番茄幼苗对接种晚疫病菌的生理响应

以番茄晚疫病抗病品系CLN2037E、感病品系5号自交系及其杂种一代F1为材料,人工接种番茄晚疫病菌生理小种T1、T2、T3,研究番茄苗期抵抗晚疫病的生理响应.结果显示：（1）感病品系的膜脂过氧化产物丙二醛（MDA）与过氧化氢（H2O2）的含量增加幅度较大,抗病品系的含量则相对稳定,F1代的变化趋势接近感病品系;（2）抗病品系和感病品系的多酚氧化酶（PPO）、过氧化物酶（POD）和超氧化物歧化酶（SOD）活性变化都呈先升高后下降,抗病品系的酶活性高峰出现早且峰值小于感病品系.研究发现,抗病番茄品系幼苗的多项生理指标在接种晚疫病菌后变化幅度小而稳定,并能在短时间内基本恢复到原来的正常状态,从而表现出较强的抗病性.     

水稻对受体植物化感作用的遗传生态学研究

选用化感作用潜力差异较大的 5个水稻品种 (系 ) ,按不完全双列杂交设计 (4× 5 )配制成一套包括亲本、F1两个世代的遗传材料 ,在不同环境条件下 ,测定其不同叶龄时期对受体植物莴苣幼苗茎长的抑制作用 .采用包括基因型与环境互作的数量性状加性 显性发育遗传模型 ,分析了水稻化感作用的动态遗传及与环境互作效应 .结果表明 ,水稻叶龄在 7叶期对莴苣茎长的化感作用受加性效应的影响 ,在 3叶期和 6叶期由显性效应控制 ,在 5叶期和 8叶期加性和显性效应均有作用 ,以显性效应为主 ,呈现间断表达的遗传特点 .普通狭义遗传率在 5叶期、7叶期和 8叶期达显著水平 ,随叶龄增大趋于下降 .水稻化感作用受基因型与环境互作效应的影响较大 ,应注意控制水稻生长发育的环境 ,以达到最佳利用水稻化感作用潜力的目的 .     

苦瓜叶片结构与白粉病抗性的关系

以不同抗白粉病的苦瓜品系幼苗为材料,对它们的叶片及上下表皮厚度、栅栏组织及海绵组织厚度、叶片结构紧密度及疏松度、蜡质含量、比叶重、气孔及茸毛密度等叶片结构进行观察比较,探讨苦瓜白粉病抗性与其主要叶片结构指标的关系。结果显示:（1）抗病苦瓜品系叶片的蜡质含量显著高于感病品系,与病情指数呈显著负相关关系,蜡质层是其抵抗和延迟病原菌侵入的一个有力结构屏障。（2）感病品系叶片的气孔和叶背面茸毛数量显著多于抗病品系,且叶背面的气孔及茸毛密度与病情指数呈显著正相关关系,即气孔和茸毛越少越抗病。（3）抗病苦瓜品系的叶片栅栏组织以及海绵组织排列整齐、紧密,而高感品系的叶片组织出现大量孔隙,较难观察到完整细胞。（4）抗病品系叶片厚度、下表皮厚度、栅栏组织厚度、叶片结构紧密度明显高于感病品系,而感病品系的海绵组织厚度、叶片结构疏松度明显高于抗病品系;且苦瓜比叶重与其白粉病抗性关系不大。研究认为,苦瓜叶片蜡质含量、叶背面气孔及茸毛密度可以作为苦瓜白粉病抗性鉴定的参考指标。     

籽用美洲南瓜叶片对白粉病菌的抗逆生理响应

以籽用美洲南瓜(Cucurbita pepo L.)白粉病抗病品系F2和感病品系M3为试材,在人工气候箱内接种白粉病生理小种2US孢子悬浮液,考察在接种白粉病菌后南瓜幼苗植株与白粉病菌的互作、叶片活性氧代谢及保护酶活性的变化,探讨南瓜抵御白粉病的生理机制。结果表明：(1)与感病品系M3相比,接种白粉病菌后,抗病品系F2叶片上病原菌发育缓慢,较难侵染叶片。(2)抗病品系F2在感病初期叶片H₂O₂、O₂^-·含量迅速升高后逐渐下降,而感病品系在感病初期H₂O₂、O₂^-·含量上升缓慢,在达最大值后始终保持较高水平,且感病品系叶片MDA含量始终高于抗病品系;组织化学染色分析发现,抗病品系叶片着色比感病品系快,之后着色面积有所减少并趋于较低水平。(3)抗病品系F2和感病品系M3叶片抗氧化酶CAT、SOD、POD活性及PAL、PPO活性在接种白粉病菌后均显著增加,但抗病品系的活性及其增幅均高于感病品系。研究发现,籽用美洲南瓜抗病品系叶片上白粉病菌发育缓慢,较难受到侵染,生成菌丝体后叶片上粉状斑点较小;抗病品系在被白粉病菌侵染初期依靠活性氧的增加抵御病原菌的入侵,随着活性氧含量增加抗病品系通过迅速增加自身抗氧化酶活性来防止氧化胁迫;与感病品系相比,抗病品系在受病原菌侵染后能迅速增加PAL、PPO活性以抵御病原菌侵染。     

光质对水稻幼苗生长及生理特性的影响

以荧光灯为对照,采用发光二极管（light emitting diode,LED）精确调制不同光谱能量分布,研究了光质对‘武运粳7号’和‘抗优63’两种水稻幼苗生长及生理特性的影响.结果表明：光质对两个品种水稻幼苗生长有显著影响且存在差异.蓝光显著抑制幼苗株高,提高‘武运粳7号’叶片的可溶性蛋白含量及两个品种水稻五叶期幼苗的壮苗指数;红光显著提高三叶期幼苗的茎基直径、壮苗指数以及五叶期叶片的可溶性糖和淀粉含量;红蓝组合光显著提高三叶期幼苗的根数、茎基直径、壮苗指数、根系活力和可溶性糖含量,以及五叶期幼苗的鲜、干质量、壮苗指数、叶片可溶性糖和蔗糖含量;黄光可在幼苗生长初期明显增加株高,提高叶片色素含量.总体上,红蓝组合光有利于培育水稻壮苗.     

旱直播条件下强弱化感潜力水稻根际微生物的群落结构

运用末端限制性片段长度多态性(T-RFLP)技术,以强化感水稻品种PI312777和弱化感水稻品种Lemont为材料,研究了旱直播模式下5叶期和7叶期化感水稻根际土壤微生物的组成和结构。结果显示:HaeⅢ和MspⅠ2种内切酶分别检测到9—87个TRFs、15—89个TRFs,各个样本的TRFs排序间存在极显著差异,表明各样本的微生物的相对丰富度存在极显著差异。用物种丰富度(S)、香隆指数(H)、Simpson多样性指数(D)、均匀度指数(E)评价了6个样本中TRFs的多样性,香隆指数最能体现2个酶切片断中TRFs的多样性,PI7中TRFs多样性最高。聚类分析和主成分分析表明旱作条件下强弱化感潜力水稻在生育前期(5叶期以前)根际微生物群落的组成与结构相似性较大,而7叶期强弱化感水稻及对照之间微生物群落差异较大,表明水稻根际微生物的组成既受生育期的影响又受水稻品种的影响。7叶期的化感水稻根际微生物呈现最大物种丰富度和香隆-威尔指数多样性,在其特有的34个菌中有7个属于粘细菌目,另外还有一些滑行菌和一些与氮循环相关的细菌等。粘细菌可能通过次生代谢产物抑制伴生杂草种子的萌发,降低杂草的密度从而提高化感水稻的化感作用潜力。     

高粱耐盐性评价方法研究及耐盐碱资源的筛选

用5.500 g/L盐水溶液对3～5叶期高粱幼苗进行处理,用幼苗相对成活率对568份高粱种质进行分级,结果显示:5%的种质具有3级以上的耐盐性。此法可以用来进行大量种质的苗期耐盐筛选。根据植株在不同含盐量的盐碱地上生长的性状差异,对成株期的高粱进行耐盐鉴定,利用处理间性状的差异及各性状与穗重和秆重的相关性构建一个耐盐指数来评价材料对盐碱的耐性,从而对18个高粱品种和品系进行了分级,以适合于盐碱地推广品种的筛选。     

高粱耐盐性评价方法研究及耐盐资源的筛选

本文用50mmol/L的配比盐水溶液对3-5叶期高粱幼苗进行处理,用幼苗相对成活率对568份高粱种质进行分级,结果显示：5%的种质具有3级以上的耐盐性。此法可以用来进行大量种质的苗期耐盐筛选。根据植株在不同含盐量的盐碱地上生长的性状差异,对成株期的高粱进行耐盐鉴定,利用处理间性状的差异及各性状与穗重和秆重的相关性构建一个耐盐指数来评价材料对盐碱的耐性,从而对18个高粱品种和品系进行了分级,适合于盐碱地推广品种的筛选。     

光周期和温度对小麦(Triticum eastivum L.)酯酶、α-淀粉酶同工酶的影响

本工作考察了三个春麦品种的抽穗习性及品种间光周期敏感性差异。以聚丙烯酰胺凝胶电泳分析了三个品种在冬季自然条件下,秋季较高温度与不同光周期条件下,叶酯酶、α-淀粉酶同工酶的变化。结果表明:小麦叶内两种酶系的电泳类型随植物生长年龄而变动,并可在5叶期和2叶期形成特定强带。供试品种在冬播自然条件下表现熟期相近,5叶期同工酶电泳类型彼此类同。在秋季较高温度下品种间对短日照敏感性表现出的明显差异,5叶期同工酶表型出现相应分歧:两个较不敏感品种在连续光照下5叶期产生的特征性酶带,在敏感品种中则提早出现于2叶期,或者于短日照下5叶期。     

不同抗性泡核桃对褐斑病病原菌侵染的生理生化响应北大核心CSCD

以抗病和感病泡核桃无性系为实验材料,人工接种褐斑病病原菌后测定不同时期叶片中保护酶活性、总酚、类黄酮、叶绿素含量等相关生理生化指标,探讨不同抗性泡核桃响应褐斑病病原菌侵染的生理生化差异。结果表明:(1)接种病原菌后,感病无性系64叶片带菌率随着侵染时间的增加而升高,且显著高于抗病无性系199(P<0.05)。(2)抗病无性系199和感病无性系64叶片的SOD、POD、CAT、APX和PPO活性随着侵染时间均呈现先升高后降低的变化趋势,其中SOD、POD和APX活性均在16 d时达到最大值;与较感病无性系相比,接种后抗病无性系的POD和APX活性较强;在接种前期(1~16 d),感病无性系PPO活性高于抗病无性系,后期(16~34 d)CAT活性也较抗病无性系高。(3)抗病无性系叶片叶绿素含量始终高于感病无性系;抗病无性系MDA含量在接种后无明显变化,而感病无性系先增加后降低,其细胞膜脂过氧化较重。(4)两个无性系叶片可溶性蛋白和可溶性糖含量变化较平缓,且差异不显著,在接种后期(34 d)有升高的趋势;接种5 d以后,感病无性系叶片类黄酮和总酚含量始终显著高于抗病无性系。研究发现,泡核桃抗病无性系叶片带菌率较低,较难受到侵染,并且通过提高POD和APX活性以及积累较多叶绿素、可溶性蛋白和可溶性糖来应对病原菌侵染引起的氧化胁迫,抑制病原菌的繁殖,从而提高其抗病能力。     

Screening for Barley yellow dwarf virus-Resistant Barley Genotypes by Assessment of Virus Content in Inoculated Seedlings

The content of Barley yellow dwarf virus (BYDV) in roots and leaves of barley seedling plants differing in their level of resistance was assessed by quantitative ELISA 1–42 days after inoculation with the strain of BYDV (PAV). High virus accumulation in roots and low concentration in leaves was characteristic of the period 9–15 days after inoculation. In leaves, the differences in virus content between resistant and susceptible genotypes became significant after 15 days and resistance to virus accumulation was better expressed 30–39 days after inoculation. Roots of resistant materials exhibited evident retardation of virus accumulation and the greatest difference in virus content between resistant and susceptible plants was detected 9 days after inoculation. By these criteria, the selected winter and spring barley cultivars and lines (in total 44 materials) fell in to five groups according to field reactions and the presence or absence of the Yd2 resistance gene. There were highly significant and positive relations between ELISA values and 5‐year field data on symptomatic reactions and grain‐yield reductions due to infection. Using the described method, resistant and moderately resistant genotypes (both Yd2 and non‐Yd2) were significantly differentiated from susceptible genotypes. The possible use of this method in screening for BYDV resistance is discussed.     

Study of resistance components of some promising wheat lines to yellow rust disease in the seedling stage

The most reliable method to control the wheat yellow rust disease is cultivation of resistance cultivars. To provide resistance, it is necessary to be aware of the amount and the quality of pathogenesis of disease factors and resistant specifications. In this study, 82 wheat promising lines with Bolani susceptible cultivar in randomised complete block design were tested in the seedling stage. This experiment was carried out in greenhouse condition, and it was assessed by two races: 166E254A+Yr27+ and 6E150A+, which were more and less pathogenic, respectively. The attributes of resistance were measured for infection type (IT), latent period (LP), pustule size (PS) and density. Results of variance analysis relating two races between wheat genotypes for these four attributes of resistance showed that there is a difference in the probability at 1% level. The statistical analyses for these components of resistance indicated that there is negative and high solidarity between IT and LP, and also among the number and density of pustules. The correlation between IT and LP and both races were -0.90 and -0.98, respectively. Cluster analysis of lines to each race was classified as resistant, semi-resistant and susceptible. The first group of the resistant lines were 27 lines in which their ITs of 0–2, mean LP of 18?days PS of 2.8 and pustule density of 1.1 were recorded.     

Quantitative resistance of some Elite wheat lines to Puccinia striiformis f. sp. tritici

Host resistance is the most economical way to manage wheat stripe rust caused by Puccinia striiformis f. sp. tritici. Slow rusting, a type of quantitative resistance, has been reported to last for a long time. Quantitative resistance, in terms of slow rusting parameters including final rust severity (FRS), apparent infection rate (r), relative area under disease progress curve (rAUDPC) and coefficient of infection (CI), was evaluated in a set of 29 wheat genotypes along with susceptible control during 2008–2009 and 2009–2010 cropping seasons. This study was conducted in field plots at Ardabil Agricultural Research Station (Iran) under natural infection conditions with two times artificial inoculation. Artificial inoculation was carried out by yellow rust inoculum having virulent genes against Yr2, Yr6, Yr7, Yr9, Yr22, Yr23, Yr24, Yr25, Yr26, Yr27, YrA and YrSU. Results of mean comparison for resistance parameters showed that lines C-86-1, C-86-2, C-87-1 and C-87-3 along with susceptible had the highest values of FRS, CI, r and rAUDPC, therefore were selected as susceptible lines. The lines C-86-3, C-86-9, C-87-2, C-87-6, C-87-8, C-87-11 and C-87-18 were susceptible at the seedling stage and had low level infection at adult plant stage. Consequently, these lines with low different parameters most probably have slow rusting resistance. The remaining lines had no infection or were at low level of infection. Thus, they were selected as resistant or moderately resistant lines. In this study, correlation coefficient between different parameters of slow rusting was significantly high (r = 0.92–0.99).     

拔节期与抽穗期玉米抗纹枯病相关QTL的初步定位

以玉米自交系R15(抗)×478(感)的F_2分离群体为作图群体,构建了包含146个SSR标记位点的遗传连锁图谱,覆盖玉米基因组1666 cM,平均图距11．4 cM。通过麦粒嵌入法对229个F_(2：4)家系进行人工接种纹枯病菌,于玉米拔节期和抽穗期进行纹枯病的抗性鉴定。应用复合区间作图法分析两个时期的抗病QTL及遗传效应。结果共检测到17个抗性QTL,其中以拔节期病情指数为指标共检测到9个QTL,分别位于第1、2、3、4、5、6、和10染色体上,可解释的表型变异为3．72%-9．26%;以抽穗期的病情指数为指标共在7条染色体上检测到10个抗玉米纹枯病的QTL,分布于第2、3、4、5、6、8和9染色体上。单个QTL可解释的表型变异为4．27%-9．27%。两个时期共检测出2个共同QTL,它们分别位于第2染色体的bnlgl662-bnlg1940区间和第6染色体的umc1006-umc1723区间。定位结果表明两个时期检测出的抗性QTL的差异表达与玉米不同发育时期基因的时空表达有密切关系,从而反映在纹枯病的抗性位点差异性上．这为玉米抗病选育提供新的信息。     

吉林省部分玉米种质资源抗玉米弯孢菌叶斑病鉴定研究

玉米弯孢菌叶斑病主要是由弯孢菌（Curvularia lunata）引起的侵染性病害。近年来,该病害在我国玉米主产区发生面积逐年扩大,已成为玉米重要病害之一。本文研究了吉林省主要玉米杂交种和自交系抗病性差异,结果表明：玉米杂交种间以及自交系间抗病性差异明显;吉63、黄早4、自330、丹9046、丹9041、铁7922、掖478、沈5003、丹340和E28等一批应用多年的种质资源均为感病类型（MS-HS）;而新选育的各类群一些种质和具有热带、亚热带血缘的78599等一些外来种质资源均为抗病类型（R～HR）。杂交种的抗病性与双亲的抗病性有密切关系;玉米杂交种苗期较抗病,抽丝期极为感病,这表明杂交种抗性随植株生长而递减。     

Resistance reactions of Cucumis melo to inoculation with Pseudoperonospora cubensis

Reactions of several cultivars and breeding lines of melons to artificial inoculation at the seedling stage with a local isolate of Pseudoperonospora cubensis were compared under growth chamber and field conditions. Four different reactions were distinguishable: highly susceptible, susceptible, partially resistant and resistant. The differences in the reactions were more clear-cut under growth chamber conditions. Selection for resistance could be carried out at the seedling stage using sporangia production and lesion size, shape, colour and number as criteria. Under growth chamber conditions, plants of resistant lines had minimal sporangia production and circular or angular lesions 1–2 cm in diameter which became necrotic within 5 days after inoculation.     

Mapping quantitative trait loci associated with spot blotch and net blotch resistance in a doubled-haploid barley population

Spot blotch and net blotch are important foliar barley (Hordeum vulgare L.) diseases in Canada and elsewhere. These diseases result in significant yield reduction and, more importantly, loss of grain quality, downgrading barley from malt to feed. Combining resistance to these diseases is a breeding priority but is a significant challenge using conventional breeding methodology. In the present investigation, an evaluation of the inheritance of resistance to spot and net blotch was conducted in a doubled-haploid barley population from the cross CDC Bold (susceptible)?×?TR251 (resistant). The population was screened at the seedling stage in the Phytotron and at the adult-plant stage in the field for several years. Chi-squared analysis indicated one- to four-gene segregation depending on disease, isolate, plant development stage, location and year. A major seedling and adult-plant resistance quantitative trait locus (QTL), designated QRpt6, was re-confirmed for net-form net blotch resistance, explaining 32?C61% of phenotypic variation in different experiments. Additional QTL for seedling and adult-plant resistance to net blotch were identified. For spot blotch resistance, a major seedling resistance QTL (QRcss1) was detected on chromosome 1H for isolate WRS1909, explaining 79% of the phenotypic variation. A highly significant QTL on 3H (QRcs3) was identified for seedling resistance to isolate WRS1908 and adult-plant resistance at Brandon, MB, Canada in 2008. The identification of QTL at only one location or from 1?year suggests spot blotch resistance is complex and highly influenced by the environment. Efforts are being made to combine spot and net blotch resistance in elite barley lines using molecular marker-assisted selection.