Análise biométrica da qualidade fisiológica de sementes de milho

• Ano de defesa: 2010
• Autor(a) principal: Moterle, Lia Mara
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual de Maringá; Brasil; Programa de Pós-Graduação em Agronomia; UEM; Maringá, PR; Departamento de Agronomia
• Palavras-chave em Português: Milho-pipoca (Zea mays L.); Milho (Zea mays L.); Qualidade fisiológica; Germinação de sementes; Melhoramento genético; Capacidade de combinação; Milho; Semente; Milho híbrido; Germinação e vigor; Capacidade de expansão; Rendimento de grãos; Paraná; (Estado); Brasil.; Zea mays L; Combining ability; Germination and vigour; Popping expansion; Grain yield; Parana; State; Brazil.; Ciências Agrárias; Agronomia
• Link de acesso: http://repositorio.uem.br:8080/jspui/handle/1/1095

In spite of the many advances in the field of agronomic trait improvement for popcorn and corn crops, data on the heterotic effect on seed quality if has shown inconsistent. Thus, the objective was to quantify the combining ability of inbred lines of popcorn and corn for seed quality and agronomic traits and, to evaluate the potential of these lines and their hybrids. Thus, seeds from nine popcorn lines and nine corn lines were produced in the experimental area of the State University of Maringá (UEM), state of Paraná, Brazil. Therefore, two complete diallels - one for popcorn and the other for corn - with 36 (F1's) and 72 (F1's and reciprocals) crosses, respectively. In the evaluation of the physiological quality of the popcorn seeds had used tests of germination (first count-PC, and final count-GER), accelerated aging (ENV), modified cold (FRIO), electrical conductivity (bulk system) (COE), seedling emergence in sand bed (EA), speed of emergence in sand (emergence speed formulas-VE, and emergence speed index-IVE), seedling length (shoot-CPA e root-CRP) (CPA and CRP) and seedling dry biomass (BS). The same tests were used for corn, with the exception of tests ENV, COE, CPA, CRP and BS. The agronomic traits of popcorn evaluated in triple lattice were: plant height (AP); first ear insertion height (AE); number of lodged plants (NPA); number of broken plants (NPQ); final stand (SF); number of ears (NE); number of poorly hulled ears (NEME); grain yield (RG) and popping expansion. For corn, the same traits were evaluated, with the exception of number of ears and popping expansion. For diallel analysis, Griffing's methods 4 and 3 were used for popcorn and corn, respectively, both in the fixed model. With popcorn, the results had allowed to conclude that, for most of the evaluated traits, the effects of the specific combining ability prevailed, evidencing the greater importance of non-additive gene effects for the genetic control of the physiological quality of popcorn seeds. The Zélia and CMS42 inbred lines show promise for obtaining hybrids, either for seeds with superior physiological quality or popping expansion, and they can be used as testers to evaluate the SCA of other lineage groups. GCA estimates for the CMS42, IAC-112 and Zaeli inbred lines confirm their potential in the exploration of heterosis for grain yield and popping expansion. The combinations CMS42xIAC-112, ZéliaxIAC-112, ZéliaxZaeli and UEM-J1xZaeli were the most promising with regards to SCA for physiological quality of seeds, and can be recommended in breeding programs. The hybrids ZéliaxIAC-112, CMS43-1xIAC-112, UEM-M2-2xZaeli, ZéliaxUEM-M2-1, CMS42xUEM-M2-1 and UEM-M2-2xZaeli are promising for traits RG and CE. The inbred line CMS42 combined high GCA physiological quality, popping expansion and grain yield. The hybrids ZéliaxIAC-112, CMS42xUEM-M2-1, CMS43-1xIAC-112 and UEM-M2-2xZaeli combined high popping expansion and yield, by standing out in at least two tests of evaluation of the physiological quality of the seeds. With corn, there was a greater importance of non-additive gene effects for the genetic control of the physiological quality of popcorn seeds. The inbred lines Flash, Dekalb350, 30F80, 8330 and CD3121-1 show promise for obtaining hybrids with superior seed quality. The combinations CD3121-1x30F80 and 8330xCD3121-1 they must be used to obtain superior segregates for germination and vigor of corn seeds. In the FRIO and EA tests, there was a reciprocal effect for hybrids CD3121-1xCD3121-2 and AG8080xSpeed, respectively. The inbred lines Dekalb350 and AG8080 are useful for the synthesis of promising hybrids for the regular and winter season harvests in northwestern Paraná. On the basis of the estimates, there was a reciprocal effect in hybrids FlashxStrike, 8330xSpeed for the plant height trait. The inbred lines Flash, Dekalb350 and 30F80 combined high SCA physiological quality seeds and grain yield. The combinations CD3121-1x30F80, SpeedxCD3121-2, 8330xAG8080, Dekalb350xCD3121-2 are the most promising among the evaluated hybrids, with high SCA estimates for physiological quality and yield during the regular season harvest.