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Abstract: Lentil anthracnose (Colletotrichum truncatum (Schwein.) Andrus et W.D. Moore is a potential threat in many lentil (Lens culinaris Medik.) production regions of North America. In the lentil germplasm maintained in Germany and North America, 16 lines were reported to have resistance to race Ct1, but none has resistance reported to race Ct0. The objective of this study was to examine accessions of wild Lens species for their resistance to races Ct1 and Ct0 of lentil anthracnose. Five hundred and seventy-four wild accessions of six species and control lines were screened in two replications under both field and greenhouse conditions using a 1–9 scoring scale (1, highly resistant; 2–3, resistant; 4–5, moderately resistant; 6–7, susceptible; and 8–9, highly susceptible). Indianhead and PI 320937 were resistant while Eston and Pardina were susceptible to race Ct1 as expected. However, none of the check lines were resistant to race Ct0. Among the six Lens wild species tested, accessions of Lens ervoides (Brign.) Grande had the highest level of resistance, 3–5 to race Ct1 and Ct0 followed by L. lamottei Czefr. in the field and greenhouse. Lens orientalis (Boiss.), L. odemensis L., L. nigricans (M. Bieb.) Godron and L. tomentosus L. were highly susceptible, 8–9 to race Ct0 in the greenhouse. The highest frequency of resistance, especially in L. ervoides (Brign.) Grande, was found in accessions originating from Syria and Turkey. The usefulness of these L. ervoides (Brign.) Grande accessions as sources of resistance to the more virulent race of anthracnose in a lentil breeding program is discussed.

Somatic embryo cultures of Picea mariana and the species complex P. glauca-engelmannii were each grown in 7.5-l-capacity mechanically-stirred bioreactors containing 61 medium (LP, von Arnold and Eriksson) with 30 mm sucrose. Growth of both species occurred with no observable signs of shear stress due to mechanical agitation. Growth kinetics were analysed using an array of parameters (settled culture volume, packed culture volume, osmolarity, conductivity, pH). These were compared with fresh weight, dry weight, and somatic embryo number in order to determine what parameters were highly correlated with growth and embryo number. Increasing the sucrose concentration from 30 mm to 60 mm resulted in an increase in biomass and total number of somatic embryos. For P. mariana a maximum dry weight of 6.3 gl-1 and 3076 embryos ml-1 occurred in LP medium with 60 mm sucrose after 10–12 days of culture. For P. glauca-engelmannii a maximum dry weight of 4.3 gl-1 and 2278 embryos ml-1 occurred in LP medium with 60 mm sucrose after 6–8 days culture. For all sucrose concentrations, fresh weight, dry weight and embryo number were closely correlated with packed culture volume and conductivity for P. mariana, and settled culture volume, packed culture volume and conductivity for P. glauca-engelmannii.

Summary: Embryogenic cell cultures ofPicea mariana (black spruce) and the species complexPicea glauca-engelmannii (interior spruce) were maintained either as suspensions in liquid medium in 250 or 500-ml-capacity shake-flasks, 7-liter-capacity airlift or mechanically stirred bioreactors, or on agar-solidified medium. Cultures from each of the maintenance conditions were subsequently transferred to agar-solidified LP medium containing 40M () -abscisic acid for maturation into cotyledonary stage embryos. For both species, the highest maturation frequency resulted from cultures grown in the airlift bioreactor. With black spruce cells grown in the airlift bioreactor containing LP medium with 60 mM sucrose, a maximum of 7.1 gliter−1 dry weight and 2892 embryosml−1 were obtained after 15 days. For interior spruce cells, a maximum dry weight of 5.9 gliter−1 and 2698 embryosml−1 were obtained after 21 to 30 days. During culture over 2 wk, ammonia was almost completely utilized by both species, wherease nitrate was depleted to 40% of the initial concentration. Sucrose was rapidly hydrolyzed to glucose and fructose by both species. Black spruce cultures preferentially metabolized glucose, whereas interior spruce preferentially metabolized fructose. Improved growth of interior spruce cells in mechanically stirred bioreactors occurred when cultured in LP medium with 60 mM fructose as the sole carbon source.