Inheritance of resistance to stripe rust (Puccinia striformis) in crosses between wild emmer (Triticum dicoccoides) and cultivated tetraploid and hexaploid wheats. I. Triticum durum

Summary Reciprocal crosses were carried out between Triticum dicoccoides sel. G-25-highly resistant to Puccinia striiformis race 20A-and Triticum durum cultivar Nursith 163-which served as susceptible parent.F₁ hybrids in one of the crosses showed a wide range of infection types to the test isolate, whereas in a repeated cross all F₁ plants proved highly resistant. The variable reaction pattern observed in the F₁ hybrids of the first cross suggests incomplete penetrance of the resistance factor in certain environmental conditions.The segregation ratio displayed by the F₂ progenies indicates that a single dominant factor for resistance to stripe rust race 20A was transferred from wild emmer to cultivated durum wheat.Contribution from the Agricultural Research Organization, Volcani Center, Bet Dagan, Israel. 1973 Series, No. 291-E.     

Plant–soil interactions in wheat and coriander crops driving arthropod assemblies through volatile compounds

Arthropod assemblies are frequently determined by bottom-up interactions that include emission of organic volatile compounds. Therefore, changes in soil characteristics associated with land use history can influence the volatile emissions of plants affecting the structure of arthropod assemblies in croplands. This study aims (1) to study the relationships between soil degradation levels due to land-use history, and the change in particular soil chemical characteristics; (2) to analyze plant–soil interactions quantifying the effect of soil degradation on the production of biomass and grain yield of coriander and wheat crops, and on the production and chemical composition of volatile secondary metabolites in coriander grain; (3) to find the relationship between the analyzed plant–soil interactions and the emission of volatile signals affecting arthropod assemblies; and (4) to determine the relationship between particular chemical soil characteristics and the structure of arthropod assemblies. For these purpose, two experiments were carried out in which volatile compounds were conducted from source plots with soils with different levels of degradation, sown with wheat or coriander, to sink plots with similar soil, sown with wheat. Crops were evaluated on source plots, and the arthropods communities were assessed on sink-plots. Coriander produced high biomass, grain yield and essential oil in the favorable environments and wheat produced higher biomass and grain yield in soil with low degradation than with high degradation. Particular chemical soil elements, for example, Na, Fe, Mn, N and CEC and essential oil components, for example, γ-trepanned, p-cymene, asinine and β-pinene could be involved in the arthropods assemblies. Based on these results, arthropods communities in agricultural systems are, at least, partially controlled by chemical signals, which depend on plant–soil interactions.     

Chemotypical variation in Vanilla planifolia Jack. (Orchidaceae) from the Puebla-Veracruz Totonacapan region

One of the threats in the diversity loss of the primary gene pool of Vanilla planifolia is the lack of information on existing level of polymorphism in cultivated germplasm, and the different expressions of this polymorphism. For this reason, it is proposed to study the chemical polymorphism of the four phytochemicals that define the vanilla aroma quality in fruits (vanillin, vanillic acid, p-hydroxybenzaldehyde, p-hydroxybenzoic acid) by HPLC analysis (High Performance Liquid Chromatography) of 25 collections of unknown genotype, grown in the region Totonacapan Puebla-Veracruz, Mexico. The results identified a selection process, domestication in fruit aroma of vanilla, during which increased the participation of vanillin and reduced the presence of three minor compounds (vanillic acid, p-hydroxybenzaldehyde and p-hydroxybenzoic acid) in the global aroma. We distinguished a total of six chemotypes of V. planifolia in the Totonacapan region, some chemotypes with wild aromatic characteristics (low participation of vanillin) related to the material less cultivated in the region and domesticated chemotypes with high participation of vanillin, for the most cultivated material. The results show that the diversification of the chemotypes of V. planifolia is not related to environmental variation. The data indicate that in the possible center of origin of vanilla, there is phytochemical polymorphism, which indirectly suggests the existence of genetic polymorphism, essential for the design of a breeding program for optimizing the use and conservation of diversity of the primary gene pool of Vanilla planifolia.     

Modification of ocular defects in mouse developmental glaucoma models by tyrosinase

Mutations in the cytochrome P450 family 1, subfamily B, polypeptide 1 (CYP1B1) gene are a common cause of human primary congenital glaucoma (PCG). Here we show that Cyp1b1-/- mice have ocular drainage structure abnormalities resembling those reported in human PCG patients. Using Cyp1b1-/- mice, we identified the tyrosinase gene (Tyr) as a modifier of the drainage structure phenotype, with Tyr deficiency increasing the magnitude of dysgenesis. The severe dysgenesis in eyes lacking both CYP1B1 and TYR was alleviated by administration of the tyrosinase product dihydroxyphenylalanine (l-dopa). Tyr also modified the drainage structure dysgenesis in mice with a mutant Foxc1 gene, which is also involved in PCG. These experiments raise the possibility that a tyrosinase/l-dopa pathway modifies human PCG, which could open new therapeutic avenues.     

Antibacterial activity of Coriandrum sativum L. and Foeniculum vulgare Miller Var. vulgare (Miller) essential oils

Essential oils were extracted from the fruits of Coriandrum sativum L. and Foeniculum vulgare Miller var. vulgare (Miller) and assayed in vitro for antibacterial activity to Escherichia coli and Bacillus megaterium, bacteria routinely used for comparison in the antimicrobial assays, and 27 phytopathogenic bacterial species and two mycopathogenic ones responsible for cultivated mushroom diseases. A significant antibacterial activity, as determined with the agar diffusion method, was shown by C. sativum essential oil whereas a much reduced effect was observed for F. vulgare var. vulgare oil. C. sativum and F. vulgare var. vulgare essential oils may be useful natural bactericides for the control of bacterial diseases of plants and for seed treatment, in particular, in organic agriculture. The significant antibacterial activity of essential oils to the bacterial pathogens of mushrooms appears promising.     

Ovariohysterectomy in a dog by a hybrid NOTES technique

This report demonstrates the feasibility of an elective ovariosalpingohysterectomy by natural transluminal endoscopic surgery (NOTES) hybrid technique in a dog. A 5-mm abdominal cannula was used in combination with a 10-mm cannula (vaginal access). The patient's quick recovery and the absence of complications are indicative of the effectiveness of this surgery.     

Development of rice (Oryza sativa) lines resistant to aryloxyphenoxypropionate herbicides through induced mutation with gamma rays

The aryloxyphenoxypropionate herbicides (APPs) are graminicides with excellent control of many grass weeds species, including weedy rice (Oryza sativa L.). These herbicides block the fatty acid biosynthesis by inhibiting the enzyme acetyl‐CoA carboxylase (ACCase), resulting in the death of susceptible plants. Inducing mutation with gamma rays to rice seeds, two lines resistant to APPs herbicides were developed. Plant dose–response assays confirmed the resistance to the APPS herbicides quizalofop‐p‐ethyl and haloxyfop‐p‐methyl. The carboxyltransferase domain fragments of ACCase from the resistant biotype and susceptible control were sequenced and compared. A point mutation was detected in the amino acid position 2,027 (Rice Genome Annotation Project: Os05g22940.1). Results indicated that resistance to APPs is a consequence of an altered ACCase enzyme that confers resistance. The use of APPs herbicide‐resistant rice lines represents an innovative and promising alternative for weedy rice control in paddy rice systems.