南板蓝扦插繁殖技术研究

研究了不同基质、插穗不同部位、不同节数和不同植物生长调节剂对南板蓝扦插繁殖的影响。结果表明, 不同基质、插穗不同部位、不同节数和不同植物生长调节剂对插穗生根的影响均有显著差异。其中以河沙∶珍珠岩=2∶1混合基质的扦插效果最好、生根率达93.3%;顶部插穗的生根率达94.2%;2节插穗的生根率为90.7%;100mg/LIBA扦插生根率最高,达94.5%。采用适当的方法有利于提高南板蓝扦插的繁殖系数。     

微域环境因子对落基山圆柏插穗生根的影响

以8年生落基山圆柏(Juniperus scopulorum)的嫩枝为试验材料, 采用不同扦插密度和基质等处理措施, 研究了微域环境因子对插穗生根的影响。结果表明, 两种不同扦插密度的生根部位、愈伤率、生根率、炼存率、生根效果指数(root effect index, REI)、离散度指数(rooting dispersion index, RDI)和分形特征均存在显著差异。综合分析生根率、炼存率、REI和RDI等发现, 密插处理的效果好于稀插, 稀插处理的插穗生根能力较差, 生根性状离散度较大。密插处理的插穗的根系平均分形维数是稀插处理的1.24倍, 两者差异极显著(p < 0.01)。不同扦插密度下插穗的生根部位和生根机制不同: 插穗在密插处理下形成诱生根, 在稀插处理下形成原基根。不同的扦插密度造成了落基山圆柏微域环境的显著差异, 但同一密度下不同基质种类对微域环境因子的调控作用有限。密插处理下插穗的微域环境相对湿度较高(最高可达83.5%), 温度较低, 光合有效辐射较小。这些环境因子的差异导致密插处理下插穗的净光合速率(P_n)较高, 蒸腾速率(T_r)较低。在0-60天内, 密插和稀插处理的插穗的P_n均呈上升趋势, 并且二者相差的幅度随着试验时间的延长而迅速增大; 在60天以后, 二者均呈下降趋势, 相差幅度基本保持不变。密插处理下的T_r值在0-30天内基本保持不变, 而此时稀插处理下的T_r迅速增加。在30-60天内密插处理下的T_r快速增加, 60天时达到最大值, 但仍低于稀插处理。这些结果表明, 外部微域环境因子对插穗生根的影响是通过影响其内在生理指标来实现的, 插穗营养状况的差异是造成生根机制不同的主要原因。     

插穗因素对闽楠扦插苗生根、生长及相关酶活性的影响

选择40年生无病虫害闽楠植株半木质化枝条为插穗,采用L_8(2~7)正交试验方法,设置插穗来源(枝条顶部、枝条中部)、枝条长度(10cm、15cm)和留叶数(保留1片和2片全叶)3个插穗因素,研究插穗因素对闽楠扦插苗生根、生长及理化性质等方面影响,筛选适宜插穗处理方式,揭示插穗调控扦插苗生根和生长机理。结果表明:(1)闽楠插穗来源、长度及留叶数显著影响扦插苗的生根、生长及理化特性。(2)闽楠扦插最适合的插穗处理是取长度为10cm的中部枝、保留2片叶。(3)影响闽楠扦插生根率的最主要因素是插穗来源,关键生理指标是根系PPO和POD活性;影响闽楠扦插苗新梢生长最主要的因素是插穗的留叶数,关键生理指标是根系IAAO活性和MDA含量。研究表明,各插穗因素显著影响着闽楠扦插苗的生根及生长,并以长度10cm、保留2片的中部枝为插穗最佳;该研究结果为闽楠扦插繁殖技术制定和推广应用提供理论与技术指导。     

不同生长调节剂及基质对越南粉苞茉莉扦插生根的影响

为探索越南粉苞茉莉(Jasminum dichotomum)扦插生根的影响因素,建立扦插繁育技术体系,以1年生越南粉苞茉莉枝条为插穗,采用L16(44)正交试验,探讨生长调节剂种类及其浓度、处理时间、基质种类对越南粉苞茉莉茎段扦插生根的影响,利用排队评分法和公式评分法对正交试验进行分析。结果表明,A2B3C3D2为试验的最优处理组合,即将插穗在250 mg·L-1 IBA和500 mg·L-1 NAA混合药剂中浸泡20 min后扦插于沙子上。     

3种植物生长调节剂对树头菜扦插生根的影响

利用植物生长调节剂不同种类及质量浓度处理树头菜插穗,了解其扦插生根机制并筛选出适宜扦插繁殖的生长调节剂及浓度配比,为其扩大繁殖和生产提供科学依据。以树头菜一年生枝条为材料,采用3种植物生长调节剂（IAA、NAA、ABT-1）的3种不同质量浓度进行正交试验,清水处理（CK）作为对照,扦插3个月后对其芽生长量及生根性状（生根率、生根量、最长根长、平均根长等）进行测定并综合分析。本次试验筛选出的树头菜扦插最优方案为A1B2C2,即ABT-1质量浓度为50 mg·L^-1、NAA质量浓度为200 mg·L^-1、IAA质量浓度为200 mg·L^-1,该处理生根率（83.33%）、平均根长（24.03 mm）、最长根长（46.13 mm）、平均根数（24条）、根系效果指数（19.06）为CK的2.27、2.97、3.03、4.50、12.79倍,根系发育较好。不同植物生长调节剂在适宜的浓度下混合利用可以显著增加树头菜的生根能力,进而加快生长并提高其扦插生根率。     

生长基质和激素对麻楝嫩枝扦插生根的影响

以麻楝当年生嫩枝为试验材料,开展了扦插基质,激素种类、浓度和处理时间对麻楝嫩枝扦插生根影响的研究。基质试验采用泥炭土、黄心土、河沙、蛭石为扦插基质,完全随机区组试验设计;激素试验采用激素种类（NAA、IBA、ABT1）、浓度（500、1 000、1 500 mg·L^-1）及处理时间（10 s、1 min、30 min）3因素3水平正交（L₉（3³））试验设计。结果表明：（1）泥炭土+蛭石（1：1,体积比）为最佳组合基质,其生根率达81.81%,平均生根数量为20.33条,平均根长为4.80 cm,根系效果指数达3.05;（2）激素种类对麻楝嫩枝扦插生根效果影响最大,激素浓度次之,处理时间影响最小。扦插时,采用泥炭土+蛭石（1：1）混合基质、1 000 mg·L^-1浓度的ABT1号生根粉溶液、浸泡插穗10 s的生根效果最佳。     

半枫荷扦插育苗技术

采用正交试验设计,探讨植物生长调节剂种类、浓度、处理时间以及扦插基质、插条剪制方式与木质化程度对半枫荷Semiliquidambar cathayesis扦插生根率、根系数及苗高的影响。结果表明,插条采用200 mg·L-1 ABT1生根剂浸泡30 min后扦插于基质A(一层2 cm河沙,上覆一层2 cm黄泥土)中,生根率最高(90.3%),且插条平均根系数及苗高均最佳。影响插条上述生长指标的主次因素为基质种类＞生长调节剂种类＞生长调节剂浓度＞处理时间。不同插条处理中,以截取6 cm长半木质化嫩枝进行双削面处理的生根率最高,且根系数及苗高生长指标亦最佳。     

野生何首乌茎蔓切段根芽生长影响因素研究

以野生何首乌茎蔓为材料,研究生根促进剂种类及浓度、插穗茎节数、扦插时间、扦插基质等对其切段生根及芽生长的影响.结果表明:在不同插穗茎节数处理中,以含有三个叶节的插穗成活率最高,扦插苗长势最好,含两个茎节的插穗次之,而含有一个茎节的插穗最差;不同生根促进剂种类及其浓度对扦插生根有显著或极显著影响,在九种生根试验处理中,以4×10"mg/L NAA的处理插穗生根成活率最高,4×10-4mg/L的IBA处理次之,混合药液效果最差;疏松肥沃的扦插基质有利于何首乌扦插苗生根和幼苗生长.何首乌扦插生根受温度、湿度的影响较大,在春季的3～4月扦插效果较好,生根成活率达79.8%.     

千层金嫩枝扦插繁殖技术

本研究用L_(16)(4~5)正交试验方法,研究了基质、穗条长度、植物生长调节剂及其浓度对千层金嫩枝扦插生根率的影响.结果表明,基质和生长调节物质对生根率有极显著的影响,而植物生长调节剂浓度与穗条长度对生根率有显著的影响,4个因素对干层金嫩枝大田扦插生根率影响从大到小分别是基质、生长调节物质、植物生长调节剂浓度和穗条长度.用浓度100 mg/L的NAA浸泡9 cm插穗2 h,在混和基质上扦插,平均生根率可达92%,且生根及新梢抽出时间早,侧根数量多,扦插效果最好.     

不同农林废弃物混合基质对崖柏扦插育苗的影响

为研究不同农林废弃物混合基质对崖柏扦插育苗的影响,筛选可替代草炭、成本低廉的环保型育苗基质,配制草炭+蛭石+珍珠岩(T₁)、食用菌菌渣+蛭石+珍珠岩(T₂)、炭化稻壳+蛭石+珍珠岩(T₃)、食用菌菌渣+炉渣+锯末(T₄)和炭化稻壳+食用菌菌渣+炉渣(T₅)5种混合基质,采用随机区组试验设计,综合评价不同混合基质的优劣。结果表明：T₃容重最低,其次是T₂,二者与其他混合基质差异显著;T₂的非毛管孔隙度显著大于T₁,毛管孔隙度低于T₁,总孔隙度低于T₃;T₂的全氮、全磷、全钾、碱解氮、有效磷、基质含水量和pH最高,且与其他混合基质的大多数化学指标差异显著。不同混合基质的插穗生根率和生长发育指标的隶属函数值表现为T₂>T₃>T₁>T₅     

Greenhouse propagation of Cannabis Sativa L. by vegetative cuttings

Previous work revealed significant variations in cannabinoid profiles ofCannabis sativa L. derived from a single seed source (P.1. 378939) and subjected to the same growth environment. Studies were conducted to evaluate the efficacy of propagation ofC. sativa by vegetative cuttings in order to increase uniformity of cannabinoid concentrations within a given plant population.C. sativa was successfully propagated by vegetative cuttings. However, there were both morphological and biochemical differences between seed-derived plants and their vegetative propagules. Delta-⁹-tetrahydrocannabinol concentrations were 4.1 times higher in vegetative propagules than in seed propagules. Vegetative cuttings also generally developed more profuse lateral branch growth; hence, foliage increased relative to their parent plants. Cannabinoid levels within the population of vegetative cuttings remained highly variable.     

One-Leaf Cuttings as a Model to Study Second Growth in the Potato (Solanum tuberosum) Plant

Second growth is an important physiological disorder of thepotato (Solanum tuberosum L.) plant. A model system to studysecond growth was developed using one-leaf cuttings. Photoperiod,temperature, decapitation and leaf removal treatments were carriedout on the plants from which the cuttings were taken and onthe cuttings themselves. Tuberized, one-leaf cuttings takenfrom moderately-induced plants and exposed to 35 °C afterleaf removal showed 95% second growth within 10 d after treatmentinitiation. Conditions that promoted second growth also reducedstarch and dry-matter content, even in tubers that did not developsecond growth. Cuttings, second growth, potato, Solanum tuberosum L, cv, Bintje, Solanum tuberosum L. cv., Désirée, Solanum tuberosum L. cv., Russet Burbank, tuberization, starch content, dry-matter, heat, photoperiod, decapitation, leaf removal     

Comparison of the effects of epibrassinolide and steroidal estrogens on adventitious root growth and early shoot development in mung bean cuttings

Concentrations of 24-epibrassinolide as low as 0.1 μ M consistently inhibited adventitious root formation and elongation in both hypocotyl and epicotyl cuttings from mung bean ( Phaseolus aureus L.). Similar, but less pronounced, inhibitory effects on root elongation were also observed with estrone sulphate and estradiol sulphate. With regards to root number, estrone sulphate enhanced this in both types of cutting, whereas estradiol sulphate was stimulatory in hypocotyl cuttings but inhibitory in epicotyl cuttings. Brassinolide caused a marked stimulation of epicotyl (but not hypocotyl) elongation and a swelling and splitting of the epicotyl in both types of cutting, whereas estrogens varied in their effect from inhibition of epicotyl growth to no effect. Root-applied brassinolide and estrogen sulphates brought about similar morphological abnormalities in shoots viz. epinasty and inrolling of primary leaves and delayed expansion of the first trifoliate leaf.     

Potential plant growth-promoting activity of <Emphasis Type="Italic">Serratia nematodiphila</Emphasis> NII-0928 on black pepper (<Emphasis Type="Italic">Piper nigrum</Emphasis> L.)

A potential bacterial strain designated as NII-0928 isolated from Western ghat forest soil with multiple plant growth promoting attributes, and it has been identified and characterized. Plant growth promoting traits were analyzed by determining the P-solubilization efficiency, Indole acetic acid production, HCN, siderophore production and growth in nitrogen free medium. It was able to solubilize phosphate (76.6 μg ml⁻¹), and produce indole acetic acid (58.9 μg ml⁻¹) at 28 ± 2°C. Qualitative detection of siderophore production and HCN were also observed. At 5°C it was found to express all the plant growth promotion attributes except HCN production. The ability to colonize roots is a sine qua non condition for a rhizobacteria to be considered a true plant growth-promoting rhizobacteria (PGPR). 16S rRNA gene sequencing reveals the identity of the isolate as Serratia nematodiphila with which it shares highest sequence similarity (99.4%). Seed bacterization with black pepper cuttings in greenhouse trials using Sand: Soil: FYM with three individual experimental sets with their respective control showed clearly the growth promoting activity. Hence, Serratia nematodiphila NII-0928 is a promising plant growth promoting isolate showing multiple PGPR attributes that can significantly influence black pepper cuttings. The result of this study provides a strong basis for further development of this strain as a bioinoculants to attain the desired plant growth promoting activity in black pepper growing fields.     

Impact of elevated CO<Subscript>2</Subscript> in <Emphasis Type="Italic">Casuarina equisetifolia</Emphasis> rooted stem cuttings inoculated with <Emphasis Type="Italic">Frankia</Emphasis>

Impact of different levels of elevated CO ₂ on the activity of Frankia (Nitrogen-fixing actinomycete) in Casuarina equisetifolia rooted stem cuttings has been studied to understand the relationship between C. equisetifolia, Frankia and CO₂. The stem cuttings of C. equietifolia were collected and treated with 2000 ppm of Indole Butyric Acid (IBA) for rooting. Thus vegetative propagated rooted stem cuttings of C. equisetifolia were inoculated with Frankia and placed in the Open top chambers (OTC) with elevated CO₂ facilities. These planting stocks were maintained in the OTC for 12 months under different levels of elevated CO₂ (ambient control, 600 ppm, 900 ppm). After 12 months, the nodule numbers, bio mass, growth, and photosynthesis of C. equisetifolia rooted stem cuttings inoculated with Frankia were improved under 600 ppm of CO₂. The rooted stem cuttings of C. equisetifolia inoculated with Frankia showed a higher number of nodules under 900 ppm of CO₂ and cuttings without Frankia inoculation exhibited poor growth. Tissue Nitrogen (N) content was also higher under 900 ppm of CO₂ than ambient control and 600 ppm levels. The photosynthetic rate was higher (17.8 μ mol CO₂ m^?2 s^?1) in 900 ppm of CO₂ than in 600 ppm (13.2 μ mol CO₂ m^?2 s^?1) and ambient control (8.3 μ mol CO₂ m^?2 s^?1). This study showed that Frankia can improve growth, N fixation and photosynthesis of C. equietifolia rooted stem cuttings under extreme elevated CO₂ level conditions (900 ppm).     

Effects of leaf wetting and high humidity on stomatal function in leafy cuttings and intact plants of Corylus maxima

When rooted cuttings of Corylus maxima Mill. cv. Purpurea are moved from the wet and humid conditions of the rooting environment, the leaves frequently shrivel and die. Since the newly formed adventitious root system has been shown to be functional in supplying water to the shoot, stomatal behaviour in C. maxima was investigated in relation to the failure to prevent desiccation. Stomatal conductance (g_s) in expanding leaves (L3) of cuttings increased almost 10-fold over the first 14 days in the rooting environment (fog), from 70 to 650 mmol m⁻² s⁻¹. In contrast, g_s of expanded leaves (L1) changed little and was in the region of 300 mmol m⁻² s⁻¹. Midday leaf water potential was much higher in cuttings than in leaves on the mother stock-plant (−0.5 versus −1.2 MPa) even before any roots were visible. Despite this, leaf expansion of L3 was inhibited by >50% in cuttings and stomata showed a gradual reduction in their ability to close in response to abscisic acid (ABA). To determine whether the loss of stomatal function in cuttings was due to severance or to unnaturally low vapour pressure deficit and wetting in fog, intact plants were placed alongside cuttings in the rooting environment. The intact plants displayed reductions in leaf expansion and in the ability of stomata to close in response to dark, desiccation and ABA. However, in cuttings, the additional effect of severance resulted in smaller leaves than in intact plants and more severe reduction in stomatal closure, which was associated with a 2.5-fold increase in stomatal density and distinctively rounded stomatal pores. The similarities between stomatal dysfunction in C. maxima and that observed in many species propagated in vitro are discussed, as is the possible mechanism of dysfunction.     

Rooting cuttings of<Emphasis Type="Italic"> Syringa vulgaris</Emphasis> cv. Charles Joly and<Emphasis Type="Italic"> Corylus avellana</Emphasis> cv. Aurea: the influence of stock plant pruning and shoot growth

The relationship between shoot growth and rooting was examined in two, 'difficult-to root' amenity trees, Syringa vulgaris L. cv. Charles Joly and Corylus avellana L. cv. Aurea. A range of treatments reflecting severity of pruning was imposed on field-grown stock prior to bud break. To minimise variation due to the numbers of buds that developed under different treatments, bud number was restricted to 30 per plant. Leafy cuttings were harvested at different stages of the active growth phase of each species. With Syringa, rooting decreased with later harvests, but loss of rooting potential was delayed in cuttings collected from the most severe pruning treatment. Rooting potential was associated with the extent of post-excision shoot growth on the cutting but regression analyses indicated that this relationship could not entirely explain the loss of rooting with time, nor the effects due to pruning. Similarly, in Corylus rooting was promoted by severe pruning, but the relationship between apical growth on the cutting and rooting was weaker than in Syringa, and only at the last harvest did growth play a critical role in determining rooting. Another unusual factor of the last harvest of Corylus was a bimodal distribution of roots per cutting, with very few rooted cuttings having less than five roots. This implies that, for this harvest at least, the potential of an individual cutting to root is probably not limited by the number of potential rooting sites.     

Patterns of protein synthesis in the cambial region of Scots pine shoots during reactivation

Changes in protein synthesis in cambial region cells were monitored in 1-year-old cuttings of Scots pine ( Pinus sylvestris L.) collected in November, when the cambium was dormant, and subjected to environmental conditions that promoted or inhibited cambial growth. The proteins were labelled in vivo with L-[³⁵S]-methionine and separated using 2-dimensional polyacrylamide gel electrophoresis. In budded cuttings cultured under environmental conditions favoring cambial reactivation, there was a reproducible quantitative change in 55 proteins (33 induced and 22 repressed), a less certain increase or decrease in 40 proteins, and no apparent change in about 150 proteins. Under the same conditions, 8 proteins were induced and 6 others were repressed in debudded cuttings treated apically with 1 mg indole-3-acetic acid (IAA) in 1 g lanolin, in which cambial reactivation occurred, compared with debudded cuttings treated with plain lanolin in which the cambium did not reactivate. Three of the proteins induced in the IAA-reated cuttings only appeared after cambial cell division and derivative differentiation actually began, and the same proteins were found in budded cuttings after their cambium had become reactivated. In contrast, protein expression in cuttings exposed to environmental conditions that prevented cambial reactivation was similar at the beginning and end of the experimental period. These results indicate that the cambium was in the quiescence stage of dormancy at the start of the experiment, that quiescent cambial region cells can synthesize proteins as soon as exposed to environmental conditions favoring reactivation, and that only 3 of the approximately 250 proteins detected were specifically involved in cambial growth     

Physiological responses of black willow (<Emphasis Type="Italic">Salix nigra</Emphasis>) cuttings to a range of soil moisture regimes

We quantified the physiological responses of black willow to four soil moisture regimes: no flooding (control, C), continuous flooding (CF), periodic flooding (PF), and periodic drought (PD). Stomatal limitation was one of the factors that led to the reduced photosynthetic capacity in CF cuttings. Under PD, stomatal closure, decreased leaf chlorophyll content, and increased dark fluorescence yield contributed to photosynthetic decline. CF cuttings accumulated the lowest shoot biomass while the final height and root growth were most adversely affected by PD. PF cuttings tended to allocate more photoassimilates to root growth than to shoots.