Divergent phenotypic selection for alfalfa cell wall fractions and indirect response in digestibility

2008 ◽  
Vol 88 (5) ◽  
pp. 891-898 ◽  
Author(s):  
I. Y. Tecle ◽  
J. L. Hansen ◽  
A. N. Pell ◽  
D. R. Viands
Keyword(s):  
Cell Wall ◽  
Phenotypic Selection ◽  
Breeding Strategy ◽  
Fiber Concentration ◽  
Indirect Response ◽  
Forage Digestibility ◽  
Acid Detergent Lignin ◽  
Medicago Sativa L ◽  
Selection For

An alfalfa (Medicago sativa L.) breeding strategy to decrease slowly digestible or indigestible fiber and simultaneously increase digestible fiber could improve forage quality without reducing total fiber. The objectives were: (1) to estimate selection responses from divergent and opposite direction selections of (i) hemicellulose (HEM) and acid detergent fiber (ADF), (ii) acid detergent lignin (LIG) and HEM + cellulose (CEL) and (iii) CEL and HEM + LIG, and (2) to determine correlated responses in in vitro true digestibility (IVTD). Selection progress was evaluated in replicated plot trials at two locations, sampled for 2 or 3 yr. Selection for divergent HEM and ADF resulted in change only for ADF [10.9 g kg-1 dry matter (DM)]. Selection for divergent LIG and HEM + CEL, resulted in same direction change in LIG (3.3 g kg-1 DM). Selection for divergent CEL and HEM + LIG resulted in change only in CEL (5.1 g kg-1 DM). Low LIG and high HEM + CEL, and low ADF and high HEM populations had 9.7 and 8.3 g kg-1 DM higher IVTD than their counterparts, respectively. The first cycle of selection for the fiber components simultaneously in the opposite directions was not successful. However, reduced LIG or ADF concentration appears to increase alfalfa forage digestibility and decrease total fiber concentration. Key words: Alfalfa, cell wall, hemicellulose, cellulose, lignin, digestibility

Prediction of forage digestibility from some laboratory procedures. 2. Comparison of in vivo digestibility at two institutes.

1971 ◽  
Vol 19 (2) ◽  
pp. 106-113
Author(s):  
B. Deinum
Keyword(s):  
Cell Wall ◽  
Organic Matter ◽  
Sulfuric Acid ◽  
Lignin Content ◽  
Forage Digestibility ◽  
Significant Difference ◽  
Laboratory Procedures ◽  
Sulfuric Acid Lignin

For part 1 see Abst. 1564, Vol. 40. 2. The relation between digestibilities of organic matter in vivo and in vitro did not differ significantly between the institutes at Hoorn and Wageningen. No difference was found in digestibility of the cell wall constituents in relation to the lignin content, nor was there a significant difference in the relation between the percentage of digestible cell contents and the percentage of cell contents in forage from well managed pastures. Twelve forages of highly digestible perennial ryegrass deviated from these farm forages at Wageningen, showing smaller excretion of bacterial and endogenous residue. Comparison of the 2 lignin procedures showed that 72% sulfuric acid lignin gave consistent residual standard deviations of digestibility of cell wall constituents; permanganate lignin gave smaller errors in forages at Wageningen but greater errors in forages at Hoorn. (Abstract retrieved from CAB Abstracts by CABI’s permission)

GENETIC VARIATION FOR FORAGE QUALITY OF ALFALFA STEMS

1987 ◽  
Vol 67 (4) ◽  
pp. 1057-1067 ◽  
Author(s):  
D. R. BUXTON ◽  
G. C. MARTEN ◽  
J. S. HORNSTEIN
Keyword(s):  
Cell Wall ◽  
Genetic Variation ◽  
Medicago Sativa ◽  
Crude Protein ◽  
Nutritive Value ◽  
Growth Traits ◽  
Forage Quality ◽  
In Vitro Digestibility ◽  
Medicago Sativa L

When normally harvested for hay, the basal portion of alfalfa (Medicago sativa L.) stems is low in forage quality. This study was conducted to determine whether genetic variation for in vitro digestible dry matter (IVDDM) and crude protein (CP) concentration of stems of perennial Medicago spp. could be identified and whether morphological and chemical traits were associated with variation in these characteristics of stems. The lower six nodes and internodes of stems and total herbage from 64 Plant Introduction (PI) accessions and five cultivars of field-grown plants were harvested twice when most plants were at the early seed-pod stage of maturity. Several morphological and growth traits were measured, and both stems and total herbage were evaluated for IVDDM and CP concentration. Covariant analysis was used to adjust in IVDDM and CP concentration of stems for differences in plant maturity. Significant variation for IVDDM and CP concentration in stems existed among the cultivars and among the accessions. Some accessions had significantly higher stem IVDDM or CP concentration than control cultivars. The M. sativa accession, PI 440496, had the fourth highest stem IVDDM and third highest stem CP, with concentrations of 374 and 79 g kg−1, respectively. The number of ridges on stems (stem shape) was significantly correlated with stem IVDDM and CP concentration with average correlation coefficients of 0.30 and 0.35, respectively. Cell-wall concentration and lignin concentration per unit cell wall of stems were both negatively correlated with stem IVDDM and CP concentration. Selection for improved nutritive value of stems may have potential for improving the nutritive value of alfalfa herbage.Key words: Alfalfa, forage quality, crude protein, in vitro digestibility, Medicago sativa L.

Breeding for root yield in alfalfa

1991 ◽  
Vol 71 (3) ◽  
pp. 727-735 ◽  
Author(s):  
G. Saindon ◽  
R. Michaud ◽  
C. A. St-Pierre
Keyword(s):  
Root System ◽  
Inorganic Nitrogen ◽  
Root Traits ◽  
Phenotypic Selection ◽  
Nitrogen Fertilizers ◽  
Root Yield ◽  
Root Branching ◽  
Indirect Response ◽  
Crown Width ◽  
Medicago Sativa L

Winter survival of alfalfa (Medicago sauva L.) has often been associated with the size of the root system but breeding for a larger root system has never received much attention. The objectives of this study were to detect variability for root traits among seven alfalfa entries grown under two nitrogen fertilizer treatments (R- and N-treatments) which consisted of Rhizobium nitrogen fixation and inorganic nitrogen fertilizers, respectively; to select for root yield in two alfalfa cultivars grown under the same two treatments and to measure resulting progress; and to determine which of the two N regimes is more appropriate for root yield selection. Variability for root yield, number of laterals, crown width and top yield was found among R-treated entries whereas only the crown width varied among the N-treated ones. The evaluation under both treatments showed that one cycle of bidirectional phenotypic selection made under both the R- and N-treatments was sufficient to allow the formation of divergent populations for root yield with the exception of Apica-derived populations which showed inconsistent or no responses when evaluated under the N-treatment. Independently of the cultivars and treatments used for selection and evaluation, asymmetries of response were observed. Possible explanations are proposed but additional cycles of selection are needed to provide definitive conclusions. Indirect selection responses observed for top yield, crown width, and root branching should make selection for increasing root yield in alfalfa attractive. Key words: Medicago sativa L., root branching, realized heritability, asymmetry of response, indirect response

scholarly journals Recurrent Selection for Improved Germination under Water Stress in Russian Dandelion

2017 ◽  
Vol 142 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Katrina J.M. Hodgson-Kratky ◽  
Olivier M. Stoffyn ◽  
David J. Wolyn
Keyword(s):  
Polyethylene Glycol ◽  
Water Stress ◽  
Recurrent Selection ◽  
Field Experiments ◽  
Phenotypic Selection ◽  
Bare Soil ◽  
Promising Candidate ◽  
Breeding Programs ◽  
Selection For

Russian dandelion [Taraxacum kok-saghyz (TKS)] is a promising candidate for introducing natural rubber production into North America. Seeds normally germinate in a humid microenvironment, such as the thatch layer of a lawn or under a canopy of grass; however, 5% to 15% establishment is often observed on bare soil, presumably due to water stress. Phenotypic selection and half-sib family recurrent selection were conducted for three cycles to improve germination in vitro, under low osmotic potential (Ψs), using a polyethylene glycol (PEG) solution. Populations were then tested for establishment on bare soil in the greenhouse and field. Germination under water stress in vitro increased from 5.8% for the cycle 0 (C0) population to 40.8% and 47.8% for the C3-phenotypic and C3-half-sib family populations, respectively. Soil establishment in the greenhouse and field was improved up to two- and 4-fold, respectively, compared with the C0, in two of four greenhouse experiments and three of eight field experiments. Overall, recurrent selection for germination under water stress in vitro has potential to improve establishment in the field and can be incorporated into current breeding programs to support the overall goal of creating cultivars with high-rubber yield.

SELECTION IN ALFALFA FOR TOLERANCE TO TOXIC LEVELS OF ALUMINUM

1988 ◽  
Vol 68 (3) ◽  
pp. 743-753 ◽  
Author(s):  
T. A. CAMPBELL ◽  
J. H. ELGIN JR. ◽  
C. D. FOY ◽  
J. E. McMURTREY III
Keyword(s):  
Honey Bees ◽  
Shoot Growth ◽  
Recurrent Selection ◽  
Selection Procedure ◽  
Phenotypic Selection ◽  
Al Tolerance ◽  
Medicago Sativa L ◽  
Selection For ◽  
Nutrient Solutions ◽  
Made In

The alfalfa (Medicago sativa L.) population ’B13’ was screened through four cycles of recurrent phenotypic selection for tolerance to toxic levels of Al in growth chambers; germplasm from cycles 1 through 4 was designated B13-A11, B13-A12, B13-A13, and B13-A14, respectively. Cycles 1 and 2 were screened in Tatum clay-loam subsoil (36% Al saturation for cycle 1 and 61% Al saturation for cycle 2), and cycles 3 and 4 were screened in a modified Steinberg solution (111 μmol Al, pH 4.5). Selection was based on root growth in the first two cycles and shoot growth in the latter two cycles. Selections were intercrossed with honey bees (Apis mellifera L.) at the end of each cycle. Efficacy of the selection procedure was evaluated in pH 4.5 Steinberg solutions (Al concentration of 0 or 111 μmol), and in Tatum soil (0 or 68% Al saturation). Regression analysis indicated that significant but minimal progress was made in developing synthetics with improved vigor under Al toxic conditions. B13-A14 was among the least impaired of the entries in the ability to take up nutrients whereas AS-4 and Williamsburg (susceptible checks) were among the most impaired. It was concluded that tolerance to Al in nutrient solutions and soil could involve different mechanisms and that the screening procedure used here was much more effective in selecting for vigor than for Al tolerance. Alternative breeding approaches were proposed.Key words: Alfalfa, plant breeding, germplasm, recurrent selection, hydroponic, nutrient solution

Characterization of alfalfa (Medicago sativa L.) following in vitro selection for salt tolerance

Euphytica ◽  
1996 ◽  
Vol 92 (1-2) ◽  
pp. 55-61 ◽  
Author(s):  
A. Safarnejad ◽  
H. A. Collin ◽  
K. D. Bruce ◽  
T. McNeilly
Keyword(s):  
Salt Tolerance ◽  
Medicago Sativa ◽  
In Vitro Selection ◽  
Medicago Sativa L ◽  
Selection For

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.

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