Glucosinolates of wild and cultivated Brassica species

Major differences were found in the occurrence of glucosinolates in the leaves of different wild species of the Brassica oleracea (2n = 18) group. The distribution of glucosinolates supports the present classification with the exception of the inclusion of both Tunisian and Sardinian populations within B. insuloris. The results also support the hypothesis of a multiphyletic origin of cultivated forms of B. oleracea from a number of wild species. In contrast, wild populations of B. rapa had very similar glucosinolate contents. Wild populations had a considerably higher total glucosinolate content than cultivars which may limit their usefulness in breeding programmes.     

Calystegines in wild and cultivated Erythroxylum species

Calystegines were identified in the genus Erythroxylum for the first time. Erythroxylum novogranatense var. novogranatense, a species cultivated for cocaine production, contained 0.2% total calystegines in dry leaves. Forty six Erythroxylum herbarium species consisting mostly of leaf tissue were analysed for calystegines, and 38 were found positive. Calystegines were compared qualitatively and quantitatively between individual Erythroxylum species. Calystegines A(3) and B(2) were the major calystegines in most species. Total calystegine content reached up to 0.32% dry mass. The simultaneous occurrence of calystegines, cocaine, other alkaloids of a 3alpha-hydroxy- or 3beta-hydroxytropane structure together with nicotine supports the concept of common biosynthetic steps of these alkaloids in Erythroxylum. The present results are the basis for further investigations of the phylogenetic origin of tropane alkaloid biosynthesis in the taxonomically remote families Solanaceae and Erythroxylaceae.     

食用菌栽培种类野生种质的评价

我国是食用菌野生种质资源丰富的国家,目前已查明自然分布可栽培野生种类93种,分布于担子菌的33个属。我国人工栽培种类近70种（变种）,不同规模栽培有50种,商业规模栽培33种,分布于5目,12科,18属。与绿色植物的自养型光合作用合成有机物质相反,食用菌将植物光合作用合成的有机物分解,以体壁吸收方式摄取营养建造自身。这种生理特点的不同,导致其种质资源评价要求的不同。由于子实体形态相对于绿色植物简单,且易受环境条件的影响,常常导致以形态特征为主要依据进行分类鉴定陷入困境。另一方面,形态相似的多个可栽培近缘种在侧耳（Pleurotus）、木耳（Auricularia）、蜜环菌（Armillaria）等中广泛存在,完全靠形态特征进行分类鉴定就更加困难。因此,在食用菌可栽培种类野生种质评价中,ITS测序等成为获得菌种生物学种的常用鉴定技术。菌种的分离培养中常受到菌落形态相似真菌的污染,RAPD、ISSR或ITS测序等常用来进行菌种符合性鉴定。食用菌孢子传播的特点,使其分布地理区域广泛,地理区域的隔离产生种内的个体或群体间的差异,形成种群的多样性,常用拮抗反应进行营养亲和群（个体、菌株）的鉴定。不同区域气候和生态条件下的个体,长期的进化和对环境条件适应性的形成,导致可栽培利用的特点不同。栽培性状要通过栽培试验进行评价。栽培性状主要包括菌丝长速、温度反应、结实性、丰产性、抗性、商品形态和耐贮运性等。为了充分利用远缘优势,对于具可利用栽培性状的种质还需要与栽培菌株间的遗传距离分析,通常用生物化学和分子生物学方法进行。     

Restriction fragment variation in the nuclear and chloroplast genomes of cultivated and wild Sorghum bicolor

Summary Fifty-six accessions of cultivated and wild sorghum were surveyed for genetic diversity using 50 low-copy-number nuclear DNA sequence probes to detect restriction fragment length polymorphisms (RFLPs). These probes revealed greater genetic diversity in wild sorghum than in cultivated sorghum, including a larger number of alleles per locus and a greater portion of polymorphic loci in wild sorghum. In comparison to previously published isozyme analyses of the same accessions, RFLP analysis reveals a greater number of alleles per locus. Furthermore, many RFLP alleles have frequencies between 0.25–0.75, while the vast majority of isozyme alleles are either rare (< 0.25) or near fixation (> 0.75). Correlations between genetic and geographic distances among the accessions were stronger when calculated with RFLP than with isozyme data. Systematic relationships revealed by nuclear and chloroplast restriction site analysis indicate that cultivated sorghum is derived from the wild ssp. arundinaceum. The portion of the wild gene pool most genetically similar to the cultivars is from central-northeastern Africa. Previous published data also suggested that this is most likely the principal area of domestication of sorghum. Introgression between wild and cultivated sorghum was inferred from disconcordant relationships shown by nuclear and chloroplast DNA markers. Introgression apparently occurs infrequently enough that the crop and its wild relatives maintain distinct genetic constitutions.     

黄麻两个栽培种及其野生类型与三个近缘种的核型分析

本研究选取黄麻属（Corchorus）2个栽培品种及其4个野生类型和3个野生近缘种为材料,采用常规根尖压片法对黄麻属供试材料的染色体数目和核型进行研究。结果表明：染色体数目均为2n=14。核型公式分别为：宽叶长果（长果黄麻栽培种）2n=2x=14=14m(4SAT);南阳野生长果（长果黄麻野生类型）2n=2x=14=14m(2SAT);坦桑尼亚野生长果（长果黄麻野生类型）2n=2x=14=2M+12m;闽麻5号（圆果黄麻栽培种）2n=2x=14=12m+2sm;爱店野生圆果（圆果黄麻野生类型）2n=2x=14=14m ;廉江野生圆果（圆果黄麻野生类型） 2n=2x=14=4M+10m;假黄麻（黄麻属野生近缘种）2n=2x=14=2M+12m;假长果（黄麻属野生近缘种）2n=2x=14=2M+12m;甜麻（黄麻属野生近缘种）2n=2x=14=14m。其中除了宽叶长果核型分类为1B外,其他的都为1A型。本文还讨论了黄麻野生近缘种甜麻的分类学地位。     

Molecular characterisation of two novel starch granule proteins 1 in wild and cultivated diploid A genome wheat species

Starch synthase IIa, also known as starch granule protein 1 (SGP-1), plays a key role in amylopectin biosynthesis. The absence of SGP-1 in cereal grains is correlated to dramatic changes in the grains’ starch content, structure, and composition. An extensive investigation of starch granule proteins in this study revealed a polymorphism in the electrophoretic mobility of SGP-1 between two species of wheat, Triticum urartu and T. monococcum; this protein was, however, conserved among all other Triticum species that share the A genome inherited from their progenitor T. urartu. Two different electrophoretic profiles were identified: SGP-A1 proteins of T. urartu accessions had a SDS–PAGE mobility similar to those of tetraploid and hexaploid wheat species; conversely, SGP-A1 proteins of T. monococcum ssp. monococcum and ssp. boeoticum accessions showed a different electrophoretic mobility. The entire coding region of the two genes was isolated and sequenced in an attempt to explain the polymorphism identified. Several single nucleotide polymorphisms (SNPs) responsible for amino acid changes were identified, but no indel polymorphism was observed to explain the difference in electrophoretic mobility. Amylose content did not differ significantly among T. urartu, T. monococcum ssp. boeoticum and T. monococcum ssp. monococcum, except in one accession of the ssp. boeoticum. Conversely, several interspecific differences were observed in viscosity properties (investigated as viscosity profiles using a rapid visco analyzer—RVA profiles) of these cereal grains. T. monococcum ssp. boeoticum accessions had the lowest RVA profiles, T. urartu accessions had an intermediate RVA profile, whereas T. monococcum ssp. monococcum showed the highest RVA profile. These differences could be associated with the numerous amino acid and structural changes evident among the SGP-1 proteins.     

Georeferenced phylogenetic analysis of a global collection of wild and cultivated Citrullus species

The geographical origin of watermelon (Citrullus lanatus) remains debated. While a first hypothesis suggests the center of origin to be West Africa, where the endemic sister species C. mucosospermus thrives, a second hypothesis suggests northeastern Africa where the white‐fleshed Sudanese Kordophan melon is cultivated. In this study, we infer biogeographical and haplotype genealogy for C. lanatus, C. mucosospermus, C. amarus, and C. colocynthis using noncoding cpDNA sequences (trnT‐trnL and ndhF‐rpl32 regions) from a global collection of 135 accessions. In total, we identified 38 haplotypes in C. lanatus, C. mucosospermus, C. amarus, and C. colocynthis; of these, 21 were found in Africa and 17 appear endemic to the continent. The least diverse species was C. mucosospermus (5 haplotypes) and the most diverse was C. colocynthis (16 haplotypes). Some haplotypes of C. mucosospermus were nearly exclusive to West Africa, and C. lanatus and C. mucosospermus shared haplotypes that were distinct from those of both C. amarus and C. colocynthis. The results support previous findings that revealed C. mucosospermus to be the closest relative to C. lanatus (including subsp. cordophanus). West Africa, as a center of endemism of C. mucosospermus, is an area of interest in the search of the origin of C. lanatus. This calls for further historical and phylogeographical investigations and wider collection of samples in West and northeastern Africa.     

Population structure and diversity in cultivated and wild Luffa species

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Introgression of wild species into the cultivated strawberry using synthetic octoploids

Synthetic octoploids reresent one method of integrating wild species germplasm into the cultivated octoploid strawberry. Several strawberry genotypes derived from Guelph synthetic octopoloids and 3–4 generations of outcrossing were evaluted for horticultural performance. Pollen stainability of the genotypes was improved by outcrossing and selection and was not considered a limiting factor to yield. Yield and berry weight of the genotypes improved to a level where several genotypes had yields as good as, or greater than, the mean of the check cultivars. There was no significant difference in the yield of genotypes that were either three or four outcrosses removed from the synthetic octoploids. Some genotypes displayed an everbearing habit accompanied by poor runnering characteristics which may have contributed to their reduced yield in the second season. Synthetic octoploids are composed of a diversity of germplasms distinct from the cultivated octoploid. However, by carefully selecting parents for the outcrossing program and rigorous selection for important horticultural traits, it was possible to restore performance close to the elite level in as few as three generations.     

中国扁桃亚属四种野生扁桃的系统发育与物种分化

基于核基因ITS序列研究中国4种野生扁桃: 新疆野扁桃(Amygdalus ledebouriana)、蒙古扁桃(A. mongolica)、长柄扁桃(A. pedunculata)和西康扁桃(A. tangutica)的系统发育关系和物种分化, 为4种植物的遗传与演化研究提供数据支撑。利用单倍型网络和主坐标分析揭示单倍型的聚类关系; 利用最大似然树和贝叶斯系统树分析单倍型的系统发育关系; 利用R语言“ecospat”包分析4种扁桃的生态位分化及其环境驱动因子。4种扁桃ITS1-ITS4片段总长为634 bp, 鉴别出27个核苷酸变异位点, 共定义了28个单倍型。4种扁桃种间最小遗传距离均大于种内最大遗传距离, 种间存在显著的遗传分化。4种扁桃的单倍型聚为两支: 新疆野扁桃、蒙古扁桃和西康扁桃聚为一支, 长柄扁桃为另一支; 单倍型网络和主坐标分析揭示的单倍型聚类关系与系统树一致。西康扁桃与蒙古扁桃、与长柄扁桃之间均表现出了显著的生态位分化, 最暖月最高气温、年平均气温、最冷月最低气温和最暖季降水量是驱动物种生态位分化的关键因子。     

Genetic diversity of root anatomy in wild and cultivated Manihot species

An anatomical study of roots was conducted on two wild Manihot species, namely M. glaziovii and M. fortalezensis, and two cassava varieties, M. esculenta Crantz variety UnB 201 and M. esculenta variety UnB 122, to identify taxonomic differences in primary growth. Anatomical characters of cassava roots have been rarely investigated. Their study may help cassava breeders to identify varieties with economically important characters, such as tolerance to drought. We investigated tap and lateral adventitious roots of two specimens of each clone or species. Free-hand cross-sections of roots were drawn; these had been clarified with 20% sodium hypochlorite solution, stained with 1% safranin-alcian blue ethanolic solution, dehydrated in ethanol series and butyl acetate and mounted in synthetic resin. Anatomical differences among Manihot species and varieties were found in the epidermal and exodermal cell shape and wall thickness, content of cortical parenchyma, and number of xylem poles. Wall thickness of the epidermis and exodermis of tap root were similar in all species, while in the lateral root there were differences in cell shape and wall thickness. Epidermal cells with thick walls were found in the tap root of all species and in lateral roots of cassava varieties. This character is apparently associated with tolerance to drought and disease. The variation in the number of xylem poles of cassava varieties was larger (4-8) than in wild species (4-6), and appears to support the hybrid origin of cassava.     

Different regeneration potential of mesophyll protoplasts from cultivated and a wild species of tomato

Mesophyll protoplasts were isolated from leaves of three cultivars of Lycopersicon esculentum (L.) Mill., namely Hilda 72, Rutgers and Rentita, and from the wild tomato species Lycopersicon peruvianum (L.) Mill. Protoplasts from L. peruvianum divided and grew actively in a liquid medium according to Zapata et al. (1977), whereas protoplasts from the tomato cultivars Hilda 72 and Rutgers showed comparable rates for cell division only, when the content of major elements in this medium was reduced to one half of the original concentration and when mannitol as osmoticum was replaced by glucose. In Rentita protoplasts no cell division could be observed in about 15 different modifications of the five basic culture media tested. The morphogenetic potential of these tomato cells was assessed by comparing the root and shoot formation of protoplasts and of leaf explants. L. peruvianum exhibited the highest potential. Calli derived from protoplasts regenerated roots on Murastrige-Skoog agar containing 1 M benzylaminopurine (BAP) plus 10 M indole-3-acetic acid (IAA) and 0.1 M BAP plus 1 M IAA. Shoot formation occurred in the combinations of 10 M BAP with 0.1, 1.0, and 10 M IAA. Plantlets regenerated from the L. peruvianum calli could be grown in soil. No shoots or roots were regenerated from calli of Hilda 72 and Rutgers protoplasts in all combinations of BAP and IAA tested in the range from 0.1 M to 100 M, thus indicating the rather low morphogenetic potential of these protoplasts as compared to protoplasts from L. peruvianum leaves.Abbreviations BAP benzylaminopurine - IAA indole-acetic acid - TMV tobacco mosaic virus     

Identification of wild and cultivated Hordeum species using two-primer RAPD fragments

Random amplified polymorphic DNAs (RAPD) analysis has been adapted to assess the degree of RAPD polymorphism within the genus Hordeum to determine if this approach can distinguish wild and cultivated species. Nineteen wild and seven cultivated accessions were evaluated using 4 random 10-mer primers. The potential of the RAPD assay was further increased by combining two primers in a single polymerase chain reaction (PCR). RAPD fragments generated by two pairs of arbitrary 10-mer primers discriminated six wild species and one cultivated species by banding profiles. The size of the amplified DNA fragments ranged from 150 to 2300 base pairs. 33 %percent of the fragments were common to both wild and cultivated species; 67% were specific to either wild or cultivated species. The average difference in fragments was less within the species than among the species. By comparing RAPD fingerprints of wild and cultivated barley, markers were identified among the set of amplified DNA fragments which could be used to distinguish wild and cultivated Hordeum species. This revised version was published online in July 2006 with corrections to the Cover Date.     

Adaptation to chilling: photosynthetic characteristics of the cultivated tomato and a high altitude wild species

Abstract When tomato plants of the high-altitude species Lycopersicon hirsutum and of the cultivated Lycopersicon esculentum were grown at 24/18°C (day/night), the effects of temperature, photon flux density, and intercellular CO₂ concentration up to about 600 μl l^?1 on net CO₂ uptake were similar in the two species. Acclimation of these plants at 12/6°C (day/night) resulted, after 4 d or longer, in a similar downward shift of about 5°C in the optimum temperature for CO₂ uptake. However, in comparison with the cultivated species, the high-altitude plants achieved a higher rate of CO₂ uptake at saturating concentrations of intercellular CO₂, maintained a higher level of saturating-light CO₂ uptake rate at 10°C after exposure to chilling stress (10°C and photon flux density of 400 μmol m^?2s^?1 d and 5°C night) for 7–18 d, and displayed a better capacity for rapid recovery after prolonged stress. The greater capacity for CO₂ uptake observed in the high-altitude species during and after exposure to chilling stress was also reflected in its higher growth rate under those conditions compared with plants of L. esculentum. These advantages of the high-altitude species may partly explain its ability to survive and complete its life cycle under the environmental conditions prevailing in its natural habitat.     

Ribosomal gene spacer length variability in cultivated and wild rice species

Summary Restriction fragment length polymorphism of the rDNA spacer was studied in the genus Oryza using a cloned rice rDNA probe. One-hundred-five accessions, including 58 cultivated rice and 47 wild species with various genome types, were analysed. Seven size classes differing from one another by an increment of ca. 300 bp were observed amongst the Asiatic cultivated rice of the species O. sativa. A general tendency from a smaller spacer in the Japonica subtypes to longer ones in Indica is observed. Classification as Japonica or Indica on the basis of rDNA pattern generally agrees with classification based on isozyme patterns. In contrast, African rice of the species O. glaberrima does not display any rDNA size variation. When wild species are considered, extensive variation is observed, but the fragment sizes do not fall into regularly increasing size classes except for O. rufipogon and O. longistaminata. The variation is greater in these species than in the cultivated ones.     

Divergent regulation of terpenoid metabolism in the trichomes of wild and cultivated tomato species

The diversification of chemical production in glandular trichomes is important in the development of resistance against pathogens and pests in two species of tomato. We have used genetic and genomic approaches to uncover some of the biochemical and molecular mechanisms that underlie the divergence in trichome metabolism between the wild species Solanum habrochaites LA1777 and its cultivated relative, Solanum lycopersicum. LA1777 produces high amounts of insecticidal sesquiterpene carboxylic acids (SCAs), whereas cultivated tomatoes lack SCAs and are more susceptible to pests. We show that trichomes of the two species have nearly opposite terpenoid profiles, consisting mainly of monoterpenes and low levels of sesquiterpenes in S. lycopersicum and mainly of SCAs and very low monoterpene levels in LA1777. The accumulation patterns of these terpenoids are different during development, in contrast to the developmental expression profiles of terpenoid pathway genes, which are similar in the two species, but they do not correlate in either case with terpenoid accumulation. However, our data suggest that the accumulation of monoterpenes in S. lycopersicum and major sesquiterpenes in LA1777 are linked both genetically and biochemically. Metabolite analyses after targeted gene silencing, inhibitor treatments, and precursor feeding all show that sesquiterpene biosynthesis relies mainly on products from the plastidic 2-C-methyl-d-erythritol-4-phosphate pathway in LA1777 but less so in the cultivated species. Furthermore, two classes of sesquiterpenes produced by the wild species may be synthesized from distinct pools of precursors via cytosolic and plastidial cyclases. However, highly trichome-expressed sesquiterpene cyclase-like enzymes were ruled out as being involved in the production of major LA1777 sesquiterpenes.     

Molecular characterization and diversity of the Pina and Pinb genes in cultivated and wild diploid wheat

Grain hardness is one of the most important characteristics of wheat quality. Soft endosperm is associated with the presence of two proteins in the wild form, puroindoline a and b. The puroindoline genes and their derived proteins are present in the putative wheat diploid ancestors which are thought to be the donors of the A, B and D genomes in common and durum wheat. In this study, we investigated the variability of grain hardness in einkorn, along with the nucleotide diversity of Pina and Pinb genes in a collection of einkorn wheat and T. urartu, in addition to studying the neutrality and linkage disequilibrium of these genes. Various alleles were detected for Pina and Pinb genes including three novel alleles for the Pinb locus: Pinb-A ^m 1i, Pinb-A ^m 1j and Pinb-A ^m 1k. Some differences were found in grain hardness between the different genotypes. The neutrality test showed a different pattern of variation between the two Pin genes. The genetic analysis of a diploid wheat collection has demonstrated that these species are a potential source of novel puroindoline variants. Our data suggest that, although further studies must be carried out, these variants could be used to expand the range of grain texture in durum and common wheat, which would permit the development of new materials adapted to novel uses in the baking and pasta industry.     

Independent domestications of cultivated tree peonies from different wild peony species

An understanding of plant domestication history provides insights into general mechanisms of plant adaptation and diversification and can guide breeding programmes that aim to improve cultivated species. Cultivated tree peonies (genus Paeonia L.) are among the most popular ornamental plants in the world; yet, the history of their domestication is still unresolved. Here, we explored whether the domestication in China of historically cultivated peonies, that is, the common and flare cultivated tree peonies, was a single event or whether independent domestications occurred. We used 14 nuclear microsatellite markers and a comprehensive set of 553 tree peonies collected across China, including common tree peonies, flare tree peonies and the wild species or subspecies that are potential contributors to the cultivated tree peonies, that is, Paeonia rockii ssp. rockii, P. rockii ssp. atava, P. jishanensis and P. decomposita. Assignment methods, a principal component analysis and approximate Bayesian computations provided clear evidence for independent domestications of these common tree and flare tree peonies from two distinct and allopatric wild species, P. jishanensis and P. rockii ssp. atava, respectively. This study provides the first example of independent domestications of cultivated trees from distinct species and locations. This work also yields crucial insight into the history of domestication of one of the most popular woody ornamental plants. The cultivated peonies represent an interesting case of parallel and convergent evolution. The information obtained in this study will be valuable both for improving current tree peony breeding strategies and for understanding the mechanisms of domestication, diversification and adaptation in plants.