排序方式: 共有81条查询结果,搜索用时 15 毫秒
1.
2.
3.
对不同品种的孔雀草F2代植株进行人工授粉,对人工授粉与自然授粉花朵的结实率进行比较研究。结果表明:品种间结实率存在差异。20号品种的结实率最高,13号品种的结实率最低;除6号、7号与13号品种外,舌状花植株的结实率比筒状花植株的结实率要高;人工授粉的结实率普遍比自然授粉的结实率高,除3号与6号品种外,其中8号品种授粉处理下结实率的差异最为显著,2号品种的差异最小。 相似文献
4.
AM真菌对3种花卉生长发育的影响 总被引:2,自引:0,他引:2
研究3种AM真菌对大丽花、孔雀草和金盏菊生长发育的影响.结果表明:接种AM真菌,提高了花卉幼苗的移栽成活率,叶片叶绿素含量和氮、磷、钾含量增加,生长量增加,开花期提前,盛花期的着花数增多,花期延长.大丽花和金盏菊对摩西球囊霉的依赖性最强,孔雀草对地表球囊霉的依赖性最强. 相似文献
5.
Background: The minimum set of sub-models for simulating stand dynamics on an individual-tree basis consists of tree-level models for diameter increment and survival. Ingrowth model is a necessary third component in uneven-aged management. The development of this type of model set needs data from permanent plots, in which all trees have been numbered and measured at regular intervals for diameter and survival. New trees passing the ingrowth limit should also be numbered and measured. Unfortunately, few datasets meet all these requirements. The trees may not have numbers or the length of the measurement interval varies. Ingrowth trees may not have been measured, or the number tags may have disappeared causing errors in tree identification. Methods: This article discussed and demonstrated the use of an optimization-based approach to individual-tree growth modelling, which makes it possible to utilize data sets having one or several of the above deficiencies. The idea is to estimate all parameters of the sub-models of a growth simulator simultaneously in such a way that, when simulation begins from the diameter distribution at the first measurement occasion, it yields a similar ending diameter distribution as measured in the second measurement occasion. The method was applied to Pinus patula permanent sample plot data from Kenya. In this dataset, trees were correctly numbered and identified but measurement interval varied from 1 to 13 years. Two simple regression approaches were used and compared to the optimization-based model recovery approach. Results: The optimization-based approach resulted in far more accurate simulations of stand basal area and number of surviving trees than the equations fitted through regression analysis. Conclusions: The optimization-based modelling approach can be recommended for growth modelling when the modelling data have been collected at irregular measurement intervals. 相似文献
6.
多效唑对波斯菊和孔雀草种苗矮化效应的研究 总被引:1,自引:0,他引:1
波斯菊和孔雀草是两种常用的园林花卉。为解决其种苗生产中常因下胚轴伸长等因素造成的种苗过高,株型散乱问题,本文研究了不同品牌的多效唑在不同浓度和不同施用方式的条件下对种苗矮化效果的影响,以期找到调控的最佳品牌、最佳施用方式和最佳浓度,为种苗的高质量、规模化生产提供理论的指导参考。研究发现:七洲牌多效唑溶液对波斯菊和孔雀草的矮化效果最好,矮化效果最好的处理都是以2mg/L的七洲牌多效唑溶液采用低浓度多次施用的处理。 相似文献
7.
8.
白孔雀草,别名硬枝满天星,引入国内时间短,用量大,姿态优美,一年四季均可开花。种植要求条件简单,经济效益高,单位面积产量高,具广阔市场前景。 相似文献
9.
10.
不同浓度镉胁迫对孔雀草DNA甲基化的影响 总被引:2,自引:0,他引:2
随着人类活动、工业化发展进程的加快,重金属污染对环境造成了严重危害。本研究通过盆栽试验,利用甲基化敏感扩增多态性(MSAP)技术,对不同浓度镉(Cd)胁迫下孔雀草(Tagetes patula)基因组DNA甲基化变化情况进行了分析研究。结果表明,经0、50、250和500mg·kg-1浓度Cd~(2+)处理后,基因组MSAP比率分别为24%、30%、35%和41%,全甲基化率分别为20%、23%、25%和27%,这表明重金属胁迫处理后,DNA总甲基化水平随Cd~(2+)浓度升高而呈上升趋势;在DNA甲基化模式变化方面,50、250和500 mg·kg-1浓度胁迫下重新甲基化率分别为10%、10%和11%,重新甲基化为主要的甲基化变化模式。本研究可以为揭示重金属胁迫对植物DNA甲基化变化规律及植物对重金属胁迫耐受性机制提供理论参考。 相似文献