Giant otter Pteronura brasiliensis breeding programmes: challenges and current developments

2020 ◽  
Vol 54 (1) ◽  
pp. 72-79
Author(s):  
T. F. Schikora
Keyword(s):  
Breeding Programmes ◽  
Pteronura Brasiliensis

PROFILING OF GUAVA GENOTYPES GROWN IN VIDARBHA CONDITIONS ON THE BASIS OF MORPHOLOGICAL TRAITS

2017 ◽  
Vol 23 (1) ◽  
Author(s):  
R.A. PATIL ◽  
S.G. BHARAD ◽  
S.N. SAWANT
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Morphological Traits ◽  
Considerable Extent ◽  
Fruit Traits ◽  
Breeding Programmes ◽  
Tree Leaf ◽  
Qualitative Characteristics ◽  
Intrapopulation Diversity

Assessment of genetic diversity in the available germplasm is the prerequisite for development of improved genotypes through planned breeding programmes. In the view of this Forty-eight genotypes of seedling origin guava along with 1 check (L-49/Sardar) collected and conserved at germplasm block, Main Garden, Department of Horticulture, Dr. P. D. A. University, Akola were evaluated for genetic variability and diversity based on the qualitative characteristics. The genotypes were evaluated for sixteen morphological traitsviz. tree, leaf, floral and fruit traits. Results Show considerable extent of variability amongst the 49 genotypes in each traits. A sizeable amount of intrapopulation diversity recorded can be used to identify diverse parents which can be utilized in hybridization programmes.

Hybrid maize breeding with doubled haploids: Comparison between selection criteria

2006 ◽  
Vol 54 (3) ◽  
pp. 343-350 ◽  
Author(s):  
C. F. H. Longin ◽  
H. F. Utz ◽  
A. E. Melchinger ◽  
J.C. Reif
Keyword(s):  
Selection Criteria ◽  
Doubled Haploids ◽  
Optimum Allocation ◽  
Finite Sample ◽  
Sample Sizes ◽  
Maize Breeding ◽  
Selection Gain ◽  
Breeding Programmes ◽  
Hybrid Maize ◽  
Breeding Resources

The optimum allocation of breeding resources is crucial for the efficiency of breeding programmes. The objectives were to (i) compare selection gain ΔGk for finite and infinite sample sizes, (ii) compare ΔGk and the probability of identifying superior hybrids (Pk), and (iii) determine the optimum allocation of the number of hybrids and test locations in hybrid maize breeding using doubled haploids. Infinite compared to finite sample sizes led to almost identical optimum allocation of test resources, but to an inflation of ΔGk. This inflation decreased as the budget and the number of finally selected hybrids increased. A reasonable Pk was reached for hybrids belonging to the q = 1% best of the population. The optimum allocations for Pk(q) and ΔGkwere similar, indicating that Pk(q) is promising for optimizing breeding programmes.

Improvement of effectiveness in maize breeding

2006 ◽  
Vol 54 (3) ◽  
pp. 351-358 ◽  
Author(s):  
P. Pepó
Keyword(s):  
Recurrent Selection ◽  
Genetic Manipulation ◽  
Field Testing ◽  
Tissue Cultures ◽  
Maize Breeding ◽  
Breeding Programmes ◽  
Speed Up ◽  
Selection For

Plant regeneration via tissue culture is becoming increasingly more common in monocots such as maize (Zea mays L.). Pollen (gametophytic) selection for resistance to aflatoxin in maize can greatly facilitate recurrent selection and the screening of germplasm for resistance at much less cost and in a shorter time than field testing. In vivo and in vitro techniques have been integrated in maize breeding programmes to obtain desirable agronomic attributes, enhance the genes responsible for them and speed up the breeding process. The efficiency of anther and tissue cultures in maize and wheat has reached the stage where they can be used in breeding programmes to some extent and many new cultivars produced by genetic manipulation have now reached the market.

Doubled haploid production in maize under Sub-montane Himalayan conditions using R1-nj-based haploid inducer TAILP1

2020 ◽  
Vol 80 (03) ◽  
Author(s):  
R. K Khulbe ◽  
A. Pattanayak ◽  
Lakshmi Kant ◽  
G. S. Bisht ◽  
M. C. Pant ◽  
...  
Keyword(s):  
Doubled Haploid ◽  
Sweet Corn ◽  
Haploid Induction ◽  
Maize Breeding ◽  
Line Production ◽  
Haploid Inducer ◽  
Breeding Programmes ◽  
Source Populations ◽  
Developmental Phases

The use of in vivo haploid induction system makes the doubled haploid (DH) technology easier to adopt for the conventional maize breeders. However, despite having played an important role in the initial developmental phases of DH technology, Indian maize research has yet to harvest its benefits. Haploid Inducer Lines (HILs) developed by CIMMYT are being widely used in maize breeding programmes in many countries including India. There, however, is no published information on the efficiency of DH line production using CIMMYT HILs in Indian maize breeding programmes. In the present study, the efficiency of DH production using CIMMYT’s tropically adapted inducer line TAILP1 was investigated with eight source populations including two of sweet corn. The average haploid induction rate (HIR) of TAILP1 was 5.48% with a range of 2.01 to 10.03%. Efficiency of DH production ranged from 0.14 to 1.87% for different source populations with an average of 1.07%. The information generated will be useful for maize breeders intending to use DH technology for accelerated development of completely homozygous lines.

Genetic diversity of native cultivated cacao accessions (Theobroma cacao L.) in Nicaragua

2012 ◽  
Vol 10 (3) ◽  
pp. 254-257
Author(s):  
Erwin Aragon ◽  
Claudia Rivera ◽  
Helena Korpelainen ◽  
Aldo Rojas ◽  
Paula Elomaa ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Theobroma Cacao ◽  
Phytophthora Palmivora ◽  
Genetic Composition ◽  
Breeding Programmes ◽  
Black Pod ◽  
Black Pod Disease ◽  
Parental Lines ◽  
Resistant Genotypes ◽  
Theobroma Cacao L

A total of 60 farmers' cacao accessions (Theobroma cacao L.) from Nicaragua were investigated using microsatellite markers to reveal their genetic composition and to identify potentially resistant genotypes against the black pod disease caused by Phytophthora palmivora. These accessions were compared with 21 breeders' accessions maintained locally, two Criollo accessions from Costa Rica and two accessions from Ecuador. The analyses showed a low level of differentiation among groups of farmers' accessions (FST = 0.06) and that six Nicaraguan accessions were genetically closely related to the two Criollo accessions used as a reference. In addition, seven distinct genotypes were found to have allelic composition that may indicate linkage to resistance alleles, thus being potential parental lines in future breeding programmes.

scholarly journals Effect of captivity on morphology: negligible changes in external morphology mask significant changes in internal morphology

2018 ◽  
Vol 5 (5) ◽  
pp. 172470 ◽  
Author(s):  
Stephanie K. Courtney Jones ◽  
Adam J. Munn ◽  
Phillip G. Byrne
Keyword(s):  
Sexual Dimorphism ◽  
Captive Breeding ◽  
Morphological Changes ◽  
External Morphology ◽  
Wild Animals ◽  
Internal Morphology ◽  
In Captivity ◽  
Two Generations ◽  
Breeding Programmes ◽  
Source Populations

Captive breeding programmes are increasingly relied upon for threatened species management. Changes in morphology can occur in captivity, often with unknown consequences for reintroductions. Few studies have examined the morphological changes that occur in captive animals compared with wild animals. Further, the effect of multiple generations being maintained in captivity, and the potential effects of captivity on sexual dimorphism remain poorly understood. We compared external and internal morphology of captive and wild animals using house mouse ( Mus musculus ) as a model species. In addition, we looked at morphology across two captive generations, and compared morphology between sexes. We found no statistically significant differences in external morphology, but after one generation in captivity there was evidence for a shift in the internal morphology of captive-reared mice; captive-reared mice (two generations bred) had lighter combined kidney and spleen masses compared with wild-caught mice. Sexual dimorphism was maintained in captivity. Our findings demonstrate that captive breeding can alter internal morphology. Given that these morphological changes may impact organismal functioning and viability following release, further investigation is warranted. If the morphological change is shown to be maladaptive, these changes would have significant implications for captive-source populations that are used for reintroduction, including reduced survivorship.

Insights into the heat-responsive transcriptional network of tomato contrasting genotypes

2021 ◽  
Vol 19 (1) ◽  
pp. 44-57
Author(s):  
Sirine Werghi ◽  
Charfeddine Gharsallah ◽  
Nishi Kant Bhardwaj ◽  
Hatem Fakhfakh ◽  
Faten Gorsane
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Candidate Genes ◽  
Expression Patterns ◽  
Response Strategies ◽  
Transcriptional Reprogramming ◽  
Genes Encoding ◽  
Breeding Programmes ◽  
Gene Transcripts ◽  
Resource Data

AbstractDuring recent decades, global warming has intensified, altering crop growth, development and survival. To overcome changes in their environment, plants undergo transcriptional reprogramming to activate stress response strategies/pathways. To evaluate the genetic bases of the response to heat stress, Conserved DNA-derived Polymorphism (CDDP) markers were applied across tomato genome of eight cultivars. Despite scattered genotypes, cluster analysis allowed two neighbouring panels to be discriminate. Tomato CDDP-genotypic and visual phenotypic assortment permitted the selection of two contrasting heat-tolerant and heat-sensitive cultivars. Further analysis explored differential expression in transcript levels of genes, encoding heat shock transcription factors (HSFs, HsfA1, HsfA2, HsfB1), members of the heat shock protein (HSP) family (HSP101, HSP17, HSP90) and ascorbate peroxidase (APX) enzymes (APX1, APX2). Based on discriminating CDDP-markers, a protein functional network was built allowing prediction of candidate genes and their regulating miRNA. Expression patterns analysis revealed that miR156d and miR397 were heat-responsive showing a typical inverse relation with the abundance of their target gene transcripts. Heat stress is inducing a set of candidate genes, whose expression seems to be modulated through a complex regulatory network. Integrating genetic resource data is required for identifying valuable tomato genotypes that can be considered in marker-assisted breeding programmes to improve tomato heat tolerance.

scholarly journals Improving Drought Tolerance in Mungbean (Vigna radiata L. Wilczek): Morpho-Physiological, Biochemical and Molecular Perspectives

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1534
Author(s):  
Chandra Mohan Singh ◽  
Poornima Singh ◽  
Chandrakant Tiwari ◽  
Shalini Purwar ◽  
Mukul Kumar ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Crop Production ◽  
Mitigation Strategies ◽  
Theoretical Research ◽  
Whole Genome Sequence ◽  
Complex Nature ◽  
Drought Tolerant ◽  
Breeding Programmes ◽  
The Impact

Drought stress is considered a severe threat to crop production. It adversely affects the morpho-physiological, biochemical and molecular functions of the plants, especially in short duration crops like mungbean. In the past few decades, significant progress has been made towards enhancing climate resilience in legumes through classical and next-generation breeding coupled with omics approaches. Various defence mechanisms have been reported as key players in crop adaptation to drought stress. Many researchers have identified potential donors, QTLs/genes and candidate genes associated to drought tolerance-related traits. However, cloning and exploitation of these loci/gene(s) in breeding programmes are still limited. To bridge the gap between theoretical research and practical breeding, we need to reveal the omics-assisted genetic variations associated with drought tolerance in mungbean to tackle this stress. Furthermore, the use of wild relatives in breeding programmes for drought tolerance is also limited and needs to be focused. Even after six years of decoding the whole genome sequence of mungbean, the genome-wide characterization and expression of various gene families and transcriptional factors are still lacking. Due to the complex nature of drought tolerance, it also requires integrating high throughput multi-omics approaches to increase breeding efficiency and genomic selection for rapid genetic gains to develop drought-tolerant mungbean cultivars. This review highlights the impact of drought stress on mungbean and mitigation strategies for breeding high-yielding drought-tolerant mungbean varieties through classical and modern omics technologies.

scholarly journals Giant otter Pteronura brasiliensis density and abundance in Llanos Orientales de Colombia in the Orinoco basin

Oryx ◽  
2020 ◽  
pp. 1-4
Author(s):  
Germán Garrote ◽  
Beyker Castañeda ◽  
Jose Manuel Escobar ◽  
Laura Pérez ◽  
Brayan Marín ◽  
...  
Keyword(s):  
South America ◽  
Population Size ◽  
20Th Century ◽  
Conservation Status ◽  
Species Conservation ◽  
Iucn Red List ◽  
Red List ◽  
Recreational Fishing ◽  
Pteronura Brasiliensis ◽  
Direct Counts

Abstract The giant otter Pteronura brasiliensis, categorized as Endangered on the IUCN Red List, was once widely distributed throughout South America. By the middle of the 20th century the giant otter had become locally extinct along the main rivers of the Orinoco basin. Although some populations seem to have recovered, the paucity of information available does not permit a full evaluation of the species' conservation status. The objective of this study was to estimate the abundance and density of the giant otter population along the Orinoco river in the municipality of Puerto Carreño, Vichada, Colombia, where there is important commercial and recreational fishing. Thirty-nine linear km were surveyed, repeatedly, with a total of 315 km of surveys. Population size was estimated by direct counts of individuals. All individuals detected were photographed and identified individually from their throat pelage patterns. In total, 30 otters were identified, giving a minimum density of 0.77 individuals per km, one of the highest reported for the species in Colombia. Given the high density in this well-developed area, our results highlight the importance of this population for the conservation of the species.

scholarly journals Multi-omics-based prediction of hybrid performance in canola

2021 ◽  
Author(s):  
Dominic Knoch ◽  
Christian R. Werner ◽  
Rhonda C. Meyer ◽  
David Riewe ◽  
Amine Abbadi ◽  
...  
Keyword(s):  
Hilbert Space ◽  
Genetic Markers ◽  
Reproducing Kernel ◽  
Prediction Models ◽  
Agronomic Traits ◽  
Reproducing Kernel Hilbert Space ◽  
Hybrid Performance ◽  
Hybrid Prediction ◽  
Gaussian Kernels ◽  
Breeding Programmes

Abstract Key message Complementing or replacing genetic markers with transcriptomic data and use of reproducing kernel Hilbert space regression based on Gaussian kernels increases hybrid prediction accuracies for complex agronomic traits in canola. In plant breeding, hybrids gained particular importance due to heterosis, the superior performance of offspring compared to their inbred parents. Since the development of new top performing hybrids requires labour-intensive and costly breeding programmes, including testing of large numbers of experimental hybrids, the prediction of hybrid performance is of utmost interest to plant breeders. In this study, we tested the effectiveness of hybrid prediction models in spring-type oilseed rape (Brassica napus L./canola) employing different omics profiles, individually and in combination. To this end, a population of 950 F1 hybrids was evaluated for seed yield and six other agronomically relevant traits in commercial field trials at several locations throughout Europe. A subset of these hybrids was also evaluated in a climatized glasshouse regarding early biomass production. For each of the 477 parental rapeseed lines, 13,201 single nucleotide polymorphisms (SNPs), 154 primary metabolites, and 19,479 transcripts were determined and used as predictive variables. Both, SNP markers and transcripts, effectively predict hybrid performance using (genomic) best linear unbiased prediction models (gBLUP). Compared to models using pure genetic markers, models incorporating transcriptome data resulted in significantly higher prediction accuracies for five out of seven agronomic traits, indicating that transcripts carry important information beyond genomic data. Notably, reproducing kernel Hilbert space regression based on Gaussian kernels significantly exceeded the predictive abilities of gBLUP models for six of the seven agronomic traits, demonstrating its potential for implementation in future canola breeding programmes.

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