Identification of a major gene (Mex-1) from Coffea canephora conferring resistance to Meloidogyne exigua in Coffea arabica

Among the most damaging root-knot nematode species, Meloidogyne exigua is especially common in Latin America and constitutes a major agronomic constraint in all major coffee-growing ( Coffea arabica ) areas. Growing nematode-resistant coffee represents the most promising option for control of the pest. The present study aimed to determine the mode of inheritance of the M. exigua resistance transferred into C. arabica from a related species, Coffea canephora , and to identify associated molecular markers. Segregation data analysis of F ₂ progeny derived from a cross between the resistant introgression line T5296 and the susceptible accession Et6 showed that the resistance to M. exigua is controlled by a simply inherited major gene (designated the Mex -1 locus). The gall index distribution exhibited by the F ₂ individuals suggested incomplete dominant expression. Fourteen AFLP markers were found associated with the resistance to M. exigua and a localized genetic map of the chromosome segment carrying Mex -1 was constructed. Furthermore, the association of the identified AFLP markers with Mex -1 was confirmed by analysis of a set of genotypes involving 28 introgression Arabica lines either resistant or susceptible to M. exigua in field conditions. These results represent an important starting point to enhance backcross breeding programmes and to perform an early selection of resistant seedlings.     

我国农药残留快速检测技术的研究与应用现状

本文简述了目前农药残留快速检测技术的研究概况，分析了农药残留快速检测技术在我国的实际应用情况。     

有效碳数法研究及其在农药气相色谱分析中的应用

有机化合物结构与其所含有的有效碳数有一定的关系，本文给出了２０类结构化合物及其所含有有效碳数的关系，并对理论计算值和实测值进行了比较，结果十分接近，利用有效碳数法可以设计农药分析实验方案和无标样的情况下测定农药杂质含量。     

差量法测定猪回肠AA的真消化率及内源AA的排泄量

本文探讨了采用差量法测定猪对豆粕氨基酸(AA)的消化率和内源氨基酸排泄量的可行性.试验测得豆粕在16%、10%日粮蛋白水平上的表观氨基酸消化率分别为81.84%、78.59%,以差量法求得真消化率为87.87%.研究结果表明,差量法可以作为测定猪氨基酸真消化率和内源氨基酸排泄量的新方法.     

二化螟在茭白上的钻蛀行为及其防治方法

研究了二化螟在茭白植株上的转移、钻蛀和产卵行为以及取食选择性,并根据其行为特性,制订合理的药剂喷施方法.结果表明,二化螟90%以上的卵产在茭白的叶片上,其余部分产在叶鞘上.产卵的主要叶位是心叶、倒一叶和倒二叶.超过50%的卵块集中在叶片距叶枕0～60cm的部位.幼虫孵化后,蚁螟蛀入的部位一般在叶枕以下的叶鞘内侧,多集中于倒四、倒五叶鞘.2龄后开始钻蛀内侧叶鞘,并蛀入茭白茎的内芯,二化螟幼虫在茭白植株上通常从叶片转移到叶鞘进行钻蛀危害.幼虫嗜食茭白茎部,其次为茭白果肉和叶鞘,对叶片几乎不取食.使用叶鞘喷施杀虫可达到对茭白进行全株喷雾同样的防治效果,并可节省40%～50%的用药量,经济和生态效益十分明显.     

菜豆新品种将军油豆的选育

将军油豆是以农家品种大马掌为母本 ,家雀蛋为父本人工杂交后系统选育而成。中熟 ,蔓生 ,从播种到采收 6 5d(天 ) ,生长势强 ,嫩荚绿色 ,扁条形 ,荚尖部有红条纹 ,平均荚长 2 0cm ,荚宽 2 .4cm ,单荚质量 2 4g ,纤维少 ,肉质面 ,属典型的东北优质油豆角类型。抗炭疽病、锈病 ,适应性广 ,春秋皆可种植 ,露地、保护地兼用     

Quantifying patch distribution at multiple spatial scales: Applications to wildlife-habitat models

Multiscale analyses are widely employed for wildlife-habitat studies. In most cases, however, each scale is considered discrete and little emphasis is placed on incorporating or measuring the responses of wildlife to resources across multiple scales. We modeled the responses of three Arctic wildlife species to vegetative resources distributed at two spatial scales: patches and collections of patches aggregated across a regional area. We defined a patch as a single or homogeneous collection of pixels representing 1 of 10 unique vegetation types. We employed a spatial pattern technique, three-term local quadrat variance, to quantify the distribution of patches at a larger regional scale. We used the distance at which the variance for each of 10 vegetation types peaked to define a moving window for calculating the density of patches. When measures of vegetation patch and density were applied to resource selection functions, the most parsimonious models for wolves and grizzly bears included covariates recorded at both scales. Seasonal resource selection by caribou was best described using a model consisting of only regional scale covariates. Our results suggest that for some species and environments simple patch-scale models may not capture the full range of spatial variation in resources to which wildlife may respond. For mobile animals that range across heterogeneous areas we recommend selection models that integrate resources occurring at a number of spatial scales. Patch density is a simple technique for representing such higher-order spatial patterns.     

夏季狗牙根草坪不同建植方法及秋季交播黑麦草对成坪效果的影响

以狗牙根Cynodon dactylon种子和营养体为材料，在武汉地区，对5种不同建植方法建成的草坪从盖度变化、成坪时间、均一性、建植成本及秋季交播多年生黑麦草Lolium perenne后翌年狗牙根的草坪质量等方面进行综合比较。结果表明：采用夏季建植狗牙根草坪并于秋季交播多年生黑麦草的方法来建植四季常绿草坪，狗牙根采用撒茎覆沙法效果最佳，其他方法依次为开沟埋茎法、闻铺草皮法、穴植草茎法；种子直播法在翌年需重新建坪。     

退耕还草产业化技术经济效果评价方法探讨

以平凉市退耕还草产业化技术开发为例,以产业化系统链中各子系统间的功能协调统一为依据,以退耕还草产业化机制为纽带,在研究建立平凉市退耕还草产业化技术经济效果包括4个一级指标(基础指标、配套指标、服务指标和效益指标)和17个二级指标体系的基础上,采用层次分析法(AHP法)、隶属度函数法和综合效益指数法作为退耕还草产业化技术经济效果的评价方法.经比较得出:平凉市退耕还草产业化技术开发综合指数达到0.595 1,属初步产业化阶段,相对发展指数达到27.268%,年均产业化进步速度达到6.817%.     

植物育种的物理学方法

介绍了草原生态恢复中选育优良牧草种子的一些物理学方法,包括电场、磁场、物理辐射、激光、离子束和交变应力等在植物的生物学效应、诱变育种和转基因技术中的应用.