮食安全。解决这一问题最安全、有效的措施是选育、推广抗 病品种。源宝占是一份新育水稻材料,经鉴定,源宝占对来自广东各稻作区的25 个菌株中23 个表现为抗性,抗频达 92%,为广谱抗性材料。以源宝占与粤香占进行杂交,构建F1、F2群体,选用GD00-193a 菌株对亲本及世代群体进行 接种鉴定,结果表明F2代单株抗感分离比符合3颐1,这说明源宝占对菌株GD00-193a 的抗性是由一对显性基因或一 个主效QTL 控制。利用群体分离分析法（BSA）结合隐性群体分析法（RCA）将此基因定位于标记RM136 与RM549 之 间。 [2009]356 号）;广东省科技计划项目     

Pathotype Structure of Magnaporthe grisea in the Fields of Chongyang and Yuan’an in Hubei Province,China

[Objective] This study aimed to explore the pathotype structure of Magnaporthe grisea in Chongyang and Yuan’an in Hubei Province,China.[Method] From the rice-growing fields of Chongyang and Yuan’an in Hubei Province where rice blast occurs frequently,60 isolates which were pathotyped against two sets of host differentials:Chinese host differentials and CO39 NILs,were obtained.Then,20 pathotypes with the six indica host differentials(CO39 NILs) were observed,while 13 pathotypes in four race groups were observed out of the same single spore isolates with Chinese host differentials which consists of three indica cultivars and four japonica cultivars.The diversity of the pathotypes of M.grisea populations tested by CO39 NILs was 2.54 and the pathotype 137.1 occurred at predominantly high frequency(21.67%).The diversity of physiological races of M.grisea populations tested by Chinese host differentials was 1.22 and the race group ZA occurred at predominantly high frequency(73.33%).The diversity of physiological races of M.grisea in Chongyang and Yuan’an were also calculated.Overall,the diversity of pathotypes of M.grisea in Yuan’an was higher than that in Chongyang with the two sets of the host differentials.[Conclusion] This study provided current information on the pathotype spectrum of M.grisea populations in the rice fields of Hubei Province to allow the formulation of viable strategies for blast resistance breeding programs in Hubei Province.     

稻瘟病菌孢子qPCR方法的建立及用于监测气传菌源的研究

稻瘟病是水稻生产中最具毁灭性的真菌病害之一,监测田间空气中稻瘟病菌分生孢子数量动态变化,对于预测病情发生和指导及时防治具有重要意义。该研究以稻瘟病菌MHP1基因为靶序列,建立了1种稻瘟病菌分生孢子qPCR定量方法,并采用此方法对田间气传稻瘟病菌源进行了监测。监测数据显示,监测期间空气中稻瘟病菌分生孢子数量波动幅度较大。结合气象条件进行分析,菌源量的波动与气象条件相关。该研究建立的孢子qPCR方法可应用于监测气传稻瘟病菌源。     

Evolutionary analysis of plant jacalin-related lectins (JRLs) family and expression of rice JRLs in response to Magnaporthe oryzae

Jacalin-related lectins (JRLs) are widely distributed carbohydrate-binding proteins in the plant kingdom, which play key roles in development and pathogen defense. In this study, we profiled evolutionary trajectory of JRLs family in 30 plant species and identified domain diversification and recombination leading to different responsive patterns of JRLs in rice during defense against rice blast. All of 30 plant species analyzed in our study have two types of JRLs by containing either a single jacalin or repeated jacalin domains, while chimeric jacalins exist in more than half of the species, especially in the Poaceae family. Moreover, Poaceae species have evolved two types of unique chimeric JRLs by fusing the jacalin domain(s) with dirigent or NB_ARC domain, some of which positively regulate plant immunity. Seven Poaceae-specific JRLs are found in the rice genome. We further found expression of rice JRLs, including four Poaceae-specific JRLs, are induced by Magnaporthe oryzae infections at either early or late infection stages. Overall, the results present the evolutionary trajectory of JRLs in plant and highlight essential roles of Poaceae specific JRLs against pathogen attacks in rice.     

Integrated pest management and plant health

Crop production and livelihoods of smallholder farmers are often threatened by crop insect pests and diseases worsening the insecurity of food.  Globalization has rapidly increased the introduction and threats of invasive pests.  Climate change results in a changed suitability of landscapes to pests, further increasing the threat and uncertainty of their impact.  Providing innovative technologies for sustainable pest management to smallholder farmers is urgently needed for food security and eliminating poverty.   The most devasting diseases and insect pests to major crops such as rice, wheat, maize and potato contribute to the largest yield losses in the world.  Under the support of the Food and Agriculture Organization (FAO), Chinese plant protection scientists, in collaboration with experts of different regions, carried out a specific project to prioritize top crop diseases and insect pests that affect smallholder farmers’ production globally.  After evaluation by relevant global experts, top 10 crop diseases and insect pests have been assessed as six crop diseases and four insect pests, namely cereal blast disease, potato late blight, wheat rust disease, Fusarium head blight, maize lethal necrosis disease, banana Fusarium wilt (TR4), rice planthopper, wheat aphid, whitefly, and oriental fruit fly.  Integrated pest management (IPM) guidelines for the identified diseases and insect pests have been formulated, and will be shared through a global knowledge platform.  To share the knowledge with more researchers, the IPM of four major diseases including cereal blast disease, Fusarium head blight, maize lethal necrosis disease and potato late blight were further reviewed and presented in this special focus.   The first case study is cereal blast disease caused by fungal pathogen Magnaporthe oryzae (Zhang et al. 2022), which is a destructive filamentous fungus that infects many plants including most economically important food crops, rice, wheat, pearl millet and finger millet (Chakraborty et al. 2021; Hossain 2022).  Different pathovars of M. oryzae often infect different host plants with high specificity.  The rice blast disease caused by the Oryza pathotype (MoO) of M. oryzae can result in 10–30% yield loss in rice-growing countries, posing a major threat to rice production, especially in the small-scale farming system (Mutiga et al. 2021).  The Triticum pathotype (MoT), causing wheat blast disease, was first found in Brazil in 1985.  It has now spread to other countries in South America, and also Asian countries such as Bangladesh (Islam et al. 2016).  Wheat blast disease can result in an average yield loss of 51% in the affected field, becoming one of the most fearsome wheat diseases (Islam et al. 2020).  Because of low fungicide efficacy against the blast diseases and lack of availability of resistant varieties, control of rice and wheat blast diseases is difficult.  A combination of management strategies including early detection and utilization of biopesticides was proposed (Zhang et al. 2022), providing some helpful insights for fighting these devasting cereal blast diseases.   The second case study is the fusarium head blight (FHB) caused by FHB pathogens, which are mainly the Fusarium graminearum species complex (Chen et al. 2022).  FHB is one of the most important diseases that affects wheat production worldwide (Summerell 2019).  In general, a severe FHB epidemic occurred every four or five years in the most of wheat production regions.  Since 2010, the outbreaks of FHB have become more frequent in China.  Besides causing yield loss in affected crop field, FHB also produces mycotoxin contaminating the harvested grains, which are harmful to humans and livestock (Stepien and Chelkowski 2010).  According to the economic importance and toxicity of FHB, F. graminearum is considered as one of the world’s top 10 fungal phytopathogens (Dean et al. 2012).  Breeding resistant cultivars has been considered as the most effective strategy against FHB (Wegulo et al. 2015).  Rational use of chemical pesticides, and potential biopesticides, and good agronomic practices are also important components in the IPM programme for FHB.    The third case study is the maize lethal necrosis disease (MLND), which is a relatively new viral disease on maize (Zhan et al. 2022).  The MLND is caused by the co-infection of maize chlorotic mottle virus (MCMV) and one of cereal-infecting potyviruses, and the symptoms on maize include leaf necrosis, premature aging, small cobs and even plant death (Redinbaugh and Stewart 2018).  First reported in Americas in 1970s and 1980s, the MLND has now spread to more than fifteen countries in the Americas, Asia and Africa (Wangai et al. 2012).  The outbreaks of MLND in several Asian and African countries caused devastating damage to maize production with large impacts on smallholder farmers (Mahuku et al. 2015).  Integrated management of MLND involves effective detection methods such as serological methods, nucleic acid-based methods, and next-generation sequencing.  The practices, such as using certified seeds, sanitary measures, crop rotation, and tolerant or resistant varieties, have been considered as the effective, economical and eco-friendly approach to prevent and control MLND. The fourth case study is the potato late blight (PLB) disease (Dong and Zhou 2022).  PLB, caused by the fungal-like oomycete pathogen Phytophthora infestans, is a devastating disease worldwide that led to the infamous Irish potato famine of the 1840s.  Besides the primary host potato, P. infestans also infects other solanaceous plants such as tomato, petunia and nightshade.  These infected plants can become pathogen inoculum to potato (Kirk et al. 2003).  Originated from Central Mexico or South America, this disease has spread to almost all major potato-producing countries including the United States, Canada, China, and India (Fry et al. 2015).  Up to now, PLB remains the most important biotic constraint to potato production worldwide and presents a major threat to global food security, especially for under-developed areas that heavily depend on potato as the major source of food (Cucak et al. 2021).  Careful agronomic practices, such as using pathogen-free seed, serve as the good start for the successful management of PLB.  Chemical fungicides remain the most effective means to control the pathogen.  However, these chemical fungicides should be used more scientifically to avoid over-dosage and high cost.  Some potential environmental-friendly biopesticides have been identified (He et al. 2021).  Additionally, new technologies which may bring some innovative solutions to control PLB are also proposed.   The desert locust (Schistocerca gregaria), the most destructive migratory insect pest in the world, was also selected in the special focus (Li et al. 2022).  Desert locust is an omnivorous insect, feeding on more than 300 various host plants including many cultivated crops and wild plants (Li et al. 2021).  Formation of desert locust swarms and the outbreak of desert locusts are induced by a combination of environmental stimuli.  During its outbreak and migration, desert locust can cause serious damage to cultivated crops, such as cotton, alfalfa, beans, wheat, barley, corn, flax, tobacco, tomato, potato, and melons, posing a major threat to food security and rural livelihoods.  Since the 20th century, there have been 15 outbreaks of the desert locust, affecting about 30 million km² of Africa and Asia continents and the lives of 850 million people in 65 countries (Ceccato et al. 2007; Divi 2020).  Studies demonstrate the correlation between poor early childhood health and the desert locust swarm outbreak (Kien and Nguyen 2022).  To date, much research has been conducted regarding the ecology and management of desert locusts.  Climate change resulted in more favorable conditions, which is a major factor contributing to the recent outbreak of desert locust in 2020 (Peng et al. 2020).  A critical component of preventive management programs is being able to locate significant infestations rapidly.  The FAO provides forecasts, early warning and alerts on the timing, scale and location of invasions and breeding through its global Desert Locust Information Service (DLIS).  Integrated management of desert locust, mainly including physical control methods, chemical insecticides, microbial pesticides, and biocontrol methods, are summarized in ths review (Li et al. 2022).   Occurrence of plant diseases and insect pests have been worsened by climate change in many aspects.  Prevention of yield loss of major crops is critical for achieving global food security.  Not only the IPM strategies should be adopted, but also the inter-government cooperation should be encouraged to share knowledge, information and innovative solutions, and to jointly tackle with challenges caused by transboundary pests.  All these efforts are needed to achieve the United Nations Sustainable Development Goals (SDGs) of 2030 Agenda for Sustainable Development.     

分子标记(SSR)技术在水稻稻瘟病研究中的应用及展望

稻瘟病是北方水稻的主要病害,选育抗病品种是防治稻瘟病最经济有效的措施.微卫星DNA分子标记为辅助选育抗稻瘟病水稻新品种和抗性鉴定提供了新的方法和手段.阐述SSR对水稻抗稻瘟病研究的作用,介绍SSR的机理和方法,为今后抗稻瘟病的分子遗传机理奠定了基础.     

福建省水稻新品种对稻瘟病菌的抗性鉴定与评价

2004~2005年对福建省18个水稻新品种进行了苗期人工接菌和田间病圃自然诱发抗稻瘟病鉴定。结果表明,参试品种对1996年以前分离的稻瘟病菌株群体抗性水平高于2003和2004年分离的稻瘟病菌株。不同水稻产区采集的菌株对水稻新品种致病性有差异,以福建省的宁德、三明、龙岩三个地区的菌株致病性较强,水稻新品种室内苗瘟和田间穗颈瘟的鉴定结果较为一致。通过分析,认为宜香优673、D优15和冈优148三个水稻新品种抗病性较好,可考虑在生产上示范应用。     

水稻抗病相关基因的分离克隆和功能鉴定

水稻白叶枯病和稻瘟病分别是由白叶枯病菌(Xanthomonas oryzae pv.oryzae,Xoo)和稻瘟病菌(Magnaporthe grisea)引起,是世界水稻生产中的两大重要病害,造成的损失巨大.通过改良水稻自身防御体系来控制病害,是一种既经济义绿色的方法.鉴定水稻抗病相关基因,研究水稻抗病机理对改良水稻有着重要的理论意义和应用前景.     

水稻稻瘟病抗性基因的分子定位及克隆研究进展

 稻瘟病是全世界范围内影响水稻粮食生产的主要病害之一。培育和合理利用抗病品种是控制稻瘟病最经济、有效的措施。随着水稻（Oryza sativa）及稻瘟病菌（Magnaporthe oryzae）基因组测序的完成,水稻-稻瘟病菌的互作已成为研究植物与真菌相互作用的模式系统。在过去的50多年中,通过广泛的遗传分析,已经鉴定了84个稻瘟病抗性基因及大量的数量抗性遗传位点（quantitative trait locus）。其中,8个主效抗性基因及1个隐性部分抗性基因已被克隆。本文综述了迄今已鉴定及定位的稻瘟病抗性基因的研究情况,根据基因的定位信息将这些基因整合到一张连锁图谱中;对抗性基因簇以及簇内基因间的关系作了分析;并进一步对后基因组时代抗性基因克隆策略的变化及其对策进行了探讨。     

Effects of silicon amendment on the occurrence of rice insect pests and diseases in a field test

Rice is one of the most important staple foods for the world population,but it is attacked by a number of destructive pests.While evidence from greenhouse and laboratory tests has shown that silicon(Si)amendment can confer enhanced resistance to pests in rice,few studies have directly demonstrated the Si-mediated protection from pests in a field situation.In this study,field plots with silicon amendments at 0,75,150 and 300 kg SiO_2 ha~(–1) in early-and late-season rice were employed to evaluate the effects of silicon amendment on the occurrence of major insect pests and diseases and rice yield.Compared with the control plots without silicon amendment,plant damage by stem borer and leaf folder and population size of planthopper were significantly lower in three to five of the seven monitoring observations in each season in the plots amended with 300 kg SiO_2 ha~(–1).The disease index of rice blast in the early-season rice was lower in the plots amended with Si at 300 kg SiO_2 ha~(–1) than in the control plots,while Si protection from rice blast in the late-season rice and from rice sheath blight in the early-season rice were not apparent.An insignificant increase of rice yield by 16.4%(604 kg ha~(–1))was observed in the plots amended with 300 kg SiO_2 ha~(–1) over the control plots.Our results indicate that Si amendment at 300kg SiO_(2 )ha~(–1) can provide substantial protection from some of the rice pests under field conditions.These findings support the recommendation of silicon amendment as a key component of integrated management of rice pests.