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1.
Shamuyarira Kwame Wilson Shimelis Hussein Tapera Terence Tsilo Toi John 《Journal of Crop Science and Biotechnology》2019,22(2):169-176
Journal of Crop Science and Biotechnology - Genetic variation and heritability estimates in early generations are important in identifying superior families that can be targeted for genetic... 相似文献
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Vegetative growth and water relations of Thompson Seedless grapevines in response to applied water amounts at various fractions
of measured grapevine ETc were quantified. Treatments ranged from no applied water up to 1.4 times the water used by vines growing in a weighing lysimeter.
All treatments were irrigated at the same frequency as the vines in the lysimeter (whenever they used 2 mm of water), albeit
at their respective fraction. Soil water content and midday leaf water potential (Ψl) were measured routinely in four of the irrigation treatments across years. The amount of water depleted in the soil profile
ranged from 190 mm for the 0.2 treatment in 1993 to no water depletion for the 1.4 treatment in 1992. The irrigation treatments
significantly affected midday Ψl, total shoot length, leaf area per vine, pruning weights and trunk diameter; as applied water decreased so did vegetative
growth. Pruning weights were a linear function of the seasonal, mean midday Ψl across growing seasons. The application of water amounts in excess of evapotranspiration negatively affected vegetative growth
some of the years. A companion paper will demonstrate that over-irrigation can negatively affect reproductive growth of this
grape cultivar due to excess vegetative growth. 相似文献
4.
James A. Leigh Sharon A. Egan Philip N. Ward Terence R. Field Tracey J. Coffey 《Veterinary research》2010,41(5)
Streptococcus uberis, strain 0140J, contains a single copy sortase A (srtA), encoding a transamidase capable of covalently anchoring specific proteins to peptidoglycan. Unlike the wild-type, an isogenic mutant carrying an inactivating ISS1 insertion within srtA was only able to infect the bovine mammary gland in a transient fashion. For the first 24 h post challenge, the srtA mutant colonised at a similar rate and number to the wild type strain, but unlike the wild type did not subsequently colonise in higher numbers. Similar levels of host cell infiltration were detected in response to infection with both strains, but only in those mammary quarters infected with the wild type strain were clinical signs of disease evident. Mutants that failed to express individual sortase substrate proteins (sub0135, sub0145, sub0207, sub0241, sub0826, sub0888, sub1095, sub1154, sub1370, and sub1730) were isolated and their virulence determined in the same challenge model. This revealed that mutants lacking sub0145, sub1095 and sub1154 were attenuated in cattle. These data demonstrate that a number of sortase anchored proteins each play a distinct, non-redundant and important role in pathogenesis of S. uberis infection within the lactating bovine mammary gland. 相似文献
5.
A number of genes that contribute to the domestication traits of cultivated rice have been identified. These include Sh4, Rc, PROG1 and LABA1, which are associated with non-shattering rachis, white pericarp, erect growth and barbless awns, respectively. The mutations giving rise to the “domestication alleles” of these genes are either invariable in cultivated rice, or have variability that is strictly associated with the phenotypic trait. This observation forms the basis to those current rice domestication models that envisage a single origin for the domesticated phenotype. Such models assume that the domestication alleles are absent or rare in wild rice, emerged under cultivation and spread across all rice groups by introgressive hybridization. We examined whole-genome sequencing datasets for wild and cultivated rice to test the former two assumptions. We found that the rc and laba1 alleles occur in wild rice with broad geographical distribution, and reach frequencies as high as 13 and 15%, respectively. These results are in agreement with previous observations of the prog1 and sh4 domestication alleles in wild populations. We also show that the diversity of the genomic regions surrounding the rc, laba1, prog1 and sh4 alleles in wild accessions is greater than that in cultivated rice, suggesting that these alleles emerged prior to domestication. Our findings indicate that the possibility that independent rice groups obtained identical domestication alleles directly from the wild population needs to be considered. 相似文献
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The effect of Pseudomonas putida (isolate M17) on Rhizobium phaseoli nodulation of the common bean, Phaseolus vulgaris, was investigated under field and greenhouse conditions. The results indicated that P. putida markedly increased nodulation compared to R. phaseoli controls. Furthermore, 2-ketogluconic acid, a phosphate-solubiliring compound, was detected in P. putida M17. This could imply an increased P supply to roots of P. vutgaris, which may function to increase nodules. Bean yields and shoot fresh weight were not significantly altered by the addition of P. putida M17. 相似文献
8.
PCR systems were designed to amplify the entire 5 external transcribed spacer (ETS) region of the 18S rRNA gene of all the diploid species of Aegilops and several other taxa closely related to domesticated wheat. Phylogenetic analysis was performed on the complete ETS sequences using the neighbor-joining, maximum parsimony, and maximum likelihood methods. Among the individual taxa studied, speciation in Secale is very recent. In the case of the A genome diploids, the results support the theory that the A genomes of wheat have experienced reticulate evolution owing to introgression. The B and G genomes of tetraploid domesticated wheats form a clade with Ae. speltoides in which the B genome diverged first and the G genome more recently. It was demonstrated that the complete ETS sequences of the Triticeae yield coherent phylogenetic information. The ETS is a useful tool for studying the phylogeny of closely related species. 相似文献
9.
Paula?T.?IbellEmail author Zhihong?H.?Xu Terence?J.?Blake Carole?Wright Timothy?J.?Blumfield 《Journal of Soils and Sediments》2014,14(5):872-885
Purpose
This study investigated how nitrogen (N) nutrition and key physiological processes varied under changed water and nitrogen competition resulting from different weed control and fertilisation treatments in a 2-year-old F1 hybrid (Pinus elliottii Engelm var. elliottii?×?P. caribaea var. hondurensis Barr. ex Golf.) plantation on a grey podzolic soil type, in Southeast Queensland.Materials and methods
The study integrated a range of measures including growth variables (diameter at ground level (DGL), diameter at breast height (DBH) and height (H)), foliar variables (including foliar N concentration, foliar δ13C and δ15N) and physiological variables (including photosynthesis (An), stomatal conductance (gs), transpiration (E), intrinsic water use efficiency (WUEi) (A/gs) and xylem pressure potential (ΨXPP)) to better understand the mechanisms influencing growth under different weed control and fertilisation treatments. Five levels of weed control were applied: standard (routine), luxury, intermediate, mechanical and nil weed control, all with routine fertilisation plus an additional treatment, routine weed control and luxury fertilisation. Relative weed cover was assessed at 0.8, 1.1 and 1.6 years after plantation establishment to monitor the effectiveness of weed control treatments. Soil investigation included soil ammonium (NH4 +-N), nitrate (NO3 ?-N), potentially mineralizable N (PMN), gravimetric soil moisture content (MC), hot water extractable organic carbon (HWETC), hot water extractable total N (HWETN), total C, total N, stable C isotope composition (δ13C), stable N isotope composition (δ15N), total P and extractable K.Results and discussion
There were significant relationships between foliar N concentrations and relative weed cover and between tree growth and foliar N concentration or foliar δ15N, but initial site preparation practices also increased soil N transformations in the planting rows reducing the observable effects of weed control on foliar δ15N. A positive relationship between foliar N concentration and foliar δ13C or photosynthesis indicated that increased N availability to trees positively influenced non-stomatal limitations to photosynthesis. However, trees with increased foliar N concentrations and photosynthesis were negatively related to xylem pressure potential in the afternoons which enhanced stomatal limitations to photosynthesis and WUEi.Conclusions
Luxury and intermediate weed control and luxury fertilisation positively influenced growth at early establishment by reducing the competition for water and N resources. This influenced fundamental key physiological processes such as the relationships between foliar N concentration, A n, E, gs and ΨXPP. Results also confirmed that time from cultivation is an important factor influencing the effectiveness of using foliar δ15N as an indicator of soil N transformations.10.
Drosou Konstantina Craig Hayley Palmer Karren Kennedy Sandra L. Wishart John Oliveira Hugo R. Civáň Peter Martin Peter Brown Terence A. 《Genetic Resources and Crop Evolution》2022,69(7):2361-2381
Genetic Resources and Crop Evolution - We used genotyping-by-sequencing to investigate the evolutionary history of bere, the oldest barley variety still cultivated in Britain and possibly in all of... 相似文献