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21.
Chromosome pairing within genomes in maize-Tripsacum hybrids 总被引:1,自引:0,他引:1
When the ten chromosomes of maize were inserted inlto a polyploid (2n = 72) Tripsacum dactyloides background they formed up to five pairs at meiosis. Two plants that each contained 36 Tripsacum and 14 maize chromosomes were deprived from the F(1) of maize x Tripsacum. Chromo. somes of these plants frequently formed 25 bivalents, 18 between Tripsacum chromosomes and seven between maize chromosomes. Maize chromosomes could be distinguished from Tripsacum chromosomes on the basis of size. The withint-genome pairing is probably induced by the genetic background. 相似文献
22.
Lambert WD 《Science (New York, N.Y.)》1937,86(2221):79-80
23.
Lambert WV 《Science (New York, N.Y.)》1948,107(2773):179-183
24.
Zhang GF Maudens KE Storozhenko S Mortier KA Van Der Straeten D Lambert WE 《Journal of agricultural and food chemistry》2003,51(27):7872-7878
A procedure involving chemical conversion of all forms of folate present in plant material into para-aminobenzoic acid (PABA) and a liquid chromatographic-fluorimetric determination with on-line postcolumn derivatization is reported. All folates are cleaved with liberation of PABA by hydrogen peroxide followed by acid hydrolysis using concentrated hydrochloric acid (37%) at 110 degrees C for 6 h. The reaction yield for individual folates conversion to PABA ranged from 44.4 to 97.3%. PABA could be determined sensitively by on-line postcolumn derivatization with fluorescamine, the detection limit for PABA being 3.02 nM. On the basis of this principle, a method for the determination of total folate in plant material, including a purification step on an affinity column, is presented, which offers a sufficient sensitivity and selectivity for routine analysis of total folate in natural samples. The total folate contents of tomatoes, carrots, white cabbage, and spinach were determined, and the results were quite comparable to the data reported. The recovery of PABA and the comparison of total folate analysis in spinach on different occasions (over 6 months) are also reported. The method is reliable, universal for all folates, including polyglutamate and monoglutamate forms, and eliminates the need for a deconjugation step and multiple conversion reactions. 相似文献
25.
26.
R J Indrieri S R Creighton E H Lambert V A Lennon 《Journal of the American Veterinary Medical Association》1983,182(1):57-60
A case of the autoimmune form of myasthenia gravis and a case of what is probably a congenital form of myasthenia gravis were diagnosed in 2 unrelated cats. Neuromuscular weakness exacerbated by exercise was a prominent feature in both cats. Weakness was eliminated temporarily by administration of anticholinesterase drugs. Serum autoantibodies to acetylcholine receptors of skeletal muscle were present in the 1st cat and were not detected in the 2nd cat. A characteristic decrement in the amplitude of the compound muscle action potential during repetitive stimulation of the motor nerve was elicited in the 2nd cat. There was marked electromyographic improvement in response to anticholinesterase drugs. Electromyography was not performed in the 1st cat. 相似文献
27.
Intake and digestibility trials were conducted with sheep to evaluate the effect of adding various levels of a typical fibrous grass forage (neutral detergent fiber, NDF = 68%) to a high quality, low fiber (NDF = 22%) brassica forage. Four forage rape:orchardgrass hay diets (0, 40, 70, 100% rape content on a dry matter basis) were fed to groups of six Polled-Dorset crossbred growing wether lambs (39.6 kg) individually housed in metabolism crates. After a 7-d ad libitum intake period, a 7-d digestibility trial was conducted at 90% of the observed ad libitum intake level. Digestible dry matter intake (DDMI) per unit metabolic body weight increased as rape in the diet was increased from 0 to 70%, with increases in both dry matter intake and dry matter digestibility (DMD). However, DDMI was similar for lambs fed the 70 and 100% rape diets, with DMI decreasing to the same relative extent as DMD increased. Digestibility of the cell wall fraction of the two intermediate diets (40% rape and 70% rape) was lower than predicted from component forage digestibilities. This observation suggests the existence of an associative effect similar to that often reported when forage and concentrates are fed in various ratios. Forage brassicas appear to be utilized in the ruminant in a manner more typically resembling a concentrate than a forage. 相似文献
28.
The infertility of many cows could be treated by in vitro fertilisation. In the present study laparoscopy was utilised to recover the in vivo matured oocytes from the ovary of a standing donor. After the capacitation of fresh semen with high ionic strength medium and in vitro fertilisation, a rabbit oviduct was employed as an incubator for four to five days, in order to obtain sufficiently aged embryos to be transferred to the uterus of a recipient. Using surgical or non-surgical transfer six calves were obtained. 相似文献
29.
A 27-year-old stand of flooded gum (Eucalyptus grandis Hill ex Maiden) in the North Coast Region of N.S.W. was assessed in relation to aboveground distribution and turnover of organic matter, nitrogen, phosphorus, calcium, magnesium and potassium. Of the 453 t ha?1 of aboveground organic matter present, 394 t was in the tree, 42 t in the understorey and 28 t in the forest floor. The total nitrogen, phosphorus, calcium, magnesium and potassium contents of the stand were 739, 44, 1254 and 658 kg ha?1, respectively, and the understorey contained 35%, 35%, 16%, 24% and 49% of the above-ground distribution of these nutrients respectively. Although the developing rainforest understorey comprised a relatively small portion (9.3%) of the total aboveground biomass, it played a disproportionate role in nutrient accumulation and uptake, and had an annual net accumulation of 14%, 55%, 59%, 30%, 44% and 69% of the aboveground organic matter, nitrogen, phosphorus, calcium, magnesium and potassium respectively. The net annual removal from the soil was 30, 1, 38, 5 and 31 kg ha?1 year?1 for nitrogen, phosphorus, calcium, magnesium and potassium, respectively. Flooded gum had very high accumulations of calcium in the bark and the effect of this in nutrient cycling is discussed. An idealised management system, to exploit and optimise the nutrient cycle of flooded gum, has been hypothesided. 相似文献
30.