Micropollen Formation in F1 Hybrids and Backcrosses of Waterhemp (Amaranthus tuberculatus) X Smooth Pigweed (A. hybridus) as a Quick Method for Determination of Interspecific Hybridization Events

Abstract A quick method for determining /V-nitrosodipropylamine (NDPA) levels in trifluralin emulsifiable concentrate formulations is described. At least 18 samples can be analyzed at one time in a minimum of fumehood space, with up to 90% savings on solvents and materials. A sample aliquot is mixed with a solution containing nitrosamine recovery standards, and nitrosamines are separated by minicolumn cleanup. Internal standard is added directly to the eluate containing the nitrosamines, and levels are determined by gas chromatography with thermal energy analyzer. Recoveries of spiked nitrosamines ranged from 98 to 102%. Coefficients of variation for samples containing 0.5 ppm NDPA are 13%. Minimum detectable limit, calculated as 3 times the noise, is 0.06 ppm. Comparison with the method formerly used by this laboratory shows no significant difference in the analytical results at 95% confidence limits, and control experiments were performed to ensure that there was no artifact formation of NDPA.

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Interspecific hybridization between Coffea arabica L. and tetraploid C. canephora P. Ex Fr. II. Meiosis in F1 hybrids and back crosses to C. Arabica

Euphytica ◽

10.1007/bf00022928 ◽

1985 ◽

Vol 34 (2) ◽

pp. 355-360 ◽

Cited By ~ 11

Author(s):

J. B. O. Owuor

Keyword(s):

Interspecific Hybridization ◽

Coffea Arabica ◽

F1 Hybrids ◽

Coffea Arabica L

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A Method for Identification of Triazine Resistant and Susceptible Biotypes of Several Weeds

Weed Science ◽

10.1017/s0043174500025856 ◽

1981 ◽

Vol 29 (1) ◽

pp. 70-73 ◽

Cited By ~ 25

Author(s):

J. R. Hensley

Keyword(s):

Chenopodium Album ◽

Quick Method ◽

Amaranthus Hybridus ◽

Senecio Vulgaris ◽

Common Lambsquarters ◽

Leaf Discs ◽

Large Numbers ◽

Common Groundsel ◽

Smooth Pigweed ◽

Phosphate Medium

A simple and quick method is described for identifying biotypes of common groundsel (Senecio vulgarisL.), common lambsquarters (Chenopodium albumL.), and smooth pigweed (Amaranthus hybridusL.) that are resistant or susceptible to triazine herbicides. Leaf discs (3 mm diam) from the tested plants were vacuum infiltrated with a phosphate medium and exposed to a 3-klux light source. When 1.0 × 10−5M and higher levels of atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) were present, the leaf discs from susceptible biotypes failed to float to the surface, whereas the leaf discs from resistant biotypes floated within 1 h. The urea herbicide, fluometuron [1,1-dimethyl-3-(α,α,α-trifluoro-m-tolyl)urea] inhibited the floating of leaf discs from both the triazine-susceptible and triazine-resistant biotypes. This method can be used to evaluate large numbers of plants to determine if they are resistant or susceptible to triazines without destroying the plants or preventing seed production.

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Cytoplasmic male sterility in Desmodium

Australian Journal of Agricultural Research ◽

10.1071/ar9690227 ◽

1969 ◽

Vol 20 (2) ◽

pp. 227 ◽

Cited By ~ 5

Author(s):

KS McWhirter

Keyword(s):

Cytoplasmic Male Sterility ◽

Male Sterility ◽

Interspecific Hybrid ◽

Pollen Fertility ◽

Pollen Sterility ◽

Hybrid Origin ◽

F1 Hybrids ◽

Male Sterile ◽

Genetic Stocks

A type of male sterility found in two Desmodium plants of probably interspecific hybrid origin was cytoplasmically inherited. The cytoplasmic male-sterile character was incorporated in the tropical legume Desmodium sandwicense by backcrossing. In this genetic background pollen sterility was complete. The male-sterile character was not graft-transmissible, and it produced no detectable pleiotropic effects on growth and development. Desmodium intortum gave restoration of pollen fertility in Fl hybrids with male-sterile lines of D. sandwicense. Restored F1 hybrids produced apparently normal pollen, but tests of functional ability of the pollen disclosed that pollen fertility was less than that of Fl hybrids with normal cytoplasm. Incomplete restoration of fertility was not due to heterozygosity of fertility-restoring genes with gametophytic expression, since fertility-restoring genes were shown to act sporophytically. The results established the occurrence in the legume Desmodium of a system of determination of the male-sterile, fertility-restored phenotypes that is similar to the cytoplasmic male sterility systems described in many other angiosperm plants. A scheme utilizing the genetic stocks produced in this study for commercial production of the interspecific hybrid D. sandwicense x D. intortum as a cultivar is presented.

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