科技短讯

1.发生水稻“小穗头”症状的谷粒中含有大量水稻干尖线虫,而健康谷粒中不含线虫。“小穗头”症状是水稻干尖线虫病的一种非典型症状,应用巴丹、恶线清等药剂浸种可有效防治。——江苏丘陵地区镇江农业科学研究所(江苏句容212400)汪智渊等2.江西彭泽县棉花科学研究所从中国农科院棉花研究所引进的重点项目棉花“正反杂交制种”技术获得成功,667平方米制种产量高达225千克,试种后的棉花产量667平方米达到400千克。——中广网3.印水型杂交稻的育成和推广,从制种产量、杂种产量和米质等方面将我国杂交稻的生产水平总体提高到一个新台阶。在2005…     

人工接种测定水稻干尖线虫在水稻上的病害发展动态

 【目的】探讨近年来江苏水稻生产上的重要病害水稻—“小穗头”和水稻干尖线虫间的相互关系。【方法】在水稻“小穗头”上分离出干尖线虫，经人工培养，在温室中接种到镇稻2号和武运粳7号的芽鞘部和叶鞘部，通过测定发病程度，稻谷饱满度，谷粒中线虫虫量和线虫死亡率等指标来确定对“小穗头”形成以及对水稻生长发育的影响。【结果】 镇稻2号“小穗头”与健康稻穗相比水稻株高下降6.7%、稻穗长度减少16.4%、稻谷粒数下降13.5%。在开花期之前，线虫主要分布于叶鞘部和生长点周围，虫量增加40%;花期后，线虫主要分布于稻穗上并且虫量增幅达90.8%。饱粒种子中带虫率、线虫虫量最高，空粒种子则最低。线虫死亡率在胚乳发育正常的种子中要比胚乳发育不正常的种子低。【结论】水稻干尖线虫是造成水稻“小穗头”症状的病原。武运粳7号仅表现“小穗头”而无叶片干尖症状，说明该现象是干尖线虫在水稻上呈现的新症状。     

恶线清浸种防治水稻"小穗头"技术

室内检测和田间试验结果表明,近年来江苏省发生的大面积、多品种水稻“小穗头”的主要原因为水稻干尖线虫(Aphelenchoides besseyi)的危害,应用恶线清浸种防治效果可达90%以上。     

干尖线虫病对不同水稻品种产量相关性状的影响

为了解干尖线虫病对不同水稻品种的危害性,通过田间表型观察与室内考种试验,对自然发病状态下的4个常规粳稻品种(系)和粳稻恢复系R161进行了观察和分析。结果表明,不同水稻品种(系)被侵染后的症状存在差异,常规粳稻宁1707、宁1818、镇稻88和南粳9108被侵染后表现"干尖"和"小穗头"症状,粳稻恢复系R161只表现"干尖",不表现"小穗头"症状,且"干尖"的位置不同,分别位于剑叶叶尖,整片剑叶及倒二叶。供试材料被水稻干尖线虫侵染后均能抽穗,但是株高、穗长、结实率和千粒重均受到不同程度的影响。此外,R161被干尖线虫侵染后,不同发病部位对水稻产量的影响不同,整片剑叶干枯扭曲的稻穗受影响最大。     

干尖线虫病对不同水稻品种(系)产量相关性状的影响（英文）

[目的]该研究旨在了解干尖线虫病对不同水稻品种的影响。[方法]通过田间表型观察与室内考种试验,对自然发病状态下的4个常规粳稻品种(系)和粳稻恢复系R161进行了观察和分析。[结果]不同水稻品种(系)被侵染后的症状存在差异,常规粳稻宁1707、宁1818、镇稻88和南粳9108被侵染后表现"干尖"和"小穗头"症状,粳稻恢复系R161只表现"干尖",不表现"小穗头"症状,且"干尖"的位置不同,分别位于剑叶叶尖,整片剑叶及倒二叶。供试材料被水稻干尖线虫侵染后均能抽穗,但是株高、穗长、结实率和千粒重均受到不同程度的影响。此外,R161被干尖线虫侵染后,不同发病部位对水稻产量的影响不同,整片剑叶干枯扭曲的稻穗受影响最大。[结论]该研究为进一步阐明我国水稻干尖线虫病的危害规律和制定相应的防治措施提供依据。     

干尖线虫病对不同水稻品种（系）产量相关性状的影响

[目的]该研究旨在了解干尖线虫病对不同水稻品种的影响。[方法]通过田间表型观察与室内考种试验，对自然发病状态下的4个常规粳稻品种（系）和粳稻恢复系 R161进行了观察和分析。[结果]不同水稻品种（系）被侵染后的症状存在差异，常规粳稻宁1707、宁1818、镇稻88和南粳9108被侵染后表现"干尖"和"小穗头"症状，粳稻恢复系R161只表现"干尖"，不表现"小穗头"症状，且"干尖"的位置不同，分别位于剑叶叶尖，整片剑叶及倒二叶。供试材料被水稻干尖线虫侵染后均能抽穗，但是株高、穗长、结实率和千粒重均受到不同程度的影响。此外，R161被干尖线虫侵染后，不同发病部位对水稻产量的影响不同，整片剑叶干枯扭曲的稻穗受影响最大。[结论]该研究为进一步阐明我国水稻干尖线虫病的危害规律和制定相应的防治措施提供依据。     

江苏省水稻"小穗头"现象发生原因与防治对策研究

本研究对江苏水稻生产上推广应用的10个品种、3种类型、63个样品、315个单株稻谷进行检测的结果表明：干尖线虫病危害是造成江苏地区水稻“小穗头”大面积发生的直接原因，与恶苗病(镰刀菌)带菌率没有因果关系；“小穗头”现象是否表现，可能与水稻植株的生长发育、光合产物的代谢、积累等状况有关；药剂浸种可有效防治干尖线虫病造成的“小穗头”发生；验检结果显示，水稻浸种剂16％恶线清对水稻干尖线虫病的浸种防治效果较好，浸种剂施保克浸种对水稻“小穗头”没有防效。     

江苏省水稻"小穗头"现象的发生与防治措施研究

用防治真菌种传病害的浸种剂25％施保克乳油、25％使百克乳油和防治线虫的浸种剂95％巴丹可溶性粉剂及兼治真菌和线虫种传病害的16％恶线清可湿性粉剂、4．2％浸丰乳油分别对带线虫的武育粳3号、镇稻2号及武运梗7号种子进行浸种处理后播种，试验结果表明：使用防治线虫的浸种剂可以有效地控制水稻“小穗头”现象的发生。经南京农业大学植物保护学院线虫实验室鉴定，来自武育粳3号、武运粳8号的“小穗头”和武运粳7号小穗发病田混收稻谷内的线虫为干尖线虫。用95％巴丹可溶性粉剂、16％恶线清可湿性粉剂、4．2％浸丰乳油、25％，使百克乳油浸种及清水对照的田间“小穗头”发生率分别为0．3l％、1.34％、1．78%、44．0％和35．71％，4种浸种药剂对“小穗头”的防治效果依次为99．10％、96．90％、95．90％和-17．8％；具有防治线虫作用的浸种剂巴丹、恶线清和浸丰对“小穗头”的防治效果较好，浸种剂25％施保克乳油及25％使百克乳油等咪鲜胺类制剂对由于尖线虫造成的水稻“小穗头”没有防治效果。     

6%杀螟丹水剂对水稻翘穗头的防治效果

室内检测结果表明，应用6％杀螟丹水剂2000倍液浸种48h，对水稻种子中含有的线虫杀灭效果超过93％。田间试验结果表明，6％杀螟丹水剂对由水稻干尖线虫引起的水稻翘穗头有明显的防治作用，田间防治效果达90％以上。     

不同药剂浸种控制水稻干尖线虫病效果研究

不同药剂浸种对水稻干尖线虫病控制效果研究表明,含有杀螟丹的药剂,如16%菌虫清2号、18%盟歼,对水稻干尖线虫病具有较好的防效;25%使百克(咪鲜胺)对干尖线虫病基本没有防效,常用药剂10%浸种灵(二硫氰基甲烷)对干尖线虫的防效也很差,感病品种(如淮稻9号)不宜使用。     

Dynamic Development of Aphelenchoides besseyi on Rice Plant by Artificial Inoculation in the Greenhouse

A study was done on the relationship between Aphelenchoides besseyi and the symptoms of small grains and erect panicles. This is an important rice disease in Jiangsu Province, China. A. besseyi was extracted from small grains and erect panicles and cultured artificially, and then inoculated into bud and leaf sheaths of seedlings of two Oryza sativa cultivars, namely Zhendao 2 and Wuyunjing 7 in a greenhouse. The effect on rice growth, in particular the small grains and erect panicles, was revealed by the extent of the disease, seed expansion stages, nematode load, and nematode mortality. In contrast to healthy seedlings, the height, length, and the numbers of spikelets of unhealthy panicles of Zhendao 2 were decreased by 6.7, 16.4, and 13.5%, respectively. Before anthesis, nematodes were attracted to the leaf sheath and apical meristem, nematode load increased by 40%; after anthesis, nematodes occurred in spikelets principally and the number increased by 90.8%. The percentages of infected seeds and nematode load were highest in plump seeds and lowest in empty seeds. Nematode mortality on grain with normal endosperm was lower than seeds with abnormal endosperm. Results indicated that A. besseyi was the pathogen in rice with the symptoms of small grains and erect panicles. Wuyunjing 7 manifests only the small grains and erect panicles symptoms and not the symptoms of leaf white-tip. These symptoms of small grains and erect panicles are new symptom records for the disease caused by A. besseyi on rice.     

Dynamic Development of Aphelenchoides besseyi on Rice Plant by Artificial Inoculation in the Greenhouse

A study was done on the relationship between Aphelenchoides besseyi and the symptoms of small grains and erect panicles. This is an important rice disease in Jiangsu Province, China. A. besseyi was extracted from small grains and erect panicles and cultured artificially, and then inoculated into bud and leaf sheaths of seedlings of two Oryza sativa cultivars, namely Zhendao 2 and Wuyunjing 7 in a greenhouse. The effect on rice growth, in particular the small grains and erect panicles, was revealed by the extent of the disease, seed expansion stages, nematode load, and nematode mortality. In contrast to healthy seedlings, the height, length, and the numbers of spikelets of unhealthy panicles of Zhendao 2 were decreased by 6.7, 16.4, and 13.5%, respectively. Before anthesis, nematodes were attracted to the leaf sheath and apical meristem, nematode load increased by 40%; after anthesis, nematodes occurred in spikelets principally and the number increased by 90.8%. The percentages of infected seeds and nematode load were highest in plump seeds and lowest in empty seeds. Nematode mortality on grain with normal endosperm was lower than seeds with abnormal endosperm. Results indicated that A. besseyi was the pathogen in rice with the symptoms of small grains and erect panicles. Wuyunjing 7 manifests only the small grains and erect panicles symptoms and not the symptoms of leaf white-tip. These symptoms of small grains and erect panicles are new symptom records for the disease caused by A. besseyi on rice.     

Assessment of Rice Cultivars in China for Field Resistance to Aphelenchoides besseyi

The effect ofAphelenchoides besseyi on 27 cultivars of rice （23japonica and 4 indica） was assessed in the field for two seasons during 2010 and 2011. The vigorous pathogenic nematodes culturing on Botrytis cinerea were used for this experiment. Inoculation was carried out at the tilling stage; the growth parameters and nematode population were recorded at the end of growth of rice plants. The results showed that the cultivars differed in their response to infection. Most of cultivars were lack of the characteristic symptom of white tip, which was seen less frequently than the other two symptoms, namely small grains and erect panicles; moreover, the expression of symptoms was probably hereditary. The infection lowered the values of all the measured biological parameters, namely length of the stem and of the panicle, the number of filled grains per panicle, and 100-grain weight, in all the cultivars. The final nematode population indicated that the threshold of economic damage had also been exceeded in 10 cultivars, and none of them was immune. Three japonica cultivars proved most vulnerable whereas Tetep, an indica type, showed a level of resistance potentially useful in controlling A. besseyi.     

16%恶线清WP浸种防治水稻恶苗病的效果

比较了 16 %恶线清WP(咪鲜安 +杀螟丹 )和 2 5 %施保克EC(咪鲜安 )防治水稻恶苗病的效果。结果显示 ,恶线清浸种对水稻恶苗病的防治效果与施保克没有差异 ,因其具有使用方便 ,且可兼治水稻干尖线虫病的特点 ,在生产上更有推广应用价值     

水稻直立穗型基因多效性的研究

以直立穗型品种辽粳5号和弯曲穗型品种丰锦杂交后代来自同一F4单株的F5世代不同穗型植株为试材，对其茎叶性状和穗部性状进行测定，分析直立穗性状与其他性状的关系。结果表明：(1)直立穗型植株较矮，叶片短而宽，叶鞘长且上部节间短，而弯曲穗型则相反；(2)不同穗型植株2次枝梗、2次枝梗籽粒、2次枝梗空秕率在穗轴上的分布趋势很相近，但是直立穗型2次枝梗空秕率极显高于弯曲穗型，而1次枝梗空秕率在不同穗型间差异不明显，选育1次枝梗籽粒比率高，2次枝梗籽粒主要分布在上部的直立穗型品种，有利于改善结实性；(3)直立穗性状有可能是不完全显性。     

辽优1052及其亲本灌浆特性与源库关系的比较

对直立大穗型杂交稻辽优1052及其母本105B和父本C52做减源和减库处理,研究大穗型水稻品种籽粒灌浆特点。结果表明:三品种均为源限制型,都存在着两段灌浆现象。同一品种强弱势粒间灌浆过程差异较大。母本105B最终粒重较小,且强弱势粒间粒重差异较小;而杂交稻辽优1052及父本C52强弱势粒粒重差异较大。说明大穗小粒型品种源库矛盾较小。对于源限制型品种,减源能明显的缓和源库矛盾,尤其对最终粒重的提高有一定作用;而减库能加剧源库矛盾,使最终粒重降低。     

粳稻品质与穗部性状关系的研究

采用聚类分析、回归分析等方法对辽宁省近年来32个水稻品种(品系，以后简称品种)品质性状和穗部性状进行分析。结果表明：弯穗型品种品质指标优于半直立穗型品种，半直立穗型品种品质指标优于直立穗型品种。依品质性状参试材料可聚类为6类，第1类辽盐40组品质特点是垩白率、垩白度较高；第2类是辽粳294组，品质指标普遍很好；第3类辽粳5号组，垩白率、垩白度偏高；第4类沈农654组，直链淀粉含量较高，垩白率、垩白度较高，胶稠度较小。黎明、辽粳326各成一类．垩白率、垩白度很高。直立穗型品种成粒率、谷粒长对品质影响很大；半直立穗型品种一次枝梗、成粒率、谷粒长宽比对品质影响很大：弯穗型品种穗长、二次枝梗／一次枝梗、成粒率、一次枝梗对品质影响很大。以提高成粒率为重点，可使穗部性状各指标实现优化组合，实现优质。     

Genetical and Physiological Basis of Plant Type Model of Erect and Large Panicle Japonica Super Rice in Northern China

The historical changes in rice yields across China were explored. The physiological mechanisms and genetic basis of the erect and large panicle super-high-yield plant type model for breeding japonica super rice were analyzed mainly on the panicle type, number of large vascular bundles （LVB） in the panicle neck, and the panicle type index （PTI）. In the production point of view, we suggested that, for the breeding of super-high-yield japonica rice, the erect panicle types with more LVB numbers in the panicle neck and superior upper grains in the secondary branches would be the key factors. The information has potential significance in the rice breeding and productivity not only in China but also throughout the rice production areas of the world.     

两种穗型品种粒重和结实率在穗上不同粒位的分布差异

为了探索不同穗型品种米质差异形成的原因,研究了3个直立穗型和3个弯曲穗型粳稻品种,两种不同穗型水稻穗上不同粒位籽粒粒重和结实率的差异。结果表明:直立穗型品种和弯曲穗型品种的穗部性状差异明显,穗型特征与品种间的粒重和结实率高低没有较大联系,因品种而异。同一稻穗内不同籽粒间的粒重和结实率高低与其颖花在穗上的开花顺序有密切联系;不同部位间籽粒相比,粒重和结实率基本都表现为上部中部下部;不同枝梗间相比表现为一次枝梗二次枝梗;同一枝梗不同着粒部位相比,一次枝梗上6个粒位籽粒的粒重和结实率基本以第4、5、6粒位较高,第2粒位最低,二次枝梗上3个粒位以第1粒位最高,第2粒位最低。一次和二次枝梗与上部、中部和下部枝梗这两类粒位之间的互作对粒重有显著影响。直立穗型品种单一稻穗不同粒位间粒重和结实率的变异大于弯曲穗型品种。