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31.
Patterns of flower morphology and structural changes during interconversion between chasmogamous and cleistogamous flowers in Viola philippica 下载免费PDF全文
《植物生态学报》2017,41(11):1190
Aims Viola philippica is a species with a typical chasmogamous-cleistogamous (CH-CL) mixed breeding system. It provides a flower model system to investigate floral organs development under different photoperiods. Morphological changes of intermediate cleistogamous (inCL) flowers have been observed, the trends in variation of changes from CH flowers to CL flowers or from CL flowers to CH flowers have been analyzed, the localized effects of poorly developed stamens and petals in CL and inCL flowers have been identified. This research provided morphology and structural changes with implication for the evolutionary significance of the dimorphic flower formation for further study in dimorphic flower development.Methods We used methods of anatomy and structural analysis to observe the morphological structures of flowers under different photoperiods.Important findings Photoperiod played an important role in the development of CH and CL flowers in V. philippica. Under short-day light and intermediate-day light, both CH and inCL flowers developed simultaneously. Most of the floral buds were CH flowers under a photoperiod of short-day light, but most of the floral buds were inCL flowers under mid-day light. Complete CL flowers formed under long-day lights. However, there were a series of transitional types in the number and morphology of stamens and petals among inCL flowers, including five stamens with three petals related to CH flowers and two stamens with one petal related to CL flowers. The former type was dominant under short-day light conditions, and the latter type was dominant under mid-day light. Further more, there were localized effects in stamen and petal development for CL and inCL flowers. The development of ventral lower petal (corresponding to the lower petal with spur of CH flower) and the adjacent two stamens in inCL flowers were best, and the back petal was similar to that of CL flowers, an organ primordium structure. The adjacent stamens with the back petals tended to be poorly developed. In extreme cases, these stamens in inCL flowers had no pollen sac, only a membranous appendage or even a primordium structure. When the plants with CL or CH flowers were placed under short-day light or long-day light, the newly induced flowers all showed a series of inCL flower types, finally the CL flowers transformed into CH flowers, and the CH flowers transformed into CL flowers. This result indicates the gradual effects of different photoperiods on dimorphic flowers development of V. philippica. A long photoperiod could inhibit the development of partial stamens and petals, and a short photoperiod could prevent the suppression of long-day light and promote the development of stamens and petals. 相似文献
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Isolation and characterization of microsatellite markers for Viola mirabilis (Violaceae) using a next‐generation sequencing platform 下载免费PDF全文
We isolated and characterized microsatellite loci in Viola mirabilis (Violaceae), an endangered species from South Korea. Twenty‐three polymorphic microsatellite loci were developed and tested in Korean, Chinese and Japanese populations. The number of alleles per locus varied from two to eight. The observed and expected heterozygosities within the three populations were 0.000–0.625 and 0.469–0.695, respectively. A total of six loci in the Korean population, one locus in the Chinese population and seven loci in the Japanese population deviated from Hardy–Weinberg equilibrium. We expect that these newly developed microsatellite markers will contribute to understanding the phylogeography and population genetics of V. mirabilis, which will aid in developing conservation strategies for this species. 相似文献
34.
目的研究不同溶剂提取黄瓜香有效成分的作用效果,以期能更好提高药物的利用度。方法用盐酸林可霉素制造小鼠菌群失调模型,然后分别用黄瓜香的水、醇提取物治疗,比较治疗效果。结果醇提取物和水提取物均能调整肠道菌群平衡,与自然恢复组相比差异有统计学意义(P0.05),且醇提取物组效果要优于水提取物组(P0.05)。结论黄瓜香醇提取物是理想的微生态调节剂。 相似文献
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Observations were made on the effects of reduced rates of herbicide and nitrogen on naturally occurring populations of Viola aruensis. Progeny arising from these plants were grown in a uniform environment and monitored through to maturity. The size and number of reproductive structures produced by the maternal plants were positively correlated with the maternal plant weight. Herbicide dose affected the plant height of offspring and the effects were more pronounced in those from plants which had received 160 kg N ha-1 than 40 kg N ha-1 . Although the maternal effects on offspring size diminished with time, the number of reproductive structures in the offspring was significantly correlated with plant height during early development. Increased nitrogen availability to the maternal plant in the absence of herbicide may therefore increase the overall productivity of the subsequent generation. 相似文献
37.
Abstract Viola etrusca Erben, an endemic species of mountains of Southern Tuscany, belonging to the ser. Calcaratae Becker, is investigated under chorological and caryological aspects. On the basis of our data, the distribution area results larger than previously thought, extending to Monte Labbro and Monte Amiata. The known chromosome number is confirmed, and the caryotipic formula is reported. 相似文献
38.
Carbon-13 spin-lattice relaxation times, T1, have been measured for aqueous solutions of L-aspartic acid, L-alanine, O-phospho-L-serine, and 2-mercapto-L-succinic acid in the presence of the paramagnetic metal ions, Cu2+ and Mn2+, and Mg2+ as a diamagnetic control, at ambient temperature and neutral pH. Nitrogen-15, oxygen-17 and proton relaxation times were also obtained for L-aspartic acid and phosphorus-31 relaxation times for O-phospho-L-serine under similar conditions. The structures of these complexes in solution were determined from the various metal ion-nuclei distances calculated from the paramagaetically-induced relaxation. These results indicate that the Cu2+ interaction with L-aspartic acid is through α-amino and β-carboxyl groups while Mn2+ coordinates most strongly through α-and β-carboxyl groups, with the possibility of a weak interaction through the amino group.An examination of the coordination of these divalent metal ions to an analog of L-aspartic acid in which the β-carboxyl group is replaced by a phosphate group (O-phospho-L-serine) indicated that Cu2+ coordination is now probably through the α-amino and phosphate groups, while this analog is a monodentate ligand for Mn2+ coordinating through the phosphate group. Removal of the β-carboxyl group (L-alanine) also results in Cu2+ coordination through the α-carboxyl and α-amino groups, and the same ligand interactions are observed with Mn2+. Replacement of the α-amino group of L-aspartic acid with an - SH group (2-mercapto-L-succinate) is sufficient to eliminate any specific coordination with either Cu2+ or Mn2+. 相似文献
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THOMAS MARCUSSEN LIV BORGEN INGER NORDAL 《Botanical journal of the Linnean Society. Linnean Society of London》2005,147(1):91-98
The west Asian Viola sintenisii W.Becker, described from temperate woodlands of northern Iran and south-western Turkmenistan on the Caspian coast, was long considered a vicariant geographical subspecies of the mainly south European V. alba Besser. The new findings of V. sintenisii in four geographically separated stations in north-eastern Azerbaijan significantly expands its range of distribution. These occurrences are within the range of V. alba ssp. alba . Here the two taxa frequently co-occur but remain distinct and V. sintenisii is therefore justified at species level. It is likely that the two species are also sympatric in the Hyrcanian region, a range previously attributed uniquely to the latter. Viola sintenisii seems to be fairly common in the eastern parts of the Great Caucasus, but there are reasons to suggest that it has there been misinterpreted as V. suavis . The chromosome number of V. sintenisii , 2 n = 20, is reported here for the first time. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 147 , 91–98. 相似文献