selon laquelle les gdnes qui r6gissent I'h6r6dit6 de la goitrine et des isothiocyanates volatiles seraient li6s.

Broccoli (Brassica oleracea Italica Group) plants resistant or susceptible to clubroot (Plasmodiophora brassicae Wor. races 2 and 6) produced from 10 segregating breeding lines were analyzed for their composition of glucosinolates as determined in terms of their hydrolytic breakdown products: goitrin, volatile isothiocyanates, and thiocyanate ion. Unlike goitrin and volatile isothiocyanates, the average content of thiocyanate ion was significantly lower (548 μg·g-1 dry weight) in resistant plants than in susceptible ones (712 μg·g-1). Of 15 resistant plants derived from 10 breeding lines containing zero goitrin and/or relatively low concentrations of one or more glucosinolate products, 10 plants were free of goitrin, three were low in volatile isothiocyanates (≤100 μg·g-1), two were low in thiocyanate ion (≤200 μg·g-1), and two were low in total glucosinolates (≤600 μg·g-1).

. 1985. Effects of seeding treatment and soil moisture content on the emereence of lettuce. Can. J. Plant r99.Lettuce seeds (Lactuca satiyaL.'Boston Dark Green') were sown by fluid drill and as dry seed into soils at25%o,5OVo,75Vo andl007o field capacity (FC). Fluid drilling reduced the time to initial emergence and 5OVo emergence at soil moisture levels between 50Vo and l00Vo FC. At25Vo FC, neither seeding method performed well with fluid drilled seed being entrapped inside the carrier gel after it had dehydrated. After 2 wk, no significant difference in final percent emergence was noted between seeding treatments at any soil moisture level. In a second experiment, fluid drilled lettuce seeds emerged earlier and reached 507o emergence sooner than dry seed, germinated seed sown without gel and dry-seed in gel at 40Vo,50Vo andT5Vo FC.Gel-seeded treatments were not significantly affected by soil moisture whereas the emergence of seeding treatments without gel application was mukedly improved as soil moisture content increased. After 2 wk, the percent emergence of dry seeded lettuce at 4OVo FC was significantly lower than the other seeding treatments. No differences were noted among treatmetts at 50Vo FC whereas at 7 5Vo FC, the emergence of dry seed in gel was significantly reduced.