In situ germplasm conservation of Gossypium raimondii Ulbricht (“Algodoncillo”) in the Lambayeque region (Peru)

2021 ◽  
Vol 53 (6) ◽  
Author(s):  
Guillermo E. Delgado-Paredes ◽  
Cecilia Vásquez-Díaz ◽  
Boris Esquerre-Ibañez ◽  
Ernesto E. Hashimoto-Moncayo ◽  
Pilar Bazán-Sernaqué ◽  
...  
Keyword(s):  
Germplasm Conservation ◽  
Gossypium Raimondii

scholarly journals Identification of a genome-specific repetitive element in the Gossypium D genome

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8344
Author(s):  
Hejun Lu ◽  
Xinglei Cui ◽  
Yanyan Zhao ◽  
Richard Odongo Magwanga ◽  
Pengcheng Li ◽  
...  
Keyword(s):  
Repetitive Element ◽  
Repetitive Sequences ◽  
Long Terminal Repeat Retrotransposons ◽  
Gossypium Arboreum ◽  
D Genome ◽  
Cotton Species ◽  
A Genome ◽  
Gossypium Raimondii ◽  
The Common

The activity of genome-specific repetitive sequences is the main cause of genome variation between Gossypium A and D genomes. Through comparative analysis of the two genomes, we retrieved a repetitive element termed ICRd motif, which appears frequently in the diploid Gossypium raimondii (D5) genome but rarely in the diploid Gossypium arboreum (A2) genome. We further explored the existence of the ICRd motif in chromosomes of G. raimondii, G. arboreum, and two tetraploid (AADD) cotton species, Gossypium hirsutum and Gossypium barbadense, by fluorescence in situ hybridization (FISH), and observed that the ICRd motif exists in the D5 and D-subgenomes but not in the A2 and A-subgenomes. The ICRd motif comprises two components, a variable tandem repeat (TR) region and a conservative sequence (CS). The two constituents each have hundreds of repeats that evenly distribute across 13 chromosomes of the D5genome. The ICRd motif (and its repeats) was revealed as the common conservative region harbored by ancient Long Terminal Repeat Retrotransposons. Identification and investigation of the ICRd motif promotes the study of A and D genome differences, facilitates research on Gossypium genome evolution, and provides assistance to subgenome identification and genome assembling.

scholarly journals In Vitro Callus Proliferation from Leaf Explants of Green Gram after In Situ UV-B Exposure

2016 ◽  
Vol 4 (1) ◽  
pp. 82-91
Author(s):  
K Rajendiran ◽  
S Vidya ◽  
D Arulmozhi
Keyword(s):  
Callus Induction ◽  
Germplasm Conservation ◽  
Leaf Explants ◽  
Green Gram ◽  
Parenchyma Cells ◽  
In Situ Control ◽  
Callus Proliferation

Callus induction was tried with leaf explants (third leaf from top of canopy) harvested from in situ control and supplementary UV-B irradiated (UV-B = 2 hours daily @ 12.2 kJ m-2 d-1; ambient = 10 kJ m-2 d-1) three varieties of green gram viz. CO-8, NVL-585 and VAMBAN-2 to study their viability for germplam conservation. Callus induction occurred both in control and UV-B stressed NVL-585 leaf explants. VAMBAN-2 both in unstressed and UV-B stressed conditions did not initiate callus. Only control leaf explants from CO-8 proliferated callus. Callus of UV-B irradiated NVL-585 weighed less (51.28 %) than control. Parenchyma cells were smaller in callus inducted from in situ UV-B exposed NVL-585 leaf explants. The leaf explants from UV-B stressed NVL-585 varieties of green gram responded to in vitro callus proliferation making them fit for germplasm conservation for cultivating in UV-B elevated environment.Int J ApplSci Biotechnol, Vol 4(1): 82-91

scholarly journals Identification of a genome-specific repetitive element in the Gossypium D genome

2019 ◽  
Author(s):  
Hejun Lu ◽  
Xinglei Cui ◽  
Yanyan Zhao ◽  
Richard Odongo Magwang ◽  
Pengcheng Li ◽  
...  
Keyword(s):  
Repetitive Element ◽  
Gossypium Arboreum ◽  
Repeat Region ◽  
D Genome ◽  
A Genome ◽  
Tandem Repeat Region ◽  
Gossypium Raimondii ◽  
The Common ◽  
Length Variable

The activity of genome-specific repetitive sequence is the main cause of the genome variation between Gossypium A and D genomes. Through the comparative analysis of the two genomes, we got a repetitive element (ICRd motif), which repeats massively in the diploid Gossypium raimondii (D5) genome while almost absent in the diploid Gossypium arboreum (A2) genome. We further explored the existence of ICRd motif in G. raimondii, G. arboreum, and two tetraploids (AADD) cotton G. hirsutum and G. barbadense by fluorescence in situ hybridization (FISH), and observed the ICRd motif exists in D5 and D-subgenomes but not in A2 and A-subgenome. The ICRd motif was investigated through its two constituents , a length variable tandem repeat region (TR) and a conservative sequence (CS), which highly repeat and evenly distribute in chromosomes of D5 genome. The ICRd motif was revealed as the common conservative region of ancient LTR-TEs. The identifications and investigation of the ICRd motif promote the study on the A and D genome differences, facilitate the research on the Gossypium genome evolution, and provide assistance to subgenome identification and genome assembling.

scholarly journals Identification of a genome-specific repetitive element in the Gossypium D genome

2019 ◽  
Author(s):  
Hejun Lu ◽  
Xinglei Cui ◽  
Yanyan Zhao ◽  
Richard Odongo Magwang ◽  
Pengcheng Li ◽  
...  
Keyword(s):  
Repetitive Element ◽  
Gossypium Arboreum ◽  
Repeat Region ◽  
D Genome ◽  
A Genome ◽  
Tandem Repeat Region ◽  
Gossypium Raimondii ◽  
The Common ◽  
Length Variable

The activity of genome-specific repetitive sequence is the main cause of the genome variation between Gossypium A and D genomes. Through the comparative analysis of the two genomes, we got a repetitive element (ICRd motif), which repeats massively in the diploid Gossypium raimondii (D5) genome while almost absent in the diploid Gossypium arboreum (A2) genome. We further explored the existence of ICRd motif in G. raimondii, G. arboreum, and two tetraploids (AADD) cotton G. hirsutum and G. barbadense by fluorescence in situ hybridization (FISH), and observed the ICRd motif exists in D5 and D-subgenomes but not in A2 and A-subgenome. The ICRd motif was investigated through its two constituents , a length variable tandem repeat region (TR) and a conservative sequence (CS), which highly repeat and evenly distribute in chromosomes of D5 genome. The ICRd motif was revealed as the common conservative region of ancient LTR-TEs. The identifications and investigation of the ICRd motif promote the study on the A and D genome differences, facilitate the research on the Gossypium genome evolution, and provide assistance to subgenome identification and genome assembling.

scholarly journals Germplasm Conservation

2021 ◽  
Author(s):  
Sameer Quazi ◽  
Tanya Golani ◽  
Arnaud Martino Capuzzo
Keyword(s):  
Threatened Species ◽  
Germplasm Conservation ◽  
Seed Banks ◽  
Ex Situ ◽  
In Vitro Techniques ◽  
Or Gene ◽  
Basic Approaches ◽  
Lower Temperature

With the increase in risk of extinction of various plants, the trend has been shifted to employment of many biotechnological techniques for preservation of genetic resources of plant and is the area of research which needs to be revolutionized after a specific time period because it allows the production and selection of crop varieties with desirable characteristics during breeding process such as improved fuel, food and health facilities. Having an immense research in conservation of non-threatened species, there is a small collection of knowledge available for conservation of endangered ones. This chapter aims to highlight the various techniques in germplasm conservation of endangered or the species which are at extent of extinction and also the future directions in this field. In developing countries where most of agriculture depends upon food crops, the maintenance of genetic variation is of immense importance. On farm conservation provides the best example of preservation and evolution based on genetic variability which can occur ex-situ and in- situ environment in farms or gene bank. So, it presents the best option for conservation or maintenance of ecosystem and biodiversity which ensures survival of endangered species via germplasm. The most point to consider is that germplasm or genes have to be conserved instead of genotype. In situ conservation involves preservation of plant crops in the field condition in ecosystem where plant is adopted to grow in order to maintain self –sustaining process in natural ecosystem. Similarly ex-situ involve the collections of seed banks of genes collected from plant under natural conditions to produce desirable varieties or from tissue culture in laboratory also referred as in-vitro methodology. In –vitro techniques include cryopreservation which include freezing at much lower temperature than that of freezing point i.e. -196 °C in liquid nitrogen for preserving species which are near to extent of endangerment. Cold storage and storing at lower temperature provides best opportunity for protection against damage caused by rapid freezing. Germplasm exchange has become now a usual practice ensuring exchange of varieties between cultivated and wild types as for example in potatoes specie etc. DNA as well as gene or seed banks provide molecular sources for conservation at biotechnological level. The techniques of introgression and incorporation are basic approaches for germplasm conservation. So there is need to revolutionize and practice germplasm conservation for fulfilling future needs being aimed at conserving endangered or threatened species from conservation hotspots.

Rendez vous with Saturn's rings

1984 ◽  
Vol 75 ◽  
pp. 743-759 ◽  
Author(s):  
Kerry T. Nock
Keyword(s):  
Solar Energy ◽  
Electric Propulsion ◽  
Power Source ◽  
Propulsion System ◽  
Low Thrust ◽  
Ring Plane ◽  
The Earth ◽  
Total Impulse ◽  
Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

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