An apomictic tetraploid Paspalum chaseanum cytotype and its cytogenetic relationship with P. plicatulum (Poaceae): taxonomic and genetic implications

2013 ◽  
Vol 61 (7) ◽  
pp. 538 ◽  
Author(s):  
Patricia E. Novo ◽  
Francisco Espinoza ◽  
Camilo L. Quarin
Keyword(s):  
Genetic Improvement ◽  
Seed Set ◽  
Meiotic Chromosome ◽  
Geographic Region ◽  
Grass Species ◽  
Pollen Donor ◽  
Chaco Region ◽  
Improvement Programs ◽  
Pairing Behaviour

Paspalum chaseanum Parodi (Poaceae) is a rare species seldom found in the vast phytogeographic Chaco region of South America. It occurs in some localities as a diploid with 20 somatic chromosomes, reproduces sexually and is self-incompatible. A tetraploid cytotype was recently collected in this geographic region. This accession was determined to reproduce of aposporous apomixis and was crossed, as pollen donor, onto a sexual autotetraploid plant of P. plicatulum Michx. The meiotic chromosome pairing behaviour of both parents and their hybrids was primarily as bivalents and quadrivalents, indicating that tetraploid P. chaseanum is likely to have an autoploid origin, and that both species share basically the same genome. Although some controversies exist regarding the subgeneric taxonomic classification of P. chaseanum, these results support its inclusion in the informal Plicatula group of Paspalum. The P. plicatulum × P. chaseanum hybrids segregated for apomixis. The amount of seed set in some hybrids (up to 17%) and the presence of sexual as well as facultative apomictic individuals in the progeny suggest that gene transfer through hybridisation is a feasible tool in genetic-improvement programs concerning these forage grass species.

Reproductive biology and breeding system in Casuarina equisetifolia (Casuarinaceae) – implication for genetic improvement

2016 ◽  
Vol 64 (2) ◽  
pp. 120 ◽  
Author(s):  
Y. Zhang ◽  
C.L. Zhong ◽  
Q. Han ◽  
Q.B. Jiang ◽  
Y. Chen ◽  
...  
Keyword(s):  
Reproductive Biology ◽  
Breeding System ◽  
Genetic Improvement ◽  
Fruit Set ◽  
Seed Set ◽  
Pollen Limitation ◽  
Casuarina Equisetifolia ◽  
Open Pollination ◽  
Floral Longevity ◽  
Improvement Programs

Understanding the reproductive biology of plant species is essential for successful domestication and genetic improvement programs. Casuarina equisetifolia L. is an important plantation species in China and India but information on reproductive biology is limited. To address this issue, grafted ramets of C. equisetifolia were used to study floral biology, breeding system and progeny performance. The female floral longevity of C. equisetifolia reached 28.4 days under non-pollination conditions, which was significantly longer than that of supplementary pollination (5.5 days) and open pollination (12.2 days), implying successful pollination would accelerate senescence of female flowers. Higher fruit set (88.8%) and seed set (35.7%) under supplementary pollination were obtained, compared with 75.9% and 21.7%, respectively, under open pollination, although there were no fruit set and seed set under non-pollination conditions. Pollen limitation was evident based on pollen limitation index (0.39) in seedling plantations of C. equisetifolia. Selfed seedlings had low height and diameter growth in both nursery and field trials and markedly lower survival in field trial, indicating inbreeding depression. Microsatellite-based estimates of selfing rate of open pollinated, monoecious individuals was 42%, suggesting that monoecious C. equisetifolia individuals are self-compatible, and that the breeding system should be classified as facultative xenogamy.

scholarly journals Application of Tissue Culture in Plant Reproduction

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 342
Author(s):  
Elena Corredoira ◽  
Rita L. Costa
Keyword(s):  
Tissue Culture ◽  
Genetic Improvement ◽  
Plant Reproduction ◽  
Climatic Conditions ◽  
Improvement Programs

The increasing degradation of forests, together with a higher demand for wood and fruit, has led to the need for more efficient trees adapted to the current climatic conditions and, thus, to the need for genetic improvement programs [...]

scholarly journals Classification of Grass and Forb Species on Riverdike Using UAV LiDAR-Based Structural Indices

2021 ◽  
Vol 15 (3) ◽  
pp. 268-273
Author(s):  
Naoko Miura ◽  
Tomoyo F. Koyanagi ◽  
Susumu Yamada ◽  
Shigehiro Yokota ◽  
◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Imperata Cylindrica ◽  
Grass Species ◽  
Herbaceous Vegetation ◽  
Small Complex ◽  
Recent Developments ◽  
Aerial Vehicle ◽  
Conventional Systems ◽  
Structural Indices

Herbaceous vegetation on riverdikes plays an important role in preventing soil erosion, which, otherwise, may lead to the collapse of riverdikes and consequently, severe flooding. It is crucial for managers to keep suitable vegetation conditions, which include native grass species such as Imperata cylindrica, and to secure visibility of riverdikes for inspection. If managers can efficiently find where suitable grass and unsuitable forb species grow on vast riverdikes, it would help in vegetation management on riverdikes. Classification and quantification of herbaceous vegetation is a challenging task. It requires spatial resolution and accuracy high enough to recognize small, complex-shaped vegetation on riverdikes. Recent developments in unmanned aerial vehicle (UAV) technology combined with light detection and ranging (LiDAR) may offer the solution, since it can provide highly accurate, high-spatial resolution, and denser data than conventional systems. This paper aims to develop a model to classify grass and forb species using UAV LiDAR data alone. A combination of UAV LiDAR-based structural indices, V-bottom (presence of vegetation up to 50 cm from the ground) and V-middle (presence of vegetation 50–100 cm from the ground), was tested and validated in 94 plots owing to its ability to classify grass and forb species on riverdikes. The proposed method successfully classified the “upright” grass species and “falling” grass species / forb species with an accuracy of approximately 83%. Managers can efficiently prioritize the inspection areas on the riverdikes by using this method. The method is versatile and adjustable in other grassland environments.

scholarly journals Population structure and genetic diversity analysis in Sali (Oryza sativa) rice germplasm of Assam using microsatellite markers

2021 ◽  
Vol 58 (2) ◽  
pp. 279-286
Author(s):  
Sandhani Saikia ◽  
Pratap Jyoti Handique ◽  
Mahendra K Modi
Keyword(s):  
Genetic Diversity ◽  
Ssr Markers ◽  
Genetic Improvement ◽  
Crop Improvement ◽  
Mean Value ◽  
Diversity Analysis ◽  
Rice Cultivars ◽  
Improvement Program ◽  
Information Index ◽  
Improvement Programs

Genetic diversity is the source of novel allelic combinations that can be efficiently utilized in any crop improvement program. To facilitate future crop improvement programs in rice, a study was designed to identify the underlying genetic variations in the Sali rice germplasms of Assam using SSR markers. The 129 SSR markers that were used in the study amplified a total of 765 fragments with an average of 5.93 alleles per locus. The Shannon's Information Index was found to be in the range from 0.533 to 1.786. The Polymorphism Information Content (PIC) fell into the range from 0.304 to 0.691 with a mean value of 0.55. The overall FST value was found to be 0.519 that indicated the presence of genetic differentiation amongst the genotypes used in the study. The Sali population was divided into two clusters. The information obtained from the present study will facilitate the genetic improvement of Sali rice cultivars.

scholarly journals Performance of Various Deep-Learning Networks in the Seed Classification Problem

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1892
Author(s):  
Recep Eryigit ◽  
Bulent Tugrul
Keyword(s):  
Performance Metrics ◽  
Classification Problem ◽  
Grass Species ◽  
Test Accuracy ◽  
Learning Networks ◽  
Symmetry Properties ◽  
Depth Study ◽  
Image Set ◽  
Accuracy Performance

We report the results of an in-depth study of 15 variants of five different Convolutional Neural Network (CNN) architectures for the classification of seeds of seven different grass species that possess symmetry properties. The performance metrics of the nets are investigated in relation to the computational load and the number of parameters. The results indicate that the relation between the accuracy performance and operation count or number of parameters is linear in the same family of nets but that there is no relation between the two when comparing different CNN architectures. Using default pre-trained weights of the CNNs was found to increase the classification accuracy by ≈3% compared with training from scratch. The best performing CNN was found to be DenseNet201 with a 99.42% test accuracy for the highest resolution image set.

scholarly journals Assessment of genetic diversity in Indian Barnyard millet (Echinochloa spp. complex) using morphological and molecular markers

2016 ◽  
Vol 8 (3) ◽  
pp. 1643-1648 ◽  
Author(s):  
M. P. Moharil ◽  
Dipti Gawai ◽  
N. Dikshit ◽  
M.S. Dudhare ◽  
P. V. Jadhav
Keyword(s):  
Genetic Diversity ◽  
Molecular Markers ◽  
Genetic Improvement ◽  
Molecular Diversity ◽  
Genetic Relationships ◽  
Barnyard Millet ◽  
Clear Cut ◽  
Cultivated Species ◽  
High Degree

In the present study, morphological and molecular markers (RAPD primers) were used to analyze the genetic diversity and genetic relationships among 21 accessions of Echinochloa spp. complex comprising the wild and cultivated species collected from Melghat and adjoining regions of Vidarbha, Maharashtra. The availability of diverse genetic resources is a prerequisite for genetic improvement of any crop including barnyard millet. A high degree of molecular diversity among the landraces was detected. Among the 21 genotypes, two major groups (A and B) were formed, at 67.28 % similarity, which clearly encompasses 15 accessions of E. frumentacea and 6 accessions of E. colona. Higher similarity was observed in accessions of E. frumentacea. The accessions IC 597322 and IC 597323 also IC 597302 and IC 597304 showed more than 94% similarity among themselves. The classification of genetic diversity has enabled clear-cut grouping of barnyard millet accessions into two morphological races (E. frumentacea and E. colona).

scholarly journals Biofuel plant species and the contribution of genetic improvement

2011 ◽  
Vol 11 (spe) ◽  
pp. 16-26 ◽  
Author(s):  
Luiz Antônio dos Santos Dias
Keyword(s):  
Growth Rate ◽  
Plant Species ◽  
Genetic Improvement ◽  
Raw Materials ◽  
Environmental Security ◽  
Biodiesel Production ◽  
Special Focus ◽  
Annual Growth Rate ◽  
Breeding Programs ◽  
Improvement Programs

The paper analyses the puzzle of the food-energy-environmental security interaction, to which biofuels are part of the solution. It presents and discusses the contribution of genetic improvement to biofuels, with regard to the production of raw materials (oil and ethanol-producing plant species) and designs perspectives, opportunities, risks and challenges, with a special focus on the Brazilian scene. Bioethanol is a consolidated biofuel owing largely to the sugarcane breeding programs. These programs released 111 sugarcane cultivars and were responsible for a 20.8 % gain in productivity of bioethanol (in m³ ha-1) between 2000 and 2009. The program of Brazilian biodiesel production, initiated in 2005, had an annual growth rate of 10 % and the country is already the world's fourth largest producer. However, the contribution of breeding to biodiesel production is still modest, due to the lack of specific improvement programs for oil.

Genetic improvement programs for aquaculture species

2003 ◽  
Vol 2003 ◽  
pp. 225-225
Author(s):  
B. Gjerde ◽  
B. Villanueva
Keyword(s):  
Genetic Improvement ◽  
Human Population ◽  
Feeding Practices ◽  
Food Crops ◽  
Genetic Quality ◽  
Genetically Improved ◽  
Improvement Programs ◽  
High Yields ◽  
Aquaculture Production

The high yields obtained in agriculture rely heavily on the use of domesticated and genetically improved breeds and varieties. Until quite recently this has not been the case for most farmed aquaculture species that, in the genetic sense, are still much closer to the wild state than are the major terrestrial animals and food crops. Less than 10 % of the total world aquaculture production is based on improved strains. Due to a growing human population and a decline in production from capture fisheries, there is therefore a great disparity between the need for increased aquaculture production and the genetic quality of the strains available to meet that need. Moreover, full benefits of investments in management improvements (feed and feeding practices, control of diseases, etc.) can only be obtained through the use of genetically improved animals.

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