Vergleich der Wirkung eines Carbamatherbizids und von Colchicin auf die Mitose von Allium cepa und Hordeum vulgare

1972 ◽  
Vol 42 (7) ◽  
pp. 310-313 ◽  
Author(s):  
E. Günther ◽  
A. Nasta
Keyword(s):  
2001 ◽  
Vol 11 (1) ◽  
pp. 151 ◽  
Author(s):  
Richard G Greenland

Planting barley (Hordeum vulgare L.) as a living mulch with onions (Allium cepa L.) reduces soil erosion and protects the onions from wind damage. It can also reduce yield and size of onion bulbs if not managed correctly. In a 4-year study at the Oakes Irrigation Research Site in North Dakota, barley was planted in the spring at the same time that onions were direct-seeded. Barley rows were planted either parallel with or perpendicular to the onion rows. Barley was killed with fluazifop-P herbicide when ≈13, 18, 23, or 30 cm tall. Onion size and yields were reduced when barley was allowed to grow taller than 18 cm before killing it. Total onion yield was usually greater when barley was planted parallel with, rather than perpendicular to, onion rows. Chemical name used: (R)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]propanoic acid (fluazifop-P).


HortScience ◽  
2000 ◽  
Vol 35 (5) ◽  
pp. 853-855 ◽  
Author(s):  
Richard G Greenland

Planting barley (Hordeum vulgare L.) as a living mulch with onions (Allium cepa L.) reduces soil erosion and protects the onions from wind damage. It can also reduce yield and size of onion bulbs if not managed correctly. In a 4-year study at the Oakes Irrigation Research Site in North Dakota, barley was planted in the spring at the same time that onions were direct-seeded. Barley rows were planted either parallel with or perpendicular to the onion rows. Barley was killed with fluazifop-P herbicide when ≈13, 18, 23, or 30 cm tall. Onion size and yields were reduced when barley was allowed to grow taller than 18 cm before killing it. Total onion yield was usually greater when barley was planted parallel with, rather than perpendicular to, onion rows. Chemical name used: (R)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]propanoic acid (fluazifop-P).


1993 ◽  
Vol 3 (2) ◽  
pp. 214-218 ◽  
Author(s):  
Bernard H. Zandstra ◽  
Darryl D. Warncke

Carrots (Daucus carota L.) or onions (Allium cepa L.) were interplanted with barley (Hordeum vulgare L.) or rye (Secale cereale L.) seeded at 0, 0.5, 1.0, or 2.0 bushels/acre (0, 43.5, 87, and 174 liters-ha-i). Barley was killed at heights of 4, 8, 12, or 16 inches (10, 20, 30, or 40 cm), and rye was killed at 4, 6, 7, or 8 inches with a postemergence graminicide. Barley and rye killed at 4 inches did not reduce onion yield. If barley exceeded 8 inches and rye exceeded 7 inches when killed, onion yields were reduced. Carrot yield was reduced only by 2 bushels of barley killed at 16 inches. One bushel of barley per acre killed at 4 inches appeared to be optimal in giving good soil protection and minimal crop competition.


Author(s):  
O. E. Bradfute ◽  
R. E. Whitmoyer ◽  
L. R. Nault

A pathogen transmitted by the eriophyid mite, Aceria tulipae, infects a number of Gramineae producing symptoms similar to wheat spot mosaic virus (1). An electron microscope study of leaf ultrastructure from systemically infected Zea mays, Hordeum vulgare, and Triticum aestivum showed the presence of ovoid, double membrane bodies (0.1 - 0.2 microns) in the cytoplasm of parenchyma, phloem and epidermis cells (Fig. 1 ).


Author(s):  
R.H.M. Cross ◽  
C.E.J. Botha ◽  
A.K. Cowan ◽  
B.J. Hartley

Senescence is an ordered degenerative process leading to death of individual cells, organs and organisms. The detection of a conditional lethal mutant (achloroplastic) of Hordeum vulgare has enabled us to investigate ultrastructural changes occurring in leaf tissue during foliar senescence.Examination of the tonoplast structure in six and 14 day-old mutant tissue revealed a progressive degeneration and disappearance of the membrane, apparently starting by day six in the vicinity of the mitochondria associated with the degenerating proplastid (Fig. 1.) where neither of the plastid membrane leaflets is evident (arrows, Fig. 1.). At this stage there was evidence that the mitochondrial membranes were undergoing retrogressive changes, coupled with disorganization of cristae (Fig. 2.). Proplastids (P) lack definitive prolamellar bodies. The cytoplasmic matrix is largely agranular, with few endoplasmic reticulum (ER) cisternae or polyribosomal aggregates. Interestingly, large numbers of actively-budding dictysomes, associated with pinocytotic vesicles, were observed in close proximity to the plasmalemma of mesophyll cells (Fig. 3.). By day 14 however, mesophyll cells showed almost complete breakdown of subcellular organelle structure (Fig. 4.), and further evidence for the breakdown of the tonoplast. The final stage of senescence is characterized by the solubilization of the cell wall due to expression and activity of polygalacturonase and/or cellulose. The presence of dictyosomes with associated pinocytotic vesicles formed from the mature face, in close proximity to both the plasmalemma and the cell wall, would appear to support the model proposed by Christopherson for the secretion of cellulase. This pathway of synthesis is typical for secretory glycoproteins.


1992 ◽  
Vol 86 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Steffen Reinbothe ◽  
Christiane Reinbothe ◽  
Jorg Lehmann ◽  
Benno Parthier

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