The in vitro digestibility of parents and hybrids of cocksfoot (Dactylis glomerata L.)

1968 ◽  
Vol 19 (3) ◽  
pp. 373 ◽  
Author(s):  
R Knight ◽  
NG Yates
Keyword(s):  
Combining Ability ◽  
Dactylis Glomerata ◽  
General Combining Ability ◽  
In Vitro Digestibility ◽  
Growth Rhythm ◽  
In Vitro Technique ◽  
Selection For ◽  
Dactylis Glomerata L

The digestibility of a range of genotypes of cocksfoot (Dactylis glomerata L.) and their hybrids was estimated by an in vitro technique at eight harvests over a period of 14 months. The material for analysis was grown in a Mediterranean type environment with summer irrigation and obtained by recurrent defoliation of sward plots. Digestibility values tended to be lower in summer than in winter, although some material showed a fall in digestibility in the middle of winter. Within a harvest there were correlations between general combining ability and parental performance, but there was little uniformity in ranking of parents or their progenies from one harvest to the next, which would make selection for uniform high digestibility very difficult. Reasons for the fluctuations are not known, and were not obviously correlated with any aspect of the growth rhythm apart from a correlation with heading on one harvest occasion.

EFFECTIVENESS OF ONE CYCLE OF PHENOTYPIC SELECTION FOR IN VITRO DIGESTIBILITY IN BROMEGRASS AND ORCHARD GRASS

1977 ◽  
Vol 57 (1) ◽  
pp. 57-60 ◽  
Author(s):  
B. R. CHRISTIE
Keyword(s):  
Dactylis Glomerata ◽  
Phenotypic Selection ◽  
Bromus Inermis ◽  
The Other ◽  
In Vitro Digestibility ◽  
Orchard Grass ◽  
Selection For ◽  
Dactylis Glomerata L

Twenty-seven topcross and nine polycross progenies of bromegrass (Bromus inermis Leyss) were evaluated for in vitro digestibility (IVD) and yield. Two groups of polycross progenies of orchard grass (Dactylis glomerata L.) were also evaluated. Bromegrass plants varied in IVD from 58 to 70%, while their topcross progenies varied from 58.2 to 64.6%. The correlation between parents and progeny was 0.55. Selection for high IVD did not result in any improvement over cv. Saratoga. One group of 10 orchard grass plants was high in IVD (62–66%), while the other was low (50–58%). The polycross progenies of these two groups were similar (68.2% vs. 68.5%). Selection for IVD was not effective in altering progeny IVD values.

VARIABILITY OF IN VITRO DIGESTIBILITY AMONG CLONES OF BROMEGRASS AND ORCHARDGRASS

1968 ◽  
Vol 48 (1) ◽  
pp. 67-73 ◽  
Author(s):  
B. R. Christie ◽  
D. N. Mowat
Keyword(s):  
Dactylis Glomerata ◽  
Bromus Inermis ◽  
In Vitro Digestibility ◽  
Phenotypic Characteristics ◽  
Whole Plant ◽  
Stems And Leaves ◽  
Dactylis Glomerata L ◽  
Whole Plants ◽  
Genotypic Effects

Individual clones of bromegrass (Bromus inermis Leyss) and orchardgrass (Dactylis glomerata L.) were harvested at corresponding stages of maturity within each species. The orchardgrass clones were harvested in 1962, and the in vitro digestibility (IVD) was based on the whole plant. Bromegrass clones, harvested in 1965 and 1966, were separated into leaves and stems. The IVD of each component was determined, and from these, the IVD for the whole plant was estimated.Among 444 orchardgrass clones, IVD values ranged from 49 to 68%. Most of the variation was attributed to genotypic effects. For approximately 250 clones of bromegrass, IVD values ranged from 66 to 75%, 58 to 73%, and 62 to 74%, for leaves, stems, and whole plants respectively. Over the 2-year period, differences among stems and whole plants were significant. Correlations between leaf and stem digestibilities were significant but of low magnitude. Ten clones of bromegrass had stems and leaves of equal digestibility.In bromegrass, IVD values showed no relationship to several phenotypic characteristics.

scholarly journals VARIATION IN DIGESTIBILITY DECLINE WITH ADVANCE IN MATURITY AMONG TIMOTHY (Phleum pratense L.) GENOTYPES

1986 ◽  
Vol 66 (2) ◽  
pp. 323-328 ◽  
Author(s):  
A. R. McELROY ◽  
B. R. CHRISTIE
Keyword(s):  
Forage Quality ◽  
Phleum Pratense ◽  
In Vitro Digestibility ◽  
Single Population ◽  
Population Mean ◽  
Unit Increase ◽  
Selection For ◽  
Phleum Pratense L

The in vitro digestibility (IVD) of timothy (Phleum pratense L.) declines with advance in maturity. Forage quality reductions resulting from late harvesting could be minimized by developing cultivars with reduced IVD decline during maturation. This study examines variation for IVD decline among timothy genotypes. Clones originating from a single population were grown in simulated swards (100 plants m−2) at two Ontario locations in 1980 and 1981. Harvests were made every 5–6 d from early heading to late anthesis. Relative IVD declines were determined by regressing genotype performance on the population mean over several harvests. Considerable variation was found for relative IVD decline, but this parameter was not associated with IVD at early heading. Genotypes were identified which showed high IVD at heading and a 20% reduction in digestibility decline from heading to late anthesis. Changes in IVD were not associated with changes in the leaf content of forage. It is concluded that selection for reduced IVD decline, in addition to high digestibility at heading, might result in a 2–3% unit increase at anthesis.Key words: Timothy, Phleum pratense L., in vitro digestibility, IVD, IVD decline

scholarly journals Diallelic analysis for lysine and oil contents in maize grains

2009 ◽  
Vol 66 (2) ◽  
pp. 204-209 ◽  
Author(s):  
Leonardo Oliveira Medici ◽  
Salete Aparecida Gaziola ◽  
Vanderlei Aparecido Varisi ◽  
José Antonio Carmezini de Paula ◽  
Renato Rodrigues Ferreira ◽  
...  
Keyword(s):  
Grain Yield ◽  
Combining Ability ◽  
Oil Content ◽  
General Combining Ability ◽  
Lysine Content ◽  
Nitrogen Levels ◽  
N Level ◽  
Complete Series ◽  
Selection For ◽  
Selection Of

Six S5 lines of maize, with differences for lysine and oil contents in grains, were used to carry out a complete series of diallelic crosses. The resulting 15 hybrids were grown in a field at two nitrogen levels (10 and 130 kg N ha-1). The general combining ability (GCA) and specific combining ability (SCA) were obtained by using the method 4, model I of Griffing for grain yield, and grain lysine and oil contents. Significant (p < 0.001) interaction was observed between GCA and N levels for grain yield, indicating the selection of different lines for each N level. This interaction was not significant for lysine content, but there were significant effects of GCA for this trait at both N levels (p < 0.1). Significant effects were not observed for GCA or SCA for oil content, however a positive correlation was observed between lysine and oil contents in the hybrids, in the lines and even in the control cultivars. The results indicate the effectiveness of selection for lysine content, irrespective of N level, in the studied non-opaque maize lines, and the possibility of achieving both high lysine and oil content in grains.

AC Nordic orchardgrass (Dactylis glomerata L.)

1993 ◽  
Vol 73 (3) ◽  
pp. 845-846 ◽  
Author(s):  
A. R. McElroy
Keyword(s):  
Key Words ◽  
Stem Rust ◽  
Dactylis Glomerata ◽  
Research Centre ◽  
Mass Selection ◽  
Puccinia Graminis ◽  
Plant Research ◽  
Selection For ◽  
Dactylis Glomerata L

AC Nordic is a late-maturing orchardgrass (Dactylis glomerata L.) cultivar. It was developed by mass selection for yield, persistence and resistance to stem rust (Puccinia graminis) at the Plant Research Centre, Agriculture Canada, Ottawa. Its yield was similar to that of cv. Sumas in a total of 33 station years in Quebec. Yield in second and subsequent production years was 101.6% of cv. Sumas over 19 station years. Key words: Dactylis glomerata L., orchardgrass

scholarly journals COMBINING ABILITY OF FORAGE WATERMELON ( Citrullus lanatus var. citroides ) GERMPLASM

2017 ◽  
Vol 30 (3) ◽  
pp. 768-775 ◽  
Author(s):  
ROBERTA MACHADO SANTOS ◽  
NATONIEL FRANKLIN DE MELO ◽  
MARIA ALDETE JUSTINIANO DA FONSECA ◽  
MÁRIO ADRIANO ÁVILA QUEIROZ
Keyword(s):  
Protein Content ◽  
Dry Matter ◽  
Citrullus Lanatus ◽  
Fruit Yield ◽  
F1 Hybrids ◽  
In Vitro Digestibility ◽  
Ethereal Extract ◽  
Selection For ◽  
Number Of Seeds

ABSTRACT The aim of this study was to identify parents and promising hybrid combinations for the improvement of forage watermelon. Five parents were evaluated: BGCIA 996 (1), BGCIA 997 (2), BGCIA 998 (3), BGCIA 228 (4), Jojoba (5) and ten F1 hybrids, which were obtained from balanced diallel crosses. The experimental design was in a complete randomized block, with three replications. The morphoagronomic and bromatological traits were evaluated. The highlights were the progenitors BGCIA 997, BGCIA 998, BGCIA 228 and Jojoba for protein content, fruit yield, in vitro digestibility of dry matter and number of seeds, respectively. The hybrid 1x4 stood out for fruit length, seed number, and ethereal extract. The hybrid 2x3 stood out for rind and pulp thickness while the hybrids 3x4, 3x5 and 4x5 had exceptional digestibility, protein content and fruit yield, respectively. The analysis of the standard deviation of the SCA estimates of both SD (Sij- Sik) and SD (Sij- Skl) indicated that no hybrids were found that had SCA estimates twice that of SD (Sij- Sik) or SD (Sij- Skl), except for the hybrid 1x4 for the number of seeds per fruit. These results suggest that the parents were more promising than the hybrids. Similarly, the GCA estimates favor the intrapopulation method, which will promote greater efficiency in selection for genetic gains.

Selection for crude protein content in Phalaris tuberosa L. I. Response to selection and preliminary studies on correlated responses

1969 ◽  
Vol 20 (4) ◽  
pp. 643 ◽  
Author(s):  
RJ Clements
Keyword(s):  
Crude Protein ◽  
Nutritive Value ◽  
Breeding Population ◽  
In Vitro Digestibility ◽  
Seedling Vigour ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Selection For ◽  
Pasture Plant

In a highly variable breeding population of P. tuberosa, marked responses were obtained to three generations of selection for high and low crude protein concentration (percentage nitrogen x 6.25) in whole tillers at heading. Total response was similar in each direction, and realized heritability estimates were h2 = 0.25 and h2 = 0.20 in the high and low directions respectively. The responses were accompanied by positively correlated changes in in vitro digestibility and in characters commonly used as indicators of nutritive value of herbage. However, there were large negatively correlated changes in seedling vigour, relative growth rates, and other morphological and physiological characters. The implications of the results for pasture plant breeding are discussed.

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