自走式双行胡萝卜联合收获机的研制及试验

为了提高中国胡萝卜机械化作业水平,结合国内胡萝卜的种植模式和农艺要求,设计了自走式双行胡萝卜联合收获机,该设备可同时完成2行胡萝卜的挖掘、夹持输送、根叶分离、去土和集收等功能。收获机由自走式橡胶履带底盘带动,主要工作部件由传动系统、挖掘装置、夹持输送装置、根叶分离装置、去土集收装置等组成。挖掘铲设计成两翼张开的三角状,可有效降低挖掘阻力;根叶分离前,胡萝卜植株在一拉紧装置作用下使根部对齐,然后转入水平夹持带输送装置经一对圆盘刀完成切割,保证了切口整齐且贴近根部顶端。经田间样机收获试验检测表明,机器收净率达到了98.2%,损伤率为2.5%,生产率达到了0.11hm2/h。该研究为胡萝卜收获机械的深入研究和发展提供了参考。     

Uptake of galaxolide, tonalide, and triclosan by carrot, barley, and meadow fescue plants

Many xenobiotics entering wastewater treatment plants are known to be persistent during wastewater treatment and tend to adsorb to sewage sludge. The application of sewage sludge as fertilizer in agriculture may pose the risk of an incorporation of xenobiotics in the cultivated plants and, finally, an inclusion into the food chain. This study was performed to investigate the uptake of common sewage sludge contaminants, galaxolide, tonalide, and triclosan, by plants used for human consumption and livestock feeding. Barley, meadow fescue, and four carrot cultivars were sown and grown in spiked soils under greenhouse conditions. After harvesting the plants, roots and leaves were analyzed separately, and the respective bioconcentration factors were calculated. In carrots, a concentration gradient of the xenobiotics became evident that decreased from the root peel via root core to the leaves. A significant influence of the differing root lipid contents on the uptake rates cannot be supported by our data, but the crucial influence of soil organic carbon content was confirmed. Barley and meadow fescue roots incorporated higher amounts of the target substances than carrots, but translocation into the leaves was negligible. The results indicated that an introduction of persistent semi- and nonpolar xenobiotics into the food chain via edible plants like carrots could be of certain relevance when sludge is applied as fertilizer. Due to low rates found for the translocation of the xenobiotics into the aerial plant parts, the entrance pathway into food products via feeding livestock is less probable.     

Population evaluation in crop wild relatives for <Emphasis Type="Italic">in situ</Emphasis> conservation: a case study for raspberry <Emphasis Type="Italic">Rubus idaeus</Emphasis> L. in the Leningrad region,Russia

Many crop wild relatives are usually widely distributed species, and in this relation a question arises about selecting populations of special importance for conservation. Using Rubus idaeus as an example, we propose a compound selection of wild populations for in situ conservation. Twelve raspberry populations in the Leningrad region have been evaluated from the point of view of their significance for in situ conservation. To exclude the run-wild forms from the evaluation process, we tried to identify them applying a mathematical model developed by statusmetry method. The constructed model is based on morphological features of leaves of primocanes and helps to distinguish the wild forms from the cultivated and run-wild ones. The wild raspberry populations were screened for plants with features useful for cultivated raspberry improvement such as waxy cover presence, yellow fruiting plants, spinelessness, fruiting primocanes and others. The diversity of wild raspberry populations was assessed by variation of morphological features, presence of botanical varieties and polymorphism of seed storage proteins. The results of viability status assessment for the chosen populations reflect the perspectives of their development and permit to determine the strategy and measures for optimal conservation.     

AFLP analysis of genetic diversity in leafy kale (<Emphasis Type="Italic">Brassica oleracea</Emphasis> L. convar. <Emphasis Type="Italic">acephala</Emphasis> (DC.) Alef.) landraces,cultivars and wild populations in Europe

AFLP markers were used to characterize diversity and asses the genetic structure among 17 accessions of kale landraces, cultivars and wild populations from Europe. The range of average gene diversity in accessions was 0.11–0.27. Several landraces showed higher levels of diversity than the wild populations and one cultivar had the lowest diversity measures. The landraces that were most genetically diverse were from areas where kales are known to be extensively grown, suggesting in situ conservation in these areas as a supplement to storage of seeds in gene banks. An analysis of molecular variance (AMOVA) showed that 62% of the total variation was found within accessions. For most accessions, genetic distance was not related to geographic distance. Similarities among accessions were probably not caused by recent gene flow since they were widely separated geographically; more likely the relationship among them is due to seed dispersal through human interactions. Our results indicate that a kale population found in a natural habitat in Denmark was probably not truly wild but most likely an escape from a cultivated Danish kale that had subsequently become naturalized.     

Close Genetic Proximity Between Cultivated and Wild Bactris gasipaes Kunth Revealed by Microsatellite Markers in Western Ecuador

Bactris gasipaes Kunth (peach palm or Pejibaye) is the only domesticated palm of the Neotropics. The genetic relationships between the crop and its wild relatives are still unclear. We undertook field and laboratory work in order to describe differentiation and relationships between the wild and cultivated populations of the species in Western Ecuador, and their possible interactions. A volumetric study was undertaken on the fruits of both populations, as well as a population genetic analysis in order to clarify these relationships. Fruits from cultivated plants collected in the region of sympatry of wild and cultivated plants in North-West Ecuador showed intermediate volumes between those of reference samples for the wild and cultivated plants in allopatry. Using 8 microsatellite loci, we assessed 83 wild and cultivated individuals from Western Ecuador and cultivated plants from Amazonia and Central America as a reference for the cultivated form. We detected high polymorphism in the wild and cultivated samples and low, but significant level of genetic differentiation between wild and cultivated populations. The cultivated population in North-Western Ecuador showed close genetic proximity with the sympatric wild population, consistent with the volumetric study. These results have implications for hypotheses on evolution of this crop and for strategies of genetic conservation of the wild forms.     

基于图像处理的胡萝卜青头须根与开裂的检测方法

为了实现基于计算机视觉的胡萝卜外观品质自动分级系统,基于图像处理的方法,参照国家标准(SB/T10450-2007),该文提出影响胡萝卜外观等级的须根、青头、开裂等关键参数的提取算法.须根检测算法通过提取骨架检测端点数来实现,青头检测算法通过R分量上二值化得到,开裂检测算法使用S分量结合区域标记的方法完成,在此基础上构建了须根数、青头比和开裂度3个量化标准,对试验随机采集的520个胡萝卜图像的青头、须根和开裂进行检测,正确率分别达到了97.5%,81.8%,92.3%,总体识别率91.3%.该文所构建的胡萝卜关键特征检测方法,对研究机器视觉的胡萝卜外观品质自动检测装置与分级生产线具有积极意义.     

The Vigna angularis complex: Genetic variation and relationships revealed by RAPD analysis, and their implications for in situ conservation and domestication

The present study, using RAPD analysis, was undertaken to characterize genetic variation in three forms of V. angularis, cultivated, wild and weedy forms, and their relationships. The materials used consisted of 171 individuals (plants) or cultivars from 23 populations including 5 wild populations, 6 weedy populations, 6 cultivated populations and 6 populations with plants having wild and weedy or intermediate morphology, denoted here as complex populations. The materials used were collected on Honshu Island, Japan and seeds collected directly from the field were germinated for DNA extraction. In addition, 6 landrace accessions of V. angularis from the genebank were also analyzed. Genetic variation was highest in the wild form (H_g= 0.132; GD = 0.388), followed by the weedy form (H_g= 0.124; GD = 0.341) and the least in the cultivated form (H_g= 0.079; GD = 0.274). Intra-population genetic variation was high in the weedy and in the wild populations. However, inter-population was greater than intra-population genetic variation for all groups of populations studied in the V. angularis complex. 93% of the total diversity in the present study was exhibited by plants from complex populations and specific RAPD bands were found in these populations. Our results provide evidence that complex populations would be a logical focus for efforts to conserve the V. angularis complex in situ. Our results suggest that weedy populations are usually an ecotype of the wild form adapted to a different habitat.     

外源GA3对高原夏季胡萝卜肉质根发育的影响

为了揭示外源GA3对胡萝卜肉质根发育的影响机理,并为高原夏季胡萝卜安全高效栽培技术研究提供参考理论,本试验以耐先期抽薹的胡萝卜品种为试材,采用酶联免疫吸附法(ELISA),研究了外源GA3对高原夏季胡萝卜肉质根膨大、木质化及其内源激素含量的影响。结果表明,在叶片旺盛生长期和肉质根迅速膨大期分别喷施5.78×10-4 mol·L-1外源GA3 1次,或在苗期、叶片旺盛生长期和肉质根迅速膨大期喷施5.78×10-4 mol·L-1外源GA3 1~3次,能显著降低高原夏季胡萝卜苗期肉质根日鲜重增长速率与库活力,促进肉质根木质化。与对照相比,喷施外源GA3,可显著降低苗期肉质根内源GA3、IAA、GA4、ABA、DHZR与IPA含量,显著提高肉质根内源ZR含量;显著降低叶片旺盛生长期肉质根内源GA3、IAA、GA4、IPA含量,显著提高内源ZR含量;显著提高迅速膨大期肉质根内源IAA、GA4、ZR含量;显著降低肉质根迅速膨大期之前的IAA/ZR和GA4/ZR比值。随着外源GA3喷施次数的增多,IAA/ZR和GA4/ZR比值在肉质根迅速膨大期有逐渐增高的趋势。外源GA3通过改变内源激素含量及其平衡状态来影响高原夏季胡萝卜肉质根的发育。     

Diversification of Multipurpose Plant, <Emphasis Type="Italic">Perilla Frutescens</Emphasis>

The traditional Asian crop, Perilla frutescens has multiple uses. There are specialized cultivars for seed oil and for medicinal use, as well as wild/weedy forms growing in various habitats. Based on selective characteristics of leaf odor, anthocyanin pigmentation, seed hardness and seed diameter, the diversity of this species was investigated to clarify the intraspecific differentiation. P. frutescens was divided into five groups by the combination of three qualitative characteristics: leaf odor, anthocyanin pigmentation and seed hardness. Most of the plants cultivated for oil belonged to one group, while medicinal plants belonged to three other groups. Wild/weedy forms were in the last group. The five groups could not be distinguished by seed diameter. Though the plants cultivated for oil tended to have larger seeds than the medicinal and wild/weedy plants, there was no boundary either between the two crops, or among various phenotypes of P. frutescens.     

Reduced sexual compatibility between cultivated and wild chicory and their F1 hybrids

Crops were domesticated from wild plants not too long ago and have subsequently diverged from the wild ones, especially in traits used by humans. Whether divergence between the cultigen and wild forms has also lead to reduced reproductive compatibility is unknown for many species. Chicory (Cichorium intybus L.) has been bred as a crop at least since Roman times. To test if this has led to a loss in reproductive compatibility with wild chicory, we planted cultivar, wild, and F₁ hybrid plants into two field plots, and let them pollinate freely. On 2?days, in the beginning and middle of the flowering season, we counted the numbers of flowering capitula and open flowers per capitulum, which in combination with counts of viable pollen per flower were used to estimate the expected proportion of seeds fathered by cultivar, wild, and hybrid plants. Open capitula on wild and hybrid plants were marked, and when seeds were ripe we determined whether cultivar, wild or hybrid plants had pollinated the seeds, using AFLP markers. Cultivar plants fathered much fewer seeds than expected, both on wild and hybrid plants, suggesting that some degree of incompatibility has evolved between cultivar and wild chicory. Hybrid plants fathered more seeds than expected on some of the hybrid plants, indicating that hybrids do not suffer much from outbreeding depression. Our study thus suggests that cultivated and wild chicory, even though they belong to the same species, have diverged to an extent where reproduction between them is somewhat impaired.     

Evaluation of Wild Lens Taxa for Agro-Morphological Traits, Fungal Diseases and Moisture Stress in North Western Indian Hills

Exploitation of wild gene pool for breeding is a common practice in an increasing number of cultivated plants. The cultivated lentil could not attain the substantial improvement in the yield potential due to loss of genes for higher productivity and lack of resistance against biotic and abiotic stresses. The absence of evaluation data of wild lentils for characters of economic importance, besides biotic and abiotic stresses, is one of the constraints in their use in lentil breeding programme. In the present study, 70 wild accessions from four wild Lens subsp./sp. (L. culinaris subsp. orientalis, L. odomensis, L. ervoides and L. nigricans) along with 3 checks (Precoz, PL-406 and PL-639) were evaluated for phenological and agro-morphological characters, for their reaction to three fungal diseases (wilt, powdery mildew and rust) and screened for tolerance to moisture stress. The wild accessions showed higher performance for branches/plant as compared to cultivated genotypes. Similarly, a few accessions of L. culinaris subsp. orientalis were earlier to flower and had higher seeds and seed yield/plant as compared to cultivated lentil. However, some were comparable with cultivated genotypes for flowers/peduncle, peduncle length and plant height. The mean performance for flowers per peduncle, leaflets per leaf, plant height, seeds and seed yield per plant increased, while decreased for days to flowering and maturity, and branches per plant during the evolution of cultivated lentil from the wild Lens taxa. Of Lens taxa, L. nigricans had the maximum resistant accessions for biotic and tolerance to abiotic stresses. The valuable variation existing among wild accessions can be exploited following introgression with cultivated lentils. It will help in the flow of useful genes from wild to cultivated lentil for generating wide spectrum of variability and its subsequent use in genetic restructuring of lentil.     

Processes affecting genetic structure and conservation: a case study of wild and cultivated <Emphasis Type="Italic">Brassica rapa</Emphasis>

When planning optimal conservation strategies for wild and cultivated types of a plant species, a number of influencing biological and environmental factors should be considered from the outset. In the present study Brassica rapa was used to illustrate this: to develop Scandinavian conservation strategies for wild and cultivated B. rapa, DNA-marker analysis was performed on 15 cultivated and 17 wild accessions of B. rapa plus 8 accessions of the cross compatible B. napus. The B. rapa cultivars were bred in Sweden and Finland in 1944–1997 and the wild B. rapa material was collected from Denmark, Sweden and United Kingdom. The B. napus accessions were bred within the last 20 years in the Scandinavian countries. Results were based on scoring of 131 polymorphic ISSR markers in the total plant material. A Bayesian Markov chain Monte Carlo (MCMC) approach implemented in NewHybrids demonstrated a clear distinction of B. rapa and B. napus individuals except for three individuals that seemed to be backcrosses. The backcrossed hybrids descended from two Swedish populations, one wild and one escaped. The overall pattern of genetic variation and structure in B. rapa showed that cultivated and wild B. rapa accessions formed two almost separated clusters. Geographical origin and breeding history of cultivars were reflected in these genetic relationships. In addition, wild populations from Denmark and Sweden seemed to be closely related, except for a Swedish population, which seemingly was an escaped cultivar. The study point to that many processes, e.g. spontaneous introgression, naturalisation, breeding and agricultural practise affected the genetic structure of wild and cultivated B. rapa populations.     

Vigna vexillata (L.) A. Rich. Cultivated as a Root Crop in Bali and Timor

Vigna vexillata is considered as a pantropical distributed wild species closely related to the cowpea (Vigna uniculata) and adapted to infertile soils. The species is occasionally used for its storage roots as well as forage and erosion control plant. The objective of this study was to pursue personal communications that V. vexillata has be transformed into a cultivar in Indonesia. Seven Indonesian islands were visited (Java, Bali, Sumba, Flores, Timor, Kalimantan and Sulawesi). Wild V. vexillata was found in Java, Bali, Sumba, Flores and Timor, occasionally used as wild ‘forest food’, and cultivated V. vexillata was found in Bali and Timor, Seven cultivars were collected and two of these were made available for the National Botanic Garden of Belgium. The cultivars were primarily cultivated for their storage roots, propagated by seeds, required no scarified seeds for good germination and formed non-dehiscent pods. On-farm root yields of 18–30 t ha⁻¹ and seed yields of 0.7–1.2 t ha⁻¹ were estimated. A brief discussion about the common names of wild V. vexillata is given and it is proposed to use the name ‘tuber cowpea’ for V. vexillata accessions which are cultivated for their storage roots. The material may be of interest for regions, where the growing season is too short or the rainfall too low for sweet potato and cassava as well as to incorporate cultivar characteristics into wild V. vexillata accessions which are used for their storage roots.     

Determination and distribution of 6-methoxymellein in fresh and processed carrot puree by a rapid spectrophotometric assay.

Isocoumarin or 6-methoxymellein (6-MM) was extracted from carrot tissue using alkali saponification to solubilize the lactone portion of its structure into an aqueous phase. Acidification and subsequent organic solvent extraction allowed isolates to be quantified and verified as 6-MM by spectrophotometric determination. 6-Methoxymellein was analyzed in carrot cross sections, as a function of depth and before and after thermal processing. A natural propensity for 6-MM accumulation was observed in root tip sections exposed to ethylene, and levels increased as a result of wounding. Consecutive layer peeling demonstrated that small-diameter roots accumulated greater amounts of 6-MM in periderm tissue compared to large roots. Processing carrots into a puree resulted in 10-25% greater extraction of 6-MM than grinding fresh carrot samples, whereas steam-cooked and thermally processed purees had 15% greater extraction than unheated purees. This analytical technique will allow carrot processors to accurately estimate raw and processed products for the bitter compound 6-MM.     

Phylogenetic position of east Tibetan natural populations in Tartary buckwheat (Fagopyrum tataricum Gaert.) revealed by RAPD analyses

Phylogenetic relationships among cultivated landraces and natural populations of wild subspecies of Tartary buckwheat were investigated by constructing an NJ tree based on RAPD markers focussing on east Tibetan natural populations. Ten plants from three cultivated landraces and 29 plants from five natural populations of wild subspecies in eastern Tibet were used for RAPD analyses. The wild subspecies from eastern Tibet was classified into three types; (1) same type as cultivated landraces; (2) closely related to natural populations of northwestern Yunnan; and (3) an exceptional population, Zhuka, which was closely related to Sichuan populations. Since the type (2) is considered as the wild ancestral type of cultivated Tartary buckwheat, we conclude that eastern Tibet too may be one of the center of origin of this crop.     

Genetic Structure of Wild and Domesticated Populations of Capsicum annuum (Solanaceae) from Northwestern Mexico Analyzed by RAPDs

Levels of genetic variation and genetic structure of 15 wild populations and three domesticated populations of Capsicum annuum were studied by RAPD markers. A total of 166 bands (all of them polymorphic) and 126 bands (125 of them polymorphic) were amplified in wild and domesticated populations, respectively. Mean percentage of polymorphism was 34.2% in wild populations and 34.7% in domesticated populations. Mean and total genetic diversity were 0.069 and 0.165 for wild populations and 0.081 and 0.131 for domesticated populations. Parameters of genetic diversity estimated from 54 bands with frequencies ≥1 − (3/n) (n = sample size) showed that 56.7% of the total variation was within and 43.3% among wild populations, whereas 67.8% of the variation was within and 32.2% among domesticated populations. AMOVA indicated that total genetic diversity was equally distributed within (48.9 and 50.0%) and among (50.0 and 51.1%) populations in both wild and domesticated samples. Wild and domesticated populations were clearly resolved in a UPGMA dendrogram constructed from Jaccard’s distances (average GD = 0.197), as well as by AMOVA (17.2% of variance among populations types, p = 0.001) and by multidimensional scaling analysis. Such differentiation can be associated with domestication as well as different origin of gene pools of the wild (Northwestern Mexico) and cultivated (more probably Central Mexico) samples analyzed. The considerable genetic distances among cultivars (average GD = 0.254) as well as the high number of diagnostic bands per cultivar (33 out of 126 bands), suggest that genetic changes associated with domestication could have resulted from artificial selection intervening in different directions, but the inclusion of more domesticated samples might clarify the nature of distinctions detected here.     

Effect of seed storage on germplasm integrity of meadow fescue (Festuca pratensis Huds.)

Qualitative and quantitative changes in populations of meadow fescue (Festuca pratensis Huds.) after seed storage under different conditions were estimated. Phenotypic characters of plants grown from seeds stored for 54 months under two different storage conditions were compared. The germination of most of the seed accessions stored under favourable conditions remained at the initial level while storage under unfavourable conditions resulted in a decrease of the initial germination percentage as well as in an increase in the number of plants showing chlorophyll aberrations. There is great variability among the accessions resulting from storage under unfavourable conditions. In case of a few accessions a decrease in germination below 35% resulted in chlorophyll aberrations, faster flowering, shorter inflorescence and reduced viability of pollen grains.     

Using SSR markers to determine the population genetic structure of wild apricot (<Emphasis Type="Italic">Prunus armeniaca</Emphasis> L.) in the Ily Valley of West China

Genetic structure of three wild populations (Xinyuan, Gongliu and Daxigou) of apricot in the Ily Valley, Xinjiang Uygur Autonomous Region of China, was investigated with microsatellite (simple sequence repeat, SSR) markers. The higher polymorphism and greater transportability of these markers between Prunus species proved SSR markers were much efficient for conducting genetic diversity studies in wild apricot. Nei's gene diversity (He) and Shannon's index of diversity (I) were 0.287 and 0.458, respectively. This indicated that the wild apricot in the Ily Valley still maintained a relatively high level of diversity. The Gst of 0.137 and Fst of 0.164 revealed that genetic variation mainly resided among individuals within populations (83.6–86.3%). Population differentiation could also be found according to the distribution of SSR alleles between the populations. Mantel test showed the genetic distance between populations was significantly correlated to the geographical distance. The modest amount of gene flow (2.684) would reduce the disjunction between wild apricots. The long-distance dispersal of pollen by insects was probably the main way of gene flow between populations. Based on the study of population genetic structure, an effective conservation strategy of the species was discussed.     

Genetic data confirms field evidence for natural breeding in a wild taro population (Colocasia esculenta) in northern Queensland, Australia

Taro (Colocasia esculenta) is a vegetatively propagated, starchy root crop cultivated in tropical to temperate regions of the world. Wild forms of taro are distributed from India to southern China, Australia and Melanesia. They are widely known wild food or fodder sources, including in Aboriginal Australia, so it is unclear to what extent wild populations have been dispersed by humans, or naturally via insect-borne pollen and seed dispersal by birds or other animals. In Australia, pollinators and seedlings of taro have not been reported, and a key question is whether or not the wild taro there can breed naturally. Here we report field observations of flowering, fruit set, and an insect pollinator (Colocasiomyia, pupal stage), in a historically significant wild taro population at Hopevale in northern Queensland. The observed pupa is congeneric with two pollinating fly species that have a highly specialised, probably coevolutionary, relationship with taro in neighbouring Papua New Guinea. The field observations suggested the possibility of natural breeding at Hopevale. By analyzing microsatellite diversity within the Hopevale taro population, we found high genetic variation overall, indicative of multiple founding individuals. Two sublocations showed low genetic diversity and strongly negative inbreeding coefficients, consistent with predominantly clonal (vegetative) reproduction. A third sublocation showed high genetic diversity and a weakly negative inbreeding coefficient, indicative of sexual reproduction. This difference between sublocations may relate to microenvironmental conditions that favour seedling establishment in some parts of the site. The data constitute the first demonstration that natural breeding and population spread occurs in Australian wild taro.