Chromosome pairing at five ploidy levels in Elymus trachycaulus

Genome ◽  
1987 ◽  
Vol 29 (1) ◽  
pp. 136-143 ◽  
Author(s):  
Taing Aung ◽  
P. D. Walton
Keyword(s):  
Key Words ◽  
Chromosome Pairing ◽  
Dry Matter ◽  
Dry Matter Yield ◽  
Ploidy Levels ◽  
Elymus Trachycaulus ◽  
Ring Bivalents ◽  
Almost All ◽  
Agropyron Trachycaulum ◽  
Metaphase I

An autoallooctaploid (2n = 56) form of Elymus trachycaulus (Link) Gould ex Shinners (previously Agropyron trachycaulum (Link) Malte ex H. F. Lewis) was induced by treating allotetraploid shoots with 0.2% colchicine. Successive backcrossing to tetraploid pollen parents was successful and yielded five hexaploid (2n = 42), one pentaploid (2n = 35), and three hyperploid (2n = 31, 32, 33) plants. Metaphase I of the tetraploids was normal and 14 II chromosomes were observed, almost all of which were ring bivalents. Chromosome pairing in one octaploid, four hexploids, and one pentaploid were 4.38 IV + 0.65 III + 17.84 II + 0.85 I, 13.16 III + 0.84 II + 0.84 I, and 5.82 III + 8.18 II + 1.18 I, respectively. Efficiency of chromsome pairing (chiasmata per chromsome) was highest in tetraploids (1.29), lowest in hexaploids (0.75), and intermediate in both octaploid (0.95) and pentaploid (0.93) plants. The octaploid produced longer and broader leaves than the tetraploid, although the total dry matter produced was 14.3% lower. Total dry matter yield of the hexaploid was on an average 30.04% higher than the tetraploid and the leaves were significantly larger. The hexaploid plants were taller than both the tetraploid and the octaploid plants. Metaphase I pairing in hyperploid 1 (2n = 33) was 4.34 III + 9.66 II + 0.66 I, hyperploid 2 (2n = 32) was 2.98 III 11.03 II + 1.00 I; hyperploid 3 (2n = 30 + 1 t) was 1.97 III + 12.05 II + 0.66 I + 0.33 t. The pattern of chromosome pairing in these hyperploids suggest that they are a quintupal trisomic, a quadrupal trisomic, and a triple trisomic respectively. Backcrossing these hyperploids to euploid pollen parents was successful. Backosses and their progeny should result in a series of primary trisomiclines and some monosomic plants, which would be useful for gene mapping. Key words: octaploid, hexaploid (double triploid), pentaploid, tetraploid, hyperploid, trisomic monosomic, Agropyron.

EVALUATION OF TIMOTHY CULTIVARS FOR VOLUNTARY INTAKE AND NUTRIENT COMPONENTS

1988 ◽  
Vol 68 (4) ◽  
pp. 1121-1129 ◽  
Author(s):  
W. N. MASON ◽  
P. M. FLIPOT
Keyword(s):  
Key Words ◽  
Dry Matter ◽  
Phleum Pratense ◽  
Dry Matter Intake ◽  
Dry Matter Yield ◽  
Dry Matter Digestibility ◽  
Flower Stage ◽  
Voluntary Intake ◽  
Phleum Pratense L

Five timothy (Phleum pratense L.) cultivars, Clair, Champ, Milton, Climax and Bounty, were harvested at first flower stage during 2 consecutive years and in the regrowth for 1 yr. The forages were each offered as hay to 15 young rams to evaluate voluntary intake. Five animals were used to determine initial harvest dry matter digestibility. The cultivars varied significantly in voluntary intake at first flower stage. The highest intake (g kg−0.75 d−1) averaged for the years was obtained in the early cultivar Champ (65.9), which was 10% more than that of the medium-late cultivar Climax. The cultivars did not differ significantly in dry matter digestibility. In the regrowth, the relative intakes of the cultivars were essentially reversed from that of the initial harvest. The voluntary intake was substantially higher but the differences among forages were less marked. Climax regrowth voluntary intake was higher (P < 0.05) than all cultivars, except Bounty. A 15% range in digestible dry matter intake was present among cultivars. The ranking of the culivars for digestible dry matter was different than for dry matter yield. Key words: Timothy, Phleum pratense L., voluntary intake, dry matter digestibility

Interlocked bivalents in reconstructed metaphase I cells of bread wheat

1985 ◽  
Vol 75 (1) ◽  
pp. 85-92
Author(s):  
J.S. Heslop-Harrison ◽  
M.D. Bennett
Keyword(s):  
Triticum Aestivum ◽  
Light Microscopy ◽  
Bread Wheat ◽  
Chromosome Pairing ◽  
Light Microscope ◽  
Serial Sections ◽  
Ring Bivalents ◽  
Mother Cells ◽  
I Cells ◽  
Metaphase I

Complete reconstructions of all the bivalents were made from electron micrographs of serial sections through six pollen mother cells at metaphase I of meiosis in Triticum aestivum (hexaploid bread wheat). At least two of these metaphases contained interlocked pairs of bivalents. In one, two ring bivalents were interlocked, while in another a rod bivalent ran through the centre of a ring bivalent. Two other groups of bivalents were too closely appressed to allow separation into individual bivalents and may have contained interlocks. Meiosis in other anthers of the same plants examined by light microscopy was considered normal. The frequency of interlocking found was much higher than reported from light-microscope spreads. Not all interlocks in metaphase I cells need adversely affect meiosis, but knowledge of their regularity and form may facilitate understanding the processes of chromosome pairing.

Tolerance of annual forage legumes to herbicides in Alberta

2003 ◽  
Vol 83 (3) ◽  
pp. 649-652 ◽  
Author(s):  
J. Fraser ◽  
J. R. Moyer ◽  
A. K. Topinka ◽  
D. McCartney
Keyword(s):  
Key Words ◽  
Weed Control ◽  
Dry Matter ◽  
Stand Density ◽  
Dry Matter Yield ◽  
Forage Legumes ◽  
Berseem Clover

The effects of ethalfluralin, trifluralin, and imazethapyr herbicides were assessed on stand density, visual injury and dry matter yield of annual forage legumes under irrigation. Results indicate that recommended rates o f either ethalfluralin or imazethapyr have potential for weed control in alfalfa, berseem clover, balansa clover, fenugreek, pea, and vetches. Key words:

Azur red clover

2006 ◽  
Vol 86 (3) ◽  
pp. 749-750
Author(s):  
Bruce Coulman
Keyword(s):  
Key Words ◽  
Dry Matter ◽  
Trifolium Pratense ◽  
Growth Habit ◽  
Red Clover ◽  
Dry Matter Yield ◽  
Trifolium Pratense L ◽  
Cultivar Description ◽  
Diploid Cultivar

Azur is a diploid cultivar of red clover [Trifolium pratense (L.)], which was selected for vigor and growth habit in the year of seeding. In forage trials conducted in Québec, Azur was superior in dry matter yield to check cultivars, particularly in trials harvested in the second production year. In trials in Ontario and the Atlantic provinces, Azur was numerically superior in dry matter yield to the check cultivar, but not significantly so (P < 0.05). Key words: Red clover, Trifolium pratense (L.), cultivar description

INFLUENCE OF SOIL MASS AND DIMENSIONS ON ZINC RESPONSE IN CORN (Zea mays)

1983 ◽  
Vol 63 (3) ◽  
pp. 651-655
Author(s):  
G. J. RACZ ◽  
A. S. NYAKI ◽  
L. A. LOEWEN-RUDGERS
Keyword(s):  
Zea Mays ◽  
Key Words ◽  
Dry Matter ◽  
Field Experiments ◽  
Fine Sand ◽  
Soil Mass ◽  
Dry Matter Yield ◽  
Zn Uptake ◽  
Soil Zn ◽  
Extractable Zn

Zn increased shoot dry matter yield of 62-day-old corn grown in the greenhouse on Almasippi loamy fine sand (Gleyed Carbonated Rego Black) containing 0.77 ppm DTPA-extractable Zn whereas corn in the field on the same soil had not responded to Zn. Soil mass or dimensions had little influence upon degree of response to Zn. When no Zn was applied, Zn uptake was not influenced by soil mass, suggesting that the amount of plant-available soil Zn did not increase with increasing soil mass. Results from this study provided little evidence that restricted soil mass, limiting the amount of available soil Zn, was the primary cause of greater response to Zn fertilization in pot as compared to field experiments. Key words: Corn, soil-mass, zinc

Goliath crested wheatgrass

2006 ◽  
Vol 86 (3) ◽  
pp. 743-744 ◽  
Author(s):  
Bruce Coulman
Keyword(s):  
Key Words ◽  
Seed Weight ◽  
Dry Matter ◽  
Agropyron Cristatum ◽  
Dry Matter Yield ◽  
Canadian Prairie ◽  
Crested Wheatgrass ◽  
Cultivar Description ◽  
Seed Yields ◽  
Prairie Provinces

Goliath is a colchicine-induced tetraploid cultivar of crested wheatgrass [Agropyron cristatum (L.) Gaertner]. Relative to other cultivars of crested wheatgrass, Goliath is taller, produces fewer, heavier tillers, and has greater seed weight. It produced higher seed yields than other cultivars and had a higher mean forage dry matter yield than the check cultivar in regional trials conducted in the three Canadian prairie provinces. Key words: Crested wheatgrass, Agropyron cristatum (L.) Gaertner, colchicine-induced tetraploid, cultivar description

Optimum harvest date of maize for biogas and silage purposes

2009 ◽  
Vol 57 (2) ◽  
pp. 119-125
Author(s):  
G. Hadi
Keyword(s):  
Dry Matter ◽  
Biogas Production ◽  
Weather Conditions ◽  
Vegetation Period ◽  
Dry Mass ◽  
Matter Content ◽  
Harvest Date ◽  
Dry Matter Content ◽  
Dry Matter Yield ◽  
Vegetative Organs

The dry matter and moisture contents of the aboveground vegetative organs and kernels of four maize hybrids were studied in Martonvásár at five harvest dates, with four replications per hybrid. The dry matter yield per hectare of the kernels and other plant organs were investigated in order to obtain data on the optimum date of harvest for the purposes of biogas and silage production.It was found that the dry mass of the aboveground vegetative organs, both individually and in total, did not increase after silking. During the last third of the ripening period, however, a significant reduction in the dry matter content was sometimes observed as a function of the length of the vegetation period. The data suggest that, with the exception of extreme weather conditions or an extremely long vegetation period, the maximum dry matter yield could be expected to range from 22–42%, depending on the vegetation period of the variety. The harvest date should be chosen to give a kernel moisture content of above 35% for biogas production and below 35% for silage production. In this phenophase most varieties mature when the stalks are still green, so it is unlikely that transport costs can be reduced by waiting for the vegetative mass to dry.

Nitrogen Fertilization of Basil

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 481a-481 ◽  
Author(s):  
M. Rangappa ◽  
H.L. Bhardwaj
Keyword(s):  
Moisture Content ◽  
Dry Matter ◽  
Calcium Nitrate ◽  
Control Treatment ◽  
Dry Matter Yield ◽  
Sweet Basil ◽  
Broad Leaf ◽  
Yield Difference ◽  
Optimum N Rate ◽  
N Rates

Sweet basil (Ocimum basilicum) is an important culinary herb in Virginia and other areas. The objective of this study, conducted during 1997, was to determine optimal N rate for fresh and dry matter yield. Seed of Broad Leaf sweet basil were direct-seeded on 18 June in rows 0.75 m apart in a RCBD design with 8 replications. Four N rates (0, 25, 50, and 75 kg N/ha) were used. Calcium nitrate (15.5% N) was used as the fertilizer source. All plants from 1-m row length from middle row of each plot were harvested by hand on 23 Sept. and fresh weights were recorded. The plant material was dried at 70°C for 48 h to record dry weights. The moisture content at harvest was calculated from fresh and dry weights. The fresh yields following 0, 25, 50, and 75 kg N/ha were 3.7, 5.4, 6.4, and 6.8 kg/m2, respectively. The yield difference between two highest N rates was not significant, however, both these rates had significantly higher yield than the two lowest rates. Similar results were also obtained for dry matter yields. The highest N rate of 75 kg N/ha resulted in significantly higher dry matter yield (1.3 kg/m2) as compared to the other three rates. The lowest dry matter yield was obtained after the control treatment (0.6 kg/m2). An opposite relationship between N rate and moisture content was observed when the highest moisture content resulted from control and 50 kg N/ha treatments. These results indicate that optimum N rate for sweet basil in Virginia is 50 to 75 kg/ha.

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