scholarly journals Genetic Divergence, Implication of Diversity, and Conservation of Silkworm, Bombyx mori

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Bharat Bhusan Bindroo ◽  
Shunmugam Manthira Moorthy

Genetic diversity is critical to success in any crop breeding and it provides information about the quantum of genetic divergence and serves a platform for specific breeding objectives. It is one of the three forms of biodiversity recognized by the World Conservation Union (IUCN) as deserving conservation. Silkworm Bombyx mori, an economically important insect, reported to be domesticated over 5000 years ago by human to meet his requirements. Genetic diversity is a particular concern because greater genetic uniformity in silkworm can increase vulnerability to pests and diseases. Hence, maintenance of genetic diversity is a fundamental component in long-term management strategies for genetic improvement of silkworm which is cultivated by millions of people around the worlds for its lusture silk. In this paper genetic diversity studies carried out in silkworm using divergent methods (quantitative traits and biochemical and molecular markers) and present level of diversity and factors responsible for loss of diversity are discussed.

2016 ◽  
Vol 5 (11) ◽  
pp. 5025
Author(s):  
Zafar Iqbal Buhroo ◽  
Muzafar Ahmad Bhat*

Study on genetic diversity is critical to success in any crop breeding and it provides information about the quantum of genetic divergence and serves a platform for specific breeding objectives. Genetic diversity is a particular concern because greater genetic uniformity in silkworm can increase vulnerability to pests and diseases. Hence maintenance of genetic diversity is a fundamental component in long term management strategies for genetic improvement of silkworm which is cultivated by millions of people around the worlds for its lustrous silk. In view of the present study, genetic diversity studies carried out in silkworm using divergent methods (Quantitative traits, biochemical and molecular markers) and present level of diversity, pertaining to the literature has been reviewed. Genetic diversity is the genetic variation within species, both among geographically separated populations and among individuals within a single population. Genetic diversity is an essential aspect in conservation biology because a fundamental concept of natural selection states that the rate of evolutionary change in a population is proportional to the amount of genetic diversity present in it. Decreasing genetic diversity increases the extinction risk of populations due to a decline in fitness. Therefore, both biochemical and molecular markers have recently been employed to estimate the extent of genetic diversity present among various types of silkworm strains such as mono-, bi and multivoltines present in China, Japan, Korea, India, and several other countries.


2002 ◽  
Vol 5 (4) ◽  
pp. 312-328 ◽  
Author(s):  
Ron Goeree ◽  
Bernie J. O'Brien ◽  
Gordon Blackhouse ◽  
John Marshall ◽  
Andrew Briggs ◽  
...  

2007 ◽  
Vol 39 (6) ◽  
pp. 1391-1400 ◽  
Author(s):  
Carmine Crecchio ◽  
Maddalena Curci ◽  
Antonella Pellegrino ◽  
Patrizia Ricciuti ◽  
Nunzia Tursi ◽  
...  

1995 ◽  
Vol 1 (1) ◽  
pp. 74
Author(s):  
Martin Knapp

Advice on enuresis has been provided by a range of individuals. Many myths and misunderstandings have been responsible for the confusing range of opinions given to those who seek help. Management should be based on an understanding of the physiology of the condition and the established facts about its treatment. There is still a lack of awareness about how effective are the management strategies now proposed by those who base their practise on the extensive research that is now documented. The best results are obtained with conditioning therapy, when this is supervised and supported. There is an important role for 'wetness' alarms in conditioning. There are now body-worn mini-alarms, established by over a decade of use, that are inexpensive and reliable. There is a decreasing role for tricyclic medication. The recently introduced pharmaceutical Minirin (desmopressin) is useful in short-term management to get dryness on social occasions and, in selected individuals, might have a role in long-term control of enuresis, when conditioning has not been effective. There is an important need to provide advice and treatment facilities for all those with enuresis - a treatable condition.


Author(s):  
Bidush Ranjan Swar ◽  
V. Swarnalatha ◽  
M. Rajendar Reddy ◽  
S. Vanisree

Soybean MAGIC lines are highly variable breeding material which utilizes both recent and historic genetic recombination events. Present investigation was carried out to assess the genetic diversity present among 95 soybean MAGIC lines along with six checks for 10 different quantitative traits. All the genotypes were grouped into 16 clusters by performing Tocher’s clustering method using Mahalanobis D2 distance. Cluster I was the largest comprising of 30 genotypes followed by cluster II (23 genotypes), cluster X (15 genotypes) and cluster IX (9 genotypes). The maximum genetic distance (D2) was observed between cluster XI and XV (168.37) followed by cluster III and XV (164.3), cluster X and XV (149.64) as well as between cluster XII and cluster XVI (145.99). The cluster mean for most of the traits were high in cluster I and cluster XVI. Oil content contributed maximum (23.86%) towards total genetic diversity followed by number of pods plant-1 (18.97%), seed yield plant-1 (18.63%), 100 seed weight (11.05%) and number of branches plant-1 (10.16%) traits. The soybean MAGIC lines belong to the cluster XI (6-120) and cluster XV (6-30, 6-31, 6-5) were found to be the most divergent hence can be utilised in the recombination breeding programs to exploit maximum heterosis.


2007 ◽  
Vol 13 (1) ◽  
pp. 20 ◽  
Author(s):  
Melany H. Chapin ◽  
Mike Maunder ◽  
Katherine E. Horak

Island floras have been subject to catastrophic changes since human colonization; the Hawaiian Islands exemplify this pattern of species decline and ecological change. Archaeological and historic findings support the former existence of coastal, lowland and interior Pritchardia dominated forests. Wild Pritchardia populations are highly fragmented and exhibit poor or absent regeneration in the wild. This study records seed predation, goat grazing, pig damage, and human harvesting on six wild populations of three species and outlines requirements for the long-term management of wild populations. Only one population of the six studied was found to contain seedlings. Recommended conservation management strategies are outlined.


2020 ◽  
Vol 21 (supplement 1) ◽  
Author(s):  
Abeera Imtiyaz ◽  
K. A. Sahaf ◽  
Shabir A. Bhat ◽  
Shaheen Gul ◽  
Iqra Rafiq ◽  
...  

In the present study, susceptibility of the mulberry pest G. pyloalis to the pathogens of silkworm, Bombyx mori was ascertained. The survey was carried out at the three locations viz. Mulberry farms of College of Temperate Sericulture, Mirgund and two mulberry farms of Sericulture Development Department, J&K located at Mirgund and Tulsibagh, Srinagar. The plantation is ravaged by different pests and diseases and as many as 11 major and 10 minor insect pests have been reported from Jammu and Kashmir (Sharma and Tara, 1985; Khan et al., 2004). Under temperate conditions, G. pyloalis (Walker) causes severe damage to mulberry crop and is considered as a major pest of mulberry in Jammu and Kashmir (Fotadar et al., 1998). Zeya et al. (2003) reported 20-25 percent damage to mulberry foliage in Kashmir is due to G. Pyloalis during July to October. The survey study showed high infestation of G. Pyloalis during the month of October, 2017 and 2018. The maximum infestation of 73.03% was observed at SDD Tulsi Bagh followed by 45.20% at SDD Mirgund and 32.99% at CoTS Farm. During the study various stages of G. Pyloalis were found infected with the Microsporidian and Nuclear Polyhedral Virus whereas Fungal and bacterial pathogens were not observed during the present study. The mean incidence of Microsporidian and NPV was observed as 4.22% and 5.99% percent respectively during October, 2017. In the present study, susceptibility of the mulberry pest G. Pyloalis to the pathogens of silkworm, Bombyx mori was ascertained so that management strategies are taken accordingly


2002 ◽  
Vol 92 (3) ◽  
pp. 232-236 ◽  
Author(s):  
Seogchan Kang ◽  
John E. Ayers ◽  
Erick D. DeWolf ◽  
David M. Geiser ◽  
Gretchen Kuldau ◽  
...  

A better understanding of the phenotypic and genetic diversity of significant agricultural pathogens and how their populations change in the field is critical for designing successful, long-term disease management strategies. Although efforts to determine the genetic diversity of plant pathogens have substantially increased in recent years, mainly due to the availability of various molecular tools, complementary efforts to archive and integrate the resulting data have been very limited. As a consequence, it is often difficult to compare the available data from various laboratories because the data have been generated by diverse tools, often preventing any direct comparisons, and are saved in a format that is unsuitable for comparative studies. The establishment of an internet-based database that cross-links the digitized genotypic and phenotypic information of individual pathogens at both the species and population levels may allow us to effectively address these problems by coordinating the generation of data and its subsequent archiving. We discuss the needs, benefits, and potential structure of such a database.


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