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91.
Summary Three S1-recurrent selection programs (designated HG, HP, and HGP) for increasing protein yield of oat (Avena sativa L.) were conducted for five cycles of selection. The selection criteria in each program (line of descent) emphasized different components of protein yield; high grain yield in HG, both high protein concentration of the groats (caryopsis) and high grain yield in HP, and high protein yield per se in HGP. Heading date and height were restricted to no net change. The objectives of this study were to evaluate the agronomic performance of these three lines of descent and the correlated responses in agronomic traits due to selection. Thirty to sixty random S0-derived lines from each cycle and ten check lines were grown in hill-plot experiments at two locations in 1989. Grain yield increased in all three lines of descent; HG showed the greatest rate of gain followed by HGP and then HP (0.20, 0.10, and 0.07 Mg ha-1 per cycle, respectively). Test weight decreased in HGP by 2.6 kg m-3 per cycle and in HP by 4.0 kg m-3 per cycle, but remained constant in HG. Cycle 5 (C5) means for straw yield, height, and seed weight were not significantly different from the C0 means for any line of descent. Groat percent remained unchanged in HGP, increased from 70.1 to 71.7% in HG, and decreased from 69.9 to 67.6% in HP. Heading date decreased by 3 d in HG and HGP, but remained unchanged in HP. HG compares most favorably with commercial cultivars because of its high yield and acceptable agronomic traits, while HP tends to be low in test weight, seed weight, and groat percent.Abbreviations BM-
above ground biomass
- GP-
groat (caryopsis) percent, fraction of average seed weight that is groat rather than hulls
- GPC-
groat-protein concentration
- GPY-
groat-protein yield
- GTY-
groat yield
- GY-
grain yield
- HD-
heading date
- HG-
selection for protein yield through high grain yield
- HGP-
selection for protein yield per se
- HP-
selection for protein yield through high grain yield and high groat-protein concentration
- HT-
height
- PY-
protein yield
- SDWT-
seed weight
- SY-
straw yield
- TWT-
test weight 相似文献
92.
Florence Noël Daniel Prati Mark van Kleunen Andreas Gygax Daniel Moser Markus Fischer 《Biological conservation》2011,(1):602-609
In response to ongoing local extinction of species and the current biodiversity crisis, the number of reintroduction programs aiming to establish new populations of rare species in the wild has increased. However, only a small proportion of these programs has been planned and monitored scientifically and comparative multi-species studies are missing in this context. Therefore, the relative importance of factors involved in reintroduction success is poorly known. In 2007, we assessed population growth since introduction as a measure of establishment success of 25 wetland species (rare or extinct in the wild nationwide) and a total of 50 populations in Switzerland that had been introduced at seven restored sites with apparently adequate environmental conditions between 1997 and 2005. We related establishment success to 32 life-history traits of these species obtained from the BiolFlor database, to initial number of introduced plants (propagule pressure with 1–130 individuals introduced per population), and to the ecological distance between source sites and restored sites based on vegetation records. Our results clearly showed the importance of close ecological similarity between source and introduction sites for successful establishment of wetland species into restored pond habitats. In contrast, neither life-history traits nor propagule pressure were related to establishment success in our study. Based on our results, we strongly recommend enforcing ecological studies prior to reintroduction to accurately assess the suitability of restored sites. To unambiguously assess the key determinants of successful establishment, future reintroduction programs should be set-up according to experimental designs. 相似文献
93.
A dynamic, partially stochastic mathematical model describing the reproductive performance of a sow herd is presented. The model stimulates a herd that averages 17.27 sow days/pig produced, with a mean of 9.06 pigs weaned/litter and 2.327 litters produced/sow each year. Several alternative options are simulated. Of these, the ones that increase the litter size at weaning appear most beneficial in terms of both biological and economic efficiencies. 相似文献
94.
95.
RJ WHITTINGTON 《Australian veterinary journal》1995,72(4):132-134
SUMMARY: Virulent ovine footrot was transmitted accidentally to a group of 23 adult Merino sheep (flock B) after holding for 1 hour in sheep yards, which earlier the same day had contained another flock (flock A) with < 1% prevalence of sheep with footrot lesions. Sheep in flock B were rendered susceptible to virulent footrot by grazing 600 mm high unimproved pasture dominated by paspalum ( Paspalum dilatatum ) and kangaroo grass ( Themeda australis ) during warm, humid and wet weather. In addition to moisture, interdigital abrasions caused by the pasture might have predisposed the interdigital skin to infection with Dichelobacter nodosus . 相似文献
96.
Restriction-endonuclease analysis of Australian isolates of Leptospira interrogans serovar hardjo from cattle with agalactia and abortion 总被引:1,自引:0,他引:1
SUMMARY Polyacrylamide gel electrophoresis and agarose gel electrophoresis were used to resolve restriction endonuclease digests of 20 Australian isolates of Leptospira interrogans cultured from urine samples of cattle with agalactia and abortion. The restriction endonuclease profiles of 19 isolates closely matched the profiles of L interrogans serovar hardjo subtype hardjobovis reference strains. The remaining isolate had a different restriction profile from subtype hardjobovis and subtype hardjoprajitno reference strains and was serologically identified as serovar pomona. Silver staining of polyacrylamide gels gave enhanced resolution of restriction fragments compared with the traditional method of ethidium bromide staining of agarose gels. 相似文献
97.
98.
JT SEAMAN WS TURVEY SJ OTTAWAY AR GILMOUR RJ DIXON† 《Australian veterinary journal》1989,66(9):279-285
A field grazing trial was undertaken to monitor the health and production of crossbred sheep grazing pasture where Echium plantagineum constituted a considerable proportion of the available forage. The trial, conducted for 19 months over successive grazing seasons, demonstrated a significant difference in production, with sheep on the E. plantagineum pasture being lighter and growing less wool compared with sheep on Echium-free pasture. No mortalities involving pyrrolizidine alkaloid poisoning were recorded in sheep grazing E. plantagineum, although there was histological evidence of moderately severe liver damage associated with high liver copper concentrations in at least one sheep following the grazing of large quantities of the plant. 相似文献
99.
100.