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101.
Effect of incubation temperature regimes and culture medium on broccoli microspore culture embryogenesis 总被引:8,自引:0,他引:8
João Carlos da Silva Dias 《Euphytica》2001,119(3):389-394
Conditions for reliable induction of embryogenesis from isolated microspores were studied in ten genotypes of broccoli. Embryo
yields were significantly increased in almost all of the broccoli genotypes by the incubation at 32.5 °C for 1 day, than when the standard incubation at 30 °C for 2 days was used. Treatments of 48 hours at 32.5 °C produced less than optimal results suggesting that broccoli microspores are more sensitive to high temperatures than those
of B. napus. The use of the 1/2 NLN-13 medium yielded greater number of embryos than the standard NLN-13. The magnitude of the response to the redution of
the concentration of major salts by half in the NLN medium varied with the different genotypes. High embryogenic broccoli
cultivars, such as ‘Shogun’, ‘SDB9’, and ‘Green Valiant’, presented a better response to the reduction of the concentration
of major salts by half in NLN-13. Reduction never produced a detrimental effect on embryo yield and seems not to have any
effect in the subsequent development of embryos in plants.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
102.
103.
104.
L.?F.?García?del?MoralEmail author Y.?Rharrabti S.?Elhani V.?Martos C.?Royo 《Euphytica》2005,146(3):203-212
The components of grain yield are altered by adverse growing conditions as the effects of certain environmental factors on
crop growth and yield differ depending upon the developmental stages when these conditions occur. Path-coefficient analysis
was used to investigate the main processes influencing grain yield and its formation under Mediterranean conditions. Twenty-five
durum wheat genotypes, consisting of four Spanish commercial varieties and 21 inbred lines from the ICARDA durum wheat breeding
program, were grown during 1997 and 1998 under both rainfed and irrigated conditions in southern Spain. {P}ath-coefficient
analysis revealed that under favourable conditions grain yield depended in equal proportion on the three primary yield components
(i.e. spikes m−2, grains spike−1, and mean grain weight), whereas in the rainfed experiments, variations in grain yield were due mainly to spikes m−2 and to a lesser extent to grains spike−1. Compensatory effects were almost absent under irrigated treatments; however, under water shortage, spikes m−2 exerted a negative influence on grain spike−1 due mainly to a negative interrelationship between tiller production and apical development. These compensatory effects could
partially explain the restricted success in durum wheat breeding observed in water-limited environments of the Mediterranean
region. Under rainfed conditions the number of spikes m−2 depended mainly on the ability for tiller production, whereas in the irrigated experiments the final number of spikes was
determined mostly by tiller survival. 相似文献
105.
Ricardo Tadeu de Faria Deonisio Destro João Carlos Bespalhok Filho Rolf Dieter Illg 《Euphytica》2002,124(1):59-63
The goal of this research was to study the introgression of the high regeneration capacity of Lycopersicon pimpinellifolium Mill line WV-700, in recalcitrant tomato cultivars (L. esculentum Mill cvs. Petomech, Santa Rita and VFN-8) using backcrossing. Hypocotyl explants of in vitro germinated seeds were cultivated in half strength MS medium supplemented with 5mg/l 6-BA to assess their shoot regeneration
capacity. The apical shoot of the in vitro germinated seeds were cultured on a separate medium. Apical shoots from genotypes showing high regeneration rates were acclimated
in a glasshouse and used as pollen donors for the next backcrossing. After four backcrossings, the material showed a similar
mean fruit weight for the cultivated tomato and a high regeneration capacity similar to the wild species. It is shown that
L. pimpinellifolium can be used with success as donor parent to introgress in vitro regeneration capacity to recalcitrant tomato cultivars.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
106.
The 1997-1998 El-Niño Southern Oscillation was the most severe on record and dramatically impacted corals worldwide. However, the effect of this event on the associated community of reef organisms has received much less attention. The composition of the bryozoan assemblage from the coral reefs of Northern Bahia, Brazil were monitored annually from 1995 to 2000, allowing the investigation of the effects of this large-scale stressor on an important, diverse, yet understudied component of the coral reef system. Bryozoan samples (35 replicates/reef) were collected during April/May from four shallow bank reefs (10-40 m depth) located a few kilometres off the coast, together with measurements of the associated environmental parameters. Currently 157 species have been recorded from the study area, but significant reductions in density and diversity were apparent between pre- and post El-Niño Southern Oscillation (ENSO) years, multivariate analysis denoting significant changes in assemblage composition. A total of 61 species were unrecorded following the 1997-1998 ENSO event (22 species from 1997; 25 further species from 1998 and 14 more from 1999). These included several species endemic to Brazil, suggesting that the 1997-1998 ENSO has had a marked influence on the reef bryozoan community, resulting in the local extinction of several species. Bryozoan mortalities were probably initiated by elevated temperatures, but continued disappearance of species for 2 years after ENSO suggests other indirect factors are also influential. These results demonstrate that ENSO events can have severe long-term impacts on the biodiversity of coral reefs, with important conservation consequences. 相似文献
107.
A.?M.?Ramos-Cabrer S.?Pereira-LorenzoEmail author 《Genetic Resources and Crop Evolution》2005,52(7):879-890
This study is focused in the main chestnut growing areas from north- to south-western Spain. We studied 50 accessions corresponding
to 22 cultivars named by local growers; 11 from Andalucía, 9 from Castilla-León, and 2 from Extremadura. These were compared
with 22 types classified previously in Galicia (82 accessions). Ten morphological traits and five isoenzyme systems were used
to classify them and establish genetic relationships. A lower genetic variability has been found in Extremadura (middle Spain)
and Andalucía (south) than in Galicia (north western) which may be because of the lower importance of the crop in those areas
and the geographic barriers between them. Galicia could be the origin of the types found in Castilla-León, Extremadura, and
south-western Andalucía, and the types found in Central Andalucía were closer to those found in Castilla-León and Extremadura.
Most accessions studied (117/132) could be classified positively, making 37 out of 44 cultivars found from northern to southern
Spain. Three groups of synonymies were found in Castilla-León: ‘Brava’ and ‘Negral’, ‘Gallego’ and ‘Injerto’, and ‘Rapega’
and ‘Verdello’. Most of the Spanish types have been propagated as a principal clone. Variability within the types is important
and must be considered to select the best clones as cultivars. 相似文献
108.
J.?C.?García-GilEmail author C.?Plaza N.?Senesi G.?Brunetti A.?Polo 《Biology and Fertility of Soils》2004,39(5):320-328
The residual effects of adding 40 t ha–1 sewage sludge (SL) to a degraded soil cropped with barley were investigated after 9 and 36 months in a field experiment under semiarid conditions. The principal soil properties were apparently still affected by SL amendment 9 months after application but the effects disappeared after 36 months. With respect to control soil humic acids (HAs), the SL-HA was characterized by higher contents of S- and N-containing groups, smaller contents of acidic groups, a prevalent aliphaticity, extended molecular heterogeneity, and smaller degrees of aromatic polycondensation and humification. Amendment with SL caused an increase in N, H, S and aliphaticity contents and a decrease in C/N ratios and O and acidic functional group contents in soil HAs isolated 9 months after SL application. These effects tended to decrease after 36 months, most probably because the slightly humified SL-HA was mineralised over time through extended microbial oxidation, while only the most recalcitrant components such as S-containing and aromatic structures were partially accumulated by incorporation into soil HA. Microbial biomass, basal respiration, metabolic quotient and enzymatic activities increased in soil 9 months after SL application, possibly because of increased soil microbial metabolism and enhanced mineralisation processes. After 36 months these properties returned to values similar to those of the unamended soil, presumably due to the loss of energy sources. 相似文献
109.
Silva RD Bueno AL Gallon CW Gomes LF Kaiser S Pavei C Ortega GG Kucharski LC Jahn MP 《Fitoterapia》2011,82(6):818-826
This study analyzed the plasma lipid profile, glucose levels and fat deposits in male rats treated with aqueous extract of gross yerba mate, commercial yerba mate or water. Yerba mate treatment did not change body weight gain and lipid profile. The consumption of gross yerba mate significantly increased blood glucose (6.6 mmol/L) as compared to the water (4.8 mmol/L) and commercial group (5.2 mmol/L) and decreased epididymal and intra-abdominal deposits (10.1 mg/g and 23.7 mg/g of weight) as compared to the water (15.4 mg/g and 36.9 mg/g of weight) and commercial group (12.5 mg/g and 28 mg/g of weight). The results suggest that gross yerba mate reduces fat more efficiently but produces a greater increase in blood glucose when compared to commercial yerba mate and water groups. 相似文献
110.
Peres C Gomes da Silva MD Barreiros S 《Journal of agricultural and food chemistry》2003,51(7):1884-1888
The esterification reaction of geraniol with acetic acid catalyzed by Novozym was studied in supercritical ethane (sc-ethane) and in supercritical carbon dioxide (sc-CO(2)). Water activity (a(W)) had a very strong effect on enzyme activity, with reaction rates increasing up to a(W) = 0.25 and then decreasing for higher a(W). Salt hydrate pairs could not prevent changes in a(W) during the course of reaction but were able to control a(W) to some extent and had a beneficial effect on both initial rates of esterification and conversion in sc-ethane. The enzyme was more active in sc-ethane than in sc-CO(2), confirming the deleterious effect of the latter already observed with some enzymes. Temperatures between 40 and 60 degrees C did not have a strong effect on initial rates of esterification, although reaction progress declined considerably in that temperature range. For the mixture of 50 mM acetic acid plus 200 mM geraniol, 100% conversion was achieved at a reaction time of 10 h at 40 degrees C, 100 bar, an a(W) of incubation of 0.25, and a Novozym concentration of 0.55 mg cm(-)(3) in sc-ethane. Conversion was below 50% in sc-CO(2) at otherwise identical conditions. With an equimolar mixture of the two substrates (100 mM), 98% conversion was reached at 10 h of reaction in sc-ethane (73% conversion in sc-CO(2)). 相似文献