Mechanisms and diversity of resistance to sorghum midge, Stenodiplosis sorghicola in Sorghum bicolor

Sorghum midge, Stenodiplosis sorghicola (Coquillett) is the most important pest of grain sorghum worldwide, and plant resistance is an important component for the control of this pest. To identify sorghum genotypes with diverse mechanisms of resistance to sorghum midge, we studied oviposition, larval survival, and midge damage in 27 sorghum midge-resistant genotypes, and a susceptible check under greenhouse conditions. Observations were also recorded on floral characteristics and compensation in grain mass. Of the 28 sorghum genotypes tested, 19 showed high levels of antixenosis to oviposition as a component of resistance, and had <20% spikelets with eggs when infested with 10 or 25 sorghum midge females per panicle under no-choice conditions in the headcage. Genotypes IS 8887, IS 10712, IS 21873, IS 21881, ICSV745, and QL 39 showed antibiosis as one of the components of resistance. Lines IS 7005, IS 10712, IS 18563, IS 21873, IS 21881, PM 15936-2,ICSV 197, and ICSV 745 showed <20% spikelets with eggs, larvae,or, midge damaged chaffy spikelets across infestation levels, compared with >80% midge damaged spikelets in QL 12 - the susceptible check. Genotypes showing resistance to sorghum midge have smaller glumes than the susceptible check, QL 12. However, IS 7005, IS 18653, and ICSV745 have relatively large sized glumes, but suffered <20% midge damage suggesting that factors other than glume size also contribute to midge resistance in sorghum. Fourteen genotypes showed >20% compensation in grain mass when the panicles were reduced to 250 spikelets and infested with 10 or 25 midges per panicle. There is considerable diversity in sorghum genotypes showing resistance to sorghum midge. Genotypes with diverse combination of characteristics associated with resistance to sorghum midge can be used in breeding programs to broaden the genetic base and increase the levels of resistance to this insect. This revised version was published online in August 2006 with corrections to the Cover Date.     

Cytoplasmic male-sterility and source of pollen influence the expression of resistance to sorghum midge, Stenodiplosis sorghicola

Sorghum midge, Stenodiplosis (Contarinia) sorghicola (Coquillett), is an important pest of grain sorghum, and host plant resistance is an important aspect of control of this pest. This research investigated how cytoplasmic male-sterility and source of pollen influence the expression of resistance to sorghum midge. Sorghum midge emergence was significantly lower in panicles of midge-resistant and midge-susceptible cytoplasmic male-sterile lines when pollinated with AF 28 - a midge-resistant restorer line, than those pollinated with Swarna - a midge susceptible restorer line, indicating the presence of xenia effects. Maintainer lines (B-lines) of midge-resistant parents had significantly lower numbers of eggs and larvae than the B-lines of midge-susceptible parents. Male-sterile lines of the both midge-resistant and midge-susceptible lines were equally susceptible, indicating that resistance to sorghum midge is influenced by factors in the cytoplasm of the B-line. These findings will have an important bearing on the production of hybrids with resistance to insects. This revised version was published online in August 2006 with corrections to the Cover Date.     

抗稻瘿蚊水稻的形态结构及生理生化特性研究进展

综述了抗稻瘿蚊水稻的形态结构、受害前后生理生化变化等的研究进展,通过分析目前水稻抗稻瘿蚊研究存在的问题指出了应加强茎秆、叶鞘等结构,内源激素含量和分布等方面研究的研究方向。     

抗稻瘿蚊水稻品种的恢复力测定及其F1代抗性鉴定

以抗蚊青粘、植选4号、植选5号、植选6号、植选7号和植选8号等抗稻瘿蚊水稻品种(系)为父本与培矮64S等18个不育系所配组合F1的抗性鉴定结果表明,以植选6号、抗蚊青粘、植选8号作父本配制的F1组合对稻瘿蚊都表现为抗,而以植选5号、植选4号、植选7号配制的组合都表现为感。测交结果表明,抗蚊青粘和植选8号恢复力较好。其中,以抗蚊青粘与228A所配F1组合的结实率为86.16%,理论产量为8.6953 t/hm2,与先A、冈46A、K19A所配的F1的结实率分别为78.33%、81.81%和83.42%。以植选8号与博A、培矮64S、金23A、K18A和先A所配组合F1的结实率分别为78.78%、80.16%、81.04%、81.27%和88.43%。植选6号作父本与博A和Y华农A所配组合F1的结实率分别为85.82%和81.45%。     

枸杞红瘿蚊和枸杞白瘿蚊所致虫瘿形态结构差异

枸杞红瘿蚊是宁夏枸杞上重要成灾害虫之一。枸杞白瘿蚊是继枸杞红瘿蚊后在宁夏枸杞上新发现的另一种瘿蚊科害虫。两种瘿蚊均以幼虫为害宁夏枸杞幼嫩花蕾使其不能正常发育,但形成的虫瘿结构差异明显。本文通过外部形态观察、石蜡切片等方法对两种虫瘿发育过程中的外部形态特征、内部组织结构进行了对比。结果表明,两种瘿蚊幼虫的取食不会引起花部结构的增加或缺失,但均影响花部结构发育,使其无法正常开花结果。枸杞红瘿蚊主要造成子房细胞数量增多形成虫瘿,枸杞白瘿蚊主要造成花冠细胞体积增大形成虫瘿。此外两种虫瘿在花柱、花丝、蜜腺、花药、花柄等处均存在一定差异。     

雷州半岛稻瘿蚊田间消长规律及其防治

稻瘿蚊是雷州半岛晚造水稻主要害虫之一,其田间种群消长及危害轻重除了与越冬虫源、气候环境、水稻栽培条件等因素有关外,受天敌的影响较大.防治上要树立保护天敌与防治稻瘿蚊并重的指导思想,应以农业措施为基础,化学防治为主导,生物、物理措施为补充.化学防治除应施药拌种预防外,还要重点抓好晚造秧苗期和成虫高峰期的施药防治,拌种和喷施首选药剂为氯虫苯甲酰胺.     

龙眼叶瘿蚊虫瘿结构和发育的观察研究

采用常规石蜡切片法和Olympus SZX-16体视显微镜,观察了龙眼叶瘿蚊虫瘿的结构和发生发育过程。结果表明:龙眼叶瘿蚊雌成虫将卵产于维管组织附近,幼虫孵出后取食刺激,导致虫瘿的形成,随着幼虫的发育,虫瘿个体逐渐增大,瘿室外周组织发生分化,从外到内大致可分为外层、厚壁层和内薄壁细胞层;根据虫瘿组织的变化分期,结合解剖学特征,虫瘿的发育过程可分为虫瘿初始形成期、成长分化期、成熟期以及开裂期4个阶段;虫瘿的内部结构包括表皮层、保护层、营养层和虫室,其中外层对龙眼叶瘿蚊幼虫和蛹的安全生长提供保障,营养层主要成分是内薄壁细胞,为幼虫的生长发育提供食物来源。     

利用分子标记辅助选择改良水稻恢复系的稻瘿蚊抗性

以含有华南4种稻瘿蚊生物型显性抗性基因Gm6的籼稻材料KG18为供体,三系优质恢复系广恢998为受体,通过杂交、多次回交和自交结合分子标记辅助选择技术,将Gm6基因导入广恢998中。综合目标基因的分子检测、田间农艺性状表现以及遗传背景的回复率,筛选获得6个株系。采用稻瘿蚊生物型1和生物型4对这些改良株系进行人工接虫鉴定,6个改良株系的标葱率为0,表现免疫,而对照标葱率均在98%以上,表现高感;由改良株系组配的杂种F1标葱率在10%～20%,表现中抗。农艺性状分析表明,除1个株系在千粒重方面与对照广恢998有显著差异外,其余改良株系性状与对照无显著差异。     

水稻植株游离氨基酸含量与抗稻瘿蚊关系研究初报

为探索水稻植株游离氨基酸含量与抗稻瘿蚊的关系,测定了12个抗感稻瘿蚊水稻品种3叶期稻茎内游离氨基酸的主要种类及含量,并应用主成分分析法分析了影响水稻品种抗蚊性的主要氨基酸种类。结果表明,所测试品种稻茎内共有16种氨基酸,各品种游离氨基酸的含量不同;除品种570011外,其他参试品种的苏氨酸、天冬氨酸、谷氨酸、丝氨酸、丙氨酸含量较高,甘氨酸和蛋氨酸含量较低;甘氨酸、缬氨酸、异亮氨酸、亮氨酸、谷氨酸、脯氨酸、苏氨酸、蛋氨酸与水稻品种抗稻瘿蚊的关系比较密切,是影响水稻品种抗蚊性的主要氨基酸种类。