Soil evaluation for Castanea sativa afforestation in Northeastern Spain

This paper is focused on the soil characterisation of forest sites where Castanea sativa wood stands are located in Catalonia (NE of Spain) as a former and essential requirement to future afforestation programs with this species. From 28 sample plots field survey, several soil indexes have been calculated and, their central and marginal values have been established, defining a range of soil conditions where this species can successfully live in Catalonia. So, we can see that soils are developed on acid bedrock as parent material, basically igneous rocks such as granodiorite and granite, but they occur on schist as well. Their predominant texture is loamy-sand. Soils have low water holding capacity, mainly due to their high stoniness and steep slopes. Nevertheless, regular rainfall distribution all year around, avoids meteorological drought as well as reduces physiological drought. Annual rainfall distribution and steep slopes are responsible for the dwarf development of argic horizons. Soils are relatively poor in organic matter, and despite being generally very acid they have forest mull humus forms.     

Inheritance of resistance to four cucurbit viruses in Cucurbita moschata

Cucurbita moschata cv. Nigerian Local has been used as a source of resistance to Zucchini yellow mosaic virus (ZYMV), Watermelon mosaic virus (WMV), Papaya ringspot virus W (PRSV-W) and Cucumber mosaic virus (CMV) in breeding both Cucurbita moschata and Cucurbita pepo. We used the F₁, F₂ and BC₁ generations derived from the cross C.-moschata cv. Waltham Butternut × Nigerian Local to study the inheritance of resistance to each of the viruses. We confirmed monogenic dominant resistance to ZYMV previously attributed to Zym, and we report monogenic dominant resistance to WMV and CMV which we propose to designate Wmv and Cmv, respectively. A single recessive gene, which we propose to designate prv, controls resistance to PRSV. DNA samples were extracted from a Waltham Butternut BC₁ F₁ population screened with ZYMV and analyzed using randomly amplified polymorphic DNA markers. No RAPD markers linked to ZYMV resistance were found. This revised version was published online in July 2006 with corrections to the Cover Date.     

Dietary Lipid Requirements for Optimal Egg Quality of Redclaw Crayfish,Cherax quadricarinatus

The effect of three crude dietary lipid levels (4, 8, and 12%) on egg quality of the female redclaw crayfish, Cherax quadricarinatus, was evaluated. Three replicate groups of 40 crayfish (mean initial weight ± SD, 23.0 ± 3.0 g) per diet treatment were stocked in 15,000 ‐L tanks, at 28 C. After 75 d of culture, there were significant differences (P < 0.001) in egg area (3.52–3.90 mm²), volume (34.0–39.3 mm³), weight (4.81–5.36 mg), and diameter (2.15–2.27 mm) in response to dietary lipids in the diet. Using the quadratic equation, the maximum responses of these parameters corresponded to lipid levels from 8.60–8.84%. There were no significant differences (P > 0.05) in survival (82.1–86.9%), final weight (41.0–43.7 g), number of spawning females (18.12–27.38%), and fecundity (9.07–10.31 eggs/g female). Additionally, there were no significant differences (P > 0.05) in egg mean protein (2306.87 ± 440.08 μg/egg), lipid (441.95 ± 83.23 μg/egg) and carbohydrate (74.81 ± 10.12 μg/egg) contents, and energy (13.49 ± 2.25 kcal/egg). The optimum overall response was obtained for dietary lipid content of 8.7%, which we recommend to optimize egg quality of this freshwater crayfish.