利用高分辨率熔解曲线（HRM）分析梨微卫星标记

 以西洋梨（Pyrus communis L.）‘Nain Vert’的一个矮生型实生系与‘茌梨’（Pyrus bretschneideri Rehd.）的F1杂交群体为试材,对分别源自梨和苹果基因组的4个微卫星（即SSRs）序列多态性进行了高分辨率熔解曲线（high resolution melting,HRM）分析。结果显示,在测试群体中,TsuENH042和Hi15a13存在两种分型,TsuENH081存在3种分型,而Hi08d09只有1种类型。因此,HRM分析技术可以作为筛查果树微卫星标记多态性或对其进行基因分型的有效手段在相关研究中加以应用。     

A crop identification system (CIS) to optimise pesticide applications in orchards

Summary

In the ambit of the ISAFRUIT Project, a prototype sprayer able to adapt its spray and air distribution automatically, according to the characteristics of the target canopy, to the level of crop disease, or to environmental conditions, it is under development. In order to identify the characteristics of the target canopy, in terms of its size and density, a Crop Identification System (CIS), based on ultrasonic sensors, was studied and produced. The principles governing the functioning of the CIS system and the first experimental results obtained from spray deposition tests carried out in an apple orchard using a CIS-equipped prototype sprayer are described. The first results indicated that, by adapting the application rate to the characteristics of the target, the CIS enabled the amount of spray deposited on the leaves to be maximised with respect to lower and higher volume rates.     

利用胚性细胞悬浮系研究香蕉枯萎病抗性离体筛选技术

以香蕉(Musa spp. AAA group)胚性细胞悬浮系(Embryogenic Cell Suspension,ECS)为试材,进行抗枯萎病离体筛选技术研究。首先测试不同的γ射线(60Co)辐射剂量对ECS植株再生能力的影响;在此基础上,以不同浓度的枯萎病病原菌毒素粗滤液(FOC)为选择压力,研究FOC对ECS植株再生能力的影响,并进行离体抗性筛选。结果表明,ECS的植株再生能力与辐射剂量之间呈负相关,半致死剂量为70～80Gy。同样地,未经辐射处理的ECS其植株再生能力也随着FOC体积分数的增加而急剧下降,但经辐射处理过的ECS其植株再生能力与CK相比成倍地增加;当FOC体积分数达到12%后,只有从经80Gy辐射后的ECS获得了再生植株。这表明ECS耐FOC的能力随着辐射剂量的增加而增强。     

High throughput generation of promoter reporter (GFP) transgenic lines of low expressing genes in Arabidopsis and analysis of their expression patterns

Background  

Although the complete genome sequence and annotation of Arabidopsis were released at the end of year 2000, it is still a great challenge to understand the function of each gene in the Arabidopsis genome. One way to understand the function of genes on a genome-wide scale is expression profiling by microarrays. However, the expression level of many genes in Arabidopsis genome cannot be detected by microarray experiments. In addition, there are many more novel genes that have been discovered by experiments or predicted by new gene prediction programs. Another way to understand the function of individual genes is to investigate their in vivo expression patterns by reporter constructs in transgenic plants which can provide basic information on the patterns of gene expression.     

Response of saprophagous wood-boring beetles (Coleoptera: Cerambycidae) to severe habitat loss due to logging in an aspen-dominated boreal landscape

Logging significantly reduces the proportion of late-seral stands in managed boreal landscapes. Availability of habitat elements typical of these stand types, such as standing dead wood, decreases, and dependant species may have their abundance reduced or become locally extirpated, potentially affecting the ecosystem processes/services in which they take part. We evaluated the impact of habitat loss on saprophagous wood-boring beetles (Coleoptera: Cerambycidae) in an aspen-dominated landscape intensively logged for the past 30 years. Sixty natural snags of middle decay class were chosen along a gradient of habitat loss and disturbance age, cut down and dissected for beetle larvae. We then assessed relationships between species occurrence and percentage of residual cover and age of disturbance at spatial scales ranging from 40 to 2000 m radii. The most common species, Anthophylax attenuatus, showed no response, being abundant regardless of the intensity of habitat loss. The second most common species, Bellamira scalaris, showed a negative response, especially in sites which had been fragmented for a longer time. A third species, Trachysida mutabilis, showed an inverse trend, having a higher probability of presence where habitat loss was more severe. Our study shows that some saprophagous wood-borers do react negatively to habitat loss, but that within a relatively homogenous group the response can vary significantly between species. Saprophagous wood-borers should be considered potentially sensitive to habitat loss, and their response to fragmentation remains to be evaluated on a longer time frame.     

Antioxidant capacity is correlated with susceptibility to leaf spot caused by a rapid temperature drop in Saintpaulia (African violet)

The relationship between the susceptibility to rapid temperature drop induced leaf injury, i.e. “leaf spot”, and the antioxidant capacities of several Saintpaulia (African violet) cultivars was examined. Cultivars ‘Ritali’ and ‘Tamiko’, that are more susceptible to leaf spot caused by a rapid drop in leaf temperature from 30 to 15°C than are cultivars ‘Maui’ and ‘New Jersey’. The susceptible cultivars were also more susceptible to oxidative stress caused by H₂O₂ and active chlorine than the tolerant cultivars. Reduction of available chlorine, considered to be accelerated by antioxidants of leaf tissue, was rapid in ‘Maui’ and ‘New Jersey’. Activity of the antioxidant enzymes superoxide dismutase and catalase were higher in the leaves of ‘Maui’ and ‘New Jersey’ than in the susceptible cultivars. These findings show a correlation between leaf spot injury and antioxidant capacity in Saintpaulia leaves.     

An increase in citrus fruit (Kiyomi tangor) abscission induced by ABA is accompanied by an IAA increase in the abscission zone and ethylene production

Summary

Change in IAA concentrations in the peduncle, branch and intervening abscission zone were measured to clarify the involvement of IAA in citrus fruit drop in response to ABA application. Results indicating the importance of an IAA increase in the abscission zone were obtained. One day after application of ABA, the concentration of IAA in the abscission zone showed a temporary increase and then a decrease. The concentration of IAA in the abscission zone was dependent on the concentration of ABA applied. Changes in the production of ethylene, which is involved in the process of abscission and which is induced by IAA, in explants from treated leafy inflorescences, were examined. The fruit-abscission ratios were also investigated in relation to the time required for preparation. Explants sampled 0±1.d after application showed little abscission or ethylene production during the first 24 h incubation. During the next 24 h, almost all the ABA-applied explants abscinded, as did the control, but the former produced 3±4 times more ethylene. ABA-applied explants, sampled 2.d after application, abscinded and produced ethylene markedly during the first 24.h, whereas the control explants did not abscind. Control and ABA-applied explants, sampled 3 d after application, showed no differences in their abscission ratios and ethylene production. These findings indicate that a temporary IAA rise in the abscission zone, observed one day after application, is involved in ethylene production in ABA-induced citrus fruit drop.     

Inter-simple sequence repeat (ISSR)-PCR analysis to assess genetic diversity in a collection of wild cloudberry (Rubus chamaemorus L.) clones

Summary

Forty-eight wild cloudberry (Rubus chamaemorus L.) clones, collected from four Canadian Provinces, were assessed for genetic variability using inter-simple sequence repeat (ISSR)-PCR methods. Nine primers generated 138 polymorphic ISSR bands. A substantial degree of genetic diversity was found among the wild collection. Cluster analysis by the unweighted pair-group method with arithmetic averages (UPGMA) separated the 48 wild clones into six main clusters, and identified the one remaining clone as an outlier. Furthermore, within four of the clusters, the clones tended to form sub-clusters that were in agreement with a principal coordinate (PCO) analysis. Geographical distribution explained 8% of the total variation revealed by analysis of molecular variance (AMOVA). The ISSR markers detected a sufficient degree of polymorphism to differentiate among cloudberry clones, making this technology valuable for germplasm management, and more efficient choices of parents in current cloudberry breeding programmes.     

茄子青枯病抗性基因的遗传分析及其AFLP标记

 以茄子高感青枯病品种‘三月茄’与高抗品种‘S69’的F1、F2为材料, 对青枯病抗性遗传进行了分析, 同时开展了与抗性基因连锁的AFLP标记鉴定。结果表明: ‘S69’对青枯病的抗病性属于不完全隐性遗传, 感病性属于不完全显性; 抗性由1～2对基因控制。对86个F2单株AFLP分析, 鉴定出1个与‘S69’抗性基因连锁的AFLP标记39A980 (该引物组合为E-ACC /M-CTG) , 该标记与抗性基因间的交换值为4.65% , 遗传距离为4.9 cM。     

Response of evergreen perennial tree crops to gibberellic acid is crop load-dependent: II. GA3 increases yield and fruit size of ‘Hass’ avocado only in the on-crop year of an alternate bearing orchard

Despite problems of low fruit set, small fruit size and alternate bearing, the Hass cultivar dominates commercial avocado production worldwide. To increase yield and fruit size, gibberellic acid (GA₃) (25 mg L⁻¹) was applied at different stages of ‘Hass’ avocado tree phenology: (i) mid–late April (flower abscission), end of June–beginning of July (fruit abscission and beginning of the exponential phase of fruit growth), and mid-January (beginning of pre-harvest fruit drop); (ii) end of June–beginning of July; and (iii) mid-September (near the end of the major fruit abscission period; period of exponential fruit growth). In both years of the research, applications of GA₃ in April and June–July were within the periods of intense flower and fruit abscission, respectively; fruit abscission was low in September and January. Maximum air temperature was not related to flower or fruit abscission. In the on-crop year (391 fruit per untreated control tree), a single application of GA₃ at the end of June–beginning of July significantly increased total yield (kilograms only) and yield of commercially valuable fruit (178–325 g/fruit) (as kilograms and number per tree) compared with the control (P < 0.0001). GA₃ applied in September increased total yield (kilograms only) and yield of commercially valuable fruit (kilograms and number per tree) to values intermediate to and not significantly different from all other treatments, except trees receiving multiple applications of GA₃. This treatment reduced total yield and yield of commercially valuable fruit (kilograms and number per tree) relative to all treatments (P ≤ 0.0002). In contrast, during the off-crop year (32 fruit per control tree), no GA₃ treatment had a significant effect on yield or fruit size compared with the control and all other GA₃ treatments. For ‘Hass’ avocado, there was no negative effect from applying GA₃ at the end of June–beginning of July in both the off- and on-crop years; 2-year cumulative total yield and yield of commercially valuable fruit were increased by 27 kg (128 fruit) and 22 kg (101 fruit) per tree, respectively, above the yield of untreated control trees (P < 0.0001).     

Response of evergreen perennial tree crops to gibberellic acid is crop load-dependent. I: GA3 increases the yield of commercially valuable ‘Nules’ Clementine Mandarin fruit only in the off-crop year of an alternate bearing orchard

Worldwide, gibberellic acid (GA₃) is used routinely to increase fruit number and size of seedless mandarins. The efficacy of seven combinations of GA₃ concentrations and application times to maximize total yield and yield of commercially valuable fruit (diameter 57.2–76.2 mm) of ‘Nules’ Clementine mandarin (Citrus reticulata Blanco) was determined in a commercial orchard. GA₃ applied during the period of intense flower abscission failed to reduce the total number of abscised flowers in both the light off- and heavy on-bloom years. No GA₃ treatment reduced fruit abscission when trees were setting the low yield off-crop. However, all trees receiving GA₃ in the high yield on-crop year had fewer abscised fruit than untreated control trees (P = 0.0188) and GA₃ applied 10 days after 75% petal fall and in July increased the number of fruit retained on tagged branches >20% compared to control trees (P = 0.0005). Maximum air temperature was not related to flower or fruit abscission. In the off-crop year (548 fruit per untreated control tree), it was necessary to apply 15 or 25 mg L⁻¹ GA₃ at 60% bloom, 90% bloom, 75% petal fall and 10 days after 75% petal fall to significantly increase the number of fruit per tree and yield of commercially valuable fruit (kilograms and number per tree) (P < 0.0001) above that of control trees, with no reduction in total kilograms per tree. In the following on-crop year, it was better not to apply GA₃: no treatment increased total yield or fruit size and five of seven GA₃ treatments tested reduced total yield as kilograms and number of fruit per tree (P = 0.0003). The results provide strong evidence that GA₃ efficacy is crop load-dependent and dictate that crop load should be considered when using GA₃ to increase fruit set or fruit size of mandarins.     

Using spatial analysis to drive reserve design: a case study of a national wildlife refuge in Indiana and Illinois (USA)

Our refuge design strategy involves a landscape approach formulated to complement existing management efforts and employ restoration in the heavily degraded Kankakee River watershed in northeastern Indiana and northwestern Illinois. The watershed historically contained an approximately 400,000 ha wetland (Grand Marsh), a diverse riverine system, oak savanna, and prairie. Today only fragments of these habitats remain. The U.S. Fish and Wildlife Service developed a preliminary project proposal (PPP) during the summer of 1996 to protect and restore habitat within the watershed by establishing the Grand Kankakee Marsh National Wildlife Refuge. The Indiana and Illinois Gap Analysis projects provided the resources to move beyond the expert workshop approach to a data-driven method for initial reserve design. Using visual analysis of various Gap Analysis data layers, we established Focus Areas that formed the basis for the Environmental Assessment and the Economic Impact Study required under the National Environmental Policy Act (NEPA). We have initiated Phase II of the reserve design analysis using preliminary results of the Indiana Gap Analysis project and C-Plan software in conjunction with the New South Wales National Parks and Wildlife Service.     

山葡萄种间杂交F_1～F_4代对霜霉病抗性的遗传分析

1973—2006年对我国东北山葡萄抗寒的种质资源(品种、品系)与不抗寒的欧亚种酿造葡萄品种进行种间杂交、回交和重复杂交。共定植42个组合杂种苗,定植成活7680株。观察42个组合7680株杂种苗F1￣F4代对霜霉病抗性的的抗性分离,共分离出抗病(2￣3级)3747株,占杂种苗总株数48.8%。其中抗病×抗病的10个组合共分离出抗病2303株、占69.3%,分别高于抗病×不抗病、中等感病×中等感病、中等感病×高感病、高感病×高感病的组合的23.2、29.2、45.3和54.8个百分点。遗传规律是:山葡萄种间杂交后代F1￣F4对霜霉病抗性分离,表现为连续分布,倾向于抗病亲本,后代群体抗病性主要由亲本抗病性决定,杂交组合中抗病亲本越多,分离出的抗病单株越多,为多基因控制的数量性状遗传、"抗病基因"有累加效应、呈显性遗传给后代。已选育出抗霜霉病、抗寒、可酿造干红山葡萄酒的新品种左优红、品系94-7-75、94-8-168、95-2-482和2002-1-135。     

A mathematical approach to simulate spatio-temporal patterns of an insect-pest,the corn rootworm Diabrotica speciosa (Coleoptera: Chrysomelidae) in intercropping systems

We report on the use of a spatially explicit model and clustering analysis in order to investigate habitat manipulation as a strategy to regulate natural population densities of the insect-pest Diabrotica speciosa. Habitat manipulation involved four major agricultural plants used as hosts by this herbivore to compose intercropping landscapes. Available biological parameters for D. speciosa on bean, soybean, potato and corn obtained under laboratory conditions were used to group the homogeneous landscapes, composed by each host plant, by a similarity measure of host suitability either for larval survival and development, and adult survival and fecundity. The results pointed corn as the most dissimilar culture. Therefore, intercropping corn with any other crop system tested could reduce insect spread through landscape. This was proved using a cellular automata model which simulate the physiological and behavioural traits of this insect, and also different spatial configurations of the intercropping. Spatio-temporal patterns obtained by simulations demonstrated that the availability of corn bordering the field edge, which are areas more likely to invasion, is key for insect population control.     

Improved connectivity analysis using multiple low-cost paths to evaluate habitat for the endangered San Martin titi monkey (Plecturocebus oenanthe) in north-central Peru

Context

Graph-theoretic evaluations of habitat connectivity often rely upon least-cost path analyses to evaluate connectedness of habitat patches, based on an underlying cost surface. We present two improvements upon these methods.

Objectives

As a case study to test these methods, we evaluated habitat connectivity for the endangered San Martin titi monkey (Plecturocebus oenanthe) in north-central Peru, to prioritize habitat patches for conservation.

Methods

First, rather than using a single least-cost path between habitat patches, we analyzed multigraphs made up of multiple low-cost paths. This allows us to differentiate between patches connected through a single narrow corridor, and patches connected by a wide swath of traversable land. We evaluate potential movement pathways by iteratively removing paths and recomputing connectivity metrics. Second, instead of performing a sensitivity analysis by varying costs uniformly across the landscape, we generated landscapes with spatially varying costs.

Results

This approach produced a more informative assessment of connectivity than standard graph analyses. Of the 4340 habitat patches considered across the landscape, we identified the most important 100, those frequently ranked highly through repeated network modifications, for multiple metrics and cost surfaces.

Conclusions

These methods represent a novel approach for assessing connectivity, better accounting for spatial configurations of habitat patches and uncertainty in cost surfaces. The ability to identify habitat patches with more possible routes to other patches is of interest for resiliency planning and prioritization in the face of continued habitat loss and climate change. These methods should be broadly applicable to conservation planning for other wildlife species.

     

西瓜抗枯萎病菌生理小种1与2的遗传和染色体定位分析

<正>目的与意义:西瓜枯萎病是一种世界性的毁灭性土传真菌病害,是导致全球西瓜产量和品质降低的最严重障碍。西瓜枯萎病是由半知菌亚门镰孢属尖孢镰刀菌引起的,研究西瓜抗枯萎病菌生理小种1和2的遗传分析和染色体定位,将有利于高效改良栽培西瓜的枯萎病抗性,为开展西瓜抗枯萎病分子辅助育种提供技术支撑。     

甘肃中部梨资源遗传变异和亲缘关系的SSR分析

用6对SSR特异性引物对甘肃中部46个梨品种或类型的遗传变异和亲缘关系进行了分析,结果表明,SSR位点的期望杂合度为0.446～0.738,平均为0.639,显示了良好的品种鉴定能力。采用UPGMA聚类分析法构建的系统树将供试梨品种或类型分为7个大组:木梨组、白梨组、秋子梨组、褐梨组、西洋梨组和2个可能以秋子梨为基本种而形成的复杂的种间杂种组。唯一的砂梨品种黄花梨包含在白梨组中。新疆梨的5个品种没有独立成组,而是分别包含在木梨、白梨及秋子梨组中。一些原来根据形态学无法归类的品种和类型分别和木梨、白梨和西洋梨聚合在一起,显示出和这些梨系统的亲缘关系;木梨虽然采集地相对集中,但也显示出丰富的遗传多样性。