共查询到20条相似文献,搜索用时 59 毫秒
1.
山茶花组织培养过程中的防外植体褐化试验 总被引:5,自引:0,他引:5
针对山茶花组织培养过程中外植体出现褐化的问题,用山茶花的嫩茎段及芽尖为外植体作不同的处理试验,以比较其减轻外植体褐化的效果。得出的结论为:黑暗条件下培养外植体、用1/1000抗坏血酸处理外植体、在培养基中加入一定比例的活性碳、在接种前再剪去一部分茎段外植体、对外植体勤转瓶这些措施在一定程度上可以减轻山茶花组培过程中外植体的褐化程度,从而提高其组培的成功率。 相似文献
2.
植物组织培养技术是红锥(Castanopsis hystrix)优树无性化推广的重要途径,但外植体诱导培养过程中的褐化现象严重影响了其高效组织培养再生体系的建立。文章通过对红锥外植体取材季节、木质化程度、灭菌处理、光照等技术要素以及防褐化剂种类等进行生长对比试验,结果表明:外植体取材季节对褐化率无显著影响;外植体木质化程度对褐化率有极显著影响(P <0.01);采用75%酒精进行外植体灭菌与未采用酒精的外植体相比,褐化率增加15.0个百分点,褐化程度加剧,其中采用2 min 的新吉尔灭(1%)+2.5 min 升汞(0.1%)两者结合进行灭菌效果较好;低温预处理外植体及暗培养均未达到抑制褐化的效果;添加防褐化剂 PVP 80 mg·L -1、VC 1.0 g·L -1均能有效抑制褐化,褐化率分别为33.3%、12.2%,且腋芽长势好。 相似文献
3.
遮荫对天女木兰光合特性及生长的影响 总被引:3,自引:0,他引:3
研究不同程度的遮荫(A:0,B:25.8%,C:61.3%,D:90.3%)对天女木兰光合特性及生长的影响。结果表明:天女木兰的地径、苗高和生物量均表现为B>A>C>D。天女木兰的光补偿点和光饱和点均较低,且随着遮荫程度的提高,其值以及暗呼吸速率均依次降低。天女木兰净光合速率日变化规律在不同的遮荫处理下均呈现双峰型曲线,有明显的光合\"午休\"现象,净光合速率日最大值为B>A>C>D。B处理是这4种遮荫处理中天女木兰生长最适宜的遮荫强度,适度遮荫可增强天女木兰叶片的光合作用,促进其生长。 相似文献
4.
5.
6.
7.
8.
地涌金莲组织培养中的褐化抑制 总被引:2,自引:0,他引:2
地涌金莲组织培养中的褐化问题一直是其优良品种选育及规模化生产的技术瓶颈。为解决这一问题,以地涌金莲未成熟雄花为试材,研究了外植体消毒方式、植物生长调节剂种类及配比和不同抗褐化剂对愈伤组织褐化的影响。结果表明,未经消毒的外植体其污染率为0%,且褐化率和褐化指数均显著低于消毒后的外植体;6-BA在地涌金莲愈伤组织诱导中起主要作用,浓度为2 mg·L-1、3 mg·L-1时有利于愈伤组织的诱导,能显著降低褐化指数;添加柠檬酸+抗坏血酸(VC)混合液、表面添加VC均对地涌金莲褐化未起到明显抑制作用,姜汁和阿魏酸对抑制愈伤组织褐化有较好的效果,48.5 mg·L-1的阿魏酸能显著降低愈伤组织的褐化,使愈伤组织分化率达17.9%,较对照的2.9%提高了15%。 相似文献
9.
天冬氨酸蛋白酶在天女木兰种子萌发过程中发挥着重要作用。以天女木兰种子为试验材料,利用同源克隆法RACE技术,从天女木兰种子中克隆得到天冬氨酸蛋白酶基因,全长1 545 bp,可以编码514个氨基酸残基。同源性分析显示,目的序列推导的氨基酸序列与其它植物中已知的天冬氨酸蛋白酶基因的氨基酸序列的同源性都在85%以上;采用生物信息学的方法进行分析,初步预测该基因编码的蛋白属于跨膜的分泌蛋白,大部分区域属于疏水结构;结构域的预测分析显示,此类蛋白包含约100个植物组织蛋白酶所特有的区域,该区域可能在植物液泡中发挥着重要作用。本研究为下一步系统、全面地研究天女木兰种子休眠的分子机理奠定了基础。 相似文献
10.
以滇牡丹Paeonia delavayi Franch成熟种胚诱导出的愈伤组织为试验材料,研究了PVP、VC、结冷胶、AgNO3、水解乳蛋白(LH)5种抗褐化剂在牡丹愈伤组织继代培养过程中的褐化控制作用和对愈伤组织生长量的影响。结果表明:愈伤组织褐化主要发生在第一次继代转接后的10 d内;在愈伤组织两次继代培养过程中,3.5g/L的结冷胶处理抗褐化效果最好,LH和AgNO3在整个继代过程中也表现了一定的抗褐化性,PVP和VC抗褐化性能相对较差。AgNO3对愈伤组织生长具有明显的促进作用。 相似文献
11.
A novel aporphine alkaloid, magnofficine (1), has been isolated from the root barks of the Chinese medicinal plant Magnolia officinalis, along with seven known compounds. Elucidations of their structures were achieved by spectroscopic methods. Magnofficine is the first example of an adduct of aporphine alkaloid and 4-hydroxyphenethylamino bridged by a methylene. 相似文献
12.
The survival and growth of Quercus germana Schltdl. & Cham., Q. xalapensis Humb. & Bonpl. and Magnolia dealbata Zucc. was evaluated in three treatments: (1) under the canopy of Pinus maximinoi H.E. Moore; (2) under the canopy of Liquidambar macrophylla Oersted, and (3) in open areas. The following hypothesis was presented: P. maximinoi and L. macrophylla canopy facilitate the establishment of Quercus germana, Q. xalapensis, and Magnolia dealbata. After one year, the survival of seedlings and the growth rate in height and basal diameter were significantly different between treatments and species (p < 0.05). The results suggest a facilitation establishment of Magnolia dealbata under the canopy of Pinus and Liquidambar, whereas the tolerance was observed for Quercus germana and Q. xalapensis. The results will allow to identify restoration strategies of the mountain cloud forest in Mexico.Resumen. Se evaluó la supervivencia y crecimiento de Quercus germana, Q. xalapensis y Magnolia dealbata, en tres tratamientos; (1) bajo el dosel de Pinus maximinoi, (2) bajo el dosel de Liquidambar macrophylla y (3) en áreas abiertas. La hipótesis planteada fue; la cobertura de P. maximinoi y L. macrophylla facilitan el establecimiento de Quercus germana, Q. xalapensis y Magnolia dealbata. Después de un año, la sobrevivencia de plántulas, y las tasas de crecimiento en altura y diámetro de la base, fueron significativamente diferentes entre tratamientos y especies (p < 0.05). Los resultados sugieren que el establecimiento de Magnolia dealbata es facilitado bajo el dosel de Pinus y Liquidambar, mientras que para Quercus germana y Q. xalapensis se observó tolerancia. Los resultados permitirán identificar estrategias de rehabilitación del bosque mesófilo de montaña en México. 相似文献
13.
14.
A.A. da Silva Filho D.O. Resende M.J. Fukui F.F. Santos P.M. Pauletti W.R. Cunha M.L.A. Silva L.E. Gregrio J.K. Bastos N.P.D. Nanayakkara 《Fitoterapia》2009,80(8):478-482
Baccharis dracunculifolia (Asteraceae), the most important plant source of the Brazilian green propolis (GPE), displayed in vitro activity against Leishmania donovani, with an IC50 value of 45 µg/mL, while GPE presented an IC50 value of 49 µg/mL. Among the isolated compounds of B. dracunculifolia, ursolic acid, and hautriwaic acid lactone showed IC50 values of 3.7 µg/mL and 7.0 µg/mL, respectively. Uvaol, acacetin, and ermanin displayed moderate antileishmanial activity. Regarding the antiplasmodial assay against Plasmodium falciparum, BdE and GPE gave similar IC50 values (about 20 µg/mL), while Hautriwaic acid lactone led to an IC50 value of 0.8 µg/mL (D6 clone). 相似文献
15.
Ophiostoma species were isolated from bark beetles and Abies mariesii, A. veitchii and A. homolepis attacked by the beetles in Nikko, Tochigi, central Honshu, Japan. One to two Ophiostoma species were frequently isolated from each species of bark beetle. Ophiostoma subalpinum was the most common associate of Cryphalus montanus. Ophiostoma sp. B as well as O. subalpinum was a common fungus associated with Polygraphus proximus. Ophiostoma europhioides was isolated from Dryocoetes hectographus and D. autographus as one of the common associates. Ophiostoma sp. J and Ophiostoma sp. S were frequently isolated from D. autographus and D. striatus, respectively. These fungi seem to have specific relationships with particular bark beetles. Ophiostoma sp. B, Ophiostoma sp. J and Ophiostoma sp. S have unique morphological characteristics and appear to be new species. Five trees of A. veitchii, approximately 43 years old, were inoculated with five Ophiostoma species to assess the relative virulence of the fungi. Ophiostoma subalpinum, Ophiostoma sp. B, and O. europhioides had relatively higher virulence than the other species studied. 相似文献
16.
17.
The geographic distributions ofCastanopsis sieboldii andCastanopsis cuspidata overlap each other on the Pacific coast of Japan, but on the Japan Sea coastC. sieboldii tends to dominate at similar temperatures. The authors attempted to explain this phenomenon by analyzing the effects of climatic
factors. Nuts were collected from the Pacific and Japan Sea coasts of the Kinki and Chugoku districts, and the nut characteristics
and the number of layers of epidermis in the leaves of the seedlings were investigated. The distribution ofC. sieboldii andC. cuspidata was satisfactorily explained by a multiple regression equation that was developed using three climatic factors: maximum snow
depth in winter, lowest temperature in the coldest month, and annual mean temperature, out of fourteen such factors that were
considered. The estimated distribution ofC. sieboldii andC. cuspidata from the multiple regression equation agreed with 66.2% of the actual observations. 相似文献
18.
The aim of this study was to quantify the effects of different soil scarification methods on tree growth. Soil scarification influenced stem volume and stem biomass yield of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) in a 17-year-old field trial in boreal Sweden. Soil scarification (disc trenching, mounding and ploughing) resulted in an average stem volume yield of 3.1 and 34.2 m3 ha–1 on the poor and intermediate sites, respectively, while corresponding values for no soil scarification were 0.9 and 16.7 m3 ha–1. In comparison to no scarification, ploughing increased volume yields by 500% on the poor site and by 200% on the intermediate sites. The ranking according to stem volume yield was ploughing > disc trenching = mounding no soil scarification. Averaged over the two sites, the mean annual increment of stem biomass was 219% and 145% higher (in d.w., 0.26 kg and 0.34 kg per sample tree) after ploughing compared with no soil scarification, for the average and dominant sample trees, respectively. Although not significant, the increased growth rate after soil scarification decreased the average stem basic wood density of the sample trees with 1.6% and 5.3%, at the poor and intermediate sites, respectively. In conclusion, soil scarification significantly increased the 17-year stem volume yield compared with no scarification. The results also indicate that the difference in stem biomass yield between ploughing and the other methods, especially no soil scarification, will increase even more in the near future. 相似文献
19.
Our study focuses on predicting the ultimate short-term load carrying capacity of timber-to-timber connections with dowel-type fasteners. The wide range of possible configurations in practice makes the resolution of these values by tests unrealistic. Moreover, different current regulations do not consider some specific failure mechanisms. In many countries, the reduction of resistance involved by this phenomenon is taken into account by considering an effective number of dowels (nef) smaller than the actual number of dowels (n) in the connection. However, these different regulations disagree on the values of nef and on other points (spacing, partial coefficient of security, formulas). These discrepancies in design rules invite the fundamental research on this topic and, therefore, new methods are sought in order to estimate the load carrying capacities of the connections. In the light of these, our approach consists of predicting the load carrying capacity with the neural network numerical tool. The results obtained by this analysis tool are satisfactory, although the model remains complex. Subsequently, we focus on the simplification of this numerical model with classical regression techniques in order to implement it in a design code. 相似文献
20.
明确角倍蚜、角倍与寄主盐肤木协同生长过程中游离氨基酸变化的营养关系。
用全自动氨基酸分析仪Biochrom30+检测角倍发育初、中、后期的角倍蚜、角倍、有倍叶、无倍叶及无角倍盐肤木叶片(CK)的游离氨基酸含量,分析不同时期各试样游离氨基酸总量(FAA)、昆虫必需氨基酸总量(EAA)、昆虫必需氨基酸总量与检出物质总量比值(EAA/TAA)及几种游离氨基酸含量的变化。
表明:不同时期各试样均检出32种游离氨基酸(包括17种蛋白氨基酸和15种非蛋白氨基酸),2种其他组分(不含氨),其中,游离氨基酸含量从大到小依次为角倍蚜(5.569)>角倍(2.122)>有倍叶(0.560)>无倍叶(0.537)>CK(-0.114)。从角倍生长初期至后期,角倍蚜体内必需氨基酸总量呈递增变化,而其他材料EAA/TAA变化幅度从大到小依次为CK(1.73%)>有倍叶(0.52%)=无倍叶(0.52%)>角倍(0.43%)>角倍蚜(0.02%),但角倍蚜EAA/TAA稳定为(27.91±0.01)%,角倍蚜对寄主盐肤木叶片EAA/TAA的变化幅度有显著减缓影响。在角倍生长发育期间,角倍蚜体内精氨酸和苯丙氨酸含量均增加2.93倍;而寄主植物组织中脯氨酸含量发生变化,增幅大小为角倍(0.028)>有倍叶(0.003)>无倍叶(-0.001)>CK(-0.018)。
角倍蚜取食盐肤木不会改变寄主盐肤木叶片中游离氨基酸组分,但可使其游离氨基酸含量增加;在角倍生长过程中,盐肤木植株游离氨基酸总量与角倍蚜个体数量和角倍体积的增加趋势基本一致,反映了角倍蚜取食与盐肤木防御之间的平衡。

