Dwarf germplasm: the key to giant <Emphasis Type="Italic">Cannabis</Emphasis> hempseed and cannabinoid crops

After a century of banishment, both euphoric (“marijuana”) and non-euphoric (“industrial hemp”) classes of Cannabis sativa are attracting billions of dollars of investment as new legitimate crops. Most domesticated C. sativa is very tall, a phenotype that is desirable only for hemp fibre obtained from the stems. However, because the principal demands today are for chemicals from the inflorescence and oilseeds from the infructescence, an architecture maximizing reproductive tissues while minimizing stems is appropriate. Such a design was the basis of the greatest short-term increases in crop productivity in the history of agriculture: the creation of short-stature (“semi-dwarf”), high-harvest-index grain cultivars, especially by ideotype breeding, as demonstrated during the “Green Revolution.” This paradigm has considerable promise for C. sativa. The most critical dwarfing character for breeding such productivity into C. sativa is contraction of internodes. This reduces stem tissues (essentially a waste product except for fibre hemp) and results in compact inflorescences (which, on an area basis, maximize cannabinoid chemicals) and infructescences (which maximize oilseed production), as well as contributing to ease of harvesting and efficiency of production on an area basis. Four sources of germplasm useful for breeding semi-dwarf biotypes deserve special attention: (1) Naturally short northern Eurasian wild plants (often photoperiodically day-neutral, unlike like most biotypes) adapted to the stress of very short seasons by maximizing relative development of reproductive tissues. (2) Short, high-harvest-index, oilseed plants selected in northern regions of Eurasia. (3) “Indica type” marijuana, an ancient semi-dwarf cultigen tracing to the Afghanistan-Pakistan area. (4) Semi-dwarf strains of marijuana bred illegally in recent decades to avoid detection when grown clandestinely indoors for the black market. Although the high THC content in marijuana strains limits their usage as germplasm for low-THC cultivars, modern breeding techniques can control this variable. The current elimination of all marijuana germplasm from breeding of hemp cultivars is short-sighted because marijuana biotypes possess a particularly wide range of genes. There is an urgent need to develop public gene bank collections of Cannabis.     

Mars-like soils in the Atacama Desert, Chile, and the dry limit of microbial life

The Viking missions showed the martian soil to be lifeless and depleted in organic material and indicated the presence of one or more reactive oxidants. Here we report the presence of Mars-like soils in the extreme arid region of the Atacama Desert. Samples from this region had organic species only at trace levels and extremely low levels of culturable bacteria. Two samples from the extreme arid region were tested for DNA and none was recovered. Incubation experiments, patterned after the Viking labeled-release experiment but with separate biological and nonbiological isomers, show active decomposition of organic species in these soils by nonbiological processes.     

A photoinduced persistent structural transformation of the special pair of a bacterial reaction center

Structural modification of photosynthetic reaction centers is an important approach for understanding their charge-separation processes. An unprecedented persistent structural transformation of the special pair (dimer) of bacteriochlorophyll molecules can be produced by light absorption alone. The nonphotochemical hole-burned spectra for the reaction center of Rhodopseudomonas viridis show that the phototransformation leads to a red shift of 150 wave numbers for the special pair's lowest energy absorption band, P960, and a comparable blue shift for a state at 850 nanometers, which can now be definitively assigned as being most closely associated with the upper dimer component. Additional insights on excited-state electronic structure include the identification of a new state.     

Daily oviposition patterns of the African malaria mosquito <Emphasis Type="Italic">Anopheles gambiae</Emphasis> Giles (Diptera: Culicidae) on different types of aqueous substrates

Background  

Anopheles gambiae Giles is the most important vector of human malaria in sub-Saharan Africa. Knowledge of the factors that influence its daily oviposition pattern is crucial if field interventions targeting gravid females are to be successful. This laboratory study investigated the effect of oviposition substrate and time of blood feeding on daily oviposition patterns of An. gambiae mosquitoes.     

Different Culture Media Requirements of IVF and Nuclear Transfer Bovine Embryos

Important differences exist between in vitro fertilized (IVF) and nuclear transfer (NT) bovine embryos. Studies have shown that although in vitro development is comparable, post-implantation survival is greatly reduced in NT embryos. In this study, we compare serum and bovine serum albumin (BSA) supplementation during oocyte maturation and embryo culture of IVF and NT embryos. In experiment 1, oocytes and embryos were randomly distributed into different treatment groups consisting of synthetic oviductal fluid (SOF) medium supplemented with either serum, fatty acid-free BSA (FAF) or fraction V BSA during maturation and/or culture to assess IVF embryo development. In experiment 2, oocytes were matured in SOF + serum or SOF + FAF and reconstructed embryos were cultured in SOF + FAF to assess NT embryo development. Among the IVF treatment groups, a greater number of blastocysts were observed in the steer serum (SER) group (IVM and IVC in SOF + serum) on day 6; however, no significant differences were seen in blastocyst development from day 8 onwards. Hatching frequencies on days 8 and 9 were significantly greater in groups with serum, with the exception of FAF (IVM and IVC in SOF + FAF) on day 9. For the NT treatment groups, the presence of serum during IVM resulted in a higher proportion of MII oocytes and increased blastocyst development and hatching rates were compared with supplementation of FAF. These results indicate that both serum and FAF provide comparable embryo development for IVF but not for NT bovine embryos.     

A field study of watery mouth: clinical, epidemiological, biochemical, haematological and bacteriological observations

More than 500 cases of watery mouth in newborn lambs were recorded in 11 flocks and a detailed examination was performed in more than 200 cases. The condition occurred predominantly in lambs aged 24 to 48 hours. The incidence in a flock varied from 1 per cent to 24 per cent and the mortality in affected lambs varied from 7 per cent to 83 per cent. A bacteraemia was found in 38 per cent of the affected lambs. There were no consistent abnormalities of clinical biochemistry or haematology. Watery mouth was more common in twins and especially in triplets than in single lambs. In twins the highest incidence of watery mouth was recorded in lambs born to ewes in poor body condition. Antibiotic given orally within 15 minutes of birth greatly reduced the incidence of watery mouth.