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Grouping of tropical mid-altitude maize inbred lines on the basis of yield data and molecular markers 总被引:1,自引:0,他引:1
Menkir A Melake-Berhan A The C Ingelbrecht I Adepoju A 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2004,108(8):1582-1590
The classification of maize inbred lines into heterotic groups is an important undertaking in hybrid breeding. The objectives of our research were to: (1) separate selected tropical mid-altitude maize inbred lines into heterotic groups based on grain yield data; (2) assess the genetic relationships among these inbred lines using amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers; (3) examine the consistency between yield-based and marker-based groupings of the inbred lines. Thirty-eight tropical mid-altitude maize inbred lines were crossed to two inbred line testers representing the flint and dent heterotic pattern, respectively. The resulting testcrosses were evaluated in a trial at three locations for 2 years. Significant general combining ability (GCA) and specific combining ability (SCA) effects for grain yield were detected among the inbred lines. The tester inbred lines classified 23 of the 38 tested inbred lines into two heterotic groups based on SCA effects and testcross mean grain yields. This grouping was not related to endosperm type of the inbred lines. The outstanding performance of testcrosses of the remaining 15 inbred lines indicates the presence of significant genetic diversity that may allow the assignment of the lines into more than two heterotic groups. Diversity analysis of the 40 maize inbred lines using AFLP and SSR markers found high levels of genetic diversity among these lines and subdivided them into two main groups with subdivision into sub-groups consistent with breeding history, origin and parentage of the lines. However, heterotic groups formed using yield-based combining ability were different from the groups established on the basis of molecular markers. Considering the diversity of the genetic backgrounds of the mid-altitude inbred lines, the marker-based grouping may serve as the basis to design and carry out combining ability studies in the field to establish clearly defined heterotic groups with a greater genetic similarity within groups.Communicated by H.H. Geiger 相似文献
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Mary L. Taub IL Suk Yang Yue Wang 《In vitro cellular & developmental biology. Plant》1989,25(9):770-775
Summary A primary rabbit kidney epithelial cell culture system has been developed which retains differentiated functions of the renal
proximal tubule. In addition, the cells have a distinctive metabolism and spectrum of hormone responses. The primary cell
were observed to retain in vitro a Na+-dependent sugar transport system (distinctive of the proximal segment of the nephron) and a Na+-dependent phosphate transport system. Both of these transport processes are localized on the apical membrane of proximal
tubule cells in vivo. In addition, probenicid-sensitivep-aminohippurate (PAH) uptake was observed in basolateral membranes of the primary tubule cells, and the PAH uptake by these
vesicles occurred at a rate that was very similar to that observed with membranes derived from the original tissue. Several
other characteristics of the primary cells were examined, including hormone-sensitive cyclic AMP production and phosphoenolpyruvate
carboxykinase (PEPCK) activity. Like the cells in vivo, the primary proximal tubule cells were observed to produce significant
cyclic AMP in response to parathyroid hormone, but not in response to arginine vasopressin or salmon calcitonin. Significant
PEPCK acivity was observed in the particulate fraction derived from a homogenate of primary rabbit kidney proximal tubule
cells.
This paper was presented at a Symposium on the Physiology and Toxicology of the Kidney In Vitro co-sponsored by The Society
of Toxicology (SOT) and the Tissue Culture Association held at the 27th annual meeting of the SOT in Dallas, Texas in 1988.
This work was supported by Grant 9 RO1 DK40286-07 from the National Institutes of Health, Bethesda, MD, and NIH Research Career
Development Award 1 K04 CA 0088-01 to M.T. 相似文献
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Adebola AJ Raji James V Anderson Olufisayo A Kolade Chike D Ugwu Alfred GO Dixon Ivan L Ingelbrecht 《BMC plant biology》2009,9(1):118-11
Background
Cassava (Manihot esculenta Crantz), a starchy root crop grown in tropical and subtropical climates, is the sixth most important crop in the world after wheat, rice, maize, potato and barley. The repertoire of simple sequence repeat (SSR) markers for cassava is limited and warrants a need for a larger number of polymorphic SSRs for germplasm characterization and breeding applications. 相似文献25.
Background
When photosynthetic organisms are exposed to harsh environmental conditions such as high light intensities or cold stress, the production of reactive oxygen species like singlet oxygen is stimulated in the chloroplast. In Chlamydomonas reinhardtii singlet oxygen was shown to act as a specific signal inducing the expression of the nuclear glutathione peroxidase gene GPXH/GPX5 during high light stress, but little is known about the cellular mechanisms involved in this response. To investigate components affecting singlet oxygen signaling in C. reinhardtii, a mutant screen was performed. 相似文献26.
Thomas C. de Bang Adebola A. Raji Ivan L. Ingelbrecht 《Plant Molecular Biology Reporter》2011,29(3):655-662
Current methods for molecular fingerprinting of cassava (Manihot esculenta Crantz) have limited throughput or are costly, thus preventing the characterization of large germplasm collections such as
those held by the International Agricultural Research Centers or National Research Institutions, which comprise hundreds to
thousands of accessions. Here, we report the development of a fluorescence-based multiplex simple sequence repeat (SSR) marker
kit that enables accurate and cost-effective cassava fingerprinting. The kit comprises 16 SSR markers assembled into five
multiplex panels and was tested on 21 cassava cultivars alongside one accession of Manihot epruinosa, a wild relative. A total of 68 alleles were detected with, on average, 4.25 alleles per locus and a polymorphism information
content of 0.53. The marker kit reported here is comparable to previously published amplified fragment length polymorphism
and SSR marker systems in terms of discriminating power and informativeness while offering significant advantages in speed
and cost of marker analysis. Previous molecular genetic diversity studies have suggested that cassava germplasm collections
contain duplicate entries based on the occurrence of identical genetic profiles. Using the newly developed microsatellite
kit, three out of six putative duplicate accessions could be readily differentiated, showing that these are distinct genotypes.
The relevance of these findings with respect to the characterization and management of large cassava germplasm collections
is discussed. 相似文献
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AimsRecent studies have shown that splenocytes may act as a possible neogenic source with regard to β-cells in rodent diabetic models. Accordingly, we sought to determine whether splenocytes played an important role in promoting β-cell function and mass among type 2 diabetic rats with and without spleen.Main methodsWe randomly divided female 90% pancreatectomized (Px) Sprague Dawley rats into three groups: splenectomy (SPX), splenectomy plus the injection of male splenocytes (SPI), and no splenectomy (NSP). They were administered with 40 energy percent fat diets over the course of five weeks. At the end of the experimental period, insulin secretion capacity was measured by hyperglycemic clamp. At 6 h after BrdU+ injection, the pancreas was prepared with 4% paraformaldehyde in order to perform immunohistochemistry.Key findingsSPX increased and sustained serum glucose levels more than NSP and SPI during oral glucose tolerance testing. During hyperglycemic clamp, first and second phase insulin secretion decreased in the SPX rats while splenocyte injections counteracted this. Beta-cell mass in the SPX group was reduced more than among NSP and SPI. This was the result of a decrease in the number of small β-cell clusters in SPX, which is indicative of a decrease in β-cell neogenesis.SignificanceSplenocytes play an important role with regard to the neogenesis of β-cells in insulin deficient type 2 diabetic rats, although they are not critical for β-cell regeneration. 相似文献
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Menkir A Olowolafe MO Ingelbrecht I Fawole I Badu-Apraku B Vroh BI 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2006,113(1):90-99
Introduction of exotic maize (Zea mays L.) into adapted tropical germplasm may enhance genetic variability and lead to greater progress from selection. The first objective of this study was to determine if yellow endosperm lines derived from adapted × exotic backcrosses contain exotic alleles that are superior to the recurrent adapted parental line for yield and other agronomic traits in tropical environments. Thirteen exotic yellow maize inbred lines were crossed to an adapted orange line (KUSR) and the F1s were backcrossed to KUSR to generate the first backcrosses. Fifty BC1F4 lines derived from these backcrosses and the recurrent parent were crossed to a common inbred tester (L4001) to form testcrosses, which were evaluated at eight environments in Nigeria. Testcrosses of the BC-derived lines differed significantly for grain yield and other agronomic traits. Only two testcrosses yielded significantly less than L4001 × KUSR, with the best 15 testcrosses producing between 289 and 1,056 kg/ha more grain yield than L4001 × KUSR. The best testcrosses were similar to or better than L4001 × KUSR for other agronomic traits. The second objective of this study was to assess the extent of genetic diversity present among the BC-derived lines. We genotyped 46 BC-derived lines including KUSR and L4001 with 10 AFLP primer pairs and found 491 polymorphic fragments. The average allelic diversity of the lines was 0.30 ± 0.01. The genetic distance of each BC-derived line from KUSR ranged between 0.49 and 0.91. The average genetic distance for all pairs of the BC-derived lines was 0.68 ± 0.004, varying from 0.34 to 0.92. The increased grain yield and genetic diversity observed in these studies provide evidence that exotic germplasm can contribute new alleles to expand the genetic base of tropical maize and develop high-yielding hybrids. 相似文献
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