ALBERT

Notes: The economic value of wheat grain is determined by the kernel morphology which is an important parameter for manufacturing different food products requiring specific grain characteristics. Although kernel size and shape have emerged as important breeding objectives, not much information is available about the number or location of associated gene(s)/quantitative trait loci. In the present study, a recombinant inbred line population of 106 plants (F7) was phenotyped for four traits, namely kernel length, width, weight and factor form density (FFD) and genotyped with different polymerase chain reaction-based markers. Transgressive segregants were observed for all the traits and genetic correlation studies showed positive correlations between the majority of the traits. The number of markers associated with each trait ranged from two to nine and the phenotypic contribution by an individual marker ranged from 3.3 to 16.6%. Many of the markers showed linkage to more than one trait. Strategies for improving the wheat grain quality traits and the utility of such markers in marker-assisted selection (MAS) efforts are discussed.

Notes: A germplasm collection of 152 diverse rapeseed accessions from Canada, China, France, India, Poland and South Korea was assayed for identifying new fertility restorers and sterility maintainers for a Tournefortii (tour) cytoplasmic male sterility (CMS) system in rape-seed. Only 16 (10.5%) genotypes showed complete fertility restoration following hybridization with tour CMS line NE 409A. Notable among these were GSL 8851, GSL 8953, Mokpo # 9, Mali, Buk-wuk-13, Kuju-27 and Mokpo # 84. As many as 78 (51.3%) genotypes were perfect maintainers of sterility, the remaining 58 (38.2%) genotypes were classified as partial maintainers. To study the inheritance of fertility restoration, 20 CMS (tour) rapeseed lines were crossed with the four best fertility restorers, namely GSL 8851, GSL 8953, Kuju-27 and Mokpo # 9, to obtain F2 and test cross populations. Segregation data indicated that fertility restoration for tour CMS was governed by two genes, of which, one is stronger than the other (χ212:3:1). Differences in gene interactions were also observed (χ29:3:4) which could be explained on the basis of influence of female parent genotypes/or modified expression of the restorer gene(s) in different genetic backgrounds. Tests of allelism indicated that the restorer genes present in the four restorers evaluated were allelic.

Notes: Biochemical and respiratory changes in the common carp Cyprinus carpio, were studied 6, 24, 96 and 168 h upon exposure to hypoxia (0·5 mgO2 l−1). Modification of kinetic properties of phosphofructokinase (PFK-1), coupled with a decreased in PFK-1 activities, were evident in muscle. No changes in kinetics and activities could be observed in muscle pyruvate kinase (PK) and lactate dehydrogenase (LDH). A decrease in muscle citrate synthase (CS) and an increase in muscle cytochrome c oxidase (CCO) were found. The common carp was able to maintain a constant level of muscle glycogen, muscle ATP, and liver CS throughout the 168-h experimental period. Changes in activities of liver LDH and muscle CCO were observed only at 168 h, which indicates that common carp may switch to alternative metabolic pathway to deal with prolonged hypoxia. A severe decrease in liver glycogen was accompanied by increases in lactate levels in both the muscle and liver. Oxygen consumption rate was reduced under hypoxia, but resumed to normoxic levels within 2 h upon return to normoxic condition. Overall, these results indicate that carp adopt different strategies in an attempt to deal with short term and long term hypoxia in the natural environment.

Notes: Substituting the nuclear genome of Brassica rapa into the cytoplasmic background of Enarthrocarpus lyratus through backcross substitution helped in developing cytoplasmic male sterility (CMS). Alloplasmic male sterile plants had pale green leaves, small flowers with narrow petals and rudimentary anthers. Female fertility, low initially, improved considerably with advanced backcross generations. Male sterility expression was stable throughout the growing season. Except for EC 339014, all B. rapa accessions (38) evaluated were partial maintainers of the male sterility. Introgression of gene(s) for fertility restoration from the cytoplasm donor species was facilitated by homoeologous pairing between B. rapa and E. lyratus genomes, as was apparent from the very frequent occurrence of a trivalent in the monosomic addition plants (2n = 10 II + 1 I). Backcrossing of fertile monosomic addition plants with B. rapa led to the recovery of male fertile plants possessing the stable euploid chromosome number (2n = 20). These plants restored male fertility in crosses with different (lyr) CMS B. rapa genotypes, confirming the introgression of fertility restorer gene(s) from E. lyratus, the cytoplasm donor species.

Notes: Assessment of genetic diversity in a crop species is prerequisite to its improvement. The use of germplasm with distinct DNA profiles will help to generate genetically diversified breeding populations. The aims of the present experiment were to study molecular diversity among selected groundnut accessions and identify those with distinct DNA profiles for mapping and genetic enhancement. Twenty-six accessions and eight primers of a 10-mer were selected for random amplified polymorphic DNA assay. The genetic similarity (Sij) ranged from 59.0% to 98.8%, with an average of 86.2%. Both multidimensional scaling and unweighted pair-group method with arithmetic averages (UPGMA) dendrograms revealed the existence of five distinct clusters. However, this classification could not be related to known biological information about the accessions falling into different clusters. Some accessions with diverse DNA profiles (ICG 1448, 7101, and 1471, and ICGV 99006 and 99014) were identified for mapping and genetic enhancement in groundnut.

Notes: The leaf rust resistance gene Lr19, transferred from Agropyron elongatum into wheat (Triticum aestivum L.) imparts resistance to all pathotypes of leaf rust (Puccinia recondita f.sp. tritici) in South-east Asia. A segregating F2 population from a cross between the leaf rust resistant parent ‘HW 2046’ carrying Lr19 and a susceptible parent ‘Agra Local’ was screened in the phytotron against a virulent pathotype 77-5 of leaf rust with the objective of identifying the molecular markers linked to Lr19. The gene was first tagged with a randomly amplified polymorphic DNA (RAPD) marker S73728. The RAPD marker linked to the gene Lr19 which mapped at 6.4 ± 0.035 cM distance, was converted to a sequence characterized amplified region (SCAR) marker. The SCAR marker (SCS73719) was specific to Lr19 and was not amplified in the near-isogenic lines (NILs) carrying other equally effective alien genes Lr9, Lr28 and Lr32 enabling breeders to pyramid Lr19 with these genes.

Notes: Synthesis of results from several Arctic and boreal research programmes provides evidence for the strong role of high-latitude ecosystems in the climate system. Average surface air temperature has increased 0.3 °C per decade during the twentieth century in the western North American Arctic and boreal forest zones. Precipitation has also increased, but changes in soil moisture are uncertain. Disturbance rates have increased in the boreal forest; for example, there has been a doubling of the area burned in North America in the past 20 years. The disturbance regime in tundra may not have changed. Tundra has a 3–6-fold higher winter albedo than boreal forest, but summer albedo and energy partitioning differ more strongly among ecosystems within either tundra or boreal forest than between these two biomes. This indicates a need to improve our understanding of vegetation dynamics within, as well as between, biomes. If regional surface warming were to continue, changes in albedo and energy absorption would likely act as a positive feedback to regional warming due to earlier melting of snow and, over the long term, the northward movement of treeline. Surface drying and a change in dominance from mosses to vascular plants would also enhance sensible heat flux and regional warming in tundra. In the boreal forest of western North America, deciduous forests have twice the albedo of conifer forests in both winter and summer, 50–80% higher evapotranspiration, and therefore only 30–50% of the sensible heat flux of conifers in summer. Therefore, a warming-induced increase in fire frequency that increased the proportion of deciduous forests in the landscape, would act as a negative feedback to regional warming.Changes in thermokarst and the aerial extent of wetlands, lakes, and ponds would alter high-latitude methane flux. There is currently a wide discrepancy among estimates of the size and direction of CO2 flux between high-latitude ecosystems and the atmosphere. These discrepancies relate more strongly to the approach and assumptions for extrapolation than to inconsistencies in the underlying data. Inverse modelling from atmospheric CO2 concentrations suggests that high latitudes are neutral or net sinks for atmospheric CO2, whereas field measurements suggest that high latitudes are neutral or a net CO2 source. Both approaches rely on assumptions that are difficult to verify. The most parsimonious explanation of the available data is that drying in tundra and disturbance in boreal forest enhance CO2 efflux. Nevertheless, many areas of both tundra and boreal forests remain net sinks due to regional variation in climate and local variation in topographically determined soil moisture. Improved understanding of the role of high-latitude ecosystems in the climate system requires a concerted research effort that focuses on geographical variation in the processes controlling land–atmosphere exchange, species composition, and ecosystem structure. Future studies must be conducted over a long enough time-period to detect and quantify ecosystem feedbacks.

Notes: Mycoplasma agalactiae, the causative agent of contagious agalactia in small ruminants, produces a protein, named P80, that is detectable in all wild-type isolates examined to date and that appears expressed during the early phase of infection. We describe here the identification, cloning and expression of the gene encoding P80 (ma-mp81). The deduced amino acid sequence is consistent with a hydrophobic and basic protein that possesses a lipoprotein signal peptide. Sequence analysis of gene ma-mp81 suggests that P80 is a membrane lipoprotein that shows significant homology with other putative lipoproteins of M. pneumoniae. An internal 1-kb fragment of ma-mp81 was expressed in Escherichia coli as a 6×His-tagged protein. The purified recombinant protein greatly reacted with polyclonal anti-P80 sera raised in lamb.