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181.
182.
Neomorph and leaf differentiation as alternative morphogenetic pathways in soybean tissue culture. 总被引:1,自引:0,他引:1
Somatic embryogenesis and organogenesis were induced on immature cotyledons of different soybean cultivars. The anatomical investigation of morphogenesis proved neomorph differentiation instead of somatic embryos, and leaf formation instead of shoot development. While normal embryos were induced in 0-3.1% of the explants, neomorphs developed at a much higher rate i.e. in 10.5-78.9% depending on the genotype. Likewise organogenesis preferably followed the pathway of leaflet development (3.1-26.3%) than that of shoot tip formation (0-2.6%). Low plant regeneration frequency of soybean can partly be explained with these two alternative abortive pathways of morphogenesis probably induced with higher frequency than the normal pathways by the generally used in vitro methods. 相似文献
183.
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185.
Moisés Rodríguez-Ma?ero Paul Schurmann Miguel Valderrábano 《Indian pacing and electrophysiology journal》2015,15(6):303-304
A perceived distinctive feature of cryoablation is the stability (cryoadherence) of the catheter tip during cold temperatures at the desired location, even during tachycardia. We report the case report of a young patient with a parahisian accessory pathway where stability of the ablation catheter was not achieved despite using the cryocatheter with a steerable sheath. Ultimately, stability at the desired location was achieved robotically by means of Hansen system (Hansen Medical, Mountain View, CA, USA). 相似文献
186.
Christian Alvarez Glaucia Gon?alves Barbosa Raquel de Vasconcellos Carvalhaes de Oliveira Bernardina Penarrieta Morales Bodo Wanke Márcia dos Santos Lazéra 《Memórias do Instituto Oswaldo Cruz》2013,108(1):126-129
In this study, we evaluated several techniques for the detection of the yeast form of Cryptococcus in decaying wood and measured the viability of these fungi in environmental samples stored in the laboratory. Samples were collected from a tree known to be positive for Cryptococcus and were each inoculated on 10 Niger seed agar (NSA) plates. The conventional technique (CT) yielded a greater number of positive samples and indicated a higher fungal density [in colony forming units per gram of wood (CFU.g-1) ] compared to the humid swab technique (ST). However, the difference in positive and false negative results between the CT-ST was not significant. The threshold of detection for the CT was 0.05.103 CFU.g-1, while the threshold for the ST was greater than 0.1.103 CFU-1. No colonies were recovered using the dry swab technique. We also determined the viability of Cryptococcus in wood samples stored for 45 days at 25ºC using the CT and ST and found that samples not only continued to yield a positive response, but also exhibited an increase in CFU.g-1, suggesting that Cryptococcus is able to grow in stored environmental samples. The ST.1, in which samples collected with swabs were immediately plated on NSA medium, was more efficient and less laborious than either the CT or ST and required approximately 10 min to perform; however, additional studies are needed to validate this technique. 相似文献
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188.
Estimating the extent of biological invasions is critical in predicting the effect of exotic species. We investigated the occurrence and number of alien freshwater plants and give information on the composition of alien aquatic flora, their trend in time, invasion pathway, and their invasive character. 相似文献
189.
Adventitious root formation in vitro in 1-mm stem slices cut from microshoots of apple cv. Jork 9 was studied using light
and electron microscopy. When indole-3-butyric acid (IBA) had been added to the medium, starch grains accumulated during the
first 24 h of culture in cells of the cambial region and in cells in the vicinity of vascular tissue and in the primary rays.
This accumulation occurred only in the basal part of explants. After that, the nuclei in these cells were activated, and the
density of the cytoplasm and the number of cell organelles increased, whereas starch was broken down. Cambium cells started
to divide transversely and at 96 h, after several divisions, a continuous ring of isodiametric cytoplasmic cells had appeared
around the xylem near the basal cutting surface. The cells in this ring were rich in cell structures, and did not contain
large starch grains and a central vacuole. Root meristemoids regenerated from the portions of the ring that were localized
in the primary rays. From the other cells in the ring, callus developed. The meristemoids did not grow into the direction
of the epidermis as in shoots, but along the vascular bundles. After emergence from the cutting surface, the meristemoids
were transformed into small, dome-like primordia. They developed a typical root apex with root cap, root ground meristem and
tracheid connection with shoot vascular tissue.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
190.