共查询到20条相似文献，搜索用时 15 毫秒
1.
珍稀濒危植物掌叶木的开花生物学特性与繁育系统 总被引：1，自引：0，他引：1
通过野外观察、杂交指数估算、授粉特性分析及人工控制授粉试验等方法对珍稀濒危植物掌叶木（Handeliodendron bodinieri）开花生物学特性和繁育系统进行研究。结果表明：（1）掌叶木每年开花1次,花期在4月下旬到5月中下旬,开花的起止时间及花期的长短受当地气候影响较大;（2）花多为假两性花,即形态上为雌、雄蕊完整的两性花,而功能上为雌、雄蕊选择性败育形成的单性花,偶见雌、雄蕊可育的真两性花植株;单性花通常雌、雄异株,且雌株较雄株少,花序较雄株短5.6 cm,花期也较雄株短2周左右,雄株花序上偶尔见雌花单花;（3）单花经历萌动、露白、展开、盛开、凋落5个阶段,历时5 ~ 6 d;雄花从萌动到开花1 d的花粉活力高达90.5%,开花2 d后活力显著下降;雌花柱头在展开前部分具可授性,展开后1 ~ 3 d均具可授性,花粉活力与柱头可授性重叠;（4）雄花单花花粉量为51 461个,雌花单花胚珠数6,花粉胚珠比（P/O）为8 577,杂交指数为4,结合人工授粉、套袋、套网和自然授粉坐果率判断,掌叶木繁育系统为专性异交,传粉过程需要传粉者,可能存在无融合生殖。（5）掌叶木花性别分化复杂,可孕花数量较不孕花少,可育雌、雄蕊存在较大的空间隔离,加之不稳定的传粉环境,可能是其濒危的重要生殖生物学原因。 相似文献
2.
为筛选出诱导西葫芦雄花的最佳时期和AgNO3浓度,于3个不同的生长时期,用3种不同浓度(300,400,500 mg/L)的AgNO3处理西葫芦幼苗。试验结果表明,在不同时期用AgNO3可提高西葫芦第一雄花节位,增加2花芽/叶腋数,减少雌花数,且处理时间越早,第一雄花节位越高,雌花数越多;同一处理时期,随着AgNO3浓度的增加,雌花数减少,2花芽/叶腋数增加,子叶平展期和1叶1心期用400 mg/L AgNO3处理西葫芦幼苗,雄花数最多,花粉活力最高;仅1叶1心期和2叶1心期可诱导两性花产生,且随着处理时间的推迟和AgNO3浓度的增加,两性花越多,植株长势减弱。研究结果表明,子叶平展期用400 mg/L AgNO3处理西葫芦幼苗,诱雄效果最佳。 相似文献
3.
The effects of ethephon or GA3 on sex expression of Chinese chestnut (Castanea mollissima BL.) were opposite to the effects of these plant growth regulators on cucumber, pumpkin and Chinese white-flowered gourd. Ethephon at 100–500 mg 1?1 inhibited the development of female flowers and promoted that of male flowers. GA3 at 50–500 mg 1?1 caused a significantly lower number of male inflorescences, but increased the number of female flowers. Urea applications decreased the number of male inflorescences and increased the number of female flowers. For plants grown on phosphorous-deficient soils, fertilizing with superphosphate also increased the number of female flowers. Spraying trees with GA3, urea or a mixture of both increased the number of female flowers. Therefore, it is proposed that such applications should be employed at the onset of differentiation of flower primordia of Chinese chestnut to increase the ratio of female to male flowers. 相似文献
4.
5.
Michael G. Mullins 《The Journal of Horticultural Science and Biotechnology》2013,88(3):237-247
A distinctive seasonal pattern in the outgrowth of shoots was observed in upright maiden apple trees. Until midsummer, extension shoot growth was confined to the apical region of the trunk. After midsummer, vigorous shoots grew from the basal region of the trunk, and the production of these shoots coincided with a decline in growth rates of shoots in the apical region. A similar pattern of shoot growth was evident in trees grown in horizontal and inverted positions but was modified by the effects of gravity, viz. growth curvatures, effects on the symmetry of shoot production about the axis, and changes in the vigour of shoots in the apical and basal regions of the trunk. Growing trees in horizontal and inverted positions caused a reduction in terminal extension growth, but did not reduce the total amount of shoot growth compared with vertically-grown trees. Changing the orientation of the trunk caused differences in the pattern of axillary flower bud formation, but had no detectable effect on the total numbers of flower buds initiated. 相似文献
6.
A. Garcia-Luis M. Kandušer J. L. Guardiola 《The Journal of Horticultural Science and Biotechnology》2013,88(5):817-825
SummaryThe effect of chilling temperatures on bud sprouting and flower formation was compared on fruiting and non-fruiting ‘Owari’ satsuma mandarin (Citrus unshiu Marc) trees. On non-fruiting trees, bud dormancy was weak, and a significant proportion of buds were able to sprout at high temperatures without being chilled. Separate effects of low temperatures on bud sprouting and flower induction were demonstrated. On fruiting trees these two effects of low temperatures were also demonstrated on summer-flush buds, but not on older (spring-flush) buds. The spring-flush buds from fruiting trees scarcely sprouted without being chilled. These buds required a longer chilling period for dormancy release than for flower induction, and it was not possible to separate the effect of low temperature on flower induction from the effect on dormancy release. The presence of fruit reduced flower formation by reducing bud sprouting. Furthermore, fruit had a direct inhibitive effect on vernalization which resulted in increased formation of vegetative shoots. The effect of fruit and low temperature on flowering was unrelated to carbohydrate accumulation in the leaves or the roots. 相似文献
7.
8.
不同施肥处理对银桂幼树生长及生理特性的影响 总被引：2，自引：0，他引：2
以4 a 生银桂(Osmanthus fragrans 'yingui')为试材,研究施用不同类型的肥料对银桂树的影响.结果表明:各种施肥处理都不同程度的促进了桂花幼树的生长,提高了各种光合色素含量,促进叶片净光合速率(Pn)提高,增加叶片可溶性糖和可溶性蛋白质含量,为桂花幼树日后花芽分化,早产丰产提供了营养基础. 相似文献
9.
以7 a生的冬枣(Zizyphus jujuba Mill.)为试材,采用不同时间覆网并辅之根剪措施,研究防护网对冬枣生长及果实品质的影响。结果表明:冬枣开花前搭覆防护网结合根剪显著抑制了冬枣的二次枝生长、枣吊数量、坐果率、花量及产量,并明显降低了果实中的维生素C和可溶性糖含量,但未造成果实农药残留。而坐果后覆网加根剪对二次枝、坐果率、产量的抑制效果较小,并对枣吊数量和花量无明显影响作用。虽然坐果后覆网果实中检测到了农药残留,但相比对照显著降低,未对果实品质带来不利影响。2种覆网方式均降低了冬枣的光合特性。综合分析认为,坐果后覆网与根剪相结合是提高果实品质的有效措施。 相似文献
10.
砧木对柑桔嫁接幼树早果影响的生理生化研究 总被引：9，自引：1，他引：8
本文研究了枳和红桔两种砧木对柑桔嫁接幼树结果早晚影响的生理生化差异。1.枳砧树较红桔树至少提早二年开花,枳砧树的单叶面积、株高、新梢生长量和干径均小于红桔砧树;2.花芽生理分化期枳砧树叶片的可溶性糖、淀粉及还原糖的含量均高于红桔砧树,叶片总氮含量变化不大,但在花芽形态分化期,砧木对叶片可溶性蛋白质含量的影响较大。叶片C/N比值与花芽形成存在一定相关关系。10月上中旬各因子二种砧木树的相对含量有一明显逆转过程,3.花芽生理分化期枳砧树叶片内源玉米素和脱落酸含量高于红桔砧树,赤霉素(GA_3)低于红桔砧树,整个试验期间,Z/GA_3和ABA/GA_3比值均为枳砧树高于红桔砧树。 相似文献
11.
12.
西瓜3种性型花器官性别分化的细胞形态学观察 总被引：1，自引：0，他引：1
以西瓜3种性型(雌雄异花同株系、全雌系和完全花雄花系)的雄花、雌花和完全花3种花芽为材料,制成石蜡切片,进行西瓜花芽不同发育时期的细胞形态学观察。结果表明:西瓜3种性型之间性别分化起始及同种性别之间花器官发育过程并没有明显的形态学差异。雄花、雌花和完全花3种花芽分化首先要经过一个两性期,即雄蕊原基和雌蕊原基同时存在时期,在两性期之前三者不存在明显的形态学差异;当花芽长度为0.8~1.0mm时两性期结束,开始雄花、雌花和完全花的差异发育,此后雄花和完全花的雄蕊原基快速增大,雌花和完全花的雌蕊原基开始分化为柱头和子房。在3种花芽发育过程中,完全花的花芽在两性期后明显比同时期的雄花、雌花的花芽长度更长。全雌系中的"畸形雌花"出现在两性期后,雌蕊原基的凹陷发育过程受阻,而本该停止发育的雄蕊原基继续分化,最终发育成可产生少量成熟花粉粒的雄蕊。 相似文献
13.
螺旋环剥对幼龄荔枝树生长结果的调控作用 总被引：12，自引：2，他引：10
‘糯米糍’和‘桂味’荔枝幼树不挂果现象相当普遍。采用螺旋环剥能显著促进成花、改善花质、减少落果、增加产量,改善品质。糯米糍、桂味幼树在生理落果期间出现旺盛的根梢生长峰,但其成年树和坐果比较正常的怀枝幼树都没有出现这种旺盛生长,表明了品种和树龄特性的差异。螺旋环剥明显减少生理落果期间的根与梢的生长量,使果实在与根、梢之间的库力竞争中获得优势,因而有利于坐果和果实生长。 相似文献
14.
15.
苹果苗木类型和栽植时间对幼树生长特性的影响 总被引：1，自引：0，他引：1
【目的】为了研究不同栽植时间下不同苗木类型的生长特性,【方法】以3 a生‘长富2号’/‘M26’/八棱海棠为试材,测定3个栽植时间(2010年3月10日、4月10日和5月10日)下分枝苗、去分枝苗和单干苗生长特性相关指标。【结果】5月份栽植植株的生长势弱于3、4月栽植的植株;单干苗生长势弱于分枝苗和去分枝苗。栽植后第2年,3、4月栽植植株的株高、主干粗度显著大于5月栽植的植株。去分枝苗和单干苗株高显著大于分枝苗。3种苗木类型主干粗度依次为分枝苗>去分枝苗>单干苗,且相互差异显著。分枝苗和去分枝苗冠径显著大于单干苗。栽植后第3年,分枝苗的花芽数显著高于去分枝苗和单干苗。【结论】苹果苗木在冷藏条件下,4月栽植是可行的,本试验中3月份栽植较为适宜。分枝苗有利于促进幼树提早开花结果。 相似文献
16.
多效唑对桃树生长和结果的影响 总被引：3，自引：0，他引：3
应用多效唑对桃树进行土施和叶面喷布等不同方法,不同剂量的试验。土施0.125～1.0g/m~2,叶面喷布500ppm×2以上的浓度都可有效地抑制植株营养生长。它降低了新梢生长长度,抑制了副梢的发生和生长,以及干周的增长。多效唑在抑制营养生长的同时也促进了生殖生长,有效地促进花芽形成,降低了始花节位,增加了成花节位数和复花芽节位数。对果实大小也有促进作用。成倍地提高了早期产量。施用同等剂量,土施的效果优于叶面喷布。在我国中部地带,陇海沿线沙壤土上以0.25/m~2的剂量为好,第二年以后用量减半。在土施情况下它的“呆滞期”只1.0～1.5个月。土施应在旺盛生长前1.5～2.0个月以前施入。 相似文献
17.
18.
乙烯利对苦瓜种子的萌发及其生长发育的影响 总被引：1，自引：0，他引：1
以苦瓜品种早苦瓜为试材,利用不同浓度(50、100、150、200、250mg·L-1)的乙烯利处理苦瓜种子,研究乙烯利对苦瓜种子的萌发及其生长发育的影响,结果表明:乙烯利对苦瓜种子萌发有促进作用,对植株的生长具有一定的后效作用。发芽势、发芽率、发芽指数、活力指数、雌花数、产量、定植后期的叶面积及茎粗均随着乙烯利浓度的增加表现出先上升后下降的趋势,第1雌花节位和雄花数随着乙烯利浓度的增加表现出先下降后上升的趋势。其中150mg·L-1乙烯利处理效果最佳,各项指标与对照的差异均达到显著水平。 相似文献
19.
20.
D. G. Hill-Cottingham R. R. Williams 《The Journal of Horticultural Science and Biotechnology》2013,88(4):319-338
Fertilizer nitrogen was applied to pot-grown trees during the year of initial scion growth either as “spring N”, “summer N” or “autumn N”, while other trees were left untreated—“minus N”. Tree performance was followed until fruit set the following summer.At regular intervals whole trees were sampled, divided into as many as seven different parts, which were separately weighed, dried and analysed for total nitrogen. Specimens were also taken for histological examination of flower bud development.The large amount of fertilizer given as “spring N” resulted in extensive root damage from which the trees did not recover fully; nevertheless they produced large, vigorous scions. After “spring N” and “summer N” at lower dosages the total N content of all parts increased substantially and rapidly. “Autumn N” was absorbed more slowly and remained largely in the roots during the winter, when a considerable amount of root growth took place.Flowers were initiated in late July or early August on all trees except those given “spring N”, on which flower primordia were not initiated until September. The development of flower buds was accelerated during September on “summer N” trees compared with those left untreated. From the end of November until the end of March no further differentiation took place on “minus N” or “spring N” trees, but it continued on the other treatments, especially following “autumn N”.“Summer N” and “autumn N” trees were 4–5 days in advance of the others in flowering. “Summer N” trees had large flowers and large green primary leaves, whereas those on “autumn N” trees were smaller and the leaves were initially pale, though turning dark green during blossoming.When the blossoms were self-pollinated under controlled conditions virtually no fruit was set on “minus N” and “spring N” trees, but “summer N” gave an appreciable set and “autumn N” a heavy set. Only the “summer N” and ”autumn N” flowers had ovules that remained viable six days after anthesis, which was the minimum period found necessary for the pollen tubes to effect fertilization.It is suggested that fertilizer nitrogen stimulates the synthesis of a kinin-like factor in the roots and that the difference in response to applications at different times of year depends upon the stage of development of the flower buds when this factor reaches them. 相似文献