Data/hora: 16/06/2024 10:18:17

Biblioteca(s): | Embrapa Cerrados.
Data corrente: | 25/09/1998
Data da última atualização: | 25/09/1998
Autoria: | FONSECA, C. L.
Título: | Breeding for neutral detergent-soluble fiber and associations among forage quality traits, vigor, and disease resistance in alfafa.
Ano de publicação: | 1998
Fonte/Imprenta: | [Ithaca]: Cornell University, 1998.
Páginas: | 123p.
Idioma: | Inglês
Notas: | PhD Dissertation.
Conteúdo: | Little is known about breeding for neutral detergent-soluble fiber (NDSF) and about the genetic relationship among diseases, quality traits, and vigor in alfalfa (Medicago sativa L.). We conducted a study to determine the potencial use of near infrared reflectance spectroscopy (NIRS) to predict NDSF concentration, mostly pectin in alfalfa, and to estimate heritability and expected gains from selection for NDSF concentration. Data were collected from herbage harvested three times in 1996 and twice in 1997 from two alfalfa half-sib (HS) progeny tests. Initially, a comparison between 90 and 80% ethanol extractions was made for NIRS calibration using samples from the second harves, 1996. Both 90 and 80% ethanol extraction was used to assay all of the remaining samples. The calibration equation standard errors for predicting NDSF from individual harvest were small, ranging from 4.71 to 7.54 g kg 1-. Squared coefficients of multiple determination (R) ranged from 0.72 to 0.97. Near infrared reflectance spectroscopy (NIRS) can be a useful tool quickly evaluate NDSF concentration from a large number of forage samples. Selection of parent genotypes with high NDSF concentrations based on HS family evaluation and NIRS equations may be effective. In a separate study, the same populations were evaluated for resistance to five diseases, nutritional quality, and vigor. Simple, phenotypic, and additive genetic correlation coefficients were estimated for all possible combinations of traits from independent experiments for each dissease and quality trait. Selection for bacterial wilt resistance in some populations may have a positive impact on Fusarium wilt resistance. Selection for higher NDSF concentrations may decrease the concentrations of the other cell-wall fiber components and increase true in vitro dry matter digestibility. Selections for lower fiber and/or higher crude protein concentrations may decrese vigor. Significant correlations between quality traits, disease resistances, and vigor were not of sufficient magnitude to adversely affect the improvement of these traits. Direct selection for all traits, except for phytophthora root rot, based on HS progeny tests, may be effective for both populations.
Palavras-Chave: | Anthracnosis; Bacterioses; Correlacao genetica; Espectrofotometro infra-vermelho; Fibres; Fungal diseases; Herdabilidade; Infrared spectrophotometry; Lignins; Murcha de verticilium; NIRS; Phenotypes; Phytophtora; Surface active agents.
Thesagro: | Alfafa; Antracnose; Detergente; Fenótipo; Fibra; Fungo; Fusarium; Lignina; Medicago Sativa; Melhoramento Genético Vegetal; Murcha Bacteriana; Murcha de Fusarium; Pectina; Podridão da Raiz; Solubilidade; Verticillium.
Thesaurus Nal: | fungi; genetic correlation; heritability; pectins; plant breeding; solubility.
Categoria do assunto: | --
Registro original: | Embrapa Cerrados (CPAC)
Exemplares: | CPAC - (19335-1) - ADD - TS - -- - T007/98 - FON - T007/98 - DIS