紫色甘薯新引品种简易贮藏试验

[目的]为薯农提供耐贮藏的优良紫色甘薯品种及探索最佳的简易贮藏方法.[方法]对引进的紫色甘薯良种11-07、16-08、Y1和SCZ,分别采用陶罐、塑料整理箱、纸箱和网袋4种贮藏方法进行4个月的贮藏试验,并设加工房、工具房和宿舍3个重复,对比不同贮藏方法对紫色甘薯薯块贮藏完好率的影响.[结果]加工房中陶罐贮藏、塑料整理箱贮藏、纸箱贮藏和网袋贮藏的薯块完好率分别为42.5%~55.0%、20.7%~33.3%、20.0%~30.0%和15.0%~30.0%,均高于工具房和宿舍对应的薯块贮藏完好率;不同贮藏处理中,以陶罐贮藏的完好率最高(11-07为72.4%、16-08为78.5%、Y1为66.3%、SCZ为66.1%),其次是纸箱贮藏;不同紫色甘薯品种的平均贮藏完好率以16-08的最高,且与Y1、SCZ两个品种均达极显著差异.[结论]紫色甘薯16-08的耐贮藏性较好,可作为商品型品种在云南玉溪推广种植;贮藏地点以在一楼通风阴凉的地方为宜;在进行简易贮藏时以陶罐贮藏最佳,无陶罐时也可考虑用纸箱进行贮藏.     

轮枝镰孢SSR标记开发及在玉米分离群体遗传多样性分析中的应用

【目的】开发轮枝镰孢（Fusarium verticillioides）的SSR标记,为轮枝镰孢遗传多样性研究提供技术支持。【方法】利用Fastpcr在轮枝镰孢基因组中查找符合条件的SSR位点,采用Primer5.0软件设计引物,利用NTSYS及Popgene分析来自玉米的轮枝镰孢单孢分离物群体的PCR扩增结果。【结果】共设计有效扩增SSR引物158对,经筛选,109对（69.0%）可扩增出2条及以上的条带,其中55对引物（34.8%）多态性较好,可扩增出3条及以上的条带。从11条已组装的轮枝镰孢染色体上各选出2对多态性引物,计22对引物,对66株轮枝镰孢玉米分离物进行扩增,共获得125个等位变异,变异范围为2-11个,平均为5.68个。轮枝镰孢玉米分离物之间Nei’s基因多样性指数为0.1139-0.8687,平均为0.6199,表现出较高的遗传多样性。【结论】基于轮枝镰孢基因组序列开发的SSR标记具有很好的多态性,可用于轮枝镰孢的遗传多样性分析。用22对SSR引物扩增,以遗传相似系数0.3进行划分,可将66株轮枝镰孢玉米分离物分为3群;中国轮枝镰孢玉米分离物的遗传多样性与地理分布无相关性。     

Correlated responses to neonicotinoid insecticides in clones of the peach-potato aphid, Myzus persicae (Hemiptera: Aphididae)

BACKGROUND: Although there are still no confirmed reports of strong resistance to neonicotinoid insecticides in aphids, the peach-potato aphid (Myzus persicae Sulzer) shows variation in response, with some clones exhibiting up to tenfold resistance to imidacloprid. Five clones varying in response to imidacloprid were tested with four other neonicotinoid molecules to investigate the extent of cross-resistance.RESULTS: All four compounds-thiamethoxam, thiacloprid, clothianidin and dinotefuran-were cross-resisted, with ED(50) values ranked in the same order as for imidacloprid. Resistance factors ranged up to 11 for imidacloprid, 18 for thiamethoxam, 13 for thiacloprid, 100 for clothianidin and 6 for dinotefuran.CONCLUSION: This variation in response does not appear to be sufficient to compromise the field performance of neonicotinoids aimed at controlling aphids. However, it highlights the need for careful vigilance and stewardship in all M. persicae populations, and a need to consider neonicotinoids as a single cross-resisted group for management purposes.     

Resistance monitoring in codling moth: a need for standardization

BACKGROUND: A wide range of methods has been used for monitoring resistance in Cydia pomonella L. However, the results from specific tests are not always concordant and they generate doubts over the extent to which the data represent the field situation. Therefore, the variability in the expression of resistance mechanisms and in resistance ratios between developmental stages and their reliability in a field situation were studied. RESULTS: Neonate larvae showed the highest insecticide resistance, except to spinosad. Resistance ratios were from 2 to 9.5, depending on the insecticide and the strain tested, when compared with the susceptible strain. Spinosad exhibited the highest resistance ratio for diapausing larvae (4.4, 12.2 and 4.4 for Raz, Rdfb and RΔ strains, respectively). Enzymatic ratios were higher in adults than in neonates or diapausing larvae, and the highest enzymatic ratios were observed for mixed‐function oxidases (7.3–36.7 for adults of resistant strains). CONCLUSIONS: The sensitivity of different instars depends on the insecticides used, and there is a differential expression of resistance mechanisms between stages. For the population considered in this study, tests on neonates provided the most consistent results to the field situation, but adult response to chlorpyrifos‐ethyl and azinphos‐methyl in the laboratory was also consistent with the field results. Copyright © 2008 Society of Chemical Industry     

A SSR Linkage Map of Maize×Teosinte F2 Population and Analysis of Segregation Distortion

In this study,a linkage genetic map was constructed using a F2 population derived from a cross between a elite maize inbred,B73,and its progenitor,Teosinte(Z. mays ssp.mexicana),through 205 simple sequence repeat(SSR)markers and one morphological marker.By Mapmaker 3.0,polymorphic markers were clustered into 1 0 groups,covering 10 chromosomes of maizexteosinte,with a total length of 2002.4 cM and an average interval of 9.7 cM.Genotyping errors were detected using R/QTL(LOD=2.0)in 109 markers referring to 176 individuals,distributed across all 10 chromosomes with a ratio 1.2%.Projected error loci were re-run and 304 out of the 460 were confirmed as errors and replaced.A new linkage map was constructed,in which markers maintained the same order but the total map length decreased to 1947.8 cM,with an average interval of 9.4 cM between markers.In total,25.2%(P<0.05)markers were identified to have segregation distortion,in which 34.6%deviated towards the pollination parent(B73),30.8%deviated towards Teosinte,32.7%deviated towards heterozygote and 1.9%deviated towards both parents,This map was also compared with published nlaizexteosinte and maize IBM map.     

不同类型酚酸物质对莴苣的化感作用

以莴苣为受体,采取室内生测的方法,测定了4种苯甲酸型酚酸(对羟基苯甲酸、水杨酸、香草酸、丁香酸)和4种肉桂酸型酚酸(肉桂酸、阿魏酸、对香豆酸、咖啡酸),以及2种类型混合酚酸对莴苣的化感作用,对其抑制率进行回归分析并计算IC50(半抑制浓度值).结果表明,单一或混合酚酸浓度高时明显抑制莴苣生长,浓度低时抑制能力减弱或表现促进作用.苯甲酸型混合酚酸对莴苣根长和株高的IC50分别为2.71×10~(-4)和1.56×10-3mol·L~(-1),而肉桂酸型混合酚酸对莴苣根长和株高的IC50分别为8.01×10~(-4)和1.77×10~(-3)mol·L~(-1).可见,苯甲酸型酚酸的抑制作用高于肉桂酸型酚酸,且混合酚酸的抑制作用高于单一组分酚酸.     

Persistence of sulfentrazone in soil under soybean and its carryover effect on bioindicators

To assess the persistence and dissipation kinetics of sulfentrazone in soil, terminal residues in soybean and carryover effect on bioindicator species, field experiment was carried out under Indian tropical conditions. The sulfentrazone was applied at 360, 480 and 720?g a.i. ha^?1 rates as pre-emergence herbicide. Its residues in soil and in soybean at harvest were analyzed by high pressure liquid chromatography. Results showed that the sulfentrazone dissipation in soil followed first-order reaction kinetics with the half-lives of 5.5 to 14.8 days. Terminal residue in shoot and grain showed that sulfentazone at 360?g ha^?1 can be safely applied for weed control in soybean since there was no phytotoxicity injury to the crop. The residue in soybean grain was within the safe limits (0.05?µg g^?1) as proposed by US. However, the detection of sulfentrazone residue in soil at harvest and carryover injury to bioindicator signified the risk for crops in succession. Hence the use of this herbicide in soil with low organic matter and coarse texture is questionable as it is highly mobile. Further biomagnifications of sulfentrazone residue in soil and crop produce under continuous use and interaction of climatic variables and soil properties on its persistence, sorption and leaching behavior need to be investigated.     

籼粳交重组自交系的亚种属性与稻米品质性状的关系

2006—2007年以典型籼稻七山占和典型粳稻秋光构建的重组自交系(RILs)F8的92个株系和F9的142个株系为试材,分别以程氏指数(ChI)和籼粳特异SSR标记(Dj)为群体形态分化与遗传分化的指标,同时测定11项主要稻米品质性状,分析群体稻米品质性状类型间差异及籼粳属性与稻米品质性状的相关性。结果表明,两世代RILs群体形态分化均表现为接近正态的连续分布,籼型和粳型株系数接近,遗传分化则均表现为明显偏粳的连续分布;根据ChI将RILs群体划分为籼型和粳型,除F9粒宽外两世代品质性状类型间差异均未达到显著水平;根据Dj将RILs群体划分为偏粳型和粳型,两世代粳型糙米率、整精米率、粒宽显著或极显著高于偏粳型,长宽比极显著低于偏粳型;两世代RILs群体ChI与所有品质性状的相关性均未达到显著水平;Dj与糙米率、整精米率和粒宽呈显著或极显著正相关,而与长宽比呈显著或极显著负相关。形态分化与北方粳稻品质性状没有直接关系,而遗传分化中粳稻血缘比例增加可能通过粒形间接改善碾磨品质。     

贵州地方水稻品种的SSR遗传多样性分析

利用21对SSR引物对74份贵州"禾"水稻品种及6份国际上常用的典型籼稻和粳稻品种进行遗传多样性研究。共检测到92个等位基因,每个位点的等位基因数变幅为2~9个,平均4.381个;平均Shannon信息指数为0.935,变幅为0·2793~1.8732;期望杂合度为0.5145,范围在0.0988~0.8313;品种间遗传相似系数为0.64~0.98。UPGMA聚类分析表明,在相似系数为0.682处可将"禾"品种分为4大类,大部分材料被聚类到典型粳稻的附近,品种间的亲缘关系与地理来源关系不大;主坐标分析结果与UPGMA聚类结果基本吻合。SSR检测结果表明,贵州省水稻地方品种——"禾"的多样性程度较低,且大多数属于粳稻。     

北方杂交粳稻亲本籼粳成分与杂种产量和稻米品质性状的关系

以北方杂交粳稻骨干亲本及其组合为材料,采用程氏指数法和微卫星分子标记法,对亲本籼粳成分与杂种产量和稻米品质性状的关系进行了研究。杂交粳稻骨干亲本的程氏指数为13.5～19.3,偏籼系数为0.12～0.38,采用程氏指数和分子标记法对亲本进行籼粳分类的结果并不完全一致。父本程氏指数与产量杂种优势和杂种性状的相关性强于母本,而对于偏籼系数则相反。亲本程氏指数差异与产量杂种优势和杂种性状的相关性强于分子标记差异。亲本籼粳成分及其差异与多数杂种性状和产量杂种优势呈明显的二次曲线关系,存在临界极值;亲本籼粳成分及其差异与杂种产量性状和稻米品质性状的相关性相反。因此,要获得产量杂种优势和杂种表现最佳、高产与优质相结合,父母本籼粳成分应适度搭配。