Identification of popcorn inbred lines for aluminum resistance

• Ano de defesa: 2016
• Autor(a) principal: Rahim, Faisal
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa
• Palavras-chave em Português: Milho de pipoca - Melhoramento genético; Milho de pipoca - Efeito do alumínio; Raízes - Crescimento; Genética Quantitativa
• Link de acesso: http://www.locus.ufv.br/handle/123456789/9490

Genetic improvement of crops is an essential approach to overcome the aluminum toxicity in acidic soils. The objective of the present investigation was to assess popcorn inbred lines for aluminum resistance. Eighteen tropical popcorn inbreds were assessed in three experiments in the presence and absence of aluminum, in a complete randomized design with three or five replications. The aluminum concentration in the nutrient solution was 540 μM AlCl 3 (160 μM Al 3+ ). The first experiment provided an initial assessment of these inbreds. Then, in a second experiment we assessed ten of the 18 inbred lines, including the two most resistant, the two less resistant, and other six with intermediate performance, choose at random. Finally, we assessed the two most contrasting inbred lines in a third experiment, including also a resistant check (hybrid 2B710PW). The inbred lines were assessed for relative root growth (RRG), hematoxylin staining, aluminum content and external morphology of roots, based on stereoscopic and electron microscopy analyses. The inbred 11-60 showed the lowest RRG (0.02 and 0.06), the greatest aluminum accumulation (1,660 μg/g), and exhibited stronger blue staining with intense epidermal degradation. The inbred 11-133 showed the greatest RRG (0.15 to 0.37) and the lowest hematoxylin staining score, aluminum accumulation (926.4 μg/g) and root inhibition in the root tips, associated with no damages on root apices. Scanning electron micrographs showed severe cell disruption and deep ruptures of the protodermic and outer cortex layers of the root cells of 11-60. The inbred line 11- 133 was as resistant as the check.