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2.
Studying molecular genetic relationships can substantially contribute to the understanding of the pathways of domestication of a species. Although an increasing number of molecular genetic studies have been performed on Lablab purpureus (hyacinth bean), many covered germplasm of restricted geographic origin or limited intra-specific systematic position. Integrating the molecular diversity found with phenotypic or morpho-agronomic diversity is also deficient. This investigation combines findings of eight molecular genetic studies that include about 400 accessions of both wild and cultivated germplasm, thus providing the largest assessment of diversity in Lablab purpureus to date. In particular, results from a recent molecular investigation (Robotham and Chapman 2015) are revisited and reinterpreted by integrating them with known phenotypic diversity. Wild accessions clearly fall into two types, with characteristic pods—2-seeded and 4-seeded. The large majority of cultivated types are more closely related to 4-seeded pod-types. Certain cultivated 2-seeded pod-type accessions from Ethiopia are genetically closer to wild 2-seeded pod-types. These two major phenotypes are reflected in two chloroplast DNA haplotypes A and B. Hence, two domestication events appear to exist in L. purpureus based on this combined data. No other geographic patterns of diversity, which might assist to trace the dispersal of L. purpureus, were found as cultivated accessions predominantly fell into 2-3 major groups. In all studies, the greatest genetic diversity was found in Africa, making Ethiopia one of the probable centers of domestication.  相似文献   

3.
In tropical savannas where soils are generally sandy and nutrient poor, organic farming associated with enhanced soil biological activity may result in increased nutrient availability. Therefore, legumes have been introduced in the humid savanna zone of Côte d’Ivoire, owing to their ability to fix atmospheric N and to continually supply soil with great quantity of organic materials in relatively short time. The main objective of this study was to assess the influence of two legume (Cajanus cajan and Lablab purpureus) cultivations on earthworm communities and P and N availability. Trials were carried out under farmers' field conditions; C. cajan was planted on savanna soils (trial 1) while L. purpureus was established on new Chromolaena odorata-dominated fallow soils (trial 2). Native vegetations were considered as controls. Changes in soil properties (earthworm abundance and diversity, microbial biomass carbon (MBC), and plant available P and N) were assessed using the biosequential sampling. After 1 year, both the legume stands showed a significantly higher density of earthworms, compared with the respective controls. This trend was linked to an increase in the abundance of the detritivores Dichogaster baeri Sciacchitano 1952 and Dichogaster saliens Beddard 1893, and the polyhumic Stuhlmannia zielae Omodeo 1963. Equally, legume had beneficial impacts on the average number of earthworm species, the Shannon–Weaver index of diversity and MBC in savanna (trial 1). Available P and ammonium significantly increased under both legume cultivations and were significantly and concurrently linked to litter quality and earthworm activities as shown by multiple regressions. As a result, legumes could improve nutrient availability in the sandy soils of central Côte d’Ivoire by positively affecting soil biological activity and this could bring farmers to cultivate crops on savanna lands.  相似文献   

4.
Drought is a major environmental factor hampering alfalfa productivity worldwide. Gene banks provide an array of trait diversity, frequently consisting of specific seed collection projects that focused on acquiring germplasm adapted to specific traits such as drought tolerance. These subsets provide a logical starting point to identify useful breeding resources. In the present study, we investigated the genetic diversity and evaluated 18 agronomic, physiological and quality traits associated with drought tolerance in a subset of 198 alfalfa accessions collected for their potential drought resistance. Significant differences were found among accessions for most of the traits evaluated. Water deficit significantly decreased biomass dry yield by 61.9% compared with well-watered control. A positive correlation was found between relative water content (RWC) and drought susceptible index, while negative correlations were found between RWC and leaf senescence (LS), and between RWC and canopy temperature (CT). Alfalfa accessions with high RWC showed relative lower yield reduction, cooler CT and delayed LS. Genetic variation for forage quality was also investigated and the correlation between agronomic and quality traits was analyzed. Biomass yield under drought was negatively correlated with total protein, relative feed value and relative forage quality, suggesting that the efforts to improve yield under drought tend to negatively affect forage quality. Therefore, maintaining forage quality should be considered for breeding alfalfa with drought resistance. Alfalfa accessions with high drought resistance scores and minimum loss of quality were identified in this study and can be used as genetic resources for developing alfalfa varieties with improved drought resistance and water use efficiency while maintaining forage quality.  相似文献   

5.
This study aimed to investigate the effect of inoculation with plant growth-promoting Rhizobium and Pseudomonas species on NaCl-affected maize. Two cultivars of maize (cv. Agaiti 2002 and cv. Av 4001) selected on the basis of their yield potential were grown in pots outdoors under natural conditions during July. Microorganisms were applied at seedling stage and salt stress was induced 21 days after sowing and maintained up to 50% flowering after 120 days of stress. The salt treatment caused a detrimental effect on growth and development of plants. Co-inoculation resulted in some positive adaptative responses of maize plants under salinity. The salt tolerance from inoculation was generally mediated by decreases in electrolyte leakage and in osmotic potential, an increase in osmoregulant (proline) production, maintenance of relative water content of leaves, and selective uptake of K ions. Generally, the microbial strain acted synergistically. However, under unstressed conditions, Rhizobium was more effective than Pseudomonas but under salt stress the favorable effect was observed even if some exceptions were also observed. The maize cv. Agaiti 2002 appeared to be more responsive to inoculation and was relatively less tolerant to salt compared to that of cv. Av 4001.  相似文献   

6.
Tepary bean is a highly abiotic stress tolerant orphan crop for which there has been limited research on its nutritional value and cooking characteristics. These are key aspects when considering the potential for broader adoption of tepary bean. Therefore, the goal of this study was to evaluate a large set of seed composition and cooking traits related to human nutrition using both landraces and breeding lines of domesticated tepary bean from replicated field trials and to compare the traits in tepary with those in common bean. Tepary bean showed reduced fat and ash concentration and higher sucrose concentration as compared to common bean. Of the twelve amino acids evaluated, only proline in one of the two trials was statistically different between the two species. There were statistically significant differences between tepary and common bean for the concentration of some elements in this study; however, the elemental concentrations fell within the range of those found for common bean in previous studies. The majority of tepary bean lines showed consistently short cooking times and a high percentage of seeds showed measurable water uptake, while some showed a hardshell trait (low water uptake) and longer cooking times. Principal component analysis on a subset of traits showed a distinct group of common beans and two tepary bean groups that were divided on the basis of several agronomic, cooking, and elemental composition traits. Tepary bean, as with other pulses, is a highly nutritious crop with the range of composition and cooking characteristics similar to those of common bean. The variability for seed composition and cooking traits found within tepary bean can be exploited for its improvement.  相似文献   

7.
Stylosanthes Sw. is considered one of the economically most important tropical forage legumes. The genus is essentially Neotropical, and Brazil, Venezuela and Mesoamerica are the main centres of species diversification. In view of its importance, an extensive review of Venezuelan Stylosanthes genetic resources was carried out. Firstly, the known natural distributions of all 11 species based on herbarium specimens were georeferenced and mapped and, by comparing them with information of germplasm (=seed) collection site distributions, for each species regions were identified which in terms of collecting and safeguarding genetic resources of Stylosanthes had not been explored yet. Secondly, the actual status of the Stylosanthes collection in Venezuela in terms of collected seed samples and available germplasm is discussed, as is the need for further explorations, including targeting ecologically important locations. Finally, the different Stylosanthes species in Venezuela are grouped according to their perceived agronomic value and potential as forage for animal production systems, and recommendations are given regarding research, collection and preservation needs. Overall, this study compiled baseline information for future considerations of an important genetic resource in Venezuela. The endangerment of the three endemic species, Stylosanthes falconensis Calles et Schultze-Kr., Stylosanthes sericeiceps S.F. Blake and Stylosanthes venezuelensis Calles et Schultze-Kr. should be a major concern and warrants priority considerations for preservation.  相似文献   

8.
This study was carried out to estimate the level of diversity existing within some common bean landraces still cultivated in Nebrodi mountains, North-western area of Sicily. The multidisciplinary approach adopted to reach this goal involved the characterisation of collected material through morphological, biochemical and molecular marker analyses. The nutritional quality of seeds was also investigated in view of the proposition of the best landraces as niche products. Results showed that those bean landraces retain a considerable level of heterogeneity. The use of both biochemical and molecular markers showed that all landraces clustered into two main groups, corresponding to the Andean and Mesoamerican gene pools. Our results suggest that the best strategy for preserving the diversity of common bean from a restricted area such as Nebrodi mountains, necessitates of a deep knowledge of germplasm to avoid the loss of precious genetic resources or, on the contrary, the safeguard of populations genetically redundant.  相似文献   

9.
Neglected and underutilized species often play a vital role in securing food and livestock feed, income generation and energy needs of rural populations. In spite of their great potential little attention has been given to these species. This increases the possibility of genetic erosion which would further restrict the survival strategies of people in rural areas. Ziziphus spina-christi is a plant species that has edible fruits and a number of other beneficial applications that include the use of leaves as fodder, branches for fencing, wood as fuel, for construction and furniture making, and the utilization of different parts e.g. Fruits, leaves, roots and bark in folk medicine. Moreover, the plant is adapted to dry and hot climates which make it suitable for cultivation in an environment characterized by increasing degradation of land and water resources. Lack of research in Z. spina-christi hinders its successful improvement and promotion. Therefore, studies are needed to fully exploit this species. This article aims at summarizing information on different aspects of Z. spina-christi to stimulate interest in this crop which is of importance in Sudan and other countries of the semi-arid tropics.
Amina Sirag SaiedEmail:
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10.
Calamintha nepeta and Micromeria thymifolia have been traditionally used in the Mediterranean area as condiments and medicinal plants for a long time. Whereas in parts of Italy C. nepeta (special recipes have been developed in Lazio and Tuscany) is also an established garden plant showing different evolutionary products and their interaction among each other and the wild progenitor, M. thymifolia is being developed into a new crop plant. Both plants and their uses are described with regard to Italy. There is a marked tendency to broaden the use of condiments and spices which results in new crop plants which have to be documented and elaborated in further studies. Many species of Labiatae are predisposed to use by man and new items can be found even in areas which have to be considered as well studied.  相似文献   

11.
Variation in response to climatic and edaphic factors has resulted in the geographic differentiation and specific adaptation of lentil germplasm to its environment. The germination of lentil seeds can be affected by waterlogging caused by relay sowing into standing rice crops. Consequently, there is a demand for waterlogging-adapted lentil genotypes, particularly at germination. This experimentation investigated the effects of waterlogging at germination on a germplasm collection. Firstly, two contrasting genotypes, ATC 70876 and Nugget, were waterlogged for six durations (0, 3, 6, 9, 14 and 21 days) in a pot soil system in the glasshouse. Six days of waterlogging was the duration for germination where genotypes showed the largest contrast in germination rate; therefore, this duration was applied to a larger number (127) of genotypes from 11 countries in a screening trial. Finally, all 127 genotypes were grown in pots in the open to phenotype morphological traits (seed size, above-ground biomass, time to flower and maturity). There was significant variation among genotypes, and those originating from Bangladesh had the highest germination at 21.2 %. The heritability of germination on waterlogged soil among genotypes was intermediate at H2 = 44.8 %. Correlations between morphological and physiological traits showed that the capability of seeds to germinate on waterlogged soil was negatively correlated to time to maturity (r = ?0.643). It was concluded that genotypes from Bangladesh are adapted to waterlogging at germination. With an intermediate heritability for germination under waterlogging conditions, selection for relay sowing through waterlogging tolerance at germination is practicable.  相似文献   

12.
Among 371 oat accessions from the world collection of the Vavilov Institute of Plant Genetic Resources (VIR) mostly represented by the landraces from Asia (Maritime Territory of Russian Federation, Mongolia, China, Japan, North Korea, India, Iran, Afghanistan, and Bhutan) ninety five were heterogeneous for resistance to the North Caucasus populations of the greenbug (Schizaphis graminum Rondani). Damage ratings of resistance in 47 accessions were high, low level of resistance was identified in 48 genotypes. Higher frequency of greenbug resistant accessions (60.5%) was found among landraces from Mongolia. Lines with high expression of the resistance were selected from seven landraces with wide range of damage ratings. North Caucasus populations of S. graminum from Krasnodar area and Dagestan significantly differ by the frequencies of virulence to host plant. Seven virulence phenotypes differentially interacting with oat genotypes were found in the Krasnodar population and 10 phenotypes were revealed in the Dagestan population. Results of the experiments with the greenbug test clones revealed that all the lines selected from the accessions VIR-2490, VIR-2539, VIR-4074, VIR-12213, VIR-12214 (Mongolia), VIR-6688 (India) and VIR-13624 (North Korea) are protected by diverse alleles of resistance genes which differ from the earlier identified gene Grb3. These lines are supposed to have aphid resistance genes nonidentical to the Grb1 and Grb2. The accessions VIR-6688, VIR-4074 and VIR-12214 possess high resistance to Krasnodar and Dagestan greenbug populations and the accession VIR-13624 is protected by the most effective gene (genes) of resistance to the both populations from North Caucasus.  相似文献   

13.
This study reports for the first time the presence of diazotrophic bacteria belonging to the genera Achromobacter and Zoogloea associated with wheat plants. These bacterial strains were identified by the analysis of 16S rDNA sequences. The bacterium IAC-AT-8 was identified as Azospirillum brasiliense, whereas isolates IAC-HT-11 and IAC-HT-12 were identified as Achromobacter insolitus and Zoogloea ramigera, respectively. A greenhouse experiment involving a non-sterilized soil was carried out with the aim to study the endophytic feature of these strains. After 40 days from inoculation, all the strains were in the inner of roots, but they were not detected in soil. In order to assess the location inside wheat plants, an experiment was conducted under axenic conditions. Fifteen days after inoculation, preparations of inoculated plants were observed by the scanning electron microscope, using the cryofracture technique, and by the transmission electron microscope. It was observed that all isolates were present on the external part of the roots and in the inner part at the elongation region, in cortex cells, but not in the endodermis or in the vascular bundle region. No colonizing bacterial cells were observed in wheat leaves.  相似文献   

14.
A total of 8117 suitable SSR-contaning ESTs were acquired by screening from a Malus EST database, among which dinudeotide SSRs were the most abundant repeat motif, within which, CT/TC followed by AG/GA were predominant. Based on the suitable sequences, we developed 147 SSR primer pairs, of which 94 pairs gave amplifications within the expected size range while 65 pairs were found to be polymorphic after a preliminary test. Eighteen primer pairs selected randomly were further used to assess genetic relationship among 20 Malus species or cultivars. As a result, these primers displayed high level of polymorphism with a mean of 6.94 alleles per locus and UPGMA cluster analysis grouped twenty Malus accessions into five groups at the similarity level of 0.6800 that were largely congruent to the traditional taxonomy. Subsequently, all of the 94 primer pairs were tested on four accessions of Pyrus to evaluate the transferability of the markers, and 40 of 72 functional SSRs produced polymorphic amplicons from which 8 SSR loci selected randomly were employed to analyze genetic diversity and relationship among a collection of Pyrus. The 8 primer pairs produced expected bands with the similar size in apples with an average of 7.375 alleles per locus. The observed heterozygosity of different loci ranged from 0.29 (MES96) to 0.83 (MES138), with a mean of 0.55 which is lower than 0.63 reported in genome-derived SSR marker analysis in Pyrus. The UPGMA dendrogram was similar to the previous results obtained by using RAPD and AFLP markers. Our results showed that these EST-SSR markers displayed reliable amplification and considerable polymorphism in both Malus and Pyrus, and will contribute to the knowledge of genetic study of Malus and genetically closed genera.  相似文献   

15.
Trigeneric hybrids may help establish evolutionary relationships among different genomes present in the same cellular-genetic background, and also offers the possibility to transfer different alien characters into cultivated wheat. In this study, a new trigeneric hybrid involving species from the Triticum, Psathyrostachys and Secale was synthesized by crossing wheat-P. huashanica amphiploid (PHW-SA) with wheat-S. cereale amphiploid (Zhongsi 828). The crossability of F1 hybrid was high with 35.13%, and the fertility was 41.95%. The morphological characteristics of F1 plants resembled the parent Zhongsi 828. The trigeneric hybrids pollen mother cells (PMCs) regularly revealed averagely 19.88 univalents, 9.63 ring bivalents, 3.97 rod bivalents, 0.60 trivalents and 0.03 tetravalents per cell. Multivalents consisted of trivalents and tetravalents can be observed in 52.7% of cells. A variation of abnormal lagging chromosome, micronuclei and chromosome bridge were formed at anaphase I and telophase II. The mean chromosomes number of F2 progenies was 2n = 46.13, and the distribution range was 42–53. GISH results revealed that most F2 plants had 6–12 S. cereale chromosomes, and only 0–2 P. huashanica chromosomes were detected. The results indicated that S. cereale chromosomes can be preferentially transmitted in the F2 progenies of trigeneric hybrid than P. huashanica chromosomes. A survey of disease resistances revealed that the stripe rust resistance from the PHW-SA were completely expressed in the F1 and some F2 plants. The trigeneric hybrid could be a useful bridge for the transference of P. huashanica and S. cereale chromatins to common wheat.  相似文献   

16.
Paracetamol, the most widely and globally used analgesic and antipyretic, is easily accumulated in aquatic environments. In the present study, the biodegradation of paracetamol in different media (one for general growth, one specific for sulfate reducing bacteria, a mineral salts medium and municipal wastewater) inoculated with two types of sludge (from anaerobic lagoon and from oxidation ditch) under different oxygenic conditions (anoxic; moderate oxygenation in open flasks and high oxygenation by aeration) was investigated. In addition, bacteria with relative abundances increasing simultaneously with paracetamol degradation, when this drug was the only carbon source, thus with a putative role in its degradation, were identified using 16S rRNA gene sequences. The results show that aerobic microorganisms had a major role in the degradation of paracetamol, with 50 mg/L totally removed from municipal wastewater after 2 days incubation with aeration, and that the metabolites 4-aminophenol and hydroquinone plus one compound not identified in this work were produced in the process. The identification of bacteria with a role in the degradation of paracetamol revealed a strain from genus Pseudomonas with the highest final relative abundance of 21.2%, confirming previous works reporting strains of this genus as paracetamol decomposers. Besides, genera Flavobacterium, Dokdonella and Methylophilus were also in evidence, with initial relative abundances of 1.66%, 1.48 and 0.00% (not detected) in the inoculum and 6.91%, 3.80 and 3.83% after incubation, respectively. Therefore, a putative role of these genera in paracetamol biodegradation is suggested for the first time.
Graphical Abstract ?
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17.

Purpose  

Few studies have been conducted to evaluate the effects of mixtures of chemicals in terrestrial environment. Thus, it seems important to evaluate if the combined application of pesticides currently used in agricultural fields may pose a risk to terrestrial plants.  相似文献   

18.
The karyomorphology for eight diploid species of Arachis belonging to three sections has been described for the first time, Sect. Extranervosae: A. macedoi (2n = 20m) and A. retusa (2n = 14m + 6sm); Sect. Heteranthae: A. sylvestris (2n = 16m + 4sm); Sect. Procumbentes: A. chiquitana (2n = 18m + 2sm); Sect. Arachis: A. cruziana (2n = 18m + 2sm), A. herzogii (2n = 18m + 2sm), A. simpsonii (2n = 20m) and A. williamsii (2n = 20m). A pair of satellited chromosomes was observed in all species. A chromosomes were found in A. chiquitana, A. herzogii and A. simpsonii. Karyotypic differences between sections were observed, but not enough to establish a characteristic karyotype pattern for each section. However, the species may be differentiated by the presence of A chromosomes, the type and position of satellites, and the karyotype formulae. These results are discussed with regard to karyotype evolution in Arachis to contribute to understanding the role of chromosome changes in the evolution of the genus.  相似文献   

19.
V. rhomboidea is a wild Vigna species that is a potential source of genes for pubescence which could be incorporated into cultivated cowpea for insect pests resistance. Due to the lack of reliable records on the crossability and gene pool relationships between V. rhomboidea and cowpea, crossing trials were conducted in the screenhouse to observe if V. rhomboidea is reciprocally crossable (compatible) with cowpea. Crossability of V. rhomboidea (as seed parent) with cowpea (as pollen parent) was, for the first time, successfully achieved at the rate of 5.7% from 1145 crosses. Reciprocal crosses with cowpea as seed parent and V. rhomboidea pollen parent gave an average of 22.6% pod set from 2299 crosses. It is concluded that V. rhomboidea is reciprocally compatible with cowpea. This implies that V. rhomboidea belongs to the primary gene pool of cowpea.  相似文献   

20.
In order to evaluate and compare the germplasm resources of wheat in Tibet, we analyzed the genetic diversity of 136 Triticum aestivum ssp. tibetanum Shao and 119 Tibetan wheat landraces (Triticum aestivum L.) by using Intron-Splice Junction (ISJ) primers. The results showed that polymorphism of PCR products were obtained by 33 primer combinations, which accounted for 11% of the 300 primer combinations produced by 26 ISJ primers. A total of 333 stable bands can be amplified from the T. aestivum ssp. tibetanum Shao and 243 bands were polymorphic, which accounted for 72.9% of the total bands. Tibetan wheat Landraces produced 316 stable bands, of which 197 bands were polymorphic. The polymorphic bands accounted for 62.34% of the total bands produced from Tibetan wheat landraces. The genetic diversity of T. aestivum ssp. tibetanum Shao was higher than that of Tibetan wheat landraces in Tibet, suggesting that T. aestivum ssp. tibetanum Shao can be used as important genetic resource for the breeding and genetic improvement of wheat in Tibet. Matrix (1, 0) was generated according to the presence or absence of the bands produced from a particular wheat accession. Clustering and principle coordinates analysis showed that T. aestivum ssp. tibetanum Shao and Tibetan wheat landraces were divided into two groups. We conclude that high polymorphisms produced by ISJ primers can reflect the genetic diversity between T. aestivum ssp. tibetanum Shao and Tibetan wheat landraces.  相似文献   

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