scholarly journals Vegetable Breeding Strategies

Author(s):  
Mahesh B. Ghuge ◽  
Anis Mirza

Variation present in vegetables provides plentiful of opportunity for development of breeding lines and hybrids. Germplasm development depends on incorporation of approaches such as MAGIC population, use of wild relatives, genetic transformation for transferring resistance gene and gene pyramiding. These approaches are most reliable to improve qualitative as well as quantitative characters. Since conventional methods are time consuming, molecular techniques are also utilized at appropriate stages to enhance swiftness of line development. Molecular approaches includes many tools but marker assisted selection is best to use in vegetable breeding programme. It helps to rapid back cross breeding also selection of resistance or qualitative lines from segregating populations. Double haploid is one of finest methods to create diverse pure lines in short interval. There are many ways to incorporate diverse gene in single line through double haploid technology. Hybridization mating such as line x tester or diallel are common methods instead combination breeding method is very result oriented as compared with others. The success rate of specific combination breeding is as much as double as associated with other ones.

1995 ◽  
Vol 75 (2) ◽  
pp. 437-439 ◽  
Author(s):  
G. R. Stringam ◽  
V. K. Bansal ◽  
M. R. Thiagarajah ◽  
D. F. Degenhardt ◽  
J. P. Tewari

The doubled haploid breeding method and greenhouse screening using cotyledon bio-assay were successfully applied to transfer blackleg resistance from the Australian cultivar Maluka (Brassicas napus), into susceptible advanced B. napus lines from the University of Alberta. This approach for blackleg resistance breeding was effective and efficient as several superior blackleg resistant breeding lines were identified within 4 yr from the initial cross. One of these lines (91–21864NA) was entered in the 1993 trials of the Western Canada Canola/Rapeseed Recommending Committee. Key words: Blackleg resistance, Leptosphaeria maculans, doubled haploid, Brassica napus


2006 ◽  
Vol 19 (4) ◽  
pp. 658-685 ◽  
Author(s):  
Barun Mathema ◽  
Natalia E. Kurepina ◽  
Pablo J. Bifani ◽  
Barry N. Kreiswirth

SUMMARY Molecular epidemiologic studies of tuberculosis (TB) have focused largely on utilizing molecular techniques to address short- and long-term epidemiologic questions, such as in outbreak investigations and in assessing the global dissemination of strains, respectively. This is done primarily by examining the extent of genetic diversity of clinical strains of Mycobacterium tuberculosis. When molecular methods are used in conjunction with classical epidemiology, their utility for TB control has been realized. For instance, molecular epidemiologic studies have added much-needed accuracy and precision in describing transmission dynamics, and they have facilitated investigation of previously unresolved issues, such as estimates of recent-versus-reactive disease and the extent of exogenous reinfection. In addition, there is mounting evidence to suggest that specific strains of M. tuberculosis belonging to discrete phylogenetic clusters (lineages) may differ in virulence, pathogenesis, and epidemiologic characteristics, all of which may significantly impact TB control and vaccine development strategies. Here, we review the current methods, concepts, and applications of molecular approaches used to better understand the epidemiology of TB.


2021 ◽  
pp. 34-37
Author(s):  
Р.Х. Беков

Рассмотрены важные аспекты использования геноносителей различных маркерных признаков при создании и селекции гетерозисных гибридов томата для защищенного грунта. Наряду с общими требованиями к родительским компонентам, касающимися продуктивности растений, скороспелости, устойчивости к болезням и т. д., сегодня при селекции на гетерозис для защищенного грунта к исходному материалу предъявляют более высокие требования по наличию хозяйственно полезных признаков. Эти требования касаются типа роста растений, формы, окраски и качества плодов, типа кисти, формы плодоножки и т. д. Представлены характеристики исходного материала для создания гетерозисных гибридов томата, а также даны характеристики полученных гибридов. Исследования, проведенные в отделе селекции ВНИИО (ВНИИ овощеводства – филиал ФГБНУ ФНЦО), показали большую перспективность использования при гетерозисной селекции томата для защищенного грунта геноносителей различных маркерных признаков, особенно признаков, определяющих коричневую окраску эндосперма семян (гены bs и bs-2) и несочлененную плодоножку (ген j-2). Созданные с использованием этих маркерных признаков гибриды и селекционные линии по-своему уникальны и являются приоритетным достижением этого научного учреждения, так как они представляют большой интерес для гетерозисной селекции томата в качестве исходного материала. Целый ряд гибридов F1 включен в Госреестр селекционных достижений, допущенных к использованию (Удача, Голубчик, Клад овощевода, Заур и др.). В связи с развитием фермерского и любительского овощеводства в последние годы определенное внимание было уделено созданию новых мутантных линий с розовыми, малиновыми и темно-коричневыми плодами с высокими вкусовыми качествами (учитывая, что образцы такого типа пользуются повышенным спросом у населения и стоят дороже). При создании новых гетерозисных гибридов были учтены эти признаки родительских форм. Important aspects of the use of gene carriers of various marker traits in the creation and selection of heterotic tomato hybrids for greenhouse industry are considered. Along with the general requirements for the parent components concerning plant productivity, precocity, resistance to diseases, etc., today, when breeding for heterosis for greenhouse industry, higher requirements are imposed on the source material for the presence of economically useful features. These requirements relate to the type of plant growth, shape, colour and quality of fruits, brush type, stem shape, etc. The characteristics of the initial material for creating heterotic tomato hybrids are presented, as well as the characteristics of the resulting hybrids are given. Studies conducted in the breeding department of the ARRIVG (ARRIVG – a branch of the FSBI FSCV) showed great prospects for the use of gene carriers of various marker traits, especially those that determine the brown colour of the seed endosperm (bs and bs-2 genes) and an undifferentiated peduncle (j-2 gene) in the heterosis breeding of tomatoes for greenhouses. Hybrids and breeding lines created using these marker traits are unique in their own way and are a priority achievement of this scientific institution, since they are of great interest for the heterosis breeding of tomato as a basic material. A number of F1 hybrids are included in the State Register of Breeding Achievements allowed for use (Udacha, Golubchik, Klad ovoschevoda, Zaur, etc.). Due to the development of farming and amateur vegetable growing in recent years, some attention has been paid to the creation of new mutant lines with pink, crimson and dark brown fruits with high taste qualities (given that samples of this type are in high demand among the population and are more expensive). When creating new heterotic hybrids, these features of the parent forms were taken into account.


2015 ◽  
Vol 7 ◽  
pp. e2015035 ◽  
Author(s):  
Rosangela Invernizzi ◽  
Federica Quaglia ◽  
Matteo Giovanni Della Porta

Myelodysplastic syndromes (MDS) are hematopoietic stem cell disorders characterized by dysplastic, ineffective, clonal and neoplastic hematopoiesis. MDS represent a complex hematological problem: differences in disease presentation, progression and outcome  have necessitated the use of classification systems to improve diagnosis, prognostication and treatment selection. However, since a single biological or genetic reliable diagnostic marker has not yet been discovered for MDS, quantitative and qualitative dysplastic morphological alterations of bone marrow precursors and of peripheral blood cells are still fundamental for diagnostic classification. In this paper World Health Organization (WHO) classification refinements and current minimal diagnostic criteria proposed by expert panels are highlighted and related problematic issues are discussed. The recommendations should facilitate diagnostic and prognostic evaluations in MDS and selection of patients for new effective targeted therapies. Although in the future morphology should be supplemented with new molecular techniques, the morphological approach, at least for the moment, is still the cornerstone for the diagnosis and classification of these disorders.


Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2525
Author(s):  
Xuan Wang ◽  
Xinying Guo ◽  
Xixi Ma ◽  
Liang Luo ◽  
Yaoyu Fang ◽  
...  

Brown planthopper, blast, and bacterial blight are the main biotic stressors of rice and can cause a massive loss in rice production. Aroma is an important character of rice quality. It is of far-reaching significance to breed resistant and high-quality varieties using germplasms with objective genes. In this study, the introgression and pyramiding of brown planthopper (BPH), blast, and bacterial leaf blight (BLB) resistance genes and aroma genes into elite rice maintainers and restorers were conducted through conventional cross-breeding coupled with the marker-assisted selection (MAS) breeding method. Single-plant selection was performed from F2 onwards to select desirable recombinants possessing alleles of interest with suitable phenotypes. Respective linked markers were used in each generation from intercrossing to the F7 generation for tracking the presence of targeted genes. A total of 74 improved lines (ILs) have been developed which possess a combination of 1 to 4 genes for BPH, blast, and BLB resistance and aroma. These ILs showed moderate to high resistance to multiple biotic stresses (BPH, blast and BLB) or aromatic fragrance without obvious negative effects on agronomic traits. As multiple resistance and aromatic traits have become significant objectives in rice breeding, these resistance and/or aroma gene introgressed or pyramided lines have important application prospects. Core ideas: (1) marker-assisted breeding was used to pyramid multiple genes for an elite breeding line; (2) improved lines with the introgression of 1–4 genes were developed to achieve high resistance against various biotic stresses and aroma; (3) new lines were used as donor parents to introgress multiple genes in other genetic backgrounds.


Author(s):  
Manjula A. C ◽  
Jenifer Lolita. C ◽  
Shubha Shubha ◽  
Prathibha K.Y ◽  
Keshamma E

We planned to conduct this study with the main aim to develop bivoltine breeds for our tropical climatic conditions by using silkworm breeds with known genetic backgrounds (KA, NB18 and PM) in various hybrid combinations and incorporating them over generations, followed by backcrossing and adequate selection of different generations with the objective of profitability and productivity. The isolated Bivoltin lines (R1 and R2) were reared with their parental races at different times of the year to evaluate their stability in the expression of commercial traits. For the present breeding program, the purebred Bivoltine Kalimpong-A (KA), which spin white oval cocoons, New Bivoltine18 (NB18) white cocoons with rotating dumbbells and Multivoltine Pure Mysore (PM), the yellow pointed cocoons of the mulberry silkworm Bombyx mori L., Selected. One-way and three-way crosses were made using the above three breeds. The first single cross comprised KA females and PM males. The second unique cross comprised NB18 females and PM males. Selection was performed at the egg, larva, pupal, and cocoon stages over the course to determine the desired traits. The offspring of F from the respective crosses were backcrossed with their respective bivoltine males to improve commercial traits. Heterosis in the F1 generations of crosses, including NB18 and PM, was determined by the mean score of the parents (MPV) and the best score of the parents (BPV). A significant test for heterosis was performed using a standard ANOVA table. Based on the results of our study, it was found that the performance of the characters, viz. The weight of mature larvae and the duration of the larvae over generations do not simply increase or decrease regularly, but fluctuate irregularly. The reason for this variation may be due to random genetic drift, sampling errors in estimating generational means, selection pressures, and environmental factors. Therefore, inbreeding variations due to random drift and sampling errors could be reduced by increasing the number sampled and selected.


2021 ◽  
Vol 7 (9) ◽  
pp. 125-129
Author(s):  
M. Adigozalov

The article is devoted to the study of several tomatoes introduced and created in Vegetable Growing Research Institute (Baku) and pure lines derived from them. Biological and economically-valuable characteristics of varieties and obtained pure are given. It should be noted that in Azerbaijan, 25 different varieties of tomatoes are introduced and localized. These varieties have been cultivated on farms for years and have lost their farm valuable qualities due to various biotic an abiotic factors. Although tomato is a self-pollinating plant, special selection and seeding measures are required for reproduction. Therefore, in order to restore the original characteristics of regionalized tomato varieties, it is necessary to re-study their biological characteristics and economically-valuable qualities. Our research was carried out in the direction of individual selection and acquisition of pure lines of typical plants with characteristic features and characteristics. In the course of the work, 2–3 best pure lines were separated from each variety. These lines differ from the parent varieties in terms of ripening time, fruit weight and productivity. Thus, as a result of experiments, it was determined that they give the product in 10–15 days, the characteristics of coexistence are also high, forming uniformity in shape, size and color. The obtained lines are promising, will be included in the selection of seed work as a valuable starting material, and will also be increased.


1961 ◽  
Vol 41 (1) ◽  
pp. 24-30 ◽  
Author(s):  
Chas. Walkof

The backcross breeding method was applied to a co-operative tomato improvement project that involved nine research institutions in Western Canada with highly effective results. Breeding lines have been obtained from the Earlinorth × Morden BB3 cross, in which fruit size was 117.15 per cent greater and maturity equal to Earlinorth. In other lines fruit size was 44.33 per cent greater and maturity 7 days earlier than Morden BB3. Combination improvement employing correlation data for selecting the largest-fruited, earliest-ripening genotypes contributed to breeding progress. Heritability estimates indicated the selection potential of the cross. The fasciation character was found to be associated with the development of large fruit size and late maturity in certain breeding lines.


Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4631
Author(s):  
Valtcho D. Zheljazkov ◽  
Vladimir Sikora ◽  
Ivayla Dincheva ◽  
Miroslava Kačániová ◽  
Tess Astatkie ◽  
...  

Hemp (Cannabis sativa L.) is currently one of the most controversial and promising crops. This study compared nine wild hemp (C. sativa spp. spontanea V.) accessions with 13 registered cultivars, eight breeding lines, and one cannabidiol (CBD) hemp strain belonging to C. sativa L. The first three groups had similar main essential oil (EO) constituents, but in different concentrations; the CBD hemp had a different EO profile. The concentration of the four major constituents in the industrial hemp lines and wild hemp accessions varied as follows: β-caryophyllene 11–22% and 15.4–29.6%; α-humulene 4.4–7.6% and 5.3–11.9%; caryophyllene oxide 8.6–13.7% and 0.2–31.2%; and humulene epoxide 2, 2.3–5.6% and 1.2–9.5%, respectively. The concentration of CBD in the EO of wild hemp varied from 6.9 to 52.4% of the total oil while CBD in the EO of the registered cultivars varied from 7.1 to 25%; CBD in the EO of the breeding lines and in the CBD strain varied from 6.4 to 25% and 7.4 to 8.8%, respectively. The concentrations of δ9-tetrahydrocannabinol (THC) in the EO of the three groups of hemp were significantly different, with the highest concentration being 3.5%. The EO of wild hemp had greater antimicrobial activity compared with the EO of registered cultivars. This is the first report to show that significant amounts of CBD could be accumulated in the EO of wild and registered cultivars of hemp following hydro-distillation. The amount of CBD in the EO can be greater than that in the EO of the USA strain used for commercial production of CBD. Furthermore, this is among the first reports that show greater antimicrobial activity of the EO of wild hemp vs. the EO of registered cultivars. The results suggest that wild hemp may offer an excellent opportunity for future breeding and the selection of cultivars with a desirable composition of the EO and possibly CBD-rich EO production.


2016 ◽  
Vol 15 (2) ◽  
pp. 127-137
Author(s):  
Kuyyamudi Nanaiah Ganapathy ◽  
Sujay Rakshit ◽  
Sunil Shriram Gomashe ◽  
Suri Audilakshmi ◽  
Krishna Hariprasanna ◽  
...  

Knowledge on genetic diversity is necessary to determine the relationships among the genotypes, which allow the selection of individual accessions for crop breeding programmes. The present study aimed at assessing the extent and pattern of genetic diversity within a set of 251 sorghum genotypes using SSR markers. A total of 393 alleles were detected from the 251 genotypes, with the number of alleles ranging from 2 (Xcup11) to 24 (Sb5-206) and an average of 10.07 alleles per primer pair. Pairwise Wright's FST statistic and Nei's genetic distance estimates revealed that the race and geographical origin were responsible for the pattern of diversity and structure in the genetic materials. In addition, the analysis also revealed high genetic differentiation between the rainy and post-rainy sorghum groups. Narrow diversity was observed among the different working groups in the rainy (restorers and varieties) and post-rainy (varieties and advanced breeding lines) sorghum groups. Neighbour-joining and STRUCTURE analysis also classified 44 elite lines broadly into two distinct groups (rainy and post-rainy). However, limited diversity within the rainy and post-rainy sorghum groups warranted an urgent need for the utilization of diverse germplasm accessions for broadening the genetic base of the Indian breeding programme. The diverse germplasm accessions identified from the mini-core accessions for utilization in breeding programmes are discussed.


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