Induction of bicellular pollen by trifluralin treatment and occurrence of triploids and aneuploids after fertilization in maize

Genome ◽  
1999 ◽  
Vol 42 (1) ◽  
pp. 154-157 ◽  
Author(s):  
Akio Kato
Keyword(s):  
Zea Mays ◽  
Effective Treatment ◽  
Key Words ◽  
Zea Mays L ◽  
Generative Cell ◽  
Pollen Grains ◽  
Aluminum Foil ◽  
Central Cell ◽  
Vegetative Nucleus ◽  
Chromosome Counts

By spraying tassels of maize (Zea mays L.) with a trifluralin solution before flowering, viable bicellular pollen grains (with one vegetative nucleus and one mitotically arrested diploid generative cell) were produced. Fertilization between a central cell (2n) of diploid plants and the mitotically arrested generative cell (2n) of the bicellular pollen induced by trifluralin treatment was detected by the presence of shriveled kernels on pollinated ears. A covered method (tassels covered with aluminum foil for 24 h after spraying) and a non-covered method were compared, and the non-covered treatment with 0.2-0.4% trefanocide solutions was the most effective treatment in producing viable bicellular pollen. About 40-50% of the kernels were shriveled on pollinated ears from the treatments. Chromosome counts on seedlings obtained from 0.3% non-covered treatment revealed 24% were triploid and 4% were aneuploid (2n = 19, 21, and 22).Key words: aneuploid, bicellular pollen, trifluralin, triploid, Zea mays L.

MEASUREMENT OF EVAPORATION FROM SOIL BENEATH CROP CANOPIES

1983 ◽  
Vol 63 (1) ◽  
pp. 137-141 ◽  
Author(s):  
G. K. WALKER
Keyword(s):  
Zea Mays ◽  
Key Words ◽  
Leaf Area ◽  
Energy Supply ◽  
Zea Mays L ◽  
Growing Season ◽  
Soil Core ◽  
Crop Cover ◽  
Intact Soil Core ◽  
Intact Soil

Evaporation rates beneath maize canopies were measured using an intact soil core technique. Early in the growing season evaporation rates were periodically high (4.0 mm∙day−1) following rain, but declined rapidly. At full crop cover, when energy supply normally limits evaporation, significant differences in evaporation were detected between canopies with leaf area indices of 3.0 and 4.0. Key words: Evaporation measurement, energy supply, Zea mays L., leaf area, soil evaporimeter, lysimeter

Postemergence control of quackgrass [Elytrigia repens (L) Nevski] with DPX-79406 in corn (Zea mays L)

1994 ◽  
Vol 74 (2) ◽  
pp. 375-381 ◽  
Author(s):  
M. E. Reidy ◽  
C. J. Swanton
Keyword(s):  
Zea Mays ◽  
Key Words ◽  
Significant Interaction ◽  
Growth Stage ◽  
Field Experiments ◽  
Zea Mays L ◽  
Optimum Dose ◽  
Corn Yield ◽  
Leaf Stage ◽  
Elytrigia Repens

Laboratory and field experiments were established to determine the optimum dose and timing of postemergence applications of DPX-79406 for quackgrass control. Four node quackgrass rhizome fragments from each biotype were grown under controlled conditions. At the three-to-four-leaf stage, quackgrass plants were sprayed with DPX-79406 and evaluated for control. A significant response of quackgrass biotypes to DPX-79406 was evident only at lower doses. In the field, quackgrass was effectively controlled by all doses of DPX-79406. Significant growth-stage effects were observed for quackgrass shoot and rhizome dry weights in the year of application and in the year following application. There was a significant interaction between year and growth stage. In 1990, quackgrass biomass was greater when DPX-79406 was applied at the two-to-three-leaf stage of quackgrass than at the four-to-five-leaf stage. In 1991, however, the opposite occurred. Within a growth stage, the 6.25 g ha−1 dose was as effective for controlling quackgrass as 18.5 g ha−1, in both years of the study. In 1991, significant decreases in corn yield were observed for DPX-79406 doses of > 12.5 g ha−1 applied at the four-to-five-leaf stage of quackgrass. For all the variables studied, DPX-79406 doses of 6.25–12.5 g ha−1 resulted in consistent control of quackgrass. Key words: DPX-79406, nicosulfuron, rimsulfuron, quackgrass, Elytrigia repens, corn, Zea mays

Development of sperm cells in barley

1975 ◽  
Vol 53 (10) ◽  
pp. 1051-1062 ◽  
Author(s):  
David D. Cass ◽  
Ilana Karas
Keyword(s):  
Cell Membrane ◽  
Vegetative Cell ◽  
Generative Cell ◽  
Pollen Grains ◽  
Complete Separation ◽  
Pollen Wall ◽  
Vegetative Nucleus ◽  
Sperm Cells ◽  
Subsequent Stage ◽  
Microspore Stage

Ultrastructural events in barley sperm development were examined from the uninucleate microspore stage to establishment of two mature sperm cells in pollen grains. Microspore mitosis produces a vegetative nucleus and a naked generative cell, both embedded in vegetative cell cytoplasm. The generative cell membrane is enclosed by vegetative cell membrane. The generative cell, at first apparently unattached, becomes attached to the pollen wall and acquires a cell wall by centripetal vesicle accumulation. Wall formation may be complete at the time of generative cell karyokinesis; karyokinesis occurs while the generative cell is attached to the pollen wall. Cytokinesis of the generative cell is delayed. The subsequent stage is a binucleate, attached generative cell with a wall. Generative cell cytokinesis appears to involve formation of a partition between the two sperm nuclei. Eventual complete separation of the sperm cells occurs only after the two-celled derivative of the generative cell detaches from the pollen wall. Final stages in sperm cell separation are considered to result from degradation of the partitioning and surrounding wall, not from furrowing of a naked binucleate generative cell according to previous suggestions. Mature plastids were not observed in the generative cell or the sperms.

Ultraviolet irradiation of maize (Zea Mays L.) pollen grains

1977 ◽  
Vol 49 (6) ◽  
pp. 253-258 ◽  
Author(s):  
P. L. Pfahler ◽  
H. F. Linskens
Keyword(s):  
Zea Mays ◽  
Ultraviolet Irradiation ◽  
Zea Mays L ◽  
Pollen Grains

Adjacent II segregation products in B–A translocations of maize

Genome ◽  
1991 ◽  
Vol 34 (4) ◽  
pp. 595-602 ◽  
Author(s):  
B. Kindiger ◽  
C. Curtis ◽  
J. B. Beckett
Keyword(s):  
Zea Mays ◽  
Key Words ◽  
Zea Mays L ◽  
Genetic Data ◽  
B Chromosomes ◽  
Cytological Data ◽  
Opposite Pole

In maize (Zea mays L.), meiotic events in B–A translocations that cause the A chromosome to move to one pole and the A–B and B–A chromosomes to move to the opposite pole result in the production of balanced, functional microspores and megaspores. Meiotic events that allow other combinations of chromosomes to proceed to the two poles (A A–B and A B–A) lead to the production of both duplicate (A A–B) and deficient (B–A) spores. Microspores and often megaspores that are deficient for a segment of the A chromosome are expected to abort. Duplication-bearing gametes usually function through the egg but are less able to compete with the normal gametes in the pollen. Cytological data, and genetic data from pollen, kernel, and seedling counts, were used to identify the production of A A–B gametes by B–A translocation heterozygotes and hyperploids. Adjacent II segregation of the A and A–B chromosomes of B–A heterozygotes and hyperploids has been detected in stocks of several different B–A translocations. Some B–A translocations exhibited a frequency of adjacent II segregation as high as 23%.Key words: Zea mays, adjacent segregation, B chromosomes, translocation.

scholarly journals Early events during embryogenesis in Zea mays L.

2014 ◽  
Vol 50 (1-2) ◽  
pp. 289-290 ◽  
Author(s):  
A. A. Van Lammeren
Keyword(s):  
Zea Mays ◽  
Structural Changes ◽  
Zea Mays L ◽  
Mature Embryo ◽  
Early Embryogenesis ◽  
Central Cell ◽  
Egg Cell ◽  
Cellular Endosperm ◽  
Well Differentiated

The megagametophyte of <em>Zea mays</em> L. undergoes a series of structural changes after fertilization resulting in a well differentiated mature embryo and cellular endosperm at 480 hours after pollination in greenhouse conditions. In the present work emphasis was laid on the localization of the cytoplasm in the synergids, central cell-endosperm and egg cell-zygote prior to and after fertilization. The observations are discussed in relation to the process of early embryogenesis.

CO446 corn inbred line

2010 ◽  
Vol 90 (5) ◽  
pp. 703-706
Author(s):  
L. M. Reid ◽  
X. Zhu
Keyword(s):  
Zea Mays ◽  
Key Words ◽  
Inbred Line ◽  
Combining Ability ◽  
Zea Mays L ◽  
Lodging Resistance ◽  
Cultivar Description ◽  
Short Season ◽  
Corn Inbred

CO446 is a short-season corn (Zea mays L.) inbred line with excellent combining ability and lodging resistance in hybrids. This inbred performed well as a parent with both stiff and non-stiff stalk inbreds. Excellent yields were achieved with the non-stiff stalk commercial inbred LH295 and the stiff-stalk commercial tester inbred TR2040. Key words: Corn, maize, Zea mays, cultivar description

CO445 corn inbred line

2010 ◽  
Vol 90 (5) ◽  
pp. 699-702
Author(s):  
L M Reid ◽  
X. Zhu
Keyword(s):  
Zea Mays ◽  
Key Words ◽  
Inbred Line ◽  
Combining Ability ◽  
Zea Mays L ◽  
Lodging Resistance ◽  
Cultivar Description ◽  
Short Season ◽  
Corn Inbred

CO445 is a short season corn (Zea mays L.) inbred line with excellent combining ability and lodging resistance in hybrids. This inbred performed well as a parent with both stiff stalk and non-stiff stalk inbreds. Excellent yields were achieved with the stiff stalk commercial inbreds TR2040 and MBS1236 and the non-stiff stalk commercial inbred LH176.Key words: Corn, maize, Zea mays, cultivar description

MOLYBDENUM, COBALT AND BORON UPTAKE FROM SEWAGE-SLUDGE-AMENDED SOILS

1985 ◽  
Vol 65 (3) ◽  
pp. 507-517 ◽  
Author(s):  
Y. K. SOON ◽  
T. E. BATES
Keyword(s):  
Zea Mays ◽  
Sewage Sludge ◽  
Key Words ◽  
Field Experiments ◽  
Zea Mays L ◽  
Plant Tissues ◽  
Boron Uptake ◽  
Lime Sludge ◽  
Co Concentrations ◽  
Sludge Application

Molybdenum, Co and B concentrations in, and uptake by, corn and bromegrass were measured over a period of several years from three field experiments in which sewage sludge was applied and compared with ammonium nitrate as a source of N. There was little effect of sludge on B and Co concentrations in the crops grown. Slight increases in uptake were apparently due to yield increases due to sludge. A lime-treated sludge increased Mo concentration in plant tissues after several years of sludge application. The increase in plant Mo concentration was highest in the eighth and last year of the experiments, although lime-sludge application had ceased 1–3 yr previously. The soil-sludge interactions contributing to increased Mo uptake are discussed. Key words: Molybdenum, cobalt, boron, sewage sludge, corn (Zea mays L.), bromegrass (Bromus inermiss Leyss).

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