scholarly journals PHENETIC ANALYSIS OF POPULUS NIGRA, P. LAURIFOLIA AND P. × JRTYSCHENSIS IN NATURAL HYBRIDIZATION ZONE

2018 ◽  
Vol 22 (4) ◽  
pp. 468-475 ◽  
Author(s):  
A. V. Klimov ◽  
B. V. Proshkin
Keyword(s):  
River Basin ◽  
Population Differentiation ◽  
Leaf Blade ◽  
Sharp Decrease ◽  
Population Diversity ◽  
Population Variability ◽  
Natural Hybridization ◽  
Disjunct Distribution ◽  
F1 Hybrids ◽  
Poplar Trees

The wide spread of hybridization in the genus Populus, including spontaneous hybridization, caused by cultivars, requires studying the variability and inheritance of morphological traits by hybrids for initial tracking of these processes. The analysis of endogenous, intra- and inter-population variability was performed on 533 individual poplar trees in seven populations of P. nigra, seven populations of P. laurifolia and four populations of P. × jrtyschensis in the Tom river basin. On each specimen, 15 leaves from short mid-crown branches were collected to determine the shape of the leaf blade, the shape of its tip and base, as well as the branch morphotype. Some biometric indicators were proposed for geometric assessment of the leaf blade shapes of poplar species. The analysis showed that of all the traits examined only the leaf blade shape did not meet the criterion for “phene”, since it is usually represented by several forms in the crown of one and the same tree. In all the species studied, the level of their intra-population diversity was found to be much higher than the inter-population one. According to the increase of intra-population variability of qualitative traits, the taxa could be ranked as P. nigra < P. laurifolia < P. × jrtyschensis. The share of inter-population diversity differed among the species studied, accounting for 21.5% in P. laurifolia, 13.8% in P. nigra and 8.0% in P. × jrtyschensis. The P. laurifolia populations showed the greatest inter-population differentiation, most likely because of a disjunct distribution due to narrow specialization to the montane river environment. The lower differentiation in P. nigra is probably due to the facts that this species dominates the poplar stands of the Tom River basin; its populations are not fragmented and are linked by vast gene flow. In P. nigra, an increase in the diversity of qualitative characteristics and phenotypes was observed in populations confined to hybridization centers. Natural selection is most likely the factor governing the inter-population differentiation in P. × jrtyschensis, leading to the predominance of F1 hybrids in populations and hence to a sharp decrease in inter-population variability.

Natural hybridization between an outcrossing and a selfingPhlox (Polemoniaceae): The maternal species of F1 hybrids

1999 ◽  
Vol 218 (1-2) ◽  
pp. 153-158 ◽  
Author(s):  
Carolyn J. Ferguson ◽  
Donald A. Levin ◽  
Robert K. Jansen
Keyword(s):  
Natural Hybridization ◽  
F1 Hybrids

Morphology and fitness components of wild × crop F1 hybrids of Sorghum bicolor (L.) in Ethiopia: implications for survival and introgression of crop genes in the wild pool

2013 ◽  
Vol 11 (3) ◽  
pp. 196-205 ◽  
Author(s):  
Asfaw Adugna ◽  
Endashaw Bekele
Keyword(s):  
Risk Assessment ◽  
Natural Hybridization ◽  
Relative Fitness ◽  
F1 Hybrids ◽  
Transgenic Crop ◽  
Fitness Components ◽  
Crop Species ◽  
In The Wild ◽  
Sorghum Bicolor L ◽  
Made In

Natural hybridization between wild/weedy and crop species often results in rare hybrids, which can be more weedy and difficult to control. Moreover, the advent of transgenic crop plants raises questions of biosafety risk assessment on the consequences of rare hybrids with possible fitness enhancing genes on the environment. This study aimed at measuring the fitness components of wild–crop sorghum hybrids for various juvenile survival and adult morphological and fertility characters as part of the risk assessment of transgenic sorghum in Africa where the crop was believed to have first domesticated and serves as the major staple. Out of a pool of hybrids made in 2010 from 23 wild sorghum accessions and two released cultivated sorghum varieties using hand emasculation techniques, seven were selected for the field study of their fitness components in 2011. The study confirmed that crop–wild hybrids of sorghum are fertile. Two approaches were followed (relative fitness and mid-parent heterosis) which showed that most of the hybrids were as fit as their wild parents, and in some cases they showed mid-parent heterosis for the measured traits. The results of this study highlighted a potential risk that hybrids carrying crop genes (including herbicide resistance transgenes) could pose because they could be more weedy than their wild/weedy parents if transgenic sorghum is deployed in regions where the wild and cultivated sorghum populations coexist, such as in Ethiopia and in other parts of Africa.

Contrasting Success of Natural Hybridization in Two Eucalyptus Species Pairs

1980 ◽  
Vol 28 (2) ◽  
pp. 167 ◽  
Author(s):  
DW Drake
Keyword(s):  
Principal Component ◽  
Flowering Phenology ◽  
Natural Hybridization ◽  
F1 Hybrids ◽  
Hybrid Population ◽  
Eucalyptus Species ◽  
Major Barrier ◽  
Species Pairs ◽  
Plant Hybridization ◽  
Hybrid Number

A morphological study with univariate and principal component analyses of mature tree and open-pollinated seedling populations shows that natural hybridization is occurring between Eucalyptus melanophloia and E. crebra, and E. populnea and E. crebra (subgenus Symphyomyrtus, section Adnataria). The level of successful hybridization in these two systems, where fundamental genetic (reproductive) and ecological (habitat and spatial) barriers are absent, is examined. Within the ecotone, hybrids between E. melanophloia and E. crebra are about one-fifth as frequent as those between E. populnea and E. crebra. Analyses of the phenotype/genotype compositions of the hybrid populations, the patterns of segregation, and outcrossing frequencies between the species pairs indicate the level of development of the hybrid populations. All E. melanophloia × E. crebra hybrids appear to be F1 hybrids. In contrast, the E.populnea x E. crebra hybrid population attains a much higher level of development in terms of both hybrid number and genotypic complexity. Flowering phenology is a major barrier to E. melanophloia × E. crebra hybrid formation compared with the other hybrids, although it is considered an incomplete barrier and alone may not explain the diversity of hybrid success which occurs.A theory of plant hybridization which incorporates the concept of hybridization success is presented and discussed in relation to the two hybridizing systems, as a basis for further investigating the mechanisms involved.

scholarly journals Selection and evaluation the corn lines from multiple-cross progeny based on targeted selection environment on acid soil

2021 ◽  
Vol 911 (1) ◽  
pp. 012016
Author(s):  
A Nur ◽  
M Riadi ◽  
A Yassi ◽  
M Farid ◽  
M F Anshori ◽  
...  
Keyword(s):  
Acid Soil ◽  
Block Design ◽  
Population Diversity ◽  
F1 Hybrids ◽  
South Sulawesi ◽  
Randomized Block Design ◽  
Multiple Cross ◽  
Acid Tolerant ◽  
Block Based ◽  
Augmented Design

Abstract Development of tolerant variety can be conducted in the targeted area. It will increase efficiency in producing the acid-tolerant lines. However, the availability of diversity is key in selection. Multiple crosses or crosses between F1 hybrids can be one approach in creating high population diversity. Therefore, the development and selection of offspring of the selfing 1 generation from a cross of two hybrids can be a solution in producing tolerant lines. This study aimed to select multiple-cross maize lines in the generation S1 in an acidic environment. The research was carried out from August to November 2019 at the Maros Cereal Research Center, South Sulawesi. This study was designed with an Augmented Design as an experimental design and a randomized block design as an environmental design. The lines used consisted of 100 S1 lines from crosses of NK7328/HJ28 that did not repeat and six comparison varieties, namely NK7328, HJ28, Sukmaraga, Srikandi Kuning, Bima-9, and Piooner 36 repeated in each block. Based on the results of this study, the evaluation of maize S1 lines under acid soil showed a good variability, especially on generative traits. The ear weight is the best secondary character supported the Grain weight per Ear as the main character. The result of selection showed that 20 S1 lines recommended to selfing cross for continued on the next generation.

scholarly journals Natural hybridization between two butterfly bushes in Tibet: dominance of F1 hybrids promotes strong reproductive isolation

2021 ◽  
Author(s):  
Rongli Liao ◽  
Weibang Sun ◽  
Yongpeng Ma
Keyword(s):  
Morphological Characters ◽  
Natural Hybridization ◽  
Hybrid Origin ◽  
F1 Hybrids ◽  
Sympatric Populations ◽  
Intergenic Spacers ◽  
Typical Distribution ◽  
Hybridization Origin ◽  
Butterfly Bush ◽  
Disturbed Habitats

Abstract Background: It has been recognized that certain amount of habitat disturbance is a prerequisite for occurrence of natural hybridization, yet we are currently still not aware of any studies exploring hybridization and reproductive barriers to those plants preferably occupying disturbed habitats. Buddleja plants (also called butterfly bush) generally grow in disturbed habitat, and several species with hybrid origin only on basis of morphology evidence have been proposed. Results: In the present study, we test the natural hybridization origin hypothesis of B. × wardii in two sympatric populations of three taxa including B. × wardii and its parents (B. alternifolia and B. crispa) plus 4 referenced parental populations, using four nuclear genes and three chloroplast intergenic spacers, as well as with 10 morphological characters. Our results suggest that at both sites B. × wardii was likely to be hybrids between B. alternifolia and B. crispa, and moreover, most of the hybrids examined were confirmed to be F1s. This was further supported by morphology as no transgressive characters were detected. B. crispa was found to be the maternal parent in Bahe (BH) population from the cpDNA. While in the Taji (TJ) population was difficult to distinguish the hybridization direction due to the shared haplotypes of cpDNA between B. alternifolia and B. crispa, we still predicted the similar unidirectional hybridization pattern due to results from cross-specific pollination treatments which supported the “SI x SC rule”. Conclusions: Hybrids mainly consisting of F1s can successfully impede gene flow and thus maintain species boundaries of parental species in its typical distribution of Buddleja, i.e. disturbed habitats.

scholarly journals Assessment the impacts of climate change on drought in the Ba River basin, Central Vietnam using Landsat remote sensing data

2022 ◽  
Vol 964 (1) ◽  
pp. 012006
Author(s):  
Han T N Tham ◽  
Thy T M Pham ◽  
Thi N K Truong ◽  
Huong T T Nguyen ◽  
Nguyen D Lam ◽  
...  
Keyword(s):  
Climate Change ◽  
Remote Sensing ◽  
River Basin ◽  
El Niño ◽  
Agricultural Land ◽  
El Nino ◽  
Sharp Decrease ◽  
Forest Area ◽  
Central Vietnam ◽  
Impacts Of Climate Change

Abstract Sustainable management of the river basin is a profound challenge for environmental management in the context of climate change. Drought situations in a basin occur in relation to meteorological, hydrological, agricultural factors and climate change as well. In this study, remote sensing technology was applied to assess the impacts of climate change on drought in the Ba River basin, Central Vietnam. Drought in the basin has been created by land use/land cover changes in recent years, which has resulted in a sharp decrease in forest area in the period 1989 to 2019 (-41.5%) and a significant increase of agricultural land with 38.2%. Following that, the area of drought agriculture rose by 28.8%. The remarkably high drought areas in agricultural land were in El Nino years, 2016 (99.2%) and 2019 (87.3%), which indicated that under climate change impacts, a drought occurred more severely. Moreover, drought also appeared in the forest. The forest area deceased but the drought levels in the forest increased slightly since 2005 and hit a peak drought value in 2016 with 97.0% of forest area. During El Niño years, the precipitation, atmospheric moisture, and water flow in the basin were all lower than in previous years.

Comparative growth response in Carduus nutans, C. acanthoides, and their F1 hybrids

1990 ◽  
Vol 68 (8) ◽  
pp. 1675-1679 ◽  
Author(s):  
S. I. Warwick ◽  
B. K. Thompson ◽  
L. D. Black
Keyword(s):  
Growth Response ◽  
Parental Species ◽  
Diploid Species ◽  
Dry Weight ◽  
Natural Hybridization ◽  
F1 Hybrids ◽  
Soil Conditions ◽  
Hybrid Superiority ◽  
Test Models ◽  
Better Than

The growth response of F1 hybrids relative to parental genotypes was compared in a natural hybridization system involving the diploid species Carduus acanthoides L. (2n = 22) and C. nutans L. (2n = 16). The data were used to test models of hybrid intermediacy, superiority, or greater similarity to a single parent in response to variable soil conditions and intra- and inter-genotypic competition. Progeny from paired reciprocal crosses between the two species were used in the experiments. In each of the half-sib families produced, the rapid and early identification of F1 hybrid genotypes and parental genotypes (resulting from selfing) was confirmed using allozyme markers (Pgi-2, Tpi-1, and Tpi-2). Growth of the F1 hybrids was better than C. nutans in poor soil, and both F1 hybrid and C. nutans genotypes produced significantly more dry weight than C. acanthoides in all soil treatments. F1 hybrids grew at least as well as the maternal parental species C. nutans and significantly better than C. acanthoides in the presence of intra- and inter-genotypic competitors. The F1 hybrid genotypes formed a more aggressive competitive environment than C. nutans, as evidenced by the growth of all three genotypes. These data primarily supported the model of greater hybrid similarity to one parental species rather than hybrid intermediacy, with evidence of hybrid superiority under certain extreme conditions.

Genetic evidence of natural hybridization between Podarcis sicula and Podarcis tiliguerta (Reptilia: Lacertidae)

2002 ◽  
Vol 23 (3) ◽  
pp. 313-321 ◽  
Author(s):  
Massimo Capula
Keyword(s):  
Habitat Disturbance ◽  
Genetic Evidence ◽  
Natural Hybridization ◽  
F1 Hybrids ◽  
Parent Species ◽  
Podarcis Sicula

AbstractAn allozyme survey revealed instances of natural hybridization between Podarcis sicula and P. tiliguerta from a locality of southern Sardinia. Pure specimens of both species together with some F1 hybrids were found, but no evidence of backcrossing was detected. The hybrid specimens appeared morphologically intermediate between the parent species. The absence of backcrossed individuals indicate that free interbreeding between the two species is unlikely. Hybrids were found in areas of habitat disturbance only.

Restoration of fish passage: development and results of a master plan established for the Ruhr river basin

2005 ◽  
Vol 52 (9) ◽  
pp. 77-84 ◽  
Author(s):  
M. Weyand ◽  
M. Redeker ◽  
E.A. Nusch
Keyword(s):  
Surface Water ◽  
River Basin ◽  
Ecological Status ◽  
Fish Passage ◽  
Ecological Condition ◽  
Population Diversity ◽  
Water Bodies ◽  
Suitable Habitat ◽  
Master Plan ◽  
River Continuum

According to the central aim of the European Water Framework Directive, the protection and sustained management of the aquatic ecological system, the ecological condition of a specific type of water, will be the primary parameter in future. Aiming at good ecological status in surface water bodies, population diversity and abundance of fish and macroinvertebrates is decisive. Free passage in river systems, to allow the natural migration of fish and all other aquatic organisms, is a prerequisite. To achieve this for the Ruhr River Basin a study has been commissioned in order to develop a master plan for river continuum restoration. Sustainable development aimed at promoting biodiversity in the surface water body system is a key objective. This project is complemented by investigations of the sediment – which is the nursery of the fish – in the rivers to identify river sections or tributaries which obviously provide a suitable habitat for the successful reproduction of big Salmonidae. The master plan illustrates the inherent problems of projects aimed at the restoration of fish passage in water bodies which are strongly affected by anthropogenic modifications. The results obtained may as well be transferred to other catchments with similar use patterns.

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