Forage value of superior interspecific hybrids of Paspalum

Abstract

RESUMO -O objetivo deste estudo foi avaliar a expressão de caracteres agronômicos e a tolerância ao frio de híbridos apomíticos de Paspalum plicatulum x P. guenoarum, bem como estimar suas correlações fenotípicas, em duas regiões edafoclimáticas distintas. O estudo foi conduzido em diferentes locais e anos de avaliação, em delineamento de blocos ao acaso, com três repetições. Foram avaliados quatro híbridos interespecíficos de Paspalum, dois genótipos de P. guenoarum e a cv. Aruana (Panicum maximum), utilizada como testemunha. Os híbridos H12, H13, H20 e H22 apresentaram superioridade para os caracteres agronômicos avaliados e tolerância ao frio, em relação às cvs. Rojas e Aruana e ao ecótipo Azulão, e são indicados para novas etapas de avaliação, como estimativas da produção de sementes e estudos de DHE e VCU, visando o lançamento como novas cultivares. As estimativas de correlações fenotípicas são importantes ferramentas para a seleção de progênies, com destaque para o caráter MSF que apresentou alta correlação positiva com os caracteres MST, DPP, rebrote e altura, indicando ser desnecessária a realização de separação morfológica, economizando tempo e mão de obra em um programa de melhoramento de forrageiras.Palavras-chave: Apomixia. Hibridação. Paspalum guenoarum. Paspalum plicatulum. Produção de forragem.ABSTRACT -The aim of this study was to evaluate the expression of agronomic characteristics and tolerance to cold in apomictic Paspalum plicatulum x P. guenoarum hybrids, and estimate their phenotypic correlations in two different regions of soil and climate. The study was conducted at different locations and evaluated in different years, in a randomised block design with three replications. Four interspecific hybrids of Paspalum and two genotypes of P. guenoarum were evaluated, with the Aruana cultivar (Panicum maximum) used as a control. The H12, H13, H20 and H22 hybrids proved to be superior in tolerance for cold and the agronomic traits evaluated relative to the Rojas and Aruana cultivars and the Azulão ecotype, and are suitable for new stages of assessment, such as estimates of seed production and studies of DHS and VCU, with a view to their release as new cultivars. Estimates of phenotypic correlations are important tools in progeny selection, especially the characteristic of LDM, which showed a high positive correlation with the characteristics TDM, PDP, regrowth and height, demonstrating that carrying out morphological separation is unnecessary, saving time and labour in a forage breeding program.

Reproductive Systems in Paspalum: Relevance for Germplasm Collection and Conservation, Breeding Techniques, and Adoption of Released Cultivars

“…Inter-specific hybrids were generated in the Plicatula group of Paspalum using a chromosome-doubled sexual plant of P. plicatulum and apomictic ecotypes of different species of the Plicatula group (Novo et al, 2013; Pereira et al, 2015; Novo et al, 2016; Novo et al, 2017). New highly apomictic hybrids were generated, and several were characterized as superior for forage yield, cold tolerance, and cattle preference with respect to the apomictic male parent (Da Costa Huber et al, 2016; Motta et al, 2017; Novo et al, 2017). This approach may also be used to hybridize P. vaginatum and P. distichum , since P. vaginatum is sexual and cross-pollinated and P. distichum is mainly tetraploid and apomictic (Bashaw et al, 1970; Ortiz et al, 2013).…”

Forage characters of different Paspalum species in Rio Grande do Sul: a meta-analysis

“…Because only a few trials reported the leaf:stem ratio (LSR) and harvest index (HI), we calculated these variables using the following formulae: LSR = LDMP/SDMP (PEREIRA et al, 2012;PEREIRA et al, 2015;MOTTA et al, 2017) and HI = LDMP/ TDMP (PEREIRA et al, 2012), respectively.…”

“…Data from six studies were used in the database: SANTOS (2005), STEINER (2005), SAWASATO (2007), TOWNSEND (2008), PEREIRA et al (2012), andMOTTA et al (2017) The studies produced 135 observations on the following species: Paspalum notatum, ecotypes André da Rocha and Bagual, and the commercial cultivar 'Pensacola'; P. guenoarum, ecotypes Azulão, Baio, and the cultivar 'Rojas'; P. urvillei: accessions collected in Rio Grande do Sul, in the municipalities of André da Rocha, Eldorado do Sul, and Bagé; P. lepton: accessions collected in Rio Grande do Sul, in the municipalities of Alegrete (26A and 26D) and Rosário do Sul (28B, 28C, and 28E); P. denticulatum and P. pauciciliatum. Two different species belonging to other genera, Panicum maximum Jacq.…”

“…The chromosomal set of the sexual genotype was duplicated with colchicine (SARTOR et al, 2009) to enable cross-breeding between the different species and promote the production of fertile offspring. Hybrids evaluated (H12, H13, H20, and H22) were selected for their higher TDMP, as described by PEREIRA et al (2015) and MOTTA et al (2017).…”

Production of dallisgrass in response to NPK fertilizer in southwest China and its implications for cultivation

“…is a C 4 grass widely distributed in tropical, subtropical and temperate-warm regions. It has high nutritional value and good palatability (Robinson et al, 1988); it can be green fed, sun-dried or as silage and is suitable for grazing (Motta et al, 2017;Tejera et al, 2016;Zuloaga & Morrone, 2005).…”