50 research outputs found

    From Mendel’s discovery on pea to today’s plant genetics and breeding

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    In 2015, we celebrated the 150th anniversary of the presentation of the seminal work of Gregor Johann Mendel. While Darwin’s theory of evolution was based on differential survival and differential reproductive success, Mendel’s theory of heredity relies on equality and stability throughout all stages of the life cycle. Darwin’s concepts were continuous variation and “soft” heredity; Mendel espoused discontinuous variation and “hard” heredity. Thus, the combination of Mendelian genetics with Darwin’s theory of natural selection was the process that resulted in the modern synthesis of evolutionary biology. Although biology, genetics, and genomics have been revolutionized in recent years, modern genetics will forever rely on simple principles founded on pea breeding using seven single gene characters. Purposeful use of mutants to study gene function is one of the essential tools of modern genetics. Today, over 100 plant species genomes have been sequenced. Mapping populations and their use in segregation of molecular markers and marker–trait association to map and isolate genes, were developed on the basis of Mendel's work. Genome-wide or genomic selection is a recent approach for the development of improved breeding lines. The analysis of complex traits has been enhanced by high-throughput phenotyping and developments in statistical and modeling methods for the analysis of phenotypic data. Introgression of novel alleles from landraces and wild relatives widens genetic diversity and improves traits; transgenic methodologies allow for the introduction of novel genes from diverse sources, and gene editing approaches offer possibilities to manipulate gene in a precise manner

    Optimization of growth conditions and medium composition for improved conidiation of newly isolated <i>Beauveria bassiana</i> strains

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    634-643Beauveria bassiana is an entomopathogenic fungus with high potential in controlling insect pests. In this study, we propose optimum cultural conditions and culture media for better growth of various B. bassiana strains. B. bassiana strains achieved their maximum growth during optimal incubation period of seven days. The optimum pH and temperature for maximal growth of B. bassiana strains was found to be 6-7 and 25-30ºC, respectively. All the tested carbon and nitrogen sources supported growth and development of the B. bassiana strains. Starch and peptone as carbon and nitrogen sources supported maximum radial growth (2.13-3.00 cm) and conidiospore count in both solid state culture (2.66×107 conidia/mL) and liquid state culture (9.86×107 conidia/mL). Strain BbR2 was the fastest growing strain on almost all nutrient sources studied and possessed commendable growth rate and sporulation potential. Wheat bran (WB) and rice bran (RB) in the proportion of 3:1 supported maximum conidiospores yields (1.90×107 conidia/mL) for strain BbR2 in solid state fermentation conditions
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