scholarly journals Evaluation of diversity in Bulgarian pepper cultivars by agronomical traits and ISSR markers

Genetika ◽  
2017 ◽  
Vol 49 (2) ◽  
pp. 647-662 ◽  
Author(s):  
Stefan Tsonev ◽  
Velichka Todorova ◽  
Stanislava Groseva ◽  
Teodora Popova ◽  
Elena Todorovska

Information about the genetic variation among cultivars of vegetable crops is of vital importance for improvement of plant breeding programmes worldwide. The objectives of this study were to group 19 pepper (Capsicum annuum L.) cultivars from the collection of Maritsa Vegetable Crops Research Institute, Plovdiv, Bulgariainto clusters according to their distances as estimated by agronomic traits and 9 di-and tri -nucleotide inter simple sequence repeat polymorphism (ISSR) markers and to assess the relationships between them. The phenotypic characterization during 3 consecutive years revealed significant differences among Bulgarian cultivars for the studied 13 phenotypic traits. The biplot analysis of quantitative traits showed that the most strongly correlating traits with the first axis (55.6% of variance) were fruit width, fruit weight and pericarp thickness (in the negative direction of the axis), and plant height (PH) (in the positive direction). The most discriminative traits, considering the second axis (22.6% of variance) were fruit length (FL) and to a lesser extent the stem height (StH). The correspondence analysis of the qualitative traits showed that the intensity of the colour of the fruit (before and at maturity), fruit colourbefore maturity and fruit shape in longitudinal section were the most discriminative characteristics for the first two dimensions. The agronomic traits data and 7 dinucleotide ISSR primers were used to estimate the pairwise genetic distances. Higher mean phenotypic distance (0.414) in comparison to the genotypic ones (0.214) among the cultivars was observed, indicating higher phenotypic diversity among them. A highly signi?cant, positive correlation between the agronomic data and ISSR marker-based matrices (r=0.41, p=0.001)was detected. This indicates that ISSR distance tended to re?ect that of the agronomics ones. However, additional molecular studies and large collection of highly diverse genotypes are needed to reveal associations between the marker loci and specific QTLs. The research initiated is a base for more precise estimation of genetic distances between pepper genotypes from the available large collection of landraces, local and modern cultivars including large number of highly polymorphic markers.

Author(s):  
A.O. Oguntunji ◽  
K.L. Ayorinde

SummaryPhenotypic description helps in assessing the physical attributes of species and is also an indicator of the relevance and importance attached to such attributes in their natural environments. This study was conducted to describe patterns and distribution of phenotypic diversity in Nigerian Muscovy ducks. One thousand and twenty (1 020) adult male and female Muscovy ducks reared extensively were randomly drawn from the Rain Forest, Derived Savanna and Guinea Savanna agro-ecological zones/ecotypes and were visually appraised and scored for plumage, skin, shank, feet/web, bill, bean and caruncle colours. Data on qualitative traits were analysed with descriptive statistics (percentages) while fixed effect model was used to investigate relationship between plumage and skin colours and body weight. Results revealed variations in qualitative traits; however, across ecotypes, the predominant plumage, skin, shank, feet, bill, bean and caruncle colours were mottled (45 percent), white (88 percent), yellow (50 percent), yellow (60 percent), black (58 percent), black (69 percent) and red (84 percent), respectively. Besides, significant (P < 0.05) association was observed between plumage and skin colours and body weight. The reported variations in phenotypic traits of Nigerian Muscovy ducks indicate diversity in their genome, absence of selection and the need for their selection and improvement.


2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Jaewon Lim ◽  
Hong-Tae Park ◽  
Seyoung Ko ◽  
Hyun-Eui Park ◽  
Gyumin Lee ◽  
...  

AbstractMycobacterium avium subsp. paratuberculosis (MAP) is a causative agent of Johne’s disease, which is a chronic granulomatous enteropathy in ruminants. Determining the genetic diversity of MAP is necessary to understand the epidemiology and biology of MAP, as well as establishing disease control strategies. In the present study, whole genome-based alignment and comparative analysis were performed using 40 publicly available MAP genomes, including newly sequenced Korean isolates. First, whole genome-based alignment was employed to identify new genomic structures in MAP genomes. Second, the genomic diversity of the MAP population was described by pangenome analysis. A phylogenetic tree based on the core genome and pangenome showed that the MAP was differentiated into two major types (C- and S-type), which was in keeping with the findings of previous studies. However, B-type strains were discriminated from C-type strains. Finally, functional analysis of the pangenome was performed using three virulence factor databases (i.e., PATRIC, VFDB, and Victors) to predict the phenotypic diversity of MAP in terms of pathogenicity. Based on the results of the pangenome analysis, we developed a real-time PCR technique to distinguish among S-, B- and C-type strains. In conclusion, the results of our study suggest that the phenotypic differences between MAP strains can be explained by their genetic polymorphisms. These results may help to elucidate the diversity of MAP, extending from genomic features to phenotypic traits.


Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 656
Author(s):  
Evangelia Stavridou ◽  
Georgios Lagiotis ◽  
Parthena Kalaitzidou ◽  
Ioannis Grigoriadis ◽  
Irini Bosmali ◽  
...  

A selection of sesame (Sesamum indicum L.) landraces of different eco-geographical origin and breeding history have been characterized using 28 qualitative morpho-physiological descriptors and seven expressed sequence tag-simple sequence repeat (EST-SSR) markers coupled with a high-resolution melting (HRM) analysis. The most variable qualitative traits that could efficiently discriminate landraces, as revealed by the correlation analyses, were the plant growth type and position of the branches, leaf blade width, stem pubescence, flowering initiation, capsule traits and seed coat texture. The agglomerative hierarchical clustering analysis based on a dissimilarity matrix highlighted three main groups among the sesame landraces. An EST-SSR marker analysis revealed an average polymorphism information content (PIC) value of 0.82, which indicated that the selected markers were highly polymorphic. A principal coordinate analysis and dendrogram reconstruction based on the molecular data classified the sesame genotypes into four major clades. Both the morpho-physiological and molecular analyses showed that landraces from the same geographical origin were not always grouped in the same cluster, forming heterotic groups; however, clustering patterns were observed for the Greek landraces. The selective breeding of such traits could be employed to unlock the bottleneck of local phenotypic diversity and create new cultivars with desirable traits.


Weed Science ◽  
2021 ◽  
pp. 1-37
Author(s):  
Leonard Bonilla Piveta ◽  
José Alberto Noldin ◽  
Nilda Roma-Burgos ◽  
Vívian Ebeling Viana ◽  
Lariza Benedetti ◽  
...  

Abstract Weedy rice (Oryza sativa L.) is one of the most troublesome weeds affecting rice (Oryza sativa L.) production in many countries. Weedy rice control is difficult in rice fields because the weed and crop are phenotypically and morphologically similar. Weedy rice can be a source of genetic diversity to cultivated rice. Thus, this study aimed to characterize the morphological diversity of weedy rice in Southern Brazil. Qualitative and quantitative traits of 249 accessions from eight rice growing mesoregions in Rio Grande do Sul (RS) and Santa Catarina (SC) states were analyzed. For each accession, 24 morphological descriptors (14 qualitative and 10 quantitative) were evaluated. All the 249 accessions from RS and SC are of indica lineage. Considering all the phenotypic traits evaluated, the accessions separated into 14 distinct groups. One of the largest groups consisted of plants that were predominantly tall and with green leaves, intermediate shattering, and variable in flowering time. Distinct subgroups exist within larger clusters, showing discernable phenotypic diversity within the main clusters. The variability in flowering time was high (77 to 110 d after emergence), indicating high potential for flowering synchrony with rice cultivars and, consequently, gene flow. This indicates the need to remove escapes when planting herbicide-resistant rice. Thus, weedy rice populations in Southern Brazil are highly diverse and this diversity could result in variable response to weed management.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Massimo Vischi ◽  
Nicola Zorzin ◽  
Maria Bernhart ◽  
Johanna Winkler ◽  
Dipak Santra ◽  
...  

Abstract Background Global warming and issues in favour of a more sustainable agriculture suggest a reconsideration of minor cereals in European agrosystems. Compared to other summer crops, proso millet has a remarkable drought resistance and could be used to improve crop rotation and biodiversity. Proso millet is also increasingly sought by industry to produce novel foods such as those designed for coeliac patients. In this study, a thorough characterization of 11, commercially available, proso millet (Panicum miliaceum L.) varieties was carried out as a preliminary step for crop reintroduction and breeding in Western Europe. Methods The cultivars under evaluation were introduced from Austria, Poland, Russia, and the USA (University of Nebraska–Lincoln). Plants were grown at Udine (NE Italy) and Gleisdorf (Styria, Austria), under greenhouse and field conditions, respectively. Yield components and a range of morphophysiological characters were recorded in both locations. In parallel, 85 SSR markers were tested on DNA samples extracted from randomly chosen plants of each variety and the 12 responsive markers used to genotype the whole variety set. Results Morphometric analyses showed that varieties have several diverging phenotypic traits and architectures. In all instances, yields recorded at field level were much lower than potential yields. In this respect, US selections were comparable to earlier developed European varieties, suggesting that breeding for an increased adaptation is the keystone for a stable reintroduction of millet in Western Europe. Molecular analyses uncovered remarkably low genetic differences and heterozygosity levels within cultivars, confirming millet as an essentially autogamous species; in contrast, large genetic distances were noted among cultivars selected in different environments. Results of SSR genotyping combined with those originating from phenotypic analyses indicated possible crosses to source the genetic variability necessary for selection. Conclusions This study enabled the identification of cultivars that could be used to revitalize the crop in Western Europe and to produce genetically variable hybrid progenies exploitable by breeding.


Plant Disease ◽  
2013 ◽  
Vol 97 (7) ◽  
pp. 873-881 ◽  
Author(s):  
G. Danies ◽  
I. M. Small ◽  
K. Myers ◽  
R. Childers ◽  
W. E. Fry

Phytophthora infestans, the causal agent of late blight disease, has been reported in the United States and Canada since the mid-nineteenth century. Due to the lack of or very limited sexual reproduction, the populations of P. infestans in the United States are primarily reproducing asexually and, thus, show a simple genetic structure. The emergence of new clonal lineages of P. infestans (US-22, US-23, and US-24) responsible for the late blight epidemics in the northeastern region of the United States in the summers of 2009 and 2010 stimulated an investigation into phenotypic traits associated with these genotypes. Mating type, differences in sensitivity to mefenoxam, differences in pathogenicity on potato and tomato, and differences in rate of germination were studied for clonal lineages US-8, US-22, US-23, and US-24. Both A1 and A2 mating types were detected. Lineages US-22, US-23, and US-24 were generally sensitive to mefenoxam while US-8 was resistant. US-8 and US-24 were primarily pathogenic on potato while US-22 and US-23 were pathogenic on both potato and tomato. Indirect germination was favored at lower temperatures (5 and 10°C) whereas direct germination, though uncommon, was favored at higher temperatures (20 and 25°C). Sporangia of US-24 released zoospores more rapidly than did sporangia of US-22 and US-23. The association of characteristic phenotypic traits with genotype enables the prediction of phenotypic traits from rapid genotypic analyses for improved disease management.


2010 ◽  
Vol 10 (4) ◽  
pp. 305-311 ◽  
Author(s):  
Itamar Cristiano Nava ◽  
Ismael Tiago de Lima Duarte ◽  
Marcelo Teixeira Pacheco ◽  
Luiz Carlos Federizzi

Understanding the genetic control of phenotypic traits is essential to increase the efficiency of selection for adapted, high-yielding genotypes. The purpose of this study was to determine the genetic control of nine traits of hexaploid oat. Phenotypic data were collected from a population of 162 recombinant lines derived from the cross 'UFRGS17 x UFRGS 930598-6'. For the traits plant growth habit, hairs on leaf edges and panicle type, monogenic genetic control was observed. A quantitative and/or polygenic genetic control was stated for the traits panicle weight, panicle length, vegetative cycle, plant height, test weight and grain yield. High heritability was estimated for the traits vegetative cycle (h² = 0.89) and plant height (h² = 0.79), while moderate heritability was determined for test weight (h² = 0.51) and grain yield (h² = 0.48).


2014 ◽  
Vol 42 (2) ◽  
pp. 420-430
Author(s):  
Agnieszka GRADZIELEWSKA ◽  
Mirosław TYRKA ◽  
Justyna LESNIOWSKA-NOWAK ◽  
Justyna NAZARUK

In this study the genetic similarity among Dasypyrum, Secale andTriticum species with RAPDs and ISSRs was analyzed. To show a level of similarity between the species, 12 populations of Dasypyrum (11 D. villosum and 1 D. breviaristatum), together with 12 accessions belonging to 3 Secale species and 12 accessions from 4 Triticum species were used. Genetic distances (GD) and bootstrap values were calculated and PCA analysis was conducted to present the relationships among the species. To estimate the genetic structure among and inside genera, as well as population differentiation, gene diversity (He), total genetic variation (Ht) and Wright’s fixation index (Fst) were computed. The highest values were found in Triticum, within which Ht was equal to 0.332±0.023 and Fst was 0.42. It confirmed that the material studied was highly differentiated. Both systems found Dasypyrum more related with Triticum, as compared to Secale. With RAPDs, genetic distance (GD) between Triticum and Dasypyrum was 0.435, respectively 0.460 for Secale vs Dasypyrum. In the case of ISSRs these values were 0.374 and 0.407, respectively. Despite the fact that the difference between the two GD indices was insignificant, one should not exclude the possibility of successful hybridization of Dasypyrum and Secale, especially when using bridge species.


2018 ◽  
Vol 13 (11) ◽  
pp. 526-533 ◽  
Author(s):  
Chaves de Souza Silmara ◽  
Jaime Vasconcelos Cavalcanti Jose ◽  
Pierre Cordeiro Ramos Jean ◽  
Alves Isaías ◽  
Cavalcanti dos Santos Roseane ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Rongkui Han ◽  
Maria José Truco ◽  
Dean O. Lavelle ◽  
Richard W. Michelmore

Plants undergo profound physiological changes when transitioning from vegetative to reproductive growth. These changes affect crop production, as in the case of leafy vegetables. Lettuce is one of the most valuable leafy vegetable crops in the world. Past genetic studies have identified multiple quantitative trait loci (QTLs) that affect the timing of the floral transition in lettuce. Extensive functional molecular studies in the model organism Arabidopsis provide the opportunity to transfer knowledge to lettuce to explore the mechanisms through which genetic variations translate into changes in flowering time. In this review, we integrated results from past genetic and molecular studies for flowering time in lettuce with orthology and functional inference from Arabidopsis. This summarizes the basis for all known genetic variation underlying the phenotypic diversity of flowering time in lettuce and how the genetics of flowering time in lettuce projects onto the established pathways controlling flowering time in plants. This comprehensive overview reveals patterns across experiments as well as areas in need of further study. Our review also represents a resource for developing cultivars with delayed flowering time.


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