普通小麦八个品种对赤霉病抗扩展性的双列杂交分析

本文用8个对赤霉病不同抗性的普通小麦双列杂交的试验结果,分析了病小穗数的配合力、遗传力、性状相关及扩展速度等。小麦对赤霉病的抗性主要是由基因加性效应所决定的,非加性效应虽有一定的影响,但不显著。抗赤霉病性的遗传力较低,受环境的影响较大。病小穗数与有效小穗数和小穗密度的表现型和基因型呈正相关,与株高、穗长、无效小穗数和穗粒数呈微弱负相关,对赤霉病抗性与上述性状在遗传上似无明显的关系。高感品种福龙选的潜育期最长(9.2天),高抗品种望水白的最短(5.3天),其余的差异不大(6.2～6.9天)。高抗品种的赤霉病扩展速度较慢,高感品种的较快。     

水稻细菌性基腐病菌侵染规律研究

通过抗利富平水稻基腐病菌株Ech7，研究了病菌在水稻不同生育阶段的侵染和对产量的影响，结果表明：水稻基腐病菌可以在种子萌发阶段侵入，造成烂种和烂芽，而且病菌在水稻的不同生育期，均可侵入，其中以水稻生长的前期侵入更为重要，对产量的损失较大。研究还发现，水稻基腐病菌具有潜伏侵染现象。     

β-Tubulins in Gibberella zeae: their characterization and contribution to carbendazim resistance

BACKGROUND: Fusarium head blight caused by Gibberella zeae is an important disease of wheat and barley because it reduces grain yield and quality and results in the contamination of grain with mycotoxins. Recent studies have shown that carbendazim resistance in field strains of G. zeae is not caused by mutation of the β‐tubulin gene (β₁tub), which is the case with other filamentous fungi, but that fungicide resistance is greatly increased by deletion of β₁tub. The aim of the present study was to clarify the function of β₁tub and its role in carbendazim resistance in G. zeae by artificial gene operation. RESULTS: Deletion of β₁tub reduced vegetative growth and pathogenicity but increased asexual reproduction in G. zeae. All the mutants were more resistant to carbendazim than parent strains. A three‐dimensional model of β₁tub was constructed, and the possible carbendazim binding site was analysed. CONCLUSION: β₁tub is not an essential gene in G. zeae, but it affects the sensitivity of the fungus to carbendazim. Copyright © 2012 Society of Chemical Industry     

水稻细菌性基腐病研究进展

水稻细菌性基腐病（rice bacterial foot rot）是中国及东南亚国家水稻产区重要细菌病害之一,不同年份在局部水稻产区致灾流行。本文对该病害在中国的发生危害情况、病原细菌的分类现状、侵染特性、寄主范围、致病因子、致病性等相关研究进展进行了分析,提出了该病害发生与防控研究中存在的问题。     

咪鲜胺与氟环唑及其混配对小麦赤霉病菌的抑制作用

采用菌丝生长速率法测定了咪鲜胺与氟环唑及其5种配比混剂对小麦赤霉病菌的毒力。结果表明:咪鲜胺与氟环唑及其1:1、2:1、3:1、4:1、5:1混配组合对小麦赤霉病菌的EC50分别为0.1167、0.6126、0.1412、0.1040、0.0758、0.0661、0.0775μg/mL;这5种混配组合对小麦赤霉病菌的增效系数分别是1.39、1.54、1.93、2.11、1.74,其中以4:1混配组合的增效作用最大。     

香蕉枯萎和细菌性软腐病菌的多重PCR检测

香蕉枯萎病菌Fusarium oxysporum f. sp. cubense和细菌性软腐病菌Dickeya zeae的复合侵染为害给香蕉产业发展带来严重挑战, 有必要建立相关病害的多重聚合酶链式反应(multiplex polymerase chain reaction, multiplex PCR)检测技术。本文基于尖孢镰刀菌古巴专化型1号生理小种(F. oxysporum f. sp. cubense race 1, FOC1)基因组contig 438区间(35 631-37 693 bp)(GenBank: AMGP01000438.1)和4号生理小种(F. oxysporum f. sp. cubense race 4, FOC4)基因组contig 195区间(4 028-6 126 bp)(GenBank: AMGQ01000195.1)存在160 bp插入序列差异设计特异扩增引物FOC-F/-R, 同时以香蕉细菌性软腐病菌D. zeae的促旋酶B 亚单位基因(the subunit B of gyrase gene)(GenBank: JQ284039)序列设计特异扩增引物gyrB-F/-R。多重PCR检测结果显示:本技术可在一次PCR扩增反应内同时检测香蕉枯萎病菌1号、4号生理小种和细菌性软腐病菌; 多重PCR的灵敏度结果表明:检测香蕉枯萎病菌的DNA浓度最低限为0.1 ng/μL, 细菌性软腐病菌的灵敏度为10 3cfu/mL;检测结果稳定可靠。因此, 本研究建立的多重PCR检测方法可有效应用于检测香蕉发病组织中的香蕉枯萎病菌和细菌性软腐病菌, 也可用于香蕉种苗和田间土壤带病菌的监测, 为香蕉种植保驾护航。     

水稻品种对细菌性基腐病的抗性及病原细菌致病力分化的研究

用浸根接种法测定了国内外622个水稻品种对水稻细菌性基腐病(Erwinia chrysanthemiBurkholder et al.)的抗性。结果表明,高抗品种有127个,中抗品种210个,中感品种189个,高感品种96个。粳稻发病重于籼稻,国际水稻(IR系统)品种较为抗病,而斯里兰卡水稻(BG系统)品种较为感病。用来自四个省的10个水稻菌株和2个玉米菌株(E.chrysanthemi pv.zeae)在20个水稻品种上人工接种测定,资料经统计分析,结果发现不同地区的水稻菌株并无致病性分化现象;但不同水稻品种间的抗性差异显著,玉米菌株对水稻的致病力相对较弱。     

Quantifying cropping practices in relation to inoculum levels of Fusarium graminearum on crop stubble

This study was conducted in 58 producer‐field locations in Manitoba from 2003 to 2006 to understand how cropping practices influence Fusarium graminearum inoculum levels on stubble of various crops, including wheat, collected from the soil surface. Colonies per m² (CN) were determined and converted to base‐10 logarithm values (log₁₀CN). Mean log₁₀CN of the sampled field for various crops and groups of crops grown in the 3 years prior to sampling were tested to find significant differences. Average log₁₀CN values were also used to determine significant differences between tillage systems and the effect of number of years. Average log₁₀CN values for zero and minimum tillage systems were not different but were significantly higher than values for conventional tillage. A series of three crop rotation scenarios were tested using weighted log₁₀CN values for crop, tillage, their interaction and their squared terms in step‐wise regression models to identify which model was the best predictor of log₁₀CN. This was selected as the cropping practice index (CPI) model and was expressed as: CPI = 1·98423 + 0·55975 (C₂ × C₁ × T)² + 0·4390 (C₂ × T)², where C₁, C₂ and T represent the weighted log₁₀CN values for crops grown 1 and 2 years previously and tillage system, respectively. R² value for this model was 0·933 (P < 0·0001). The reliability of the CPI model was tested using jack‐knife full cross‐validation regression. The resulting R² was 0·899. The CPI model was tested using data collected from seven wheat fields in 2006 (R² = 0·567). The relationship between CPI and FHB index (R² = 0·715) was significant.     

西藏设施茄子镰孢根腐病病原的分离及鉴定

本试验对西藏设施茄子镰孢根腐病症状和病原进行了研究。结果表明,其症状主要表现为植株根部或茎基部逐渐腐烂,后导致整个植株萎蔫枯死。根据病原菌形态特征及ITS序列分析结果,将致病菌鉴定为层出镰孢(Fusarium proliferatum),该病原菌的最适生长温度为30℃,最适碳源为树胶醛糖和甘露糖,最适氮源为硝酸钠;研究结果为该病害的综合防治提供依据。