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Gene pool conservation and tree improvement in Serbia  [PDF]
Isajev Vasilije,Iveti? Vladan,Lu?i? Aleksandar,Rakonjac Ljubinko
Genetika , 2009, DOI: 10.2298/gensr0903309i
Abstract: This paper presents the concepts applied in the gene pool conservation and tree improvement in Serbia. Gene pool conservation of tree species in Serbia includes a series of activities aiming at the sustainability and protection of genetic and species variability. This implies the investigation of genetic resources and their identification through the research of the genetic structure and the breeding system of individual species. Paper also includes the study of intra- and inter-population variability in experiments - provenance tests, progeny tests, half- and full-sib lines, etc. The increased use of the genetic potential in tree improvement in Serbia should be intensified by the following activities: improvement of production of normal forest seed, application of the concept of new selections directed primarily to the improvement of only one character, because in that case the result would be certain, establishment and management of seed orchards as specialized plantations for long-term production of genetically good-quality forest seeds, and the shortening of the improvement process by introducing new techniques and methods (molecular markers, somaclonal variation, genetic engineering, protoplast fusion, micropropagation, etc.).
Molecular markers applying in forest trees gene pool conservation  [PDF]
Milovanovi? Jelena,?ija?i?-Nikoli? Mirjana
Glasnik ?umarskog Fakulteta , 2009, DOI: 10.2298/gsf0999101m
Abstract: Many studies performed during the last years demonstrated the usefulness of neutral molecular markers in the field of conservation and population genetics of forest trees, in particular to understand the importance of migration patterns in shaping current genetic and geographic diversity and to measure important parameters such as effective population size, gene flow and past bottleneck. During the next years, a large amount of data at marker loci or at sequence level is expected to be collected, and to become excellent statistical power for the assessment of biological and evolutionary value.
Productivity and soil attributes as influenced by resource conservation technologies under rice- wheat system in Nepal  [PDF]
G Sah, SC Shah, SK Sah, RB Thapa, A McDonald, HS Sidhu, RK Gupta, P Wall
Agronomy Journal of Nepal , 2013, DOI: 10.3126/ajn.v3i0.9007
Abstract: Rice-wheat system provides food, income, and employment to over 83 % of the people and contributes to national food security in Nepal. Sustainability of the system is under threat because of increasing cultivation cost and declining soil fertility. On-farm experiments were carried out to determine the effects of tillage and crop establishment methods, crop residue management, and nitrogen levels that affect soil attributes and productivity of the rice-wheat system during 2010- 2011at Bara, Nepal. The treatment consisted of three tillage and crop establishment methods viz. Conventional tillage (CT), Permanent bed planting (PB), and Zero-tillage (ZT); two residue management levels viz. Residue retention and Residue removal; and three nitrogen levels viz. Zero nitrogen, farmer’s dose (80 and 100 kgha-1 N for rice and wheat, respectively), and abundant nitrogen (120 kgha-1 N for both rice and wheat crop). The experiments were laid out in strip-split plot design with three replications. The research results revealed that rice grain yield was significantly higher in the plots receiving N level as applied by farmers that was similar to abundant nitrogen dose. Wheat grain yield was significantly higher with zero tillage compared to permanent bed planting and conventional tillage. Significantly higher wheat grain yield was also obtained due to abundant nitrogen dose than zero dose nitrogen which was similar to farmers’ dose of N as well. There was no significant difference in grain yield of rice and wheat due to residue retention, although, it improved soil moisture. In wheat crop, zero-till planting and increased nitrogen application conserved soil moisture, enhanced soil electrical conductivity and lowered soil temperature. It can be concluded that rice and wheat can be grown successfully with zero tillage and farmer’s nitrogen dose without any yield penalty.
Genetic diversity within and between broodstocks of the white shrimp Litopenaeus vannamei (Boone, 1931) (Decapoda, Penaeidae) and its implication for the gene pool conservation
Freitas, PD.;Calgaro, MR.;Galetti Jr., PM.;
Brazilian Journal of Biology , 2007, DOI: 10.1590/S1519-69842007000500019
Abstract: genetic variation within and between fifteen closed broodstock lines of the pacific white shrimp litopenaeus vannamei, reared at different hatcheries in the brazilian coast, was assessed by rapd analysis. fifty two polymorphic loci were identified when a set of five decamer primers was used in pcr. the genetic diversity analysis within lines evidenced genetic variation loss probably related to bottleneck effects and inbreeding. in addition, the genetic divergence values between the different samples appear to reflect the initial founder composition of such stocks, in some cases, sharing a common origin, suggesting a putative importance of interbreeding for the establishment of genetic improvement programs for these broodstocks. the genetic variation monitoring appears to be helpful to the gene pool conservation of this aquaculture species, mainly if considered its exotic status in brazil and the current impossibility of new introduction of wild individuals.
Conservation and diversity of gene families explored using the CODEHOP strategy in higher plants
Marc Morant, Alain Hehn, Danièle Werck-Reichhart
BMC Plant Biology , 2002, DOI: 10.1186/1471-2229-2-7
Abstract: The method was tested with two different objectives. The first was to analyze the evolution of the CYP98 family of cytochrome P450 genes involved in 3-hydroxylation of phenolic compounds and lignification in a broad range of plant species. The second was to isolate an orthologue of the sorghum glucosyl transferase UGT85B1 and to determine the complexity of the UGT85 family in wheat. P450s of the CYP98 family or closely related sequences were found in all vascular plants. No related sequence was found in moss. Neither extensive duplication of the CYP98 genes nor an orthologue of UGT85B1 were found in wheat. The UGT85A subfamily was however found to be highly variable in wheat.Our data are in agreement with the implication of CYP98s in lignification and the evolution of 3-hydroxylation of lignin precursors with vascular plants. High conservation of the CYP98 family strongly argues in favour of an essential function in plant development. Conversely, high duplication and diversification of the UGT85A gene family in wheat suggests its involvement in adaptative response and provides a valuable pool of genes for biotechnological applications. This work demonstrates the high potential of the CODEHOP strategy for the exploration of large gene families in plants.Plants have evolved extremely diversified gene families as tools to cope with a harsh environment. Some of these families such as cytochromes P450 and UDP-glycosyltransferases (UGT) reflect the extraordinary biochemical versatility of plants and across plant species, and represent a very valuable source of genes for biotechnologies. Both gene families offer a huge potential for bioremediation and control of crop and weed pesticide tolerance [1-3], but obviously also for industrial applications. P450s, considered as the most versatile catalysts known [4], usually activate dioxygen and transfer one of its atoms into various substrates, but also catalyze a great diversity of reactions ranging from C-C and C=N bond cleava
Wheat gene bank accessions as a source of new alleles of the powdery mildew resistance gene Pm3: a large scale allele mining project
Navreet K Bhullar, Zhiqing Zhang, Thomas Wicker, Beat Keller
BMC Plant Biology , 2010, DOI: 10.1186/1471-2229-10-88
Abstract: We have undertaken large scale molecular allele mining to isolate new alleles of the powdery mildew resistance gene Pm3 from wheat gene bank accessions. The search for new Pm3 alleles was carried out on a geographically diverse set of 733 wheat accessions originating from 20 countries. Pm3 specific molecular tools as well as classical pathogenicity tests were used to characterize the accessions. Two new functional Pm3 alleles were identified out of the eight newly cloned Pm3 sequences. These new resistance alleles were isolated from accessions from China and Nepal. Thus, the repertoire of functional Pm3 alleles now includes 17 genes, making it one of the largest allelic series of plant resistance genes. The combined information on resistant and susceptible Pm3 sequences will allow to study molecular function and specificity of functional Pm3 alleles.This study demonstrates that molecular allele mining on geographically defined accessions is a useful strategy to rapidly characterize the diversity of gene bank accessions at a specific genetic locus of agronomical importance. The identified wheat accessions with new resistance specificities can be used for marker-assisted transfer of the Pm3 alleles to modern wheat lines.Enhancing productivity in a sustainable manner is essential for future agriculture. Genetic improvement of crop plants relies on the cultivation of genotypes that possess favourable alleles/genes controlling desirable agronomic traits [1]. In the past, both early domestication and the more recent modern plant breeding have resulted in severe genetic bottlenecks, reducing the levels of genetic diversity [2]. As most of the modern genotypes cultivated today have descended from a relatively small number of landraces, the genes controlling important traits have reduced diversity compared to the gene pool of landraces and wild relatives. This is likely to make the modern varieties more vulnerable to newly emerging strains of pathogens. For example, the rece
Effects of different conservation tillage measures on soil organic carbon pool in two sequence rotation systems of spring wheat and pease
不同保护性耕作措施对麦-豆轮作土壤有机碳库的影响

CAI Li-Qun,QI Peng,ZHANG Ren-Zhi,LI Ai-Zong,
蔡立群
,齐 鹏,张仁陟,李爱宗

中国生态农业学报 , 2009,
Abstract: A 5-year conservation tillage experiment was conduced in Lijiabu, Dingxi City of Gansu Province to study the effects of crop rotation and tillage on soil total carbon, active organic carbon, microbial biomass carbon and soil organic carbon pool management index. The results show that conventional tillage with straw mulching and conventional tillage, in which straw is plowed into soil, increase soil organic carbon, active organic carbon, microbial biomass carbon and soil carbon pool management index under both rotation sequences. Though zero-tillage increases soil carbon pool management index in 0 ~5 cm soil layer, it decreases index of the other soil layers. The findings then suggest that zero-tillage without straw mulching or straw plowing into the soil is non-sustainable for soil organic carbon management.
Tiger Conservation Initiatives in Nepal  [PDF]
Jhamak Bahadur Karki,Shanta Raj Jnawali,Ghana Gurung,Megh B Pandey,Gopal P Upadhyay
The Initiation , 2011, DOI: 10.3126/init.v4i0.5537
Abstract: Tiger (Panthera tigris tigris) is an icon of Asia’s natural heritage and ecological integrity. Tiger along with one-horned rhinoceros (Rhinoceros unicornis) and wild elephant (Elephas maximus) in the lowlands and snow leopard (Uncia uncia), musk deer (Muschus sp.) in mountain have been serving as a flagship species to derive worldwide conservation attention not only to benefit them but also to facilitate the survival of other associated species. However, their number is decreasing rapidly. Owing to this, various initiatives have been taken both at national and international level. This article reviews about the different initiatives taken so far and the ways forth. DOI: http://dx.doi.org/10.3126/init.v4i0.5537 The Initiation Vol.4 2011 56-68
Tetraploid Wheat Landraces in the Mediterranean Basin: Taxonomy, Evolution and Genetic Diversity  [PDF]
Hugo R. Oliveira, Michael G. Campana, Huw Jones, Harriet V. Hunt, Fiona Leigh, David I. Redhouse, Diane L. Lister, Martin K. Jones
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0037063
Abstract: The geographic distribution of genetic diversity and the population structure of tetraploid wheat landraces in the Mediterranean basin has received relatively little attention. This is complicated by the lack of consensus concerning the taxonomy of tetraploid wheats and by unresolved questions regarding the domestication and spread of naked wheats. These knowledge gaps hinder crop diversity conservation efforts and plant breeding programmes. We investigated genetic diversity and population structure in tetraploid wheats (wild emmer, emmer, rivet and durum) using nuclear and chloroplast simple sequence repeats, functional variations and insertion site-based polymorphisms. Emmer and wild emmer constitute a genetically distinct population from durum and rivet, the latter seeming to share a common gene pool. Our population structure and genetic diversity data suggest a dynamic history of introduction and extinction of genotypes in the Mediterranean fields.
An Empirical Analysis of Resource Productivity of Wheat in Eastern Tarai Region of Nepal  [PDF]
Ram B. Bhujel,Ram N. Jha,Bindeshwar Yadav
Nepal Agriculture Research Journal , 2009, DOI: 10.3126/narj.v9i0.11647
Abstract: Different types of resource conservation technology (RCT) in wheat cultivation have been recently introduced and use of seed cum fertilizer zero till drill machine is one of them which was used in eastern terai region in wheat season of 2006/2007. A survey was carried out to study the productivity of wheat and compare the production between traditional and RCT method of cultivation. Altogether 31 farmers were interviewed with semi-structured questionnaires. Model used to estimate the productivity for both the methods was significant (p < 0.01) which explained 96 and 97 per cent variation due to independent variables under study in wheat production of traditional and RCT method, respectively. Farmers used 160 kg seed/ha in traditional method while in RCT method it was 122 kg/ha. Similarly, they applied 148 and 137 kg nutrients as a total of nitrogen, phosphorus and potash in traditional and RCT method, respectively. Average production of wheat grain in traditional and RCT method was 2456 and 2714 kg/ha giving average gross margin of Rs 16750.00 and Rs 23301.00/ha, respectively. This revealed 10 per cent reduction in total costs and 29 per cent increase in return by RCT method. Nepal Agric. Res. J. Vol. 9, 2009, pp. 99-108 DOI: http://dx.doi.org/10.3126/narj.v9i0.11647
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