Development, use and assessement of genetic diversity of maize inbred lines
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StatusThe thesis was presented on the 25 November, 2021Approved by NCAA on the 22 December, 2021 Abstract – 1.13 Mb / in romanianThesisCZU 633.:15:631.52
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Keywords
maize, inbred line, hybrid, combining ability, genetic diversity, heterosis, distinctiveness, heterotic groupsSummary
Structure of the thesis: The thesis contaned on 144 pages of basic text with 57 tables, one figure, 7 pictures and contains introduction, 5 chapters, general conclusions and recommendations, bibliography of 264 sources and 16 annexes. Based on the researches, the 15 scientific papers were published. The results are protected by 6 plant variety patents.
Purpose of researches: the development of a genetically diversified inbred lines and high-performant maize hybrids with high adaptability, assessement of the phenotypic and genetic diversity of maize original inbred lines from Institute`s collection.
Objectives of the researches: the development of maize inbred lines from different sources of germplasm and initial material; the determination of the combining ability of inbred lines and identification of performant hybrid combinations for agricultural practice; the assessement of the similarity/divergence degree of the inbred lines in terms of the phenotype; the evaluation of the heterosis in related and unrelated crosses; establishing the inbred lines diversity at the level of non-additive genetic interactions; highlighting the breeding genetic value of the inbred lines; identifying the correlations between diversity indicators; the identification of the most appropriate method for classifying inbred lines into germplasm groups.
Scientific novelty and originality: For the first time, extensive research has been conducted to assess the phenotypic and genetic diversity in the original inbred lines. Arguments were brought for the affiliation of the inbred lines to germplasm groups, which allows their systematisation, management and more effective use. Minor associations were noted between the phenotypic diversity index and genetic diversity indices - the level of heterosis, SCA constants and grain yield, demonstrating the major importance of genetic diversity indicators in establishing of distinct germplasm groups.
The solved scientific problem: Establishing and deepening the knowledge on the diversity of inbred lines at phenotypic and genetic level by determining the degree of similarity/divergence between genotypes, which leads to the argumentation and confirmation of inbred lines classification to concrete germplasm groups, that allows a more efficient development and use of initial material in maize breeding.
Theoretical significance: The investigation made brought a significant contribution to the study of morphologic variability, affinity degree and breeding value of the original maize inbred lines, having demonstrated the major importance of genetic diversity indices in classifying of the inbred lines in common germplasm groups and predicting hybrid performance in the heterotic patterns.
Applicative value: The breeding programs ended by highlighting of 7 new inbred lines, used as parental forms of approved hybrids. 14 maize hybrids were registered, including 2 - in Russia, Porumbeni 228 – in Belarus and Porumbeni 427 – in Romania. The hybrids Porumbeni 365 and Porumbeni 430 are being officially tested in Moldova and Porumbeni 384 is being verified by the state network of Romania. The classification method, based on the quantitative and qualitative characters integrated in the phenotypic diversity index, may be applied to the prior systematisation of the inbred lines in maize breeding programs.
Implementation of scientific results: The systematization methodology of the maize gene pool is used in the institutional breeding program. The patented lines AG2174 and AG2448 are used to create new hybrids with low moisture in the grains. In the years 2010-2020 were produced the parental forms of the approved hybrids Porumbeni 374MRf-6928 kg, Porumbeni 427 - 8915 kg and Porumbeni 391 – 7500 kg, the production of certified hybrid seeds, being organized in ICP "Porumbeni", ETS "Pașcani" and LLC "Forever".
Oficial Reviewers
- Nadejda Mihnea
doctor, associate professor (docent) - Pantelimon Borozan
doctor, associate professor (docent)
Council's Members
- Maria Gonceariuc, president
doctor habilitat, professor, Institute of Genetics, Physiology and Plant Protection of the ASM - Eugenia Cotenco, secretary
doctor, associate professor (docent) - Simion Musteaţă, member
doctor habilitat, professor - Vasile Ţiganaş, member
doctor habilitat, associate professor (docent), Agrarian State University of Moldova - Eugenia Partas, member
doctor, associate professor (docent)
Theses
