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排序方式: 共有194条查询结果,搜索用时 15 毫秒
1.
Summary Fruit of the blackberry, Rubus pennsylvanicus Poir. (Rosaceae), were examined to determine variation in maturation characteristics. Maturation timing and rate varied greatly among individual fruits, resulting in a bi-colored fruiting display comprised largely of two maturation stages, pre-ripe (salmon and scarlet) and ripe (dark brown and black). While ripe fruit were generally larger and heavier than pre-ripe fruit, exhibiting greater fresh and dry fruit weight, diameter, water content, and total seed weight, no significant differences were found in energy content, i.e. numbers of calories per gram pulp, or in pulp:seed ratio. The differences between ripe and pre-ripe fruit appear to be due largely to an increase in water content and seed weight with maturity. The fact that little energetic benefit accrues to the preferential selection of ripe fruit suggests that bi-colored Rubus displays may be considered to be unicolored.  相似文献   
2.
Jon Ågren 《Oecologia》1988,76(2):175-183
Summary The flowering and fruiting patterns of the dioecious perennial herb Rubus chamaemorus L. were studied in frost-prone (open) and frost-sheltered (Shaded) habitats in northern Sweden over 6 years. The number of ramets with flower buds, the proportion of flower buds that opened, and fruit set varied markedly between years. In the frost-prone populations, the occurrence or absence of detrimental frosts during the development of flowers and fruit could explain much of the variation, both in the proportion of flower buds that developed into flowers, and in fruit set. In the frost-sheltered populations, most female flowers that did not develop into fruit aborted without any signs of physical damage and before any ovules had begun to enlarge. Flower mortality caused by herbivores feeding on reproductive parts was commonly low, but reached values higher than 10% in one of the shaded populations. Hand-pollination increased the proportion of ovules producing seeds in the mature fruits by about 20%, and in one year also increased fruit set significantly in one population. Fruit-producing female ramets had a higher mortality and a lower probability of flowering in the subsequent year than male ramets and non-fruiting female ramets. In R. chamaemorus, the conditions for fruit maturation are highly unpredictable at the time of flower initiation. It is suggested that the apparent over-initiation of flower buds is advantageous, as it allows the plant to attain a high reproductive success in years favourable for flowering and fruit development.  相似文献   
3.
甜茶组织培养研究   总被引:3,自引:1,他引:2  
林荣  王润珍  王秀琴   《广西植物》1985,(3):253-267
甜茶的茎段和实生苗培养在MS基本培养基中,研究植物激素对器官形成的影响,试验结果表明BA0.5-2.0毫克/升明显促进芽的形成和增殖;而对照(基本培养基)无形成芽。细胞分裂素对芽的起动是必需的。BA0.5-2.0毫克/升和GA_s1.0毫克/升配合使用,对茎段形成芽和增殖反而减少,但形成的苗较高和幼叶生长良好。通过继代培养,可繁殖大量小苗,它揭示出同一块外植体生长出许多小植株的可能,将无根苗转入含有IBA0.25-0.50毫克/升的1/2MS培养基中,能诱导生根,发展完整植株。试管苗移植土壤中,获得成功,幼苗生长良好。  相似文献   
4.
Summary The idea of trade-offs among antiherbivore defences in plants is examined using data from a South American blackberry (Rubus bogotensis). Two distinct morphs of R. bogotensis, one with glandular trichomes and one without, were compared with respect to leaf toughness, number of prickles and prickle length. The two morphs were sympatric and grew under similar environmental conditions. The morph lacking trichomes had significantly tougher leaves and also tended to have more and longer prickles. Bioassay showed that Ithomiid larvae fed to a lesser extent on tough leaves than on more tender ones. Correlations between antiherbivore defences within each phenotype revealed three significant or almost significant negative relationships. The comparisons support the hypothesis that trade-offs exist among antiherbivore defences.  相似文献   
5.
庄剑云  魏淑霞 《菌物学报》1993,12(Z1):47-50
本文报告采自四川西部九寨沟自然保护区菰帽悬钩子(Rubus pileatus Focke)上的一个锈菌新种。标本上仅见冬孢子堆,冬孢子双胞,类似柄锈菌的冬孢子。由于未见性子器,属的地位尚难确定。然而,此菌的冬孢子堆外观酷似悬钩子植物上特有的单种属阿氏锈菌属(Arthuriomyces)。镜下观察测得孢子大小为40-55(-65) × 22-28 μm,孢壁厚度为3-4.5 μm,有细皱纹,每个细胞各具一芽孔。从芽孔数及位置看符合阿氏锈菌属的特征,因而将此菌暂隶于此属,命名为悬钩子生阿氏锈菌(Arthuriomyces rubicola sp. nov.)  相似文献   
6.
Seeds of twoRubus species,R. palmatus var.coptophyllus andR. microphyllus, buried for 7.5 years in soil were subjected to germination tests to investigate their germinability and germination traits. Most of the retrieved seeds were viable, and germinated at the alternating temperatures of 20/30°C in both light and dark. The twoRubus species showed similar responses of germination to temperature and light, although the final percentages of germination were slightly higher inR. palmatus var.coptophyllus. These characteristics of seed dormancy and germination would be involved in the species' utilization of ephemeral habitats created by unpredictable and infrequent disturbances.  相似文献   
7.
悬钩子属种质的评价   总被引:30,自引:0,他引:30  
在进行了7省悬钩子资源调查的基础上,在南京建立了悬钩子属田间基因库。3年来对田间基因库内保存并开花结果的30个种进行了开花结果性状的记栽和评价。内容包括果实特征,糖、酸、维生素类、氨基酸、矿质元素含量分析,染色体计数等。分析了种间和种内多样性物存在及在良种选育中利用的可能性。  相似文献   
8.
悬钩子种质评价标准   总被引:6,自引:0,他引:6  
九十年代初在南京建立了悬钩子属田间基因库。考虑到国内外尚未发表悬钩子属种质评价标准,特拟定此标准供田间基因库使用。内容包括登记数据、引种数据、栽植数据、繁殖保存数据、植株数据、病虫害敏感性、同工酶酶谱、染色体计数和备注等9部分。在植株数据中有:1.植株类型;2.植株大小;3.生长势;4.刺;5.萌蘖;6.顶端生根习性;7.枝蔓寿命;8.叶(包括叶成分等共10项);9.花序;10.花;11.果(包括果实成分等共18项);12.适应性;13.丰产性  相似文献   
9.
高粱泡的生长调控与结实状况   总被引:3,自引:0,他引:3  
高粱泡(Rubus lambertionus Ser.)是一种有利用价值的野生果树资源。其优点为:(1)结果早,产量高,亩产量可达500kg以上;(2)适应性广,耐瘠薄,是开发利用低山丘陵的优良资源植物;(3)果实营养丰富,酸味纯正,尤其是所含红色素稳定性好,是加工果汁饮料的优质添加剂;(4)果实采收期在11月中旬到12月底,此时气温低,有利于浆果加工和贮藏,并可利用农闲季节的劳动力。上述特点表明,高粱泡有很好的开发利用前景。但本种在野生状态下蔓生性强,多刺,并具有枝顶生根的习性,因而树形紊乱而松散,栽培时搭架困难,植株占地面积大,而单位面积产量不易提高。为了便于操作管理和提高产量,减少栽培成本,增进经济效益,我们于1990~1991年进行了生长和株形调控试验,  相似文献   
10.
经引种栽培,作者观察研究了野生掌叶复盆子(Rubus chingii Hu)的栽培性状,包括植株形态、花果期、产量、果实大小等。通过对11个单株个体性状的统计分析,发现在单株产量、可育花比例、果实大小方面个体间差异极大。认为掌叶复盆子适合驯化栽培,野生种群中有很大的选优潜力。  相似文献   
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