Domestication ofEleusine coracana

Eleusine coracana (L.) Gaertn. subsp.coracana (Finger millet or eleusine) is a cereal that is widely cultivated in Africa and India. Archaeological records of finger millet are few and unsatisfactory. But, distribution, linguistic and historical evidence seem to suggest an African rather than Indian origin of the crop. Data from morphology, supplemented with cytogenetical observations and distribution revealed thatE. coracana subsp.africana is wild finger millet. This subspecies is widely distributed along the highlands of East Africa. Consequently, it is concluded that finger millet originated in the East African Highlands and was subsequently introduced into India.     

Reproductive Isolation during Domestication

It has been hypothesized that reproductive isolation should facilitate evolution under domestication. However, a systematic comparison of reproductive barrier strength between crops and their progenitors has not been conducted to test this hypothesis. Here, we present a systematic survey of reproductive barriers between 32 economically important crop species and their progenitors to better understand the role of reproductive isolation during the domestication process. We took a conservative approach, avoiding those types of reproductive isolation that are poorly known for these taxa (e.g., differences in flowering time). We show that the majority of crops surveyed are isolated from their progenitors by one or more reproductive barriers, despite the fact that the most important reproductive barrier in natural systems, geographical isolation, was absent, at least in the initial stages of domestication for most species. Thus, barriers to reproduction between crops and wild relatives are closely associated with domestication and may facilitate it, thereby raising the question whether reproductive isolation could be viewed as a long-overlooked "domestication trait." Some of the reproductive barriers observed (e.g., polyploidy and uniparental reproduction), however, may have been favored for reasons other than, or in addition to, their effects on gene flow.     

The Puzzle of Rice Domestication

The origin of cultivated rice has puzzled plant biologists for decades. This is due, at least in part, to the complex evolutionary dynamics in rice cultivars and wild progenitors, particularly rapid adaptive differentiation and continuous gene flow within and between cultivated and wild rice. The long-standing controversy over single versus multiple and annual versus perennial origins of cultivated rice has been brought into shaper focus with the rapid accumulation of genetic and phylogenetic data. Molecular phylogenetic analyses revealed ancient genomic differentiation between rice cultivars, suggesting that they were domesticated from divergent wild populations. However, the recently cloned domestication gene sh4, responsible for the reduction of grain shattering from wild to cultivated rice, seems to have originated only once. Herein, we propose two models to reconcile apparently conflicting evidence regarding rice domestication. The snowoballing model considers a single origin of cultivated rice. In this model, a core of critical domestication alleles was fixed in the founding cultivar and then acted to increase the genetic diversity of cultivars through hybridization with wild populations. The combination model considers multiple origins of cultivated rice. In this model, Initial cultivars were domesticated from divergent wild populations and fixed different sets of domestication alleles. Subsequent crosses among these semi-domesticated cultivars resulted in the fixation of a similar set of critical domestication alleles in the contemporary cultivars. In both models, introgression has played an important role in rice domestication. Recent and future introgression of beneficial genes from the wild gene pool through conventional and molecular breeding programs can be viewed as the continuation of domestication.     

Molecular Population Genetics of Rice Domestication

Domestication is a selection process that genetically modifies species to meet human needs. A most intriguing feature of domestication is the extreme phenotypic diversification among breeds. What could be the ultimate source of such genetic variations? Another notable outcome of artificial selection is the reduction in the fitness of domesticated species when they live in the wild without human assistance. The complete sequences of the two subspecies of rice cultivars provide an opportunity to address these questions. Between the two subspecies, we found much higher rates of non‐synonymous (N) than synonymous (S) substitutions and the N/S ratios are higher between cultivars than between wild species. Most interestingly, substitutions of highly dissimilar amino acids that are deleterious and uncommon between natural species are disproportionately common between the two subspecies of rice. We suggest strong selection in the absence of effective recombination may be the driving force, which we called the domestication‐associated Hill‐Robertson effect. These hitchhiking mutations may contribute to some fitness reduction in cultivars. Comparisons of the two genomes also reveal the existence of highly divergent regions in the genomes. Haplotypes in these regions often form highly polymorphic linkage blocks that are much older than speciation between wild species. Genes from such regions could contribute to the differences between indica and japonica and are likely to be involved in the diversifying selection under domestication. Their existence suggests that the amount of genetic variation within the single progenitor species Oryza rufipogon may be insufficient to account for the variation among rice cultivars, which may come from a more inclusive gene pool comprising most of the A‐genome wild species. Genes from the highly polymorphic regions also provide strong support for the independent domestication of the two subspecies. The genomic variation in rice has revealing implications for studying the genetic basis of indica‐japonica differentiation under rice domestication and subsequent improvement.     

Domestication of plants in Maya Lowlands

The Lowland Mayan culture has been one of the most successful in Mesoamerica. Being an agricultural society, part of their success was based on plant genetic resources which satisfied their needs of social reproduction. This article reviews recent evidence on early agriculture in the geographic area where Lowland Maya culture originated, and discusses its implications for the study of plant domestication and evolution under human selection within this cultural sub-area. Questions of interest for future research are posed. As working hypotheses, we list two categories of species possibly implicated in the origin of this civilization: (1) native species that could have been the subject of local human selection or to some degree of agricultural manipulation by 3400 b.c., and (2) species that could have been introduced from other cultural areas of America by 3400 b.c. and subsequently subjected to local human selection.     

黄精引种驯化栽培研究

随着天然药物、植物药的开发利用程度的加大,给药用植物资源保护及可持续利用带来了巨大压力和契机。本试验于2004年夏季开始,先后从内蒙古乌兰察布市蛮汉山引种了黄精野生药用植物,对其种子特性、繁殖方法、移栽时期、栽培技术、生长发育特性及适应性进行了引种驯化栽培研究,通过3~4年对黄精进行引种驯化栽培研究,引种成功。形成了一套较为完整并切实可行的人工栽培技术,为大面积商品化人工栽培推广应用奠定了基础。     

Domestication Shapes Recombination Patterns in Tomato

Meiotic recombination is a biological process of key importance in breeding, to generate genetic diversity and develop novel or agronomically relevant haplotypes. In crop tomato, recombination is curtailed as manifested by linkage disequilibrium decay over a longer distance and reduced diversity compared with wild relatives. Here, we compared domesticated and wild populations of tomato and found an overall conserved recombination landscape, with local changes in effective recombination rate in specific genomic regions. We also studied the dynamics of recombination hotspots resulting from domestication and found that loss of such hotspots is associated with selective sweeps, most notably in the pericentromeric heterochromatin. We detected footprints of genetic changes and structural variants, among them associated with transposable elements, linked with hotspot divergence during domestication, likely causing fine-scale alterations to recombination patterns and resulting in linkage drag.     

雪里绿引种驯化试验研究

通过对雪里绿的引种驯化试验(对温度、水分、土壤、光照条件的适应性及耐践踏性、抗贫瘠性),得出雪里绿在试验地能够完成发芽、展叶、开花、结实的年生长发育过程;能通过播种及分株方法繁殖;能忍耐的土壤最低含水量为4.1%;耐42.2℃的极端高温及-16.4℃的极端低温;能够在全光照及郁闭度为0.8的林下正常生长;能够在黄土、细沙土及建筑渣土上生长良好;叶片寿命长达18个月,全年常绿;不耐践踏,适于作观赏性草坪,不适于作运动草坪.雪里绿是北京地区园林绿化中优良的野生乡土草种.     

假芝驯化栽培及其抗氧化活性研究

假芝是一种野生药用真菌,具有抗氧化、抑肿瘤等作用,在我国及马来西亚等地均有采集销售,但是关于其人工驯化栽培报道极少,对其生长发育特性、营养成分等均不了解。为开发利用野生假芝资源,本试验首次对采自广州市白云山内的野生假芝Amauroderma rugosum菌株进行液体菌种袋料栽培试验,并对驯化的子实体进行营养分析和体外抗氧化活性评价。结果显示,假芝液体菌种培养5d即可用于生产,以玉米芯、木屑等为原材料进行栽培,接种后40d出现原基,71d成熟,生物转化率为10.84%。子实体粗多糖含量达3.22g/100g、总三萜类化合物为1.00%,粗蛋白质为14.90g/100g。体外抗氧化结果显示假芝对ABTS自由基和羟基自由基均有较好的清除作用,且清除效果优于赤灵芝和紫灵芝,是一个非常好的抗氧化材料,极具开发利用价值。     

White-tailed Deer Management Strategies and Domestication Processes

Today, people in the U.S. commonly engage in mutual relationships with white-tailed deer (WTD) in manners consistent with those that ultimately resulted in the domestication of animals in the past. Using a wide range of media depicting perspectives of sport hunters, biologists, ecologists, and game managers this paper explores: 1) the influence of anthropogenic environments on WTD behavior, 2) ‘game’ management and the ability to create valued demographics, and 3) the selection for increased antler size in farmed WTD. This study demonstrates that in order to gain a more accurate understanding of domestication, analyses should focus on the evolution of mutualisms between people and animals. Insights gleamed from this analysis also contribute toward our archaeological understanding of prehistoric animal domestication.     

Some Consequences of Animal Domestication for Humans

ABSTRACT

Throughout human evolution our species has had many kinds of interactions with others, including predatory, competitive, parasitic, mutualistic, and commensal. We still have such interactions in the modern world, with the most important resulting from our domestication of other species. Domestication created new kinds of interaction by which we controlled the freedom and reproduction of certain animals. Because domesticated populations became dependent on humans various adaptations by humans were necessary, and it is argued that these influenced the cultural, and possibly biological, evolution of our species.     

短距槽舌兰的驯化栽培与快速繁殖

为促进短距槽舌兰的资源驯化栽培, 本文对其生物学特性、生长发育规律和组织培养快速繁殖技术进行了研究。对开花植株进行人工授粉, 取种子进行观察发现, 授粉后140 d 种子才达到成熟状态; 将其接种在无植物生长调节剂的RE培养基上, 萌发率可达90%以上。将萌发的种子转接在RE＋0.2 mg·L-1 NAA＋0.2 mg·L-1 6-BA＋5 g·L-1椰粉＋2 g·L-1水解酪蛋白的培养基上可诱导原球茎大量增殖。最适壮苗生根培养基为RE＋0.6 mg·L-1 NAA＋0.2 mg·L-1 6-BA＋80 g·L-1香蕉泥, 生根率100%。试管苗移栽到直径0.3-1.7 cm的小号细树皮盆栽中, 成活率在95%以上, 试管苗栽培6个月后可分化花芽, 这为短距槽舌兰的产业化生产奠定了基础。     

Phylogeography and Domestication of Chinese Swamp Buffalo

To further probe into whether swamp buffaloes were domesticated once or multiple times in China, this survey examined the mitochondrial DNA (mtDNA) Control Region (D-loop) diversity of 471 individuals representing 22 populations of 455 Chinese swamp buffaloes and 16 river buffaloes. Phylogenetic analysis revealed that Chinese swamp buffaloes could be divided into two distinct lineages, A and B, which were defined previously. Of the two lineages, lineage A was predominant across all populations. For predominant lineage A, Southwestern buffalo populations possess the highest genetic diversity among the three hypothesized domestication centers (Southeastern, Central, and Southwestern China), suggesting Southwestern China as the most likely location for the domestication of lineage A. However, a complex pattern of diversity is detected for the lineage B, preventing the unambiguous pinpointing of the exact place of domestication center and suggesting the presence of a long-term, strong gene flow among swamp buffalo populations caused by extensive migrations of buffaloes and frequent human movements along the Yangtze River throughout history. Our current study suggests that Southwestern China is the most likely domestication center for lineage A, and may have been a primary center of swamp buffalo domestication. More archaeological and genetic evidence is needed to show the process of domestication.