Germination uniformity

The temperature of incubators must be uniform throughout and should not vary more than 0.2 C. The vegetative assay organism must be sensitive to the analyte, be stable (resistant to spontaneous change), be in the logarithmic growth phase (for uniformity of response), and be easily cultured, maintained and standardized. Spores suspension have similar criteria except that the spores must be capable of germinating with reasonable synchrony. 

Embryo cultures may be established from embryos removed from sterilized seeds, ovules, or fruits. The embryos produced from cell culture technique, known as somatic embryos, can be isolated and germinated to provide one plant per explant. Embryo culture can be employed for the rapid production of seedlings from seeds which have a protracted dormancy period. The method has many potential advantages over traditional propagation systems, such as fast turnaround, genetic uniformity, mass production, and propagation of disease-free plants. 

Since only a fraction of a grain is actually required for analysis, the seed embryo and part of the endosperm may be retained and germinated. Thus, 2-D electrophoresis may be used to screen several hundred individual kernels and the results used to select embryos that will produce uniform strains which may be crossed to demonstrate that candidate variants and wild-type pairs are indeed allelic. Whether the variants described here contribute in any important way to flour and baking quality can best be discovered by producing substrains homozygous for each. 

The small seed of these oilseed crops must be sown shallow, not more than 2-3 cm, into firm, moist soil to ensure a uniform germination and stand. Under good growing conditions emergence of the two cotyledons or seed leaves usually occurs within 4 or 5 days, followed quickly by the development of the first true leaves. The crop quickly establishes a rosette of broad leaves which tend to shade the surrounding area and reduce weed competition. 

All Cuphea species exhibit wild plant characteristics (dormancy, non-uniform germination, indeterminate flowering and seed maturation over a period of up to 8 weeks, extreme dehiscence and the... 

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