Test seeds

The responses of the test seed to increased external osmolarity were determined by germinating the seeds in a polyethylene glycol (PEG) solution of 40.3 mOsm (10). The only test seeds significantly affected by this treatment were those of tomato where PEG-treated seed germination was 69.3% of that observed in deionized water. Dilution of the aqueous extract to 1 32 (w/w) removed all inhibitory action, but the diluted solution increased wheat germination. 

The fourth isolated and identified compound from Palmer amaranth is chondri 11 asterol (5a-stigmasta-7,22-dien-30-ol), a sterol closely related structurally to the major plant sterols, stigmasterol and sitosterol. This compound, isolated as the free sterol, is not soluble in water or 0.1% DMS0, and germination bioassays required pretreatment of the test seed with a 0.1 mM solution of the sterol in DCM. 

The test seeds used for the bioassays were Mimosa pudica, Achyranthes aspera, Bidens pilosa, and Crusea calocephala (herbaceous species) Ochroma lagopus and Heliocarpus donell-smithil (arboreal species). 

The seeds of selected Onagraceae, including Oenothera picensis, O. indecora, Ludwigia longifolia, and O. L. peruviana were analyzed for their physicochemical characteristics (40). Linoleic acid was the predominant fatty acid in all tested seed oils, comprising 71.5-80.0% of the total fatty acids (Table 6) (40). These Onagraceae seed oils may be excellent dietary sources of the essential n-6 fatty acid (18 2n-6). 

Similar procedures are worked out for Xanthomonas campestrls pv campestris in cabbage seeds (19) X c pv. phaseoii (l4, 265, P s pv pisi TGo ve r nmen t Seed Test ingest at ion) and for Clavibacter michiganensis subsp. sepedonicus for testing seed potatoes in the European Community (if, if) ... 

The process of testing, seed multiplication, and release is as briefly described above. But most methods are carried out with some modifications by breeders, depending on the program and the trait(s) that are being selected. 

International Seed Testing Association. International rules for seed testing. Seed Sci Technol 1985 13 356-513. 

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