17种报春苣苔属植物的组培苗移栽季节研究

探讨不同季节对报春苣苔属植物组培苗移栽成活的影响,为其今后组培苗工厂化、规模化生产提供技术支持。以17种报春苣台属植物的组培生根苗为材料,研究季节对移栽成活的影响,分析不同物种间在同一季节的移栽成活差异以及同一物种在4个不同季节的移栽成活差异。大部分种类在春季移栽具有较高的成活率;成活率最高与最低的种类为三苞报春苣苔和粗茎报春苣苔,成活率分别为100.0%、51.3%;适宜春季移栽的种类是：贵港报春苣苔、硬叶报春苣苔、永福报春苣苔、紫花报春苣苔、三苞报春苣苔、阳朔小花苣苔、褐纹报春苣苔、柳江报春苣苔、尖萼报春苣苔、大根报春苣苔。17个种类在夏季移栽具有较低的成活率;成活率最高与最低的种类为大根报春苣苔和漓江报春苣苔,成活率分别为68.7%、15.3%。在17个种类中,超过一半的种类在秋季、冬季移栽具有较高的成活率。秋季移栽成活率最高为桂海报春苣苔、那坡报春苣苔,均为100.0%,成活率最低为褐纹报春苣苔,为20.0%;适宜秋季移栽的种类是：桂海报春苣苔、粗茎报春苣苔、那坡报春苣苔。冬季移栽以冬花报春苣苔的成活率最高,为100.0%,永福报春苣苔的成活率最低,为32.7%;适宜冬季移栽的种类是：桂中报春苣苔、紫萼报春苣苔、冬花报春苣苔、漓江报春苣苔。17个种类的移栽季节以春季的最好,夏季最差,秋季和冬季介于春季和夏季之间。不同季节不同种类移栽成活率不同,不同种类其适宜移栽的季节不同,应根据季节移栽合适的种类以保证其获得较高的成活率。     

羽裂报春苣苔的组织培养研究

以羽裂报春苣苔的叶片为外植体,通过研究不同灭菌方法、不同植物生长调节剂种类和浓度对组织培养的影响,建立了羽裂报春苣苔的组织培养体系。结果表明:羽裂报春苣苔适宜的外植体灭菌方法为采用75%酒精灭菌20 s,无菌水冲洗3次;然后用0.1%升汞灭菌6 min,无菌水冲洗3次;再用0.1%升汞灭菌6 min,无菌水冲洗3次,成活率为55.40%。不定芽的诱导培养基为MS+6-BA 1.0~2.0 mg/L+NAA 0.01~0.10 mg/L,诱导率达100.00%。在适宜的增殖培养基MS+6-BA 2.0 mg/L+NAA 0.05 mg/L+活性炭0.1 g/L上,增殖系数高达8.61;在生根培养基MS+IBA 0.5 mg/L+活性炭0.1 g/L上,生根率达100.00%,生根时间为19.10 d。移栽基质为泥炭∶珍珠岩∶河沙=4∶1∶1(V∶V∶V),移栽成活率为99.60%。     

大根唇柱苣苔的组培快繁技术

以大根唇柱苣苔叶片为外植体,以MS为基本培养基,附加不同种类和浓度的激素进行组培快繁技术研究。结果表明:适宜叶片不定芽诱导的培养基是MS+6-BA 1.00 mg/L+NAA 0.05 mg/L,继代增殖培养的适宜培养基为MS+6-BA 1.50~3.00 mg/L+NAA 0.10 mg/L,适宜的生根培养基为1/2MS+IBA 0.20~0.30 mg/L,适宜的基质是泥炭∶珍珠岩=2∶1、泥炭∶细河沙=2∶1、泥炭∶园土=2∶1。     

贵港报春苣苔的叶片组培与植株再生

以贵港报春苣苔的叶片为外植体,研究不同培养基对其不定芽诱导和增殖、愈伤组织诱导与分化以及生根的影响。结果表明,外植体叶片以纵切为宜,不定芽诱导最适培养基为MS+6-BA 4.0 mg/L+IAA 1.5 mg/L,愈伤组织诱导最适培养基为MS+6-BA3.0～5.0 mg/L+2,4-D0.5～1.0 mg/L,不定芽诱导率以及愈伤组织诱导率均为100.00%;愈伤在MS+KT 1.0 mg/L+NAA 0.2 mg/L+potato 30 g/L+banana 30 g/L+apple 20 g/L+coconut juice 100 mL/L培养基上分化系数达12.64;不定芽在MS+ZT 1.0 mg/L+NAA 0.10 mg/L+potato 30 g/L+banana 30 g/L+apple 20 g/L+coconut juice 100 mL/L培养基的增殖系数为8.55;不定芽在3/4 MS+NAA 0.01～0.05 mg/L+活性炭1.0～3.0 g/L培养基上的生根率为100.00%。综上所述,叶片纵切后能通过不定芽途径以及愈伤组织途径建立贵港报春苣苔的组织培养技术体系,在该体系下不定芽增殖系数高、愈伤分化高,组培苗生根好。     

不同因素对薰衣草扦插成活的影响

为深入研究亚热带地区薰衣草无性繁殖方法,验证在南方地区建立薰衣草育苗基地的可行性,在南宁地区研究了不同基质、枝条部位、IBA浓度和处理时间对齿叶薰衣草、甜薰衣草和羽叶薰衣草扦插成活效果的影响。结果显示,甜薰衣草扦插成活效果要显著优于齿叶薰衣草和羽叶薰衣草,河沙和珍珠岩可作为薰衣草的扦插基质,枝条中部作插穗成活效果更佳,而IBA处理浓度和时间对不同薰衣草扦插成活效果的影响差异较大。综合分析表明,齿叶薰衣草最佳扦插条件为枝条中部+河沙基质+1000 mg/L的IBA处理60 s,甜薰衣草为枝条中部+珍珠岩基质+1000 mg/L的IBA处理30 s,羽叶薰衣草为枝条基部+河沙基质+500 mg/L的IBA处理15 s。本研究表明在南宁地区进行3种薰衣草的扦插育苗是可行的。     

油茶扦插育苗技术研究

扦插育苗是油茶无性繁殖中常见的技术，影响其成活的因素较多。春夏两季均可进行，但以夏插效果较好；扦插基质要求既能保湿又可透气；插穗一般要求带顶芽，同时带叶片；为提高插穗的成活率，扦插前用100ppm浓度的ABT或IBA处理。     

文心兰花梗诱导及继代增殖培养

以文心兰的花梗腋芽为试验材料。选择适宜的灭菌方式,研究不同切割方式和激素浓度对继代增殖的影响。结果表明：适合文心兰花梗腋芽的灭菌方式是：将70％酒精倒入小烧杯浸泡30s,无茵水冲洗3次,倒入0．1％升汞浸泡约10min,再用无菌水冲洗5次,然后剥去外层包叶,切成1—2cm花梗腋芽接入培养基中。在继代培养中,只切去叶片2／3的情况下,培养基MS＋6-BA2mg／LI＋NAA1mg／L为佳。从生长点纵切的方式培养基宜用MS＋6-BA2mg／L。从生长点纵切的方法比只切去叶片2／3的方式增殖倍数较高。     

南方土壤中导致大豆皱叶的因子分析

为找出南方大豆皱叶症发生的诱因,本研究从南方土壤中非生物因素和生物因素两个角度进行探索研究。利用混池法和ICP-OES技术研究正常叶混池和皱叶混池的差异元素,利用构建的皱叶残留异质系中皱叶家系材料GY＿C和正常叶家系材料GY＿N,采用单因素随机区组试验设计,研究皱叶土壤的不同土层、营养液、灰烬、叶浆,进行土壤浸泡液、土壤消毒、氮肥等处理后大豆皱叶材料皱叶症的变化。结果表明：皱叶环境土壤的表层、中层和底层土均可导致GY＿C叶片皱缩,中层土中的GY＿C叶片皱缩程度略高于表层和底层土。氮磷钾配比失衡的营养液处理GY＿C叶片未发生皱缩。ICP-OES分析皱叶混池E₁和正常叶混池E₀的31种元素后,未发现E₁/E₀比值为1.7倍以上的元素,且E₁中锰元素含量低于E₀。皱叶灰烬及土壤浸泡液处理基质后GY＿C叶片未发生皱缩。移栽试验表明,南方土壤和基质比例超过3∶1时GY＿C长出的新叶依然皱缩,而复种的盆栽中南方土壤和基质比例低于1∶8时GY＿C叶片也会发生皱缩,且随着...     

施氮和黄顶菊混植对大喇叭口期玉米DNA甲基化变异的影响

试验设置4种玉米/黄顶菊混植比例,玉米单种(A1)、玉米/黄顶菊2∶1混种(A2)、玉米/黄顶菊4∶3混种(A3)、玉米/黄顶菊1∶1混种(A4),4种施氮梯度0(CK)、175(T1)、275(T2)、375 kg/hm^2(T3),采用甲基化敏感扩增多态性(Methylation Sensitive Amplification Polymorphism,MSAP)技术,研究不同处理下玉米叶片基因组DNA甲基化的变异特征。结果表明,筛选18对引物组合对各处理玉米叶片进行扩增,不同混植比例下各获得754条MSAP条带,在A1、A2、A3和A4混植比例下,对玉米表观遗传多样性贡献率最大的引物组合分别为EmHM21、EkHM17、EdHM21和EhHM17。A1混植比例下的未甲基化条带数、超甲基化条带数和总甲基化带数与其他3种混植比例条带数相比差异显著,4种混植比例下玉米叶片基因组DNA半甲基化和全甲基化条带数差异不显著,总甲基化条带数为79~93条,占比为10.84%~12.33%。与A1混植比例下相应施氮梯度相比,混植比例达到2∶1(A2)且施氮梯度达到175 kg/hm^2时,玉米叶片的半甲基化水平、全甲基化水平和总甲基化水平产生显著性差异。     

氮肥用量与运筹比例对机插水稻产量影响效应研究

研究不同氮肥施用量与运筹比例对机插水稻武育粳3号产量影响效应。结果表明:机插水稻氮肥用量以纯氮20kg/667m2为宜,运筹比例采用基肥:分蘖肥:穗肥为1∶2∶2处理产量最高;穗肥施用应因苗制宜,基蘖肥较多、群体较大、长势较好的选择在倒3 1(促花肥与保花肥使用倒数叶龄,下同)叶龄期施用,基蘖肥较少、群体较小、长势较差的选择在倒4 2或倒5 3叶龄期施用,以提高施氮安全性和利用率。     

不同激素种类、浓度及浸泡时间对金蒲桃扦插生根的影响

以金蒲桃半木质化枝条作为插穗,以黄心土+砂（1∶1）为基质,通过正交试验针对不同激素种类、浓度以及浸泡时间等因素研究金蒲桃扦插生根的效果,从而获得最适宜金蒲桃扦插生根的处理,为其扦插繁殖提供理论基础和技术支持。结果表明:金蒲桃以皮层组织生根为主,较好的处理插穗成活率超过90%,激素浓度是影响金蒲桃扦插生根最主要的因素,其次是激素种类,浸泡时间的影响最小。极差分析结果发现,扦插生根率最适合的因素组合A₂B₂C₃（500 mg/L IBA浸泡2 min）或A₂B₃C₁（200 mg/L IBA浸泡30 min）,扦插生根数量最适合的因素组合为A₁B₁C₁（1000 mg/L NAA浸泡30 min）,扦插生根平均根长最适合的因素组合为A₃B₃C₂（200 mg/L“根太阳”生根剂浸泡10 min）,最适合扦插生根最长根长的因素组合为A₂B₁C₂（1000 mg/L IBA浸泡10 min）,最适合扦插生根效果指数的因素组合为A₁B₁C₁（1000 mg/L NAA浸泡30 min）。主成分分析联合生根效果指数指标极差分析结果表明,A₁B₁C₁（1000 mg/L NAA浸泡30 min）和A₁B₂C₂（500 mg/L NAA浸泡10 min）是适宜金蒲桃扦插较好的组合。总之,金蒲桃是一种扦插相对比较容易的植物,该研究结果可为生产中金蒲桃的扦插繁殖提供参考。     

Production, survival and nutritive value of the perennial legumes Dorycnium hirsutum and D. rectum subjected to different cutting heights

Dorycnium hirsutum and D. rectum are perennial legumes which may have potential for use as pastures for the control of groundwater recharge in southern Australia. Little is known about the quality of the forage of Dorycnium species for grazing livestock or how these species respond to cutting. The effect of cutting height on plant survival, production of dry matter (DM), the proportion of leaf, edible stem (approximately <5 mm diameter) and woody stem in the DM and the nutritive value of the edible components was investigated. Biomass above five cutting‐height treatments (uncut, ground level, 5–8 cm, 10–15 cm and 15–30 cm above ground level) was removed at 8‐week intervals from plots of D. hirsutum and D. rectum from September 2002 to July 2003. In both species, plants subjected to lower cutting height treatments produced less DM above the height of the cut than those cut at higher heights. DM production declined over time in all treatments. Plants cut to ground level failed to regrow after the second harvest in D. hirsutum and the fourth harvest in D. rectum. Thus, these Dorycnium species were susceptible to high severity defoliations at 8‐week intervals. Negligible inedible woody stem was present in regrowth of both species after 8 weeks but D. hirsutum regrowth had a higher proportion of leaf (0·72) than D. rectum (0·56). Plants left uncut accumulated a large proportion of inedible woody stem in the DM (0·69 in both species) by July 2003, particularly at the base of the plant. Edible DM from regrowth of D. hirsutum and D. rectum had crude protein (CP) concentrations of 120 and 150 g kg^?1 DM; dry matter digestibility (DMD) values of 0·45 and 0·58; organic matter digestibility (OMD) values of 0·50 and 0·64; neutral‐detergent fibre (NDF) concentrations of 370 and 290 g kg^?1 DM; and acid‐detergent fibre (ADF) concentrations of 260 and 210 g kg^?1 DM, respectively. Medicago sativa, grown under similar conditions, had higher digestibility values (0·63 DMD and 0·66 OMD) and similar CP concentrations to D. rectum (140 g kg^?1 DM), but higher concentrations of NDF and ADF (410 and 290 g kg^?1 DM). Leaf material from both Dorycnium species had a higher nutritive value than edible stems, with DMD and OMD values of leaf of D. rectum being 0·68 and 0·74 respectively. Uncut plants had a much lower nutritive value of edible DM than the regrowth from cut treatments; older material was also of a lower nutritive value. The relatively low nutritive value of even the young regrowth of Dorycnium species suggests that forage quality is a major limitation to its use. Forage of Dorycnium species could be used during periods when other sources of forage are in short supply but infrequent grazing it is likely to produce forage of a low nutritive value.     

不同激素种类及浓度对红厚壳嫩枝扦插育苗的影响

以红厚壳（Calophyllum inophyllum）1年生嫩枝为扦插材料,探讨不同浓度梯度的萘乙酸（NAA）、吲哚丁酸（IBA）及生根粉1号（ABT）对插穗抽叶特性和生根特性的影响,并运用隶属函数值法对各处理组合的扦插效果进行综合评价。结果表明：与对照处理相比,不同激素种类及浓度处理显著影响嫩枝插穗的抽叶率、新叶数量、新叶面积等抽叶特性指标,以及生根率、偏根率、不定根数量、不定根体积、侧根数量和侧根长度等生根特性指标,但对宿叶率影响不显著。不同激素处理下嫩枝插穗的抽叶率和生根率分别为21.7%~66.7%和43.3%~98.3%,而对照处理的抽叶率和生根率均为0。基于隶属函数值法综合分析,激素处理对扦插效果的促进作用依次为NAA>ABT>IBA。NAA处理插穗的抽叶率和生根率均值为62.1%和95.4%,分别比ABT处理增加47.5%和30.2%,比IBA处理增加62.0%和57.9%。综合分析,红厚壳嫩枝扦插的最佳处理组合为1000 mg/L NAA,其抽叶率为61.7%,生根率为95.0%。     

木薯器官及其混合物水浸提液对橡胶树棒孢霉落叶病病菌的化感作用

采用生长速率法探讨不同浓度木薯器官及其混合物水浸提液于不同处理天数对橡胶树棒孢霉落叶病病菌的化感作用。结果表明:(1)根、叶水浸提液表现为化感抑制效果,浓度越大,效果越明显。(2)茎水浸提液在浓度为10~100 mg/mL时无明显化感效果;浓度达1 000 mg/mL时,处理后3~7 d时表现为显著的化感促进效果。(3)根、茎、叶比例为4:2:1的混合物水浸提液在10~100 mg/mL浓度时无明显化感效果,当浓度达1 000 mg/mL时,在处理后4~6 d表现为化感抑制效果。(4)茎、叶比例为2:1的混合物水浸提液在10 mg/mL浓度时化感效果不明显;当浓度达到100 mg/mL时,处理后2 d表现为显著的化感抑制效果,处理后3~6 d化感效果不明显;浓度达到1 000 mg/mL时,处理后2~3 d无明显的化感效果,处理后4~6 d则呈现显著的化感促进效果。建议间作木薯的胶园收获木薯后,应及早将茎干移出胶园,以减少橡胶树棒孢霉落叶病的发生。      

Influence of species, cutting date and cutting interval on the fatty acid composition of grasses

Two experiments were conducted to evaluate the effects of species, cutting date and cutting interval on the concentration of fatty acids in temperate grasses. The first experiment compared eight species, harvested in late autumn and summer. Levels of individual fatty acids were distinctive for some species, with low levels of C18:1 in Dactylis glomerata L. and high levels of C18:2 in Phleum pratense L. Differences in individual fatty acids could not be used to differentiate fescues and ryegrasses. However, fatty acid profiles could be used to differentiate species when material was managed similarly (i.e. at the same cut). There were large species × cut interaction effects, showing that management factors will be as important as plant breeding in manipulating fatty acid levels. Cultivars belonging to one Lolium perenne L. gene pool were identified as having significantly higher α-linolenic acid and total fatty acids in late-season (November) material.
The second experiment compared three ryegrass species over a growing season, with three or five cuts. All species had high concentrations of fatty acids and a high proportion of α-linolenic acid during vegetative growth (late April). Fatty acid levels declined markedly in all species after this date, recovering by autumn. Kunth Lolium multiflorum Lam. and Lolium  ×  boucheanum had higher levels of total fatty acids and α-linolenic acid in the early and late season when compared with perennial ryegrass. Fatty acid levels (particularly C18:2 and C18:3) declined when the regrowth interval was extended from 20 to 38 d.
These studies demonstrate opportunities to change the composition of ruminant products through breeding and management of grasses for altered levels of fatty acids.     

Effects of extended wilting, shading and chemical additives on the fatty acids in laboratory grass silages

This work investigated the range of fatty acid concentrations in grass silages made from the regrowth of perennial ryegrass Lolium perenne using different techniques involving combinations of shading of the crop before cutting, wilting and the use of chemical additives. The effects of the different silage additives on overall fermentation were large, with many of the formic acid and formalin-treated silages having a very restricted fermentation. Nonetheless, effects on levels and proportions of fatty acids were numerically small. The major differences between silages were generated during field operations (shading and wilting), with little further changes in fatty acids within the silage clamp. The extended wilt had the most dramatic effect on fatty acids with a marked reduction in both total fatty acids (24·6 vs. 17·5 g kg⁻¹ dry matter; s.e.d. = 0·65, P  < 0·001) as well as in the proportion of total fatty acids as α-linolenic acid (C18:3 n -3; 0·55 vs. 0·48; s.e.d. = 0·013, P  < 0·01). Shading the grass with a black plastic sheet for 24 h before cutting had a similar effect.     

Effects of nitrogen fertilization and cutting intensity on the agronomic performance of warm‐season grasses

Responses of grasses to N fertilization are affected by cutting intensity although little is known regarding the interactions of these factors in warm‐season grasses. Pre‐cutting canopy height, herbage accumulation and changes in the nutritive value of warm‐season grasses in response to four different management strategies were assessed from October 2011 to September 2014. Treatments included two cutting intensities (70 vs. 50% depletion of canopy height set by 95% light interception), two N fertilization levels (zero vs. 300 kg N ha^?1 year^?1) and six perennial C₄ grass species (Axonopus catharinensis; Cynodon spp. hybrid Tifton 85; Hemarthria altissima cv. Flórida; Megathyrsus maximus cv. Aruana; Paspalum notatum cv. Pensacola; and Urochloa brizantha cv. Marandu) grown in monoculture in a factorial experimental design. Canopy height varied among grass species, cutting intensity and N treatments, mainly among seasons, indicating that more than one management target (i.e. canopy height) existed throughout the plant growth cycle for each species. The largest herbage accumulation occurred in the N fertilization treatments for most species, regardless of cutting intensity. Nitrogen fertilization and 50% depletion of canopy height increased the leaf proportion and decreased the neutral detergent fibre content. Overall, N fertilization had a stronger positive impact than cutting intensity on the acid detergent fibre content, dry‐matter digestibility and crude protein content, but the magnitudes of the responses were species‐specific.     

海滨雀稗突变体抗旱性的评价

以3个海滨雀稗(Paspalum vaginatum)品种(Sea Isle2000、Platinum、Supreme)及其经辐射诱变筛选出的7个突变体为试验材料,在干旱胁迫条件下通过测定叶片相对含水量(RWC)、叶片相对电导率(REC)、脯氨酸(Pro)含量、可溶性总糖含量(TSC)及叶片萎蔫系数等5个生理指标,综合评价其抗旱性。结果表明:干旱胁迫导致试验材料的RWC下降,叶片萎蔫系数、Pro、TSC、REC上升,但不同品种材料的变化幅度不同。突变体"PL-40-1"、"PL-40-2"、"SP-40-2"在干旱胁迫下,其RWC下降幅度显著低于对照,叶片萎蔫系数、Pro、TSC、REC的上升幅度均明显低于对照,说明突变体"PL-40-1"、"PL-40-2"、"SP-40-2"叶片的保水能力较强,抗旱性优于其亲本;而突变体"SI-50-1"、"SI-50-5"、"SI-60-6"、"PL-40-8"抗旱性不及其亲本。