Genetic variation for seed yield and its components in alfalfa (Medicago sativa L.) populations

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.

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Field evaluation following two cycles of backcross transfer of somatic embryogenesis to commercial alfalfa germplasm

Canadian Journal of Plant Science ◽

10.4141/cjps93-016 ◽

1993 ◽

Vol 73 (1) ◽

pp. 131-137 ◽

Cited By ~ 10

Author(s):

S. R. Bowley ◽

G. A. Kielly ◽

K. Anandarajah ◽

B. D. McKersie ◽

T. Senaratna

Keyword(s):

Somatic Embryogenesis ◽

Medicago Sativa ◽

Seed Yield ◽

Field Experiments ◽

Field Evaluation ◽

Growth Characteristics ◽

Seed Technology ◽

Artificial Seed ◽

Medicago Sativa L

For successful application of artificial seed technology to alfalfa (Medicago sativa L.), parental plants must possess the necessary genes for somatic embryogenesis and produce progeny having high commercial value. A backcross procedure was initiated to transfer the ability to form somatic embryos from genotype A70-34, a selection from the cultivar Rangelander, to multiple-pest-resistant alfalfa germplasm. The objectives of this study were to evaluate the growth characteristics and seed yield of the F1; BC1 and BC2 generations to determine if introgression with commercial germplasm had improved the agronomic features of the embryogenic germplasm. This study consisted of two field experiments, each conducted at two locations. One experiment evaluated herbage growth characteristics and herbage production at Elora and Woodstock, Ontario, and the other evaluated seed yield at Elora and Delhi, Ontario. Significant increases in fall regrowth height, leaflet length:width ratio, and seed yield were detected over the cycles of crossing. By the BC2, fall dormancy and leaflet length:width ratio were similar to those in commercial populations. Although improvements in seed yield were detected, the BC2 was inferior in seed yield compared with commercial germplasm, and further introgression and (or) conscious selection for improved seed yield will be required. Through a population backcross procedure, it appears possible to develop commercial alfalfa germplasm capable of in vitro manipulation. Key words: Alfalfa, Medicago sativa L., somatic embryogenesis, artificial seed, backcross

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EFFECTS OF ESTABLISHMENT METHOD AND A RAPESEED COMPANION CROP ON ALFALFA SEED YIELD

Canadian Journal of Plant Science ◽

10.4141/cjps87-037 ◽

1987 ◽

Vol 67 (1) ◽

pp. 263-266 ◽

Cited By ~ 1

Author(s):

J. WADDINGTON ◽

N. MALIK

Keyword(s):

Medicago Sativa ◽

Seed Production ◽

Seed Yield ◽

Brassica Campestris ◽

Establishment Method ◽

Alfalfa Seed ◽

Medicago Sativa L ◽

Companion Crop

In two experiments at Melfort using alfalfa (Medicago sativa L. ’Beaver’) seeded at a rate of 2 kg ha−1 with and without a Polish rapeseed (Brassica campestris L. ’Candle’) companion crop seeded at 5.5 kg ha−1, rapeseed yields in the establishment year were maximum when alfalfa and rapeseed were mixed and planted in 15-cm rows. Alfalfa showed no consistent seed yield differences between broadcast seeding, seeding in 15- or 61-cm rows, or seeding with or without the companion crop.Key words: Alfalfa, rapeseed, Brassica campestris, seed production

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