The germplasm release of F87084, a fertile, adapted clone with multiple disease resistances

F87084 is a germplasm release that has been developed by conventional breeding methods and can be traced back to very diverse germplasm sources. This clone has excellent female fertility, round-oval tubers and is well adapted to Eastern Canada. The vine maturity is slightly later than that of Kennebec, and the mean marketable yield is 78% of Kennebec. The specific gravity, boil, bake and chip scores are somewhat lower than Kennebec. F87084 is resistant to late blight,Verticillium dahliae, early blight, and the pathotypes of wart occurring in Newfoundland. F87084 has extreme resistance to PVY^o and PVX. It is also resistant to the potato cyst nematode pathotype Ro1. Progeny analyses indicate that F87084 is duplex for the genes controlling extreme resistance to PVX as well as resistance to the potato cyst nematode (Ro1).     

Buzzing with possibilities: Training and olfactory generalization in conservation detection dogs for an endangered stonefly species

1. Professionally trained conservation detection dogs (CDDs) are taught to locate biological targets, including cryptic and low-density plant and animal species, but have been largely underused in detecting endangered invertebrates.
2. This pilot study assessed the ability of four volunteer CDD/handler teams to detect the endangered Alpine stonefly (Eustheniidae: Thaumatoperla alpina). Once trained, all teams identified 100% of the targets when present in container line-up searches, with no false alerts.
3. In the field, all available dog–handler teams (n = 3) alerted to the presence of numerous T. alpina individuals, including individuals that were not seen by experienced visual surveyors.
4. Three of the four CDDs also spontaneously alerted (i.e. exhibited olfactory generalization) to a closely related species, the Stirling stonefly (Thaumatoperla flaveola), in an initial container search.
5. These preliminary results demonstrate that volunteer dog–handler teams can be trained to detect T. alpina in situ. In addition, CDDs may be able to perform olfactory generalization effectively: from detecting a commonly occurring species to detecting a closely related, rare, or cryptic species.

     

Changes in chemical composition and digestibility of three maize stover components digested by white‐rot fungi

Maize stover (total stem and leaves) is not considered a ruminant feed of high nutritive value. Therefore, an improvement in its digestibility may increase the viability of total forage maize production systems in marginal growth regions. The objective of this study was to describe the changes in chemical composition during the storage of contrasting components of maize stover (leaf, upper stem and lower stem) treated with either of two lignin degrading white‐rot fungi (WRF; Pleurotus ostreatus, Trametes versicolor). Three components of maize stover (leaf, upper stem and lower stem), harvested at a conventional maturity for silage production, were digested with either of two WRF for one of four digestion durations (1–4 months). Samples taken prior to fungal inoculation were used to benchmark the changes that occurred. The degradation of acid detergent lignin was observed in all sample types digested with P. ostreatus; however, the loss of digestible substrate in all samples inoculated with P. ostreatus was high, and therefore, P. ostreatus‐digested samples had a lower dry matter digestibility than samples prior to inoculation. Similarly, T. veriscolor‐digested leaf underwent a non‐selective degradation of the rumen‐digestible components of fibre. The changes in chemical composition of leaf, upper stem and lower stem digested with either P. ostreatus or T. veriscolor were not beneficial to the feed value of the forage, and incurred high DM losses.     

The AIN‐76A defined rodent diet accelerates the development of heart failure in SHHF rats: A cautionary note on its use in cardiac studies

Previous studies from our laboratory have shown positive benefits of linoleic acid (LA) feeding for attenuation of rat heart failure (HF). However, another research group concluded LA feeding was detrimental to cardiac function, using the American Institute of Nutrition 76A (AIN) diet as a background diet for the experimental animals only. To reconcile these conflicting results and determine whether (i) AIN has effects on cardiovascular function, and (ii) AIN reverses the positive effects of LA feeding, studies were performed using spontaneously hypertensive heart failure (SHHF) rats in both a survival study with lifetime feeding of AIN (control: Purina 5001) and a 2 × 2 factorial design for 6 weeks in young male SHHF rats with background diet and LA as variables. During a lifetime of AIN feeding, mortality from heart failure is significantly accelerated, cardiolipin altered and triglycerides increased. In young rats, 6 weeks on the AIN diet promoted increased systolic and diastolic blood pressure, increased fed and fasting blood glucose, increased serum inflammatory eicosanoids, decreased docosahexanoic acid, increased posterior wall thickness in diastole and an altered cardiolipin subspecies profile. The addition of LA to the AIN diet was able to rescue blood pressure. However, the combination increased retroperitoneal fat mass, body weight and fed blood glucose beyond the levels with the AIN diet alone. Because the AIN diet has wide ranging effects on cardiovascular parameters, our results suggest that it should not be used in animal studies involving the cardiovascular system unless induction of cardiac dysfunction is the desired outcome.     

The use of conventional and molecular genetics to produce new diversity in seed oil composition for the use of plant breeders-progress, problems and future prospects

Summary Considerable advances in the manipulation of seed oil yield and quality have been made using conventional breeding methods. Newer methods such as induced mutation and wide crosses have also resulted in significant achievements. These techniques, however, are all limited by the gene pool available in the crop of interest and its near relatives. The prospect of diminishing supplies of non-renewable fossil hydrocarbon reserves and the reality of edible crop surpluses have focused attention on the development of industrial oilseed crops. This will require the production of types of seed fatty acids which are not available in the oilseed crop species that are grown at present.The introduction of novel oil crops via domestication is contrasted with the insertion of alien genes into existing oilseeds to create designer crops. The use of molecular genetics to alter the yield and quality of rapeseed oil is discussed, and strategies for the engineering of seven new designer rapeseed varieties are presented.     

Introduction of exotic parasitic wasps for the control of Liriomyza trifolii (Dipt., Agromyzidae) in Senegal

Abstract

Liriomyza trifolii Burgess had first been reported from Senegal in 1980. Field surveys in 1982 revealed its presence in all vegetable growing areas of the country, heaviest damage being registered in the Cap Vert. Five indigenous eulophids (larval parasitoids) plus five other rare parasitoids, frequently parasitized over 90% of the flies. These rates were higher in insecticide free fields, and very much above the 30–40% reported for 1981. The most important parasitoids were Hemiptarsensus semialbiclava (Girault), which dominated in the second half of the dry season, and two Chrysonotomyia spp., which were more abundant in the rainy season. Surveys for exotic parasitoids indicated Diaulinopsis callichroma Crawford from Trinidad to be a promising species for introduction in the New World. This parasitoid, together with eight other chalcidoids (mostly larval parasitoids) and two braconids (larval‐pupal parasitoids), were collected in the field or received from established insectary cultures. They were studied and shipped for rearing and release in Senegal. Nine species were released at the end of 1982 and in 1983. Many were recovered shortly after release, but only Opius dissitus Muesebeck was recovered in later samples and became relatively abundant.