Non-escaping frost tolerant QTL linked genetic loci at reproductive stage in six wheat DH populations

Reproductive stage frost poses a major constraint for wheat production in countries such as Australia.However,little progress has been made in identifying key genes to overcome the constraint.In the present study,a severe frost event hit two large-scale field trials consisting of six doubled haploid(DH)wheat populations at reproductive stage(young microspore stage)in Western Australia,leading to the identification of 30 robust frost QTL on 17 chromosomes.The major 18 QTL with the phenotype variation over 9.5%were located on 13 chromosomes including 2 A,2 B,2 D,3 A,4 A,4 B,4 D,5 A,5 D,6 D,7 A,7 B and7 D.Most frost QTL were closely linked to the QTL of anthesis,maturity,Zadok stages as well as linked to anthesis related genes.Out of those,six QTL were repetitively detected on the homologous regions on 2 B,4 B,4 D,5 A,5 D,7 A in more than two populations.Results showed that the frost damage is associated with alleles of Vrn-A1 a,Vrn-D1 a,Rht-B1 b,Rht-D1 b,and the high copy number of Ppd-B1.However,anthesis QTL and anthesis related genes of Vrn-B1 a and Ta FT3-1 B on chromosomes 5 B and 1 B did not lead to frost damage,indicating that these early-flowering phenotype related genes are compatible with frost tolerance and thus can be utilised in breeding.Our results also indicate that wild-type alleles Rht-B1 a and Rht-D1 a can be used when breeding for frost-tolerant varieties without delaying flowering time.     

Relative performance of two Nile tilapia ( Oreochromis niloticus Linnaeus) strains in Egypt: The Abbassa selection line and the Kafr El Sheikh commercial strain

The Abbassa selection line (developed by selective breeding) and the Kafr El Sheikh commercial strain (widely used in Egypt), both Oreochromis niloticus, were compared at two stocking densities (two and four fish m^?2). Harvest weight, length, depth, width and head length were recorded. The Abbassa line showed a superior harvest weight (28 per cent) over the Kafr El Sheikh strain. Males were heavier than females, but the between‐sex difference was greater in the commercial than in the Abbassa line (39 and 31 per cent respectively). Females in the Abbassa line grew almost as fast as males in the commercial line. Both strains grew faster at the lower density, and the percentage reduction in harvest weight at the higher density was about the same for both strains (27 per cent). The advantage of the Abbassa line was 28 per cent at both densities. Both strains had a similar survival rate (approximately 80 per cent) during the grow‐out period. We conclude that the Abbassa line is ready for release to the tilapia industry in Egypt. Further evidence is being sought in currently underway on‐farm evaluations. Measures should be taken to ensure the long‐term viability of the Abbassa line.     

Associations of <Emphasis Type="Italic">NAM</Emphasis>-<Emphasis Type="Italic">A1</Emphasis> alleles with the onset of senescence and nitrogen use efficiency under Western Australian conditions

Wheat grain yield and protein content are significantly influenced by the onset of senescence and the duration of the grain filling phase. The onset of senescence also affects Nitrogen use efficiency (NUE) through interacting pathways involving N accumulation and translocation of N into the grains. The objective of this study was to relate variation in NUE and its components with two groups of the NAM-A1 gene alleles; (i) early onset of senescence in cultivars carrying the NAM-A1a allele, (ii) delayed onset of senescence in cultivars carrying the Non-NAM-A1a allele (b, c, d) in wheat cultivars grown under Western Australia conditions. A field trial was carried out over two seasons examining 19 cultivars under different N rates and time of N application. The Normalized Difference Vegetation Index was utilized to determine the onset of senescence after anthesis. The early onset of senescence results in high grain yield, harvest index, and NUE due to improvements in the N utilization ability. Accelerating the onset of senescence results in a short grain filling period leading to grain maturity before the onset of unfavourable summer conditions. The function of alleles of NAM-A1 gene in controlling senescence hence the NUE is highly regulated by environmental conditions. This study concluded that the function of NAM-A1a allele induces the onset of senescence with a positive effect on the NUE and its components under Western Australian conditions.     

Laboratory vs. Field Calibration of HydraSCOUT Probes for Soil Water Measurement

<正>Dear Editor,Accurate measurement of volumetric soil water content (θ_v) is essential for efficient soil water management. HydraSCOUT (HS) probes are capacitance-type probes for θ_v measurement with high accuracy, but require calibration for different soil types. We aimed to     

Genetic diversity and population structure assessed through simple sequence repeat markers in Saccharum spp. hybrids from Pakistan and Sri Lanka

Genetic Resources and Crop Evolution - The Saccharum species members are extremely complex allopolyploids. In this study, sixty Saccharum spp. hybrids were analyzed using simple sequence repeat...     

Pyogenic bacterial infections in humans with IRAK-4 deficiency

Members of the Toll-like receptor (TLR) and interleukin-1 receptor (IL-1R) superfamily share an intracytoplasmic Toll-IL-1 receptor (TIR) domain, which mediates recruitment of the interleukin-1 receptor-associated kinase (IRAK) complex via TIR-containing adapter molecules. We describe three unrelated children with inherited IRAK-4 deficiency. Their blood and fibroblast cells did not activate nuclear factor kappaB and mitogen-activated protein kinase (MAPK) and failed to induce downstream cytokines in response to any of the known ligands of TIR-bearing receptors. The otherwise healthy children developed infections caused by pyogenic bacteria. These findings suggest that, in humans, the TIR-IRAK signaling pathway is crucial for protective immunity against specific bacteria but is redundant against most other microorganisms.     

Einfluß von Licht auf die Koremienbildung und ihre kreisförmige Anordnung

Zusammenfassung Der Einfluß von Licht auf die Koremienbildung und ihre ringförmige Anordnung beiPenicillium claviforme mut.olivicolor Abé et Ura und einer Varietät davon, die auf Mineralnährboden wachsen können, wurde untersucht. Unter konstanten Bedingungen hat Licht keine Wirkung auf die Entstehung der Koremien, sowie auf ihre Länge oder Dichte, dagegen erzeugt der Wechsel von Licht und Dunkelheit im 12:12-stündigen Rhythmus, sowie in anderen Rhythmen, deren Lichtperiode sehr kurz sein kann, wobei jedoch die Summe von Lichtphase und Dunkelperiode mindestens 24 Stunden betragen muß, eine ringförmige Anordnung der Koremien. Nur kurzwelliges Licht (von 350 nm bis 525 nm) ist wirksam. Die Rhythmik ist nicht endogen bedingt. Jede Lichtperiode ruft nur einen Ring hervor. Die Induktion der Koremien während der Licht-Dunkel-Zyklen findet an der Übergangsstelle von der Licht- zur Dunkelphase statt. Die lichtempfindlichste Stelle des Pilzmyzels liegt etwa 0,5 mm hinter der Myzelspitze. — Eine ringförmige Anordnung der Koremien kann auch in Dauerdunkelheit oder in Dauerlicht durch rhythmische Temperaturschwankungen von 1°C bis 3°C erzeugt werden.

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The action of light on the development and zoning of coremia

Summary A study was made about the action of light on the formation and development of coremia, as well as on coremia-zoning ofPenicillium claviforme mut.olivicolor Abé et Ura and a variety of it, which are grown on a definite nutrient medium. It was found that light, under constant conditions, had no favourable action on the production of coremia, on their hight or density, on the other hand alternating periods of 12 hours, or shorter durations, of light and darkness, whereby the length of each light-dark-cycle being no less than 24 hours, produced concentric zones of coremia. The effective part of the light spectrum, in the induction of coremia-zoning was between 350 nm and 525 nm. This rhythm is not endogenous. Only one ring is produced by each light exposure. The induction of coremial initials of cultures under light-dark-cycles took place at the transition point from the light- to dark-phase. The light sensitive point of fungal mycelium lies about 0.5 mm behind the colony margin. — In continuous darkness or continuous illumination zoning of coremia can be induced by temperature fluctuations in 12:12-hours rhythm within a range of 1°C–3°C (between 22°C and 25°C).

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Penicillium claviforme mut.olivicolor . , . 12 : 12 , , , 24 . 350 525 . . . . 0,5 . — 1° 3 °C.