湖南省103个水稻品种的抗瘟基因型鉴定

用离体接种的方法,利用22个已知无毒基因菌株,对湖南省103个水稻品种进行了抗瘟基因型鉴定和系统聚类分析.结果表明:在阈值为0.78时,可将103个品种分为13类,其中有9类81个品种可能携带已知的抗病基因,其余4类22个品种可能含有未知的抗病基因.另外,具有广谱抗瘟基因Piz5(Pi2)、 Pizt、Pi1和Pi9的品种对鉴别菌株的抗菌频率均大于60.0%.     

烟草青枯病生防菌混合接种对其定殖及防效的影响

本研究将枯草芽孢杆菌Bacillus subtilis B001、短短芽孢杆菌Brevibacillus brevis B011和侧孢芽孢杆菌Bacillus laterosporus 2-Q-9混合接种,探讨其协同防治烟草青枯病的有效性和可行性。平板拮抗试验表明,3株生防菌相互间无拮抗作用,且混合菌群的抑菌活性有所增强。定殖试验中,生防菌两两混接总体上可提升其定殖力,但3株混接对B011和2-Q-9有抑制作用;在烟株接种移栽后第60d,各混接组合的定殖总量均达到最大,其中B001＋B011和B011＋2-Q-9组合分别达7.28、7.23lg.cfu/g,远高于其它处理。小区试验表明,3株生防菌不论单用还是混用,其防治效果均优于72%农用链霉素;两菌混接优于对应的单菌处理,其中以B011＋2-Q-9组合防效最好,达83.39%,其次是B001＋B011组合,防效为78.34%;但三株混接的防效仅为45.49%,低于所有生防菌处理。     

稻曲病菌不同颜色厚垣孢子超微结构比较

 The surface and internal structure difference of yellow and black dormant chlamydospores of Ustilaginoidea virens on mid-and late-season rice were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM revealed that the spherical yellow and black chlamydospores had prominent spines, with the diameters from 3 to 6 μm and 4 to 6 μm, respectively. The spines were 200-700 nm and 400-1 100 nm long in yellow and black chlamydospores, respectively. Variance analysis showed that there was no difference in diameter of the yellow chlamydospores but significant difference among the black ones collected from both rice cropping types. Similarly, there was no difference in length of the spines on the same color chlamydospores but extremely different between the yellow and black chlamydospores collected from the two cropping types. TEM revealed that the cell wall of both color chlamydospores were composed of two layers, the thick endosporium and thin exosporium, and the thickness of the former layer of the black chlamydospores was nearly two times as that of the yellow ones. The organelles in yellow chlamydospores such as the nucleus were obviously visible, but invisible in black ones. The cytoplasm of black chlamydospores was occupied by a big lipid globule. This study suggests that the formation of dormant chlamydospores of U. virens is related with the structural changes in the cell.     

天一乐百禾对稻田阔叶杂草的药效试验

对36%二甲四氯·氯氟吡氧乙酸可湿性粉剂（天一乐百禾）防治水稻移栽田阔叶及莎草科杂草的效果进行试验。结果表明,在杂草3～4叶期,天一乐百禾防除水稻移栽田阔叶及莎草科杂草的施用浓度为750～1 500 g·hm-2,与对照药剂13%二甲四氯钠水剂防治效果相当,较200 g·L-1使它隆乳油防效好,但差异均不显著。     

湘资3150 微效抗瘟性基因鉴定

 以湘资3150 和CO39 为亲本建立F10 重组自交系群体为材料, 在桃江病圃应用自然诱发接种法对群体的田间叶瘟抗性表现进行了分析。结果表明, 在LOD 2. 5 的域值上,共检测到14 个有效的微效基因QTL 位点(LOD 值均大于2. 5),分别位于水稻第3、8 和10 染色体上,其表型变异贡献值差异比较大,介于11. 78% ~ 40. 57% 之间;表明可能控制不同抗性表型的QTL 紧密连锁或者同一个QTL 对不同的抗性表型均具有抗性贡献。     

121个水稻品种的抗瘟性鉴定

用22个稻瘟病菌株,采用离体接种的方法对121份水稻品种进行抗瘟性鉴定,同时对其中16个湖南省主栽水稻品种进行了病圃鉴定。结果表明,51个品种抗菌频率在60%以下,63个在60%～80%之间,7个品种在80%以上。湖南省16个主栽水稻品种病圃叶瘟与穗颈瘟发病率之间存在显著正相关关系,病圃叶瘟和穗颈瘟发病严重度与室内离体鉴定结果也均呈显著正相关关系。