Parâmetros genéticos em famílias de cruzamentos recíprocos de cana-de-açúcar
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Data
2017-07-25
Autores
Guimarães, Ana Carolina Ribeiro [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O melhoramento genético tem contribuído com o setor sucroalcooleiro lançando cultivares mais produtivas, resistentes ou tolerantes às principais pragas e doenças da cultura, fazendo com que o Brasil consiga suprir sua demanda por açúcar e etanol. Poucos são os estudos acerca da importância relativa dos parentais na performance das progênies para os atributos de interesse econômico em cana- de-açúcar. Os objetivos deste trabalho foram verificar a influência de efeito recíproco para caracteres de importância agronômica em cana-de-açúcar quanto ao número de colmos (lnNC), brix e tonelada de biomassa por hectare (TBIOH) e avaliar 8 famílias de cana-de-açúcar pelo método de modelos mistos, destacando as famílias e progênies superiores para os atributos analisados. Quatro cruzamentos biparentais e seus recíprocos, gerando 8 famílias de irmãos completos e a testemunha IACSP95-5000, foram avaliados em delineamento de blocos casualizados, com 20 blocos. As predições das famílias mostraram variabilidade para número de colmos (lnNC), brix e biomassa de touceira (BIO), o que permite seleção. Verificou-se a existência de efeitos maternos, paternos e interação entre eles para as características de brix e TBIOH. O parental feminino apresentou maior contribuição na determinação da performance do brix das progênies, porém, nem sempre o parental com alto teor de brix irá produzir progênie com performance superior. Entre os genótipos estudados, foi recomendada a utilização do parental feminino IACSP01-2419 e o parental masculino IACSP95-5000 para obtenção de progênies superiores quanto ao teor de sacarose (brix) e produtividade TBIOH. A cultivar RB966928 foi o parental masculino dos indivíduos com melhores valores de brix.
Sugarcane breeding has contributed to the sector, releasing varieties more productive, resistant or tolerant to major diseases and pests of the crop. The purpose of this study was to verify the influence of reciprocal effect to sugarcane agronomic traits: stalk number, brix and tonnes of biomass per hectare (TBIOH) and to evaluate eight sugarcane families by mixed model highlighting the superior families and progenies for the traits analyzed. Progenies from four biparental crosses and their reciprocal crosses were assessed in plant cane and first ratoon cane cycles. The experiment design used was completely randomized blocks, with 20 replications and 9 treatments (8 sugarcane families and a cultivated variety IACSP95-5000). Maternal, paternal and maternal x paternal interaction for the traits brix and TBIOH were observed. Significant reciprocal differences (P≤0.05) were found for stalk number brix and TBIOH in both cane cycles. Half of the assessed reciprocal crosses showed favorable effects within the reciprocals (P≤0,10) with a brix increase in the progeny means ranging from 0.9 to 1.7, using female parent IACSP98-2053. TBIOH showed significant effect within every reciprocal cross assessed in plant cane cycle. The predictions showed variability for stalk number, brix and biomass. The female parent IACSP01-2419 and the male parent IACSP95- 5000 can be indicated as female parents to obtain individual progeny with higher brix content and TBIOH productivity. The commercial variety RB966928 was the male parent of 37% among the thirty best individuals for brix.
Sugarcane breeding has contributed to the sector, releasing varieties more productive, resistant or tolerant to major diseases and pests of the crop. The purpose of this study was to verify the influence of reciprocal effect to sugarcane agronomic traits: stalk number, brix and tonnes of biomass per hectare (TBIOH) and to evaluate eight sugarcane families by mixed model highlighting the superior families and progenies for the traits analyzed. Progenies from four biparental crosses and their reciprocal crosses were assessed in plant cane and first ratoon cane cycles. The experiment design used was completely randomized blocks, with 20 replications and 9 treatments (8 sugarcane families and a cultivated variety IACSP95-5000). Maternal, paternal and maternal x paternal interaction for the traits brix and TBIOH were observed. Significant reciprocal differences (P≤0.05) were found for stalk number brix and TBIOH in both cane cycles. Half of the assessed reciprocal crosses showed favorable effects within the reciprocals (P≤0,10) with a brix increase in the progeny means ranging from 0.9 to 1.7, using female parent IACSP98-2053. TBIOH showed significant effect within every reciprocal cross assessed in plant cane cycle. The predictions showed variability for stalk number, brix and biomass. The female parent IACSP01-2419 and the male parent IACSP95- 5000 can be indicated as female parents to obtain individual progeny with higher brix content and TBIOH productivity. The commercial variety RB966928 was the male parent of 37% among the thirty best individuals for brix.
Descrição
Palavras-chave
Efeito recíproco, Brix, Biomassa, Saccharum spp, Reciprocal effect, Biomass