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报告水稻条纹叶枯病在开封市连年重发的原因及防治对策
出版时间:2007开封市为河南省重要的沿黄稻区,由于品质优经济效益高,种植面积逐年扩大。近年来,由于多种因素的影响,水稻条纹叶枯病在沿黄稻区发生普遍,为害逐年加重。一般发生田,病丛率在10%~30%,严重地块高达80%以上,造成水稻秧苗的“假枯心”或大片的“黄化枯死”,发生后期的“假白穗”,严重挫伤了稻农的种植积极性。为了从根本上探明水稻条纹叶枯病连年偏重发生的原因,确定最佳的防治时机及防治方法,有效指导群众开展科学防治,近年来,我们从水稻的苗床期开始开展了系统观察和防治对比试验,收到了显著的防治效果。据调查,近年来,开封市麦田一代灰飞虱发生数量较往年有明显上升,且带毒率高,是造成苗床秧苗“假枯心”主要根源,而大田分蘖期的感病以灰飞虱第1代成虫第2代若虫传毒为主,表现症状为“黄化枯死”。而穗期出现的“假白穗”是本地第3、第4代灰飞虱传毒所致,但以秧苗期、分蘖期发病最重,产量损失大。一般说来,第一代灰飞虱发生数量越大,传毒率高,条纹叶枯病的发病范围越广,发病程度越重,发病一定重,否则,较轻。从近几年开封市几种主要水稻品种发病情况调查对比看,不同的种植品种间病情有明显差异。主栽品种豫粳6号系列为高感病品种,其次为黄金晴。津稻1007、豫粳7号、郑稻18、原稻1号较抗条纹叶枯病。糯稻系列特别是米粒较长的糯稻品种一般不发病或很少发病。发病初期特别是秧苗期的发病没有引起群众的重视,即使个别群众及早用药,由于大面积用药偏晚而造成相互传毒危害,防治效果差。据系统观察,水稻从发芽到分蘖均为条纹叶枯病的易感病期。一般苗龄越小越易感病。近年来由于种种原因开封市黄河放水拖后,造成群众抢水播种,导致大部分地块的易感期与灰飞虱成虫转移高峰期相遇,大大增加了传毒感病的机会。从以上影响水稻条纹叶枯病的发生因素综合分析,制定了开封市的最佳防治时机:一是秧苗期即开封市的5月底至6月上旬,二是移栽后1周,即开封市的7月上中旬。防治水稻条纹叶枯病应采取“治虫防病”的防治策略,防治方法以农业防治为基础,以化学防治为主的“一看,二早,三连片”的防治方法,即系统观察、早防治、组织群众开展大面积连片统防,把灰飞虱消灭在产卵、传毒之前。3.1.1 种植抗(耐)病品种,以降低为害程度。3.1.2 由于稻飞虱有趋向狗尾草等杂草上取食产卵的习性。因此,及时铲除路边、田间杂草,可有效减少虫源,降低传毒机会。同时大田底肥要充足,特别是要增施磷钾肥,水要能灌能排,秧苗要合理密植,每墩最多3~4株,以确保秧苗的健壮生长,增强抗病能力。3.2.1 秧苗田 以治虫为主,选择用药为25%扑虱灵60g/667m2(噻嗪酮)或40%毒死蜱100ml/667m2或5%的锐劲特30~40ml/667m2,加入2%宁南霉素(菌克毒克)50~100g/667m2,分别在5月底至6月初、移栽前2~3天,各喷打一次,有显著的治秧苗、保本田的防治效果。3.2.2 大田防治 水稻移栽后7~10天,即水稻进入返苗后的分蘖期,一旦发现病叶要立即用上述药剂,同时加入促根、壮苗的植物生长调节剂如用天丰素、复硝酚钠等,以增强水稻的抗病虫能力。要每隔5~7天连防2~3次,可达到理想的防治效果。2006~2007年调查,系统防治田比群众自防田防效提高87.3%,病株率下降94.8%。 -
报告苹果霉心病综合防治技术研究
出版时间:2007苹果霉心病是近年来苹果果实上发生的一种重要病害。苹果霉心病又称苹果霉腐病、苹果心腐病,是苹果果实生长前期、采收前、贮藏期的主要病害之一,该病一般发生在果心部位,严重时可造成心室周围果肉腐烂,甚至烂到果皮下,严重影响了果农的经济收入。苹果霉心病主要是花期侵染。病菌在苹果枝干、芽体等多个部位存活,也可在树体上及土壤等处的病僵果或坏组织上存活,第二年春季开始传染。病菌随着花朵开放,首先在柱头上定殖,落花后,病菌从花柱开始向萼心间组织扩展,然后进入心室,导致果实发病。果实一般在贮藏期表现出来。在苹果霉心病防治上因群众不能够掌握住关键的防治适期,即花前、谢花后半月内的药剂防治,造成病菌的大量传播侵染,造成苹果霉心病发生重。为了更好地掌握苹果霉心病防治技术,从2005年开始,本站对苹果霉心病防治进行了系统的研究,具体研究如下:2005年,在陈村乡鱼池村进行了花期喷药防治红富士品种苹果试验。药剂主要有70%甲基托布津500倍液、80%大生300倍液、50%菌毒清300倍液、50%多菌灵300倍液、50%甲霜铝铜300倍液、50%扑海因1000倍液、12.5%特谱唑1000倍液、70%百菌清300倍液,对照喷清水,共9个处理,每个处理喷5株树。喷药日期为花期4月20日和4月25日2次。仔细喷洒花朵,尽可能不漏喷。果实9月10日采收,土窑洞贮藏95天,2005年12月15日各处理剖果600个,调查各处理心腐果率。试验设在陈村乡南庄村,共设6个试验处理,即70%甲基托布津、大生M-45、菌毒清、扑海因、特谱唑及喷清水对照药液浓度同花期用药,品种为红富士。2006年为5月3日终花期喷药,9月20日采收,土窑洞贮藏100天,于2006年12月30日剖果,各处理均剖果600个,调查心腐果烂果率。共设6个试验处理,即70%甲基托布津500倍液、80%大生300倍液、50%菌毒清300倍液、50%扑海因1000倍液、12.5%特谱唑1000倍液及喷清水对照,品种为红富士。喷药时间为4月22日花期和5月5日终药期共两次喷药。9月20日采收,土窑洞贮藏100天,于2006年12月30日剖果,各处理均剖果600个,调查心腐果烂果率。2005年花期喷甲基托布津为1.5%,大生为0.33%,菌毒清为1.83%,多菌灵为1.5%,甲霜铝铜为1.33%,扑海因为0.83%,特谱唑为0.5%,百菌清为0.67%,清水对照为6.83%。表明花期喷上述药液2次,对防治果实心腐烂果均有较好效果,以80%大生300倍液防效最好。2006年终花期喷药甲基托布津500倍液为3.17%,大生300倍液为2.17%,百菌毒清300倍液为1.67%,扑海因1000倍液为1.83%,特谱唑1000 倍液为1.5%,喷清水对照为7.17%。试验与2005年花期防效相比,终花期防效稍低于花期防效。在6种试验药剂中以80%大生300倍液和百菌毒清300倍液的防效最好。2006年花期加终花期两次喷药,甲基托布津500倍液为0.83%,大生300倍液为0.0%,百菌毒清300倍液为0.33%,扑海因1000倍液为0.5%,特谱唑1000 倍液为0.5%,喷清水对照为6.33%。在6种试验药中以80%大生300倍液和百菌毒清300倍液的防效最好。序号试验处理剖果(个)病果数病果率(%)备注170%甲基托布津500倍液60091.5280%大生300倍液60020.33350%菌毒清300倍液600111.83450%多菌灵300倍液60091.5550%甲霜铝铜300倍液60081.33650%扑海因1000倍液60050.83712.5%特谱唑1000倍液60030.5870%百菌清300倍液60040.679喷清水对照(CK)600416.83表1 2005年花期喷药防治苹果霉心病效果序号试验处理剖果(个)病果数病果率(%)花期+终花期终花期花期+终花期终花期1甲基托布津300倍液6005190.833.172大生300倍液60001302.173百菌清300倍液6002100.331.674扑海因1000倍液6003110.51.835特谱唑1000倍液600390.51.56清水对照(CK)60038436.337.17表2 2006年花期+终花期和终花期喷药防治苹果霉心病效果通过多年的防治试验示范,我们认为采用以下的综合防治措施,可收到较好的防治效果。3.1.1 清除病原 苹果采摘后清除果园内的病果、病叶、病枝、丛生的杂草,刮除树体病皮,并带出果园集中处理。3.1.2 科学管理 增施有机肥料,增强树势,提高植株抗病性;合理灌水,及时排涝,保持适宜的土壤含量,防止地面长期潮湿;科学修剪,建造合理的树体结构,保持果园通风透光良好,可有效地控制或减少霉心病的发生。采收时对田间发病较重的果实,应单存单贮。采收后24h内放入贮藏窖中,窖温最好保持在1~2℃。一般10℃以下,发病明显减轻。花前和谢花后7~10天是防治苹果霉心病的两个关键时期,有效药剂为80%大生、扑海因、多抗霉素等。3.2.1 芽前用药 苹果发芽前或花芽萌动期用3~5波美度石硫合剂+0.3%五氯酚钠,40%福美砷100倍防治。3.2.2 花前加谢花后7~10天用药,提高防治效果 药剂为:80%大生、70%甲基托布津300倍液、50%扑海因可湿性粉剂1500倍、50%退菌特可湿性粉剂600倍、70%代森锰锌可湿性粉剂500倍,可以有效防治霉心病,还能兼治轮纹斑、斑点落叶病。苹果霉心病是由霉心和心腐2种症状构成,其中霉心症状为果心发霉,但果肉不腐烂,不影响果实食用价值和商品价值,心腐症状不仅果心发霉,靠近果心的果肉也由里向外腐烂,影响食用甚至无食用价值,这种症状严重影响果品的经济效益。通过以上试验,可以看出,以花期加终花期喷药防治苹果霉心病效果最好,其次为花期两次喷药,终花期喷药防效相对差一些。但是3种防治方法对苹果霉心病均有较好防效。 -
报告棉花枯、黄萎病的防治探索
出版时间:2007开封市为河南省历史上的重要植棉基地,1998年以来抗虫棉在开封市的大面积种植,棉铃虫的发生防治已成为开封市棉花生产的一个次要害虫,而棉花枯、黄萎病却为影响开封市棉花产量及品质的两种重要病害。特别是近年来,由于气候、栽培管理、品种等因素的综合影响,棉花枯、黄萎病在开封市的发生呈逐年上升的趋势,并严重制约着开封市的棉花的优质高产。为了克服群众在防治这两种病害的恐惧心理,甚至放弃种植的现状,我们进行了大量的发生情况调查和防治探索,为开封市在生产上找到了一些有效的防治措施和方法,并指导群众进行大面积的应用,收到了较好的效果。通过多年来的大面积调查,认为生产上导致棉花枯、黄萎病偏重发生的主要因素有3种。由于枯、黄萎病菌寄主范围广,适应性强,病原菌很难根除等特点。连作棉田,土壤中、病残体等含有大量病菌,非常有利于病害的发生。据调查,相同品种在连作2年病株率增加56.2%,死株率增加5.1%,连作3年病株率增加67.5%,死株率增加7.9%。目前开封市大面积种植的抗虫棉品种如鲁棉21、欣抗3号、欣抗4号、丰抗6号、豫棉19等对枯黄萎病都有一定的抗性,但大多品种对枯萎病抗性较好,对黄萎病抗性较差,没有一个兼抗枯黄萎病的品种。据调查,近年来开封市枯萎病为中偏轻发生,而黄萎病为中度或中度偏重发生,病株率枯萎病一般为3%~7%,而黄萎病为12%~52%。因此,根据病害的发生特点,选用抗病品种,制定合理的防治措施,是病害防治的关键。开封市大部分土壤属砂壤土,漏水漏肥现象较重。相同条件下,土壤肥力不足的地块病害明显加重,而底肥充足特别是磷钾肥充足的棉田抗病性明显增强。据调查,一般亩施优质农家肥2000kg、饼肥50kg(混合堆沤10~15天,充分腐熟),专用复合肥(其氮磷钾含量为1:1:1.5,并含有适量硼、锌肥)50kg,比单用复合肥的病株率下降30%~50%。棉花枯、黄萎病虽说是棉花上没有办法根治的两种病害,但结合影响病害发生的主要因素制定简单、合理的防治方案进行大面积推广,仍收到较好的防治效果,有效的减少产量损失。防治配套措施为:近年来,棉农很少使用硫酸脱绒,一般选用包衣种子。据调查,进行硫酸脱绒后10kg种子用25%的多菌灵粉剂0.2kg或20%的灵福合剂0.2~0.3kg加入适量的细土拌种后进行播种,比包衣种子的棉花病株率下降17%~23%。开封市秋作物主要有棉花、花生、玉米、大豆、西瓜等,我们强调以棉花—小麦—玉米的栽培模式进行轮作。据调查,比其他轮作模式病株率下降20%~40%。根据开封市病害的发生特点,在枯、黄萎病特别是黄萎病发生严重的地块,推荐种植晋棉38、欣抗3号、欣抗4号、豫棉21等,在枯、黄萎病特别是枯萎病发生较重的地块推荐使用鲁棉21、丰抗6号、豫棉19等。棉田基肥我们强烈推荐农户亩施优质农家肥2000kg与饼肥50kg(混合堆沤10~15天,充分腐熟),专用复合肥(其氮磷钾含量为1:1:1.5,并含有适量硼、锌肥)50kg,最低是饼肥50kg与专用复合肥50 kg。棉苗染病前和染病初期,喷施叶面肥,增强营养,特别是棉花的蕾铃期,要及时补充营养,可提高棉株的抗病能力。如遇大雨,要及时排涝、中耕松土,可非常有效的减轻枯、黄萎病的发生程度。枯萎病盛发期是在棉花现蕾前后即开封市的6月中下旬,可在6月上中旬用OS施特灵加3%广枯灵500倍液或40%乙蒜素20~30ml加磷酸二氢钾100g,每7~10天喷施一次,连喷2~3次;黄萎病的盛发期在7、8月棉花花铃期,由于棉株较大,防治较难,防治时机在7月中下旬,用上述药剂及方法,间隔7~10天再喷一次。 -
报告豫西地区辣椒病毒病发生流行特点及综合防治方法
出版时间:2007辣椒病毒病又名辣椒花叶病,是辣椒生产的主要病害之一,近年来在三门峡地区发生日趋严重。发病田块一般减产10%~30%。花叶型初现明脉轻微褪绿或现浓、淡绿相间的斑驳,全株叶片褪绿,继续发展则叶面皱缩畸形,或形成线形叶,果实变小,植株严重矮化;黄化症状呈上升趋势,表现为叶色均匀黄化或黄色斑驳,植株矮化或矮化不明显;坏死型主要表现为枯顶症状,病株部分组织变褐坏死,植株生长点呈水渍状枯死,叶片黄化,随后叶片逐渐脱落,在叶片上,产生黄绿相间的斑驳或大型黄褐色环斑;畸形丛枝型的植株节间缩短,幼叶狭窄或呈线状,叶面皱缩,植株上部叶丛生,呈丛簇状,重病果面有深绿、浅绿相间的花斑和疣状凸起,果面凸凹不平,病果易脱落;易导致落叶、落花、落果,病株严重矮化,叶小而少,株小。果实常出现黄绿相间的花斑或黄色环斑、畸形,易腐生其他杂菌而烂果,严重影响辣椒的产量和品质。主要为前两种。在辣椒上,烟草花叶病毒和马铃薯X病毒引起系统花叶症状,烟草花叶病毒的不同株系分别引起系统花叶、系统环斑和条斑症状。黄瓜花叶病毒寄主范围非常广泛,毒源植物十分普遍。在田间主要靠蚜虫飞迁传毒,主要种类有桃蚜、萝卜蚜和瓜蚜等。种子和土壤中的病残体不能传播,摩擦传毒也不重要。烟草花叶病毒的主要初侵染源是土壤中的病残体,而带毒种子和卷烟或旱烟不是主要的初侵染源。在田间主要通过田间操作接触传播。马铃薯X病毒主要毒源是马铃薯,主要靠摩擦传播,不能通过蚜虫传毒,种子和土壤中的病残体也不能传播。辣椒病毒病发生及轻重与病毒类型、环境条件、栽培技术、品种抗病性有密切关系。栽植适龄壮苗,合理密植,早期防蚜等综合防治措施可以有效地减轻辣椒病毒病。在早春采用薄膜覆盖等提高地温和保湿防风的措施,秧苗健壮,抗病力增强,可使辣椒不发病或发病轻。而不覆盖的辣椒病毒病较重。定植健壮、适龄的幼苗比弱苗、老龄苗生长好,病毒病轻。重茬地发病重,轮作发病轻。辣椒病毒病的发生还与邻茬有关,辣椒地块的邻茬为番茄则发病重。植株生长茂密、徒长、通风不良的田块发病亦重;辣椒与茄科作物连作、移栽偏晚、地势低洼、土壤贫瘠、缺肥的田块,均可加重病毒病的发生。肥水充足,管理水平高,辣椒生长旺盛,病毒病发生较轻;反之发生较重。黄瓜花叶病毒、马铃薯Y病毒与蚜虫的发生情况关系密切,冬季高温干旱时,蚜虫等传毒介体发生多,扩展速度快,花叶和畸形等类型辣椒病毒病发生早,病害扩展速度快,为害严重。但枯顶型病毒病往往在田间湿度大时发生较多,传播较快;烟草花叶病毒和其他多种植物病毒可以经接触及伤口传播,通过整枝打杈等农事操作传染。新育成的品种如农大21号、农大22号、中椒5号、津椒3号均是抗病的优良品种。3.2.1 种子消毒 用10%硫酸三钠溶液浸种20~30min,洗净后催芽,可防治烟草花叶病毒感染。3.2.2 从无病株上采种,携带烟草花叶病毒的种子可用10%磷酸三钠溶液浸种30min,清水洗净后播种 育苗地要疏松肥沃,清除病残体,并适当早播和适当稀播。在满足幼苗对营养和水分等要求的前提下,实行昼促夜控的苗床温度管理,培育茎秆粗壮,具12~14片叶和50%以上植株现蕾的壮苗,并注意及时防治蚜虫。这样的适龄壮苗定植后一周即可转青,而且封垄早,生长健壮,抗病力强。3.2.3 营养钵育苗在育苗期间,采用塑料钵育苗 把调配好的营养土装入钵内,每钵播种3粒种子。保证成活两株幼苗,然后带钵土定植。这种方法一可减少分苗假植程序,节省用工;二可自种子出土后,就有充足的营养面积,保证幼苗粗壮;三可防止造成根部伤口,减少病毒入侵机会。3.2.4 苗龄不宜过长,应控制在70~80天。定植苗株高与植株横径相近,控制在10~15cm,具5~6片真叶。株高10~15cm时,茎基部直径应达0.5~0.6cm。叶片宽、厚、平、绿,茎尖嫩壮。幼小根系发达白嫩。为防止病毒病或减轻病毒病发生,将单株栽培习惯改为在分苗时就进行双株分苗假植,尔后双株定植,每亩栽种3000~3500墩。双株法是减轻病毒病的有效措施。采用大小垄密植栽培,一般大垄宽为50~53cm,小垄宽22~33cm,每亩4500~5000穴,每穴栽2株。春季气温低,垄作和小水灌溉比平畦和大水漫灌地温高,并且土壤疏松利于发根,提早封垄,雨季利于排水。夏季高温炎热,密植能够较早地遮严地面,降低地温和保持土壤水分,有利于植株生长,不利于病毒病发展。3.4.1 采用配方施肥技术,施足基肥。3.4.2 覆盖地膜,适当提早定植 要求秧苗株型矮而壮实,在第一分杈具有花蕾时定植为宜。3.4.3 与玉米、菜豆等高秆作物间作,避免强光高温,可有效防止病毒病。注意轮作换茬,精细整地,施足基肥,增施磷、钾肥。露地栽培可在定植时铺地膜或加盖小拱棚,并适度蹲苗,促进发根。生长前期避免大水漫灌,浇水后及时中耕,力争做到早定植,早生根,早结果,在发病盛期到来之前已花果满枝。结果期不能缺水缺肥,以防早衰。搞好田园卫生,及时清除田间路边杂草,如酸浆、反枝苋、刺儿菜及藜等,以减少病毒来源。3.5.1 苗期及生长期要及时喷药治蚜 可用2.5%溴氰菊酯乳剂2000~3000倍液,或20%速灭杀丁乳剂2000~3000倍液,或2.5%天王星乳油3000倍液,喷洒注意喷嘴对准叶背,将药液尽可能喷射到蚜虫体上。药剂有50%辟蚜雾可湿性粉剂或2.5%溴氰菊酯乳油2000~3000倍液等。3.5.2 应用弱毒性病毒进行人工免疫可减轻病毒病害,如烟草花叶病毒弱株系N14防烟草花叶病毒,烟草花叶病毒卫星核糖核酸制剂S52和S54防烟草花叶病毒,但必须在辣椒感染自然界强株系之前接种上弱毒性病毒。接种方法主要有两种:一种是人工摩擦或高压喷枪接种,苗龄在1~3叶期为宜;另一种是浸根接种,当幼苗2叶期进行第一次假植时,将幼苗拔出洗净根部后立即浸入疫苗液中5~10min。疫苗液的浓度一般为100倍液(S52和S54)和1000倍液(N14),详见产品说明。另外,也可喷洒NS-83增抗剂100倍液,定植前后各喷1次,还可在定植前、缓苗后及盛果期各喷1次0.1%硫酸锌溶液,都有一定的防病作用。3.5.3 发病始期喷施病毒A800倍液+高锰酸钾1000倍液+0.3%硫酸锌,或用叶康或小叶敌300倍液。注意用药时每隔7天喷1次,连喷3次,才能收到良好效果。3.5.4 设置生物屏障在进行定植的时候,有计划地栽种4行辣椒间种1行玉米,使玉米成为高温季节对辣椒进行遮光降温的生物屏障,降低病毒病的发生,并从栽培玉米中得到一定效益。3.5.5 钝化剂和微肥的应用 用500倍的AV-2或100倍的豆浆释液或100倍的豆制品浆水,从4叶期开始每隔10~15天叶面喷布1次,共喷3~5次,可有效的减轻病毒病的为害。锌对控制TMV侵染有明显效果,常规用量为1‰的硫酸锌水溶液,每亩用75~100kg稀释液喷布叶面,喷2~3次。 -
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报告Resistance Genetic Analysis on Space-induced Resistant Lines of Zhong-er-ruan-zhan to Rice Blast
出版时间:2007由稻瘟病菌(Pyricularia grisea Sacc.有性世代为Magnaporthe grisea)引起的稻瘟病是水稻最具毁灭性的病害之一。全球每年因稻瘟病造成的水稻产量损失达11%~30%,年平均超过1000万t[1]。我国南北各稻区每年均有不同程度的发生和流行,一般减产10%~20%,重的达40%~50%,局部田块甚至颗粒无收[2]。20世纪90年代以来,我国稻瘟病发生面积每年都在380万hm2以上,年损失稻谷达数亿千克[3],遗传抗性、选育和利用抗病品种是最有效、最经济、对环境最友好的防治策略[5]。培育抗病品种是首要任务,在生产上一般通过化学防治和种植抗性品种来控制稻瘟病害。化学防治虽然能发挥一定的作用,但在病害流行年份收效甚微,且容易造成环境污染[4]。长期的生产实践证明,利用遗传抗性是发掘新抗源和鉴定抗性基因的重要手段,为此,世界各主要产稻国几乎都投入大量人力、物力开展稻瘟病抗性遗传研究,迄今已鉴定和定位了一大批抗瘟基因,并克隆了部分抗瘟基因,为阐明水稻抗瘟性分子基础、培育广谱或持久抗瘟水稻品种奠定了基础。但是,许多抗病品种在生产上推广几年之后就丧失了抗性,如何寻找新抗源延长品种稻瘟病的抗性周期,已成为各水稻生产国水稻改良项目中的首要问题[6]。水稻航天育种(Rice Space-flight Breeding)技术是将水稻干种子搭载返回式卫星、航天飞机、飞船或高空气球,经过空间特殊环境的诱变作用产生变异,在地面上选择有益变异培育新种质、新品种的育种方法[7]。自1987年以来,我国先后多次利用返回式卫星或高空气球搭载植物、农作物种子,进行空间诱变育种研究,并取得了一批极有价值的研究材料和成果,同时,还发掘和筛选一些罕见的具有利用价值的突变体。本研究利用返回式卫星搭载,空间诱变中感稻瘟病的优质水稻品种“中二软占”[8],分析其3个抗病诱变品系的抗性遗传基础,为抗病育种提供新种质,同时为定位和克隆抗病突变基因打下基础。1.1.1 水稻材料 研究材料为H1、H2及H3,由“中二软占”干种子经返回式卫星搭载空间运行18天后返回地面种植,连续多代单株选择所获得的SP4代诱变品系,性状基本稳定。部分“中二软占”种子留在地面,作为非诱变原种对照。经38个稻瘟病代表性菌株测定,H1、H2及H3的苗瘟抗谱均为94.74%,原种对照为28.95%;3个诱变品系连续2次在代表性病圃的田间穗茎瘟抗性均表现高抗稻瘟病,而原种对照均表现高感稻瘟病(数据未发表)。1.1.2 稻瘟病菌株 菌株GD0193和GD3286被选择作为水稻材料抗性遗传分析菌株,采用中国7个鉴别寄主分别被鉴定为ZB13和ZA1小种,属于籼型致病小种;采用14个对广东稻瘟病菌具有较好鉴别能力的单基因鉴别寄主进行鉴定,致病型分别为I-01-04和I-02-03,其中GD0193可侵染Pi-k、Pi-kp、Pi-7(t)等8个单基因鉴别寄主,GD3286可侵染除Pi-zt外的13个单基因鉴别寄主。GD3286是一个广致病谱菌株,GD0193的致病谱也较广[9],2个菌株均具有较好的代表性。“中二软占”对这两个菌株均高度感病。1.2.1 诱变品系H1、H2及H3对稻瘟病的抗性遗传分析 性状稳定的SP4代突变品系H1、H2及H3作为父本分别与感病亲本丽江新团黑谷(LTH)杂交,获得F1代种子,并自交获得F2代种子。F1及F2代均分成两份,一份接种稻瘟病菌GD0193,另一份接种GD3286。F1代选择抗病单株,F2代统计各个菌株对应的抗病株数和感病株数,明确抗感分离情况,采用χ2计算抗感分离比例,分析抗性遗传基础。1.2.2 接种及病情鉴定 分别于2006年4月和8月将F1及F2代种子分成2份按2cm×1.5 cm的规格播于50cm×30cm×8cm的育秧盘中,每一盘的两侧均按同样规格播种原种对照及诱变品系各一行。秧苗长至3.5~4叶时,一份接种菌株GD0193,另一份接种GD3286。采用高压喷雾接种,接种液的孢子浓度为5×104个/ml,每盘接30~40ml孢子悬浮液。接种后于25℃暗室保湿24h,然后移至22~30℃的遮阴网室,定期喷雾保湿,7天后进行病情鉴定。病级划分按全国统一的0~9级标准进行,0~3级的定为抗病,4~9级的定为感病。鉴定结果表明,3个诱变品系H1、H2及H3与LTH杂交之F1代对2个稻瘟病代表性菌株GD0193和GD3286均表现出高抗水平。可见,其对菌株GD0193和GD3286的抗性均由显性基因控制。原种对照对这2个菌株均表现出高感水平,说明空间环境对“中二软占”产生了抗瘟性诱变,可从其后代获得有益的抗病突变体。本研究中“中二软占”为籼稻,从其空间诱变后代选育出的突变品系H1、H2及H3经形态鉴定仍属籼稻,以突变品系作为父本与国际上公认的、不含任何主效抗性基因的普感稻瘟病的粳稻品种丽江新团黑谷[10]杂交,属于籼粳亚种间杂交,其F1代植株形态上介于两者之间,很容易辨别,可完全淘汰假杂株。本研究采用抗性鉴定和形态辨别相结合的方法以确保F1代植株准确无误。由表1和表2可知,非诱变原种和LTH对稻瘟病菌株GD0193和GD3286均表现感病,突变品系H1、H2及H3对两菌株均表现抗病。H1×LTH之F2代群体对两菌株的抗感植株比都符合3:1的理论比值,表明H1对两菌株的抗性分别受一对显性主效基因的控制。H2×LTH和H3×LTH的2个F2代群体对菌株GD3286的抗感植株比均符合13:3的理论比值,符合2对显性基因控制的遗传,说明H2和H3对稻瘟病菌GD3286的抗性均受两对主效基因控制,2对抗性基因之间可能存在一定的互作。H2×LTH之F2代群体对菌株GD0193的抗感植株比既不符合13:3的分离比例,更不符合3:1或15:1的理论比值,说明其对菌株GD0193的抗性遗传基础较为复杂。H3×LTH之F2代群体对菌株GD0193的抗感植株比符合3:1的分离比例,说明H3对菌株GD0193的抗性也由一对显性主效基因控制。InoculatedmaterialsDeviationofresistanttosusceptibleRSR∶SExpectationχ2χ20.05Originalvariety015Space-inducedlineH1150Space-inducedlineH2150Space-inducedlineH3150LiJiangXinTuanHeiGu(LTH)015F2(H1×LTH)3411142.99∶13∶10.0009663.84F2(H2×LTH)4411094.05∶113∶30.2134483.84F2(H3×LTH)9772004.89∶113∶31.4069803.84Table 1 The deviation of resistant to susceptible of the original variety (CK),parents and their F2 populations inoculated by isolate GD3286InoculatedmaterialsDeviationofresistanttosusceptibleRSR∶SExpectationχ2χ20.05Originalvariety015Space-inducedlineH1150Space-inducedlineH2150Space-inducedlineH3150LiJiangXinTuanHeiGu(LTH)015F2(H1×LTH)178583.07∶13∶10.00563.843∶127.5737F2(H2×LTH)320466.96∶113∶35.43483.8415∶123.8696F2(H3×LTH)3701023.62∶13∶12.71473.84Table 2 The deviation of resistant to susceptible of the original variety (CK),parents and their F2 populations inoculated by isolate GD0193稻瘟病是水稻最主要的病害,对水稻生产危害极大。稻瘟病的化学防治成本高、污染环境,所以抗病品种的培育十分重要。而生产上要得到抗病新种质十分困难,迄今已鉴定和定位50多个主效抗瘟基因和20多个QTLs位点[4],成功地克隆了Pib、Pita、Pid2、Pi9、Pi2、Pizt和Pi-36等7个抗瘟基因[11~14],为揭示水稻抗瘟性分子基础,以及通过分子育种手段培育广谱或持久抗稻瘟病品种奠定了基础。通过空间诱变技术培育抗病品系,挖掘抗病新种质,对农业生产意义重大[15],可为水稻抗病育种开辟一条新的途径。空间诱变因太空特殊环境可以使植物产生罕见的突变体,为获得在地面上难以得到的新种质提供了一种快捷有效的途径,是产生新基因源的重要途径之一,因而越来越受重视。自开展空间诱变育种研究以来,有关水稻空间诱变材料性状变异的研究已有不少报道,但主要集中在重要农艺性状,如株高、分蘖、有效穗、千粒重等方面,而对空间诱变抗病性变异的研究目前尚处于起步阶段[16]。水稻空间诱变的机理是复杂的,基础理论研究十分薄弱,需系统地从不同角度和层次进行研究。本研究从表型上证实H1、H2和H3三个诱变品系对稻瘟病表现出广谱高抗水平,同时还保留了原品种优良的农艺性状(数据未发表),完全可作为新的抗病种质应用于育种实践。经遗传分析,确定突变品系H2对菌株GD0193的抗病性表现出较为复杂的遗传基础,非一两对基因能够解析,说明空间诱变对水稻基因组引起的变异效应并非单个位点的,有两个位点甚至多个位点的突变。突变品系H1对稻瘟病菌GD0193和GD3286的抗病性分别受一对主效基因控制,控制这两个菌株的抗性基因是否一致有待进一步的研究。突变品系H3中控制菌株GD0193抗性的一对主效基因与其控制菌株GD3286抗性的两对显性基因是否有一对重叠,抑或都不一样也是一个值得深究的问题。本研究表明,诱变品系H1、H2及H3均具有广谱的质量抗性,田间均达到高抗水平,深入剖析其质量抗性基因和数量抗性座位(QTLs),有助于对空间诱变抗性变异机理开展有益的探讨。在抗病育种实践中广谱的主效基因易于应用,可通过有性杂交、回交、复交等育种手段将其转育到目标品种中,同时利用与其紧密连锁的分子标记进行辅助选择可大大提高选择的效率。GD3286菌株是一个致病谱广、致病力强的稻瘟病菌株,本研究已证实广谱高抗突变品系H1对该菌株的抗性受一对主效基因控制,对该抗病基因的转育将具有较大的实用价值,因此定位该抗病基因显得尤为迫切。通过分子标记对广谱高抗突变品系的主效基因进行精细定位,一方面,通过育种手段将其转入到作物基因组中使目标性状得以表达;或者通过分子标记辅助选择,将分子生物学与传统遗传育种相结合,借助目标基因紧密连锁的遗传标记,分析基因型,鉴定分离群体中含有目标基因的个体,可以加快抗病育种进程;另一方面,对其进行精细定位为进一步克隆奠定基础,目前这方面的工作正在开展之中。 -
报告Research on the Relationship between Prevention of the Small Brown Planthoppers (Laodelphax striatellus) in Rice Seedling Bed and the Incidence of Rice Stripe Virus
出版时间:2007The small brown planthoppers(Laodelphax striatellus)is an important pest in single late rice seedling stage in Zhejiang province and also the vector of the rice stripe virus,threatened paddy rice production.Through the investigation of transplanting time of rice seeding,occurrence quantity and carriage rate of overwinter and the first generation of the small brown planthoppers in wheat field and weed at the beginning of 2007,the small brown planthoppers mainly immigrated Early Sowing single late rice seedling from wheat field and weeds.The generation of the small brown planthoppers is the most serious in sowing single late rice seedling,and easily arouse the outbreak of the rice stripe virus.Currently,control strategy of the rice stripe virus is"cut off a poisonous chain,cure insect to control the disease".During the last years,by investigating the small brown planthoppers quantity in rice seedling stage and adopting chemistry prevention at different number of times to control it,we research the relationship between the small brown planthoppers quantity in rice seedling stage and the incidence of the rice stripe virus for explicating the affection of insect quantity in rice seedling stage and chemistry prevention to incidence of the rice stripe virus.Now we report the result as follows.Agent:40%Chlorpyrifos(zhejiang xinnong chemical company limited).Experimental field is in the experimental area of Shuangqiao academy of agricultural science in Xiuzhou district of Jiaxing City;rice variety is Jia 991 and is offered by Jiaxing academy of agricultural science.1.2.1 Seed treatment May 10 in 2007,rice seed is immersed in 2000 times'402 liquid over72h.May 13,we took it out and flushed with the clear water,then put it in the thermostat in 37℃ in order to pregerminate and seeded on May 15.1.2.2 Experimental design The rice seedling bed is divided into 15 small areas that is 2m2 and each small area stays the partition of 30cm.Each small area is sowed seeds quantity homology.15 small areas are divided into 5 processing and the everywhere manages 3 small areas.5 processing differences expect:no application,once application,2 times application,3 times application and 4 times application in the rice seedling stage.Application of time is such as the table 1.The agent of prevention chooses to 40%Chlorpyrifos that diluted to 500 times liquids to spray.ApplicationtimeApplicationnumberoftimes0times1times2times3times4times5/24√√√√6/1√√√6/8√√6/15√Table 1 Different application number of times and time1.2.3 Investigation of the small brown planthoppers quantity in rice seedling stage and incidence of the rice stripe virus We have investigated the small brown planthoppers quantity of every small area in rice seedling bed before application since May 24.The small area is investigated in 3 point and everywhere is 0.11m2,and we statistics the average of insect quantity in each point and compare with the quantity in different processing.We statistics the amount of rice seedling and the number of infected plants in every small area on June 20 when the rice seedling transplanted to the field,and computed the incidence of the rice stripe virus in each area.1.2.4 Incidence of the rice stripe virus in the field After investigating incidence of the rice stripe virus in rice seedling stage,we transplanted the rice seedling from 5 processing area including no preventing,preventing once,2 times,3 times,4 times into the field,and periodical investigated the incidence of the rice stripe virus in the field.Each small area is chose 5 points while investigating,and investigated 250 stubs on each point and computed incidence in every small area.2.1.1 The small brown planthoppers quantity in rice seedling stage Investigate a result on May 24,The small brown planthoppers all is longwing adults in each small rice seedling area,and the insect quantity is 138 in each 0.11m2;amount of insect in the field has a little bit decrease on June 1;on June 8 it obviously reduces and the number of egg and low instar nymphst increases gradually;until June 15 it has been basically low instar nymphst.The result of investigation indicates,from June 1 to May 24,the insect quantity of every processing area presents to a descend trend,but the decrease range of the insect quantity in applicationarea is higher than in no application;From June 1 to June 15,the insect quantity of no and once application area increases gradually,which are higher than the cardinal number of ex-experiment,but the amount of insect in the other application areas have gradually decrease,see table 2,figure 1.Date(month/day)0time1time2times3times4times5/241381451621431526/11191121251161206/8211175142122986/152471991398465Rateofincreasesordecrease(%)78.9937.24-14.20-41.26-57.24Table 2 Investigation of the small brown planthoppers quantity in different processing areas of rice seedlingFigure 1 Investigation of the small brown planthoppers quantity in different processing aras of rice seeldingWith the insect quantity of ex-application in each small area for cardinal number,compared with the amount of the last investigation,the insect quantity in no and once application area increased by 78.99%and 37.24%respectively,but it in 2 times,3 times and 4 times application area reduced by 14.20%,41.26%and 57.24%respectively.Experiment indicates,application inrice seedling bed can effectively repress the small brown planthoppers quantity in the field,and with application number of times increasing,which restraint effect is strengthen and amount of insect in small area reduces 57.24%with 4 times application.2.1.2 Investigation of the incidence of the rice stripe virus in rice seedling bed The investigation of incidence of the rice stripe virus on that day when the rice seedling was transplanted to the field,there is all discovered diseased plants in each small areas,but which number in the small area of no application is obviously more than the application area.The incidence of no,once,2 times,3 times and 4 times application areas respectively is 5.53%,3.90%,2.27%,1.50%and 1.36%,see table 3.Experiment enunciation,application in the rice seedling bed is not only lower amount of the small brown planthoppers in the field,but also ease occurrence of rice stripe in rice seedling bed.ApplicationtimesInriceseedlingbedDiseasedplantAmountIncidence(%)Reductionrateofriceseedling(%)InthefieldDiseasedplantAmountIncidence(%)Reductionrateofthefield(%)0time993179655.530237129618.2901time719184293.9029.48170113814.9418.322times404178302.2758.95116102011.3737.833times270180211.5072.887311016.6363.754times247181541.3675.416114234.2976.54Table 3 The investigation of incidence of the rice stripe virus in rice seedling bed(Jiaxing,2006)Seen from the investigation of the incidence of rice stripe virus with the different processing,the incidence in rice seedling bed of no application is lowered by 29.48%compared with once time application;compared with 2 times,the incidence is lowered by 29.47%with once application,and it is descended by 13.19%compared 2 times with 3 times;but compared 4 times application with 3 times,the incidence in rice seedling bed is only lowered 2.53%.This is because of the rice stripe virus has an incubation stage in rice plant after infection,and there is 12 days at least from infecting to outbreak;than the outbreak of rice stripe virus in rice seedling bed is on June 20.So that ex-3 times application depressed the cardinal number of the small brown planthoppers,and reduced the infection and the incidence of the rice stripe virus in rice seedling bed.But it is not obviously influencing for the incidence in rice seedling bed with the 4th time application on June 15.The result that we periodic investigate the rice stripe virus in the field,the incidence in the field is basically stability after transplanting 40 days,and no longer appear a new disable plant.Because on the rice seedling stage we adopted the chemistry prevention with different number of times,the incidence of the rice stripe virus exists difference after the rice seedling transplanted to the field.The incidence is the tallest in no application small area and lowest in 4 times application small area.Along with the increment of application number of times,the incidence presents to obviously descend trend.With no,once,2 times,3 times,4 times application the incidence is in order to 18.29%,14.94%,11.37%,6.63%and 4.29%in the field.It is shown that application in the rice seedling bed depressed the small brown planthoppers quantity,and the function is very obviously for ease the occurrence of the rice stripe virus.Analyzed the incidence of the rice stripe virus in various processing,it in the field with once and two times application distinctly descend 18.23%and 37.83%compared with no application;but when with the application number of times increase to 3 times,the descends range of the incidence is 63.75%and prevent effect is obviously higher than that with 2 times application,than after 4 times application the incidence descend to come to 76.54%.The relationship between the small brown planthoppers quantity in rice seedling bed and incidence of rice stripe in rice seedling bed and field analytical,such as table 4,figure 2 shown.The relativity analyzes indicated,the small brown planthoppers quantity(x)and incidence of rice stripe in rice seedling bed(y)relation type is y=0.03 x+2.89,related coefficient r=0.99**;the small brown planthoppers quantity(x)and incidence of rice stripe in the field(y)relation type is y=0.10x+11.03,related coefficient r=0.98**.The relationship between the small brown planthoppers quantity and incidence of rice stripe virus in rice seedling bed and field present positive correlation.ApplicationtimesChangerateofthequantity(%)Incidenceinriceseedlingbed(%)Incidenceinthefield(%)0time78.995.5618.292times37.243.8914.943times-14.202.2711.375times-41.261.506.636times-57.241.364.29Table 4 The investigation of the small brown planthoppers quantity and incidence of the rice stripe virus(Jiaxing,2006)It is very obvious that preventing the small brown planthoppers in rice seedling bed for controlling the occurrence of the rice stripe virus.The result of adopting the different application times indicates,that is repressed growth of the small brown planthoppers quantity,and also eased the occurrence of the rice stripe virus with increasing the application number of times.As the result of the test shows,there is the forward relationship between the range of incidence and application times;through investigating the incidence in the field,we can confirm that reasonable application is effectively to controlling the occurrence of the rice stripe virus.Moreover analysis of the relationship between the small brown planthoppers quantity,incidence of the rice stripe virus in rice seedling bed and it in the flied,there have a positive correlation.Experiment shows,the reasonable and multiple application in rice seedling bed is the effective means to reduce the small brown planthoppers quantity and controlling the rice stripe virus.The controlling effect of the rice stripe virus is reached 70%with application 3 or 4 times on rice seedling stage.Therefore we suggest that we should pay attention to controlling the small brown planthoppers of the rice seedling bed at the rice stripe virus heavier region or age,especially in the rice seedling bed where sow seeds early and easily cause the small brown planthoppers centralize immigration.In order to prevent effectively,we should increase the number of application times to lower the small brown planthoppers quantity in the field,and control the harm of the rice stripe virus.Figure 2 Relationship between the small brown planthoppers quantity andin cidence of rice stripe virus in different prevention of rice seedling bed