Winter wheat {Triticum aestivum L., cv. Mercia) was grown in chambers under light and temperature conditions similar to the UK field environment for the 1990/1991 growing season at two levels each of atmospheric CO2 concentration (seasonal means: 361 and 692 |imol mol"^), temperature (tracking ambient and ambient +4 °C) and nitrogen application (equivalent to 87 and 489 kg ha* total N applied). Total dry matter productivity through the season, the maximum number of shoots and final ear number were stimulated by CO2 enrichment at both levels of the temperature and N treatments. At high N, there was a CO2-induced stimulation of grain yield (+15%) similar to that for total crop dry mass (+12%), and there was no significant interaction with temperature. This contrasts with other studies, where positive interactions between the effects of increases in temperature and CO2 have been found. Temperature had a direct, negative effect on yield at both levels of the N and CO2 treatments. This could be explained by the temperature-dependent shortening of the phenological stages, and therefore, the time available for accumulating resources for grain formation. At high N, there was also a reduction in grain set at ambient +4 °C temperature, but the overall negative effect of warmer temperature was greater on the number of grains (-37%) than on yield (-18%), due to a compensating increase in average grain mass. At low N, despite increasing total crop dry mass and the number of ears, elevated CO2 did not increase grain yield and caused a significant decrease under ambient temperature conditions. This can be explained in terms of a stimulation of early vegetative growth by CO2 enrichment leading to a reduction in the amount of N available later for the formation and filling of grain.

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Rye secalins are a polymorphic mixture of polypeptides which are classified into four major groups. Previous studies have shown that the structural genes for two of the groups (the ω-secalins and 40K γ-secalins) are located on the short arm of chromosome 1R and those for a third group (the high molecular weight secalins) on the long arm of the same chromosome. Analysis of F2 grain from crosses between inbred lines of S. cereale shows that the structural genes for the ω-secalins (designated Sec 1) and the high molecular weight secalins (designated Sec 3) are loosely linked (40.8 ±3.76% recombination, 57.4 ± 11.30 cM). Analysis of wheat rye addition lines shows that the structural genes for the 75K γ-secalins are present on chromosome 2R. This locus is provisionally designated Sec 2. These genes are probably derived from those for the 40K γ-secalins by duplication, divergence and translocation. Analysis of secalin fractions from wild species of rye shows that all contain 75K γ-secalins, indicating that the duplication and divergence, if not the translocation, occurred before speciation of the genus.

BackgroundThe importance of appropriate, accurate measurement and reporting of environmental parameters in plant sciences is a significant aspect of quality assurance for all researchers and their research. There is a clear need for ensuring research across the world can be compared, understood and where necessary replicated by fellow researchers. A common set of guidelines to educate, assist and encourage comparativeness is of great importance. On the other hand, the level of effort and attention to detail by an individual researcher should be commensurate with the particular research being conducted. For example, a researcher focusing on interactions of light and temperature should measure all relevant parameters and report a measurement summary that includes sufficient detail allowing for replication. Such detail may be less relevant when the impact of environmental parameters on plant growth and development is not the main research focus. However, it should be noted that the environmental experience of a plant during production can have significant impact when subsequent experiments investigate plants at a molecular, biochemical or genetic level or where species interactions are considered. Thus, researchers are encouraged to make a critical assessment of what parameters are of primary importance in their research and these parameters should be measured and reported.ContentThis paper brings together a collection of parameters that the authors, as members of International Committee on Controlled Environment Guidelines (ICCEG) in consultation with members of our three parent organizations, believe constitute those which should be recorded and reported when publishing scientific data from experiments in greenhouses. It provides recommendations to end users on when, how and where these parameters should be measured along with the appropriate internationally standardized units that should be used.

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SUMMARYHordein, the storage protein of barley grain, consists of three groups of polypeptides called B, C and D hordeins. Each group is coded for by a complex locus and these have been designated Hot 2, Hot 1 and Hot 3 respectively. Previous work has shown that Hot 1 and Hor 2 are on the short arm of chromosome 5. The results of crosses designed to evaluate the linkage relationships of Hor 3 show that it is located about 9 cM from the centromere on the long arm of chromosome 5. The loci ned and wst5 are located 8•O± 15 and 37•4±4•7 cM respectively distal to Hot 3. These results are discussed in relation to the chromosomal location of loci which code for homologous groups of storage proteins in wheat.