Systematics and taxonomic delimitation of vegetable,grain and weed amaranths: a morphological and biochemical approach

Amaranthus is a cosmopolitan genus comprising large number of species with many morphotypes cultivars/accessions having diversified morphological features. The species, morphotypes within Amaranthus are very closely related requiring microclassification even revision in present taxonomic status. Most of the works have been done employing grain Amaranthus and their putative ancestors applying morphological and molecular data. In present study along with morphological features, phenolic compounds (secondary metabolites), isozyme profile of acid phosphatase were applied to get comprehensive reflection of interrelationship and relative closeness among the species, morphotypes/accessions of few vegetable, grain and weed Amaranthus. Both the vegetable and grain Amaranthus are supposed to have originated from respective weed progenitor through occasional outcrossing and gradual domestication. The study strongly vouched the previous interpretations regarding interrelationship of grain Amaranthus and their derivation from their putative progenitor also showed clear separate clustering of vegetable and grain Amaranthus with their close relatives. A sharp congruence in cluster pattern was achieved between morphological dendrogram and cumulative dendrogram computed on morphological and biochemical parameters, which is a rare event in systematics.     

A multi-species assessment of genetic variability in Nigerian Amaranthus accessions: potential for improving intra- and interspecies hybridization breeding

Amaranthus yields could benefit from our growing understanding of the genetic variability within and among individual species of local germplasm collections. Thirty-seven Amaranthus accessions representing three different species were evaluated for seed yield and yield components across two seasons. The objectives were to characterize the genetic variability of seed yield and its components across species and determine relationships among seed yield and its components by phenotypic correlation. Significant differences (P < 0.01) existed for all the evaluated traits among the accessions. Characters such as seed yield, stem girth and leaf length showed higher heritability estimates in A. cruentus (14) than in A. hypochondriacus (12) and A. dubius (11) accessions. Seed yield was significantly and positively correlated with stem girth and thousand seed weight. However, it was significantly and negatively correlated with number of days to flowering, plant height, leaf number, number of branches. The clustering of the accessions, which was partially in agreement with species grouping, will help in the identification of diverse parents for use in the breeding program. Enormous amount of genetic variability found in seed yield and its components among Nigerian Amaranthus accessions will offer opportunity for grain and leaf yield improvement through breeding.     

Chinese Cornus officinalis: genetic resources, genetic diversity and core collection

Cornus officinalis is plant species that is widely used in traditional Chinese medicine. To help the efficient utilization and conservation of this species, the genetic diversity of 73 germplasm resources collected from Zhejiang, Henan and Shaanxi provinces in China were used in a primary core collection. The germplasm resources were classified nine types and the analysis of morphological traits and chemical components showed wide variations among the germplasm types. The primary core collection of C. officinalis was evaluated by using 18 inter-simple sequence repeat (ISSR) markers and a mini core collection was developed based on three strategies on construction of a core germplasm resources. The ISSR results showed that a total of 233 alleles were identified in these 73 accessions, the genetic diversity (P?=?91.02%, H?=?0.293, I?=?0.446) revealed with an average of 2 alleles per locus. The genetic diversity index analysis suggested that there is a great richness and uniqueness of genetic variation in this primary core collection. Cluster analysis by UPGMA and STRUCTURE placed the 73-germplasm resources into four linkage clusters. Almost all samples from one sampling location were clustered together. Compared to the RS and SW strategy, the LDSS strategy proved to be more representative in the core collection of C. officinalis. Finally, a mini core collections by LDSS, composed of 18 accessions (24.66% of the primary core collection), let more than 94.85% of polymorphic loci remained, 97.55% of the observed number of alleles and 99.28% of the effective number of alleles of the mini core collection, respectively. The Nei’s gene diversity and Shannon’s Information index of core collection were 0.294 and 0.443, respectively. Taken all together, the results indicated that mini core collections constructed by the LDSS strategy represented their primary core collections and provided a rational framework for intensive surveys of natural variation in C. officinalis genetic resources.     

Sampling variation in genetic resources of seed crops: a review

Summary The first explorations for the collection of genetic resources of crop plants took place in areas designated as centers of origin. Later, important characters were found to be present in areas other than those indicated by Vavilov. Hence collection missions were extended to cover other areas in addition to the centers of diversity with different ecogeography and agromorphological features. Collecting activities were aimed not only at providing germplasm for immediate use in breeding but also at conserving genetic variation for future contingencies. The analysis of the collected material has revealed the complex nature, amount and distribution of genetic variation present in natural populations as well as in landraces, old varieties and primitive forms. The study of variation for characters from different regions indicated that it is possible to select certain characters for detecting variability in the populations and establishing the minimum number of genotypes to be sampled. A minimum number of 20–130 plants per sample, depending on the crop, is recommended in order to capture 95% of the total variation in the field. However, it has been emphasized that the number of different populations sampled rather than the sample size per population determines the overall efficiency of a collection. The findings reported allow better utilization of the collected material and formulation of optimal and cost-effective sampling strategies for the future.     

The use of genetic resources in crop improvement: Lessons from China

The use of crop genetic resources in improvement programmes should be the ultimate objective of all undertakings in the field of germplasm resources. The present situation and future direction of the use of crop germplasm in China was assessed from responses to a questionnaire distributed to 165 plant breeders and curators nationwide. The general opinions for the limiting factors of germplasm utilization were also evaluated. Responses from the questionnaire indicated that the use of germplasm in breeding programmes is much more important than the direct use of germplasm in crop production as cultivars released. Among different types of crop genetic resources, released varieties and breeding lines contribute more to crop breeding. Wild relatives and genetic stocks, however, are expected to play a greater role in the future. Landraces will remain important in improvement. Limited useful germplasm available to breeders is the basic reason for the insufficient use of germplasm in crop breeding at present. The complex reasons which affect the availability of useful germplasm involve the research level, links between breeder and curator and others. To counter these, we propose some suggestions and measures which can be implemented in the near future.     

Malting enzyme activities, grain protein variation and yield potentials in the displaced genetic resources of barley landraces of Finland

Thirty-two unimproved landraces of barley ( Hordeum vulgare L.) based on single plant selections in SE Finland were studied. Some of the lines still had ancient features, e.g., rachis brittleness in the tip of the spike. The lines showed 17 different and 16 unique hordein patterns and three lines showed more than one pattern, suggesting heterozygosity, and six different residual grain protein patterns. The three enzyme activities (-amylase, -amylase and -glucanase) of grains germinated aseptically for 120 h were determined. The average activity levels were high compared with a standard of five global barleys and with those determined previously in wild barley (H. vulgare ssp. spontaneum (Koch) Archers et Graebn.) grown in Finland. The ssp. spontaneum sample of 257 accessions showed significantly (P<0.001) less variation in -amylase and significantly (P<0.001) lower mean activity of all three enzymes. The high variation of these chemotypes indicates great potential variation of possible use by breeders has been lost by the disappearance and displacement of local barleys with commercial cultivars since 1950 in Finland before which barley cultivation and adaptation to the local environment had occurred over more than 3000 years. Selection for currently preferable plant characteristics in the descendants of the cross of HA52 (a landrace selection) × Adorra discriminated the hordein pattern of HA52 not being directly selected. The best landraces outyield the standard cultivars especially when there was no lodging. Top yield and small grains appeared to be associated characteristics under the environmental selection pressure, conflicting with the man-made regulations of the EU.     

Chrysanthemum genetic resources and related genera of Chrysanthemum collected in China

Chrysanthemum is one of the most important and popular ornamentals over the world. Breeding of new pedigrees depends mainly on conventional crossing. Chrysanthemum genetic resources were categorized into three groups. Here we introduce the wild species and related genera of Chrysanthemum in order to extend the genetic resources that can be used for genetic improvement of chrysanthemums by hybridization. In the genus Chrysanthemum and closely related genera, there are many wild species that are able to cross successfully with modern chrysanthemums. These represent important genetic resources for introducing new characters into florist’s chrysanthemums. The genus Chrysanthemum consists of more than 40 species distributed mainly in East Asia. More than 20 species of Chrysanthemum are native to China. Unfortunately, little of this information has been published in western languages. In this paper, we also provide an overall review of the basic information of the wild species of we have collected in China in order to understand and exploit those genetic resources much better. We have collected about 17 wild species and studied their useful characters in the past several years. These species include C. oreastrum (Hance) Y. Ling, C. hypargyrum (Diels) Y. Ling et C. Shih, C. zawadskii (Herbert) Tzvelev, C. chanetii (H. Léveillé) C. Shih, C. naktongense (Nakai) Tzvelev, C. mongolicum (Y. Ling) Tzvelev, C. argyrophyllum (Y. Ling) Y. Ling et C. Shih, C. rhombifolium (Hemsley) Y. Ling, C. vestitum (Hemsley) Y. Ling, C. dichrum C. Shih, C. glabriusculum (W. W. Smith) C. Shih, C. indicum (Linnaeus) Des Moulin, C. lavandulifolium (Fischer ex Trautvetter) Kitamura, C. foliaceum G. F. Peng, Shih et S. Q. Zhang, C. nankingense (Handel-Mazzetti) X. D. Cui, C. potentilloides (Handel-Mazzetti) C. Shih and C. maximowiczii (Komarov) Tzvelev. In addition to this genus, we have collected some species of the related genera including Brachanthemum mongolicum Krascheninnikov, B. pulvinatum (Handel-Mazzetti) C. Shih, B. gobicum Krasch, Ajania fastigiata (C. Winkler) Poljakov, A. achilleoides (Turczaninow) Poljakov ex Grubov, A. khartensis (Dunn) C. Shih, A. fruticulosa (Ledebour) Poljakov, A. pallasiana (Fischer ex Besser) Poljakov, Phaeostigma salicifolia (Mattf.) Muld., Elachanthemum intricatum (Franchet)Y. Ling et Y. R. Ling and two endemic species of Opisthopappus including O. taihangensis (Ling) Shih and O. longilobus Shih in China.     

Microsatellite markers and genetic diversity assessment in Lolium temulentum

Lolium and Festuca are two important genera of cool-season forage and turf grasses worldwide. Lolium temulentum L. (darnel ryegrass) has been proposed as a model species for genomics studies of cool-season forage and turf grasses. A study with 41 darnel ryegrass, three tall fescue (Festuca arundinacea Schreb.), two tetraploid fescue (F. glaucescens), and two meadow fescue (F. pratensis) genotypes was initiated to (i) identify a set of microsatellite (simple sequence repeats) markers useful for L. temulentum L., and (ii) to utilize such markers for assessing the genetic variability of L. temulentum accessions collected from different geographical regions of the world. A total of 40 tall fescue (TF) EST-SSRs and 60 Festuca–Lolium (F × L) genomic SSRs were screened on a subset of eight genotypes. The selected 30 tall fescue EST-SSRs and 32 F × L genomic SSRs were used for further analysis of genotypes. The TF-EST- and the F × L genomic-SSRs identified 10.3 and 9.3 alleles per marker, respectively with an average polymorphic information content (PIC) value of 0.66. The phenogram based on 319 EST-SSR and 296 genomic SSR fragments, grouped L. temulentum accessions into three major clusters except for accession ABY-BA 8892.78. Lolium temulentum accession ABY-BA 8892.78 did not cluster with any other accession. The Festuca clusters were distantly related with darnel ryegrass clusters with a similarity coefficient of 0.26. The selected set of tall fescue EST- and F × L genomic SSRs were useful in assessing L. temulentum genetic diversity and could benefit the genetic improvement of members of the Festuca–Lolium complex.     

Soils and soil resources in the southern Far East and their assessment

Based on the Russian soil classification, the assessment of the soil cover and the reserves of arable lands was performed for the southern Far East taking into account its administrative division. Six groups of soils were distinguished according to their location, properties, and use. The rating of the arable lands was performed, and they were categorized in terms of erosion into strongly, moderately, and slightly eroded soils. The ecological state of the soils was considered according to their humus content, acidity, and the contents of available phosphorus and potassium.     

Evaluation of infant formula protein quality: comparison of in vitro with in vivo methods

Two-week protein efficiency ratio (2-wk PER), net protein ratio (NPR), calculated-protein efficiency ratio (C-PER), and discriminant computed-protein efficiency ratio (DC-PER) of milk- and soy-based infant formulas were compared to a 4-week protein efficiency ratio (PER). Expressed relative to ANRC casein, 2-week PER and NPR correlated significantly (P less than 0.01, r = 0.90) with PER. Although C-PER and DC-PER also correlated significantly (P less than 0.01) with PER, r = 0.71 and r = 0.87, respectively, these in vitro methods did not distinguish differences in protein quality among soy-based infant formulas. C-PER and DC-PER, as currently designed, are not applicable to the measurement of protein quality for all types of infant formulas.     

Delimitation of Amaranthus cruentus L. and Amaranthus caudatus L. using micromorphology and AFLP analysis: an application in germplasm identification

The ‘Morelos’ accessions of Amaranthus from Mexico demonstrate taxonomic ambiguity at the basic morphologic level. The main cause is the enormous morphological and genetic variation exhibited by the species in the genus. Although basic morphological criteria can be applied to herbarium specimens or germplasm collections for quick taxonomic identification, the morphological data alone can be misleading. To ascertain the taxonomic identity of the ‘Morelos’ accessions and their hypothesized species affiliation to Amaranthus caudatus or Amaranthus cruentus, we conducted a comparative analysis of phylogenetic relationships among these taxa/accessions using amplified fragment length polymorphism (AFLP) and micromorphology methods. Based on AFLP data, all the controversial ‘Morelos’ accessions can be consistently placed into a single A. cruentus species clade, which is clearly separated from the A. caudatus species clade. The AFLP-based phylogenetic relationship of ‘Morelos’ and delimitation of A. cruentus and A. caudatus are further supported by micromorphology, showing that the combination of these techniques can provide more reliable data for germplasm identification than each method used alone.     

Molecular genetic and chemical assessment of Rhizoma Curcumae in China

Rhizoma Curcumae (Ezhu) is a traditional Chinese medicine that has been used in removing blood stasis and alleviating pain for over a thousand years. Three species of Curcuma rhizomes are being used, which include Curcuma wenyujin, Curcuma phaeocaulis, and Curcuma kwangsiensis. In China, the production of Rhizoma Curcumae largely depends on agricultural farming. The essential oils are considered as active constituents in Rhizoma Curcumae, which include curdione, curcumol, and germacrone. On the basis of the yield of curdione, curcumol, and germacrone in an orthogonal array design, the optimized extraction condition was developed. The amounts of these compounds within essential oils in Rhizoma Curcumae varied according to different species and their regions of cultivation. Chemical fingerprints were generated from different species of Curcuma, which therefore could serve as identification markers. In molecular genetic identification of Rhizoma Curcumae, the 5S-rRNA spacer domains of 5 Curcuma species, including the common adulterants of this herb, were amplified, and their nucleotide sequences were determined. Diversity in DNA sequences among various species was found in their 5S-rRNA spacer domains. Thus, the chemical fingerprint together with the genetic distinction could serve as markers for quality control of Curcuma species.     

不同修复方式下土壤-稻谷中重金属含量特征及其评价

为探究不同修复方式对重金属污染土壤理化性质、土壤-稻谷中总Pb、总Cd、无机As含量的影响,2016年3月—11月以水稻品种"株两优819"为材料,以长沙县黄花镇某合作社的承包田为试验对象,设计6组不同修复方式,T1不做任何处理,T2施用生石灰,T3施用生石灰并进行优化水分管理,T4施用生石灰和楚戈土壤重金属调理剂并进行优化水分管理,T5施用生石灰和喷施叶面阻控剂并进行优化水分管理,T6施用生石灰和楚戈土壤重金属调理剂及叶面阻控剂并进行优化水分管理。运用地累积指数、潜在生态风险指数和危险指数法对土壤及其上生长的稻谷进行重金属污染评价。结果表明,T1~T6修复后土壤中的阳离子交换量、有机质及pH值与修复前相比均有变化,其中土壤中pH值增幅为0.033~1.017;T1~T6修复后土壤中的无机As含量增幅为0.072~1.481 mg/kg,而总Pb和总Cd含量均下降,降幅分别为0.481~3.133、0.038~0.113 mg/kg,且T4修复后土壤中的总Pb、总Cd含量下降最明显,分别下降了0.120、3.133mg/kg;T6修复后稻谷中的总Cd含量略低于国家二级标准,T1~T5修复后稻谷中的总Cd含量均超出国家二级标准,其中T1修复后稻谷中的总Cd含量超出国家二级标准4.5倍;T1~T6修复下稻谷的危险指数(hazard index,HI)顺序为T1T2T3T5T4T6,其中T6修复危险指数最小,说明多种修复方式的联合使用比单独种植低镉水稻品种修复效果好,更有利于研究区的稻谷安全与人体健康。     

The apple genetic resources in China: The wild species and their distributions, informative characteristics and utilisation

China is the centre of origin of the genus Malus Mill. About 80% of all species of the genus have areas in this country – among them 8 newly described ones. All species are encountered, their distribution within the provinces is listed and completed by characteristics and uses.     

Geographic distribution and genetic resources of Dactylis in Galicia (northwest Spain)

Three Dactylis glomerata subspecies can occur in Galicia (Spain): subsp. glomerata, subsp. izcoi and subsp. marina. The second includes diploid and tetraploid populations adapted to acid soils. The third subspecies comprises natural tetraploid populations mainly on sea cliffs, with high digestibility. Dactylis taxonomy is difficult due to the existence of different ploidy levels and to free hybridization at the tetraploid level. This difficulty increases in Galicia, where there is a rich flora with relics and hybrids. The advance of human technology makes necessary the collection of natural Dactylis resources. In this paper, Dactylis distribution in Galicia is described. Tetraploid populations from subsp. izcoi have a wider ecological range than diploids (Galician diploid). These diploids and the subsp. marina are more widespread than formerly recognized. Morphologically, subsp. glomerata and izcoi are more similar than hitherto reported. It is suggested that the subspecies are adapted ecotypes which hybridize. They are useful genetic resources for pasciculture on acid soils and agroforestry.     

Assessing genetic diversity in 23 early Polish oat cultivars based on molecular and morphological studies

In Poland oat breeding began at the late nineteenth century. During the World War II almost all of Polish breeding materials were lost, and then were replaced by German cultivars. The main aim of this paper was to show the level of genetic diversity of Polish oat cultivars which were bred before 1939. Simultaneously usefulness and informativeness of molecular and morphological methods were tested and compared. This study involved 23 cultivars, which were described by 25 morphological traits and three types of molecular markers (AFLP, ISSR and RAPD). Based on Dice coefficient, genetic distance between cultivars ranged from 0.17 to 0.44. The degree of morphological differentiation within the collection varied depending on trait. Nei’s genetic diversity for the combined results for the whole collection was equal to 0.202. Neither unweighted pair group method with arithmetic mean nor principal coordinate analysis showed any discrimination of cultivars according to breeding period and morphological trait. Part of morphological diversity has been preserved in the Polish early oat cultivars, do not exist anymore in contemporary cultivars, and also in landraces. The interest of breeders in early cultivars germplasm stored in genebank was and still is negligible. Breeding is confined to a few preferred by market morphotypes. So, it is very probable that the gene pools of early and contemporary cultivars could be separable.