Induction of hairy roots by Agrobacterium rhizogenes in relation to L-theanine production in Camellia sinensis

Summary

Theanine is a functional compound synthesised in roots of Camellia spp., especially tea (C. sinensis). Hairy roots were induced by two strains of Agrobacterium rhizogenes (15834 and LBA9402). The amino acid, catechin and caffeine compositions of hairy roots were determined by HPLC and compared with roots grown from tea seed. The results showed that the most suitable conditions to induce hairy roots were to use stem segments cut from 70 d-old plantlets, co-cultivated on YMB (yeast, mannitol broth) medium for 2 d, then induced on MS (Murashige and Skoog) medium for 4 weeks. Induced roots grown on LG₀ medium had 23.12 mg theanine g^–1 fresh weight, which was 23% higher than in roots grown from tea seed. Low concentrations of catechin, caffeine and epicatechin were detected in both root samples. Polymerase chain reaction (PCR) confirmed that the genes rol A, rol B and rol C of A. rhizogenes had been transferred into the DNA of the hairy root cells. The integrated genes for plant hormone synthesis from A. rhizogenes could increase hormone levels in the induced hairy roots, which in turn stimulated root growth and theanine synthesis. Hairy roots with higher concentrations of theanine, and lower levels of catechins and caffeine, are considered to be a good source for extracting L-theanine which is used as an active ingredient in food and medicine.     

利用发根农杆菌诱导毛状根的研究进展

对发根农杆菌进行了简单的介绍,重点综述了利用发根农杆菌产生发根的影响因素以及检测方法及应用情况.     

苹果矮化砧木小金海棠嫩枝扦插研究初报

小金海棠是一种优良的苹果矮化砧木,以其实生苗新梢为材料,进行嫩枝扦插试验,通过自动弥雾,遮阳网控制育苗大棚的湿度及温度,取得了较好的效果。嫩枝扦插30天后,生根率为31％,100天后,生根率达到60％,扦插苗根系发育良好。     

IBA和发根农杆菌对糠椴嫩枝扦插的影响

 研究了IBA和发根农杆菌处理对糠椴嫩枝扦插生根的影响, 并对其影响生根的机理进行了初步探讨。结果表明: IBA和发根农杆菌处理显著( P < 0.01) 提高了插条生根率, 增加了成活苗的生根数和根长, 明显缩短了生根时间。IBA和发根农杆菌处理还显著( P < 0.01) 提高了插条生根期内源GA₃和IAA、可溶性总糖和全氮的含量及IAA /ABA比值, 降低了ABA含量, 对糠椴嫩枝扦插生根有明显的促进作用, 其中以500 mg·kg^-1 IBA +发根农杆菌处理的生根效果最好, 插条的生根率、成活苗的生根数、成活苗的根长分别比对照增加了122.08%、65.75%和23.63% , 生根时间比对照缩短了14 d。     

桃砧木筑波4号和筑波5号抗根癌病鉴定评价

以当年实生筑波4号(Prunus persica‘tsukuba-4’)和筑波5号(Prunus persica‘tsuku-ba-5’)的新梢为材料,采用人工接种发根土壤杆菌(Agrobacterium rhizogenes)的方法研究了其对根癌病的抗性及其分离情况。结果表明,筑波4号实生群体中免疫、高度抗病、中度抗病、中度感病和高度感病类型分别占0.90%、1.80%、9.01%、18.92%和69.37%。筑波5号实生群体中免疫、高度抗病、中度抗病、中度感病和高度感病类型分别占1.01%、3.03%、8.08%、38.38%和49.49%。筑波4号和筑波5号对发根土壤杆菌的抗性存在显著分离现象,可从中筛选出抗性极强的植株。     

Water transport through the roots of ornamental shrub cuttings

Summary

The use of leafy cuttings to propagate ornamental shrubs such as Corylus maxima cv. Purpurea is often hampered by “weaning” problems. These arise when the rooted cuttings are removed from the supportive environment designed to promote rooting and are transferred to a more natural, but relatively stressful, environment. The shrivelling of leaves which ensues points to some failure of normal plant water relations, which may be caused either by excessive water loss from the leaves, or an inadequate water supply from the roots, or a combination of these factors. To understand this problem more fully, the root hydraulic conductance of C. maxima cv. Purpurea cuttings was investigated, and compared with that of Weigela florida cv. Variegata, a shrub which does not exhibit weaning problems. The root hydraulic conductance for both species increased with the size of the root system, and root fresh weight was shown to provide a useful basis for relative measurements of root conductance. On this basis, cuttings of W. florida exhibited a higher root hydraulic conductance than comparable C. maxima cuttings (1.5 × 10^?4 and 9.7 × 10^?5 g s^?1 MPa^?1 g_root^?1 respectively), but the difference was not sufficiently large to account for the differences in weaning of these two species. It is suggested that the adventitious root system of C. maxima is functioning normally, but that it cannot supply enough water to balance uncontrolled water loss from the leaves.     

苹果枣单芽嫩枝扦插速繁技术

5月中下旬至8月上旬，将苹果枣的半木质化，粗3mm以上的嫩枝单芽插条，用吲哚丁酸1000mg/L稀释液速蘸10－30秒，扦插于温室内蛭石和珍珠岩混合基质中，温度控制在35℃以下，适当调控喷水时间，插后35天生根率达84．4％，平均生根3．8条。共4扦插50266株，生根并移栽成活41130株，移栽成活率达81．87％。     

IBA、ABT1和发根农杆菌对大叶金叶椴嫩枝扦插生根的影响

以大叶金叶椴为试材,研究了IBA、ABT1和发根农杆菌对其嫩枝扦插生根的影响。结果表明:IBA、ABT1和发根农杆菌处理后,插条生根率、平均生根数、平均根长显著提高(P0.01),生根时间缩短。IBA、ABT1和发根农杆菌处理后,插条生根GA3和IAA含量,IAA/ABA均比对照增加,且差异极显著(P0.01);可溶性糖和全氮含量变化一致,先上升后下降与对照无显著差异,提高了IAA/ABA比值,降低了ABA和酚的含量。其中以500mg·kg~(-1) ABT1浸泡1min,再用发根农杆菌浸泡基部30min处理的嫩枝扦插生根效果最好,生根率、平均生根数、平均根长分别比对照增加了112.36%、112.61%和64.95%,生根时间比对照缩短了8d。     

Rooting of Castanea sativa Mill,shoots: Effect of Agrobacterium rhizogenes T-DNA genes

Two Agrobacterium strains, Agrobacterium tumefaciens-ORF11 and Agrobacterium rhizogenes wild type 1855, were inoculated at the base of shoots of Castanea sativa Mill, in an attempt to improve the rooting (number and quality) of the shoots, or, later, of the cuttings. The inoculum was administered in June or in July, with or without a growth regulator mixture (indolebutyric acid, polyvinylpyrolidone, a naphthol and certain vitamins), and with or without basal etiolation. A rhizogenes 1855 was always ineffective (except for callus production); but when/1. tumefaciens-ORF\l was inoculated in June and in combination with growth regulator and etiolation, rapid and viable rhizogenesis was induced on the shoots within a month. If these rooted shoots were then air layered for four months (until October) a good root system developed that allowed the plantlets to be potted immediately (rather than in the following March after four months in a mist propagation bed, as would otherwise be the case) with high survival after potting. With this method, the clonal propagation of adult chestnut trees becomes a practical possibility.     

枣树全光照连续喷雾嫩枝扦插育苗技术

以大瓜枣品种半木质化嫩枝做插穗,进行苗床生根育苗,采用全光照连续喷雾技术,经40天左右(7月中旬至8月底)的培育,床苗生根率达100%,根数8～10条,根长3～5cm,移至大田苗圃再培育,移栽成活率95%以上.经苗圃1个年周期的培育,圃苗高度达到0.8～1.0m,根径0.8cm以上,达到建园用苗标准.此苗床育苗技术设施简单,只需人工开关水管,能高密度培育床苗,达2375株/m2 ,比传统嫁接技术培育圃苗时间缩短0.5～1年,是加快良种枣繁殖速度的好方法,值得推广.     

利用发根农杆菌体系检测西瓜CRISPR/Cas9系统的靶位点

西瓜遗传转化技术周期长,过程复杂,CRISPR/Cas9基因编辑系统又存在着一定的脱靶效应,为了保障所选择的靶位点的可行性,本研究选择西瓜ClSPO11-1基因(ID:Cla003301)为靶标,利用CRISPR/Cas9基因编辑系统构建双靶点的基因敲除载体,利用发根农杆菌Ar. Qual菌株侵染西瓜子叶外植体,通过简单的组培过程,使西瓜外植体长出不定根,在不定根中检测到了在靶位点1处发生了不同程度的碱基缺失,经过与野生型氨基酸序列比对分析后发现均造成了翻译提前终止和氨基酸的突变,成功实现了对西瓜不定根的基因编辑,该方法周期短,操作简便,实现了快速鉴定在西瓜中选择的靶位点的靶向效率,为研究西瓜基因功能和遗传改良提供了保障。     

Clonal propagation in the genus Ulmus: Improvement of rooting ability by Agrobacterium rhizogenes T-DNA genes

Summary

Elm clones may be propagated by grafting, but graft incompatibility is a major problem. Rooting by cuttings does not always give satisfactory results. Shoots of elm clones resistant to Dutch Elm Disease (caused by Ophiostoma ulmi Buism.) and with poor rooting ability, were air layered after one of the following five treatments: application of growth regulator mixture; inoculation with Agrobacterium rhizogenes wild type 1855 (A.r. 1855) or Agrobacterium tumefaciens-ORF11 (A.t. ORF11); application of growth regulator mixture and inoculation with A.r. 1855 or A.t. ORF11. Shoots treated only with growth regulators exhibited low percentage of rooting; shoots inoculated with only Agrobacterium strains produced very low percentage of rooting; shoots treated with growth regulator and inoculated with Agrobacterium strains exhibited the best percentage of rooting. The results demonstrated the possibility of rooting of these recalcitrant clones, with clear advantage for the propagation of elm clones with growth regulator and A.t. ORF11.     

发根农杆菌诱导毛酸浆毛状根条件的优化

以4种发根农杆菌A4、C58C1、R1601、ATCC15834为诱导菌株侵染毛酸浆叶片、茎段,研究了发根农杆菌种类、外植体类型、不同预培养时间、不同侵染时间、不同共培养时间和乙酰丁香酮对毛酸浆毛状根诱导率的影响,并用PCR检测rolB基因。结果表明:4种发根农杆菌均能诱导毛酸浆外植体产生毛状根,ATCC15834的诱导率相对较高,叶片优于茎段;最佳侵染时间为6~8min;预培养和共培养时间均为2~3d时诱导率较高;乙酰丁香酮(AS)浓度为100μmol·L~(-1)有利于促进毛状根的产生,经PCR检测证明,rolB基因已整合到毛酸浆毛状根基因组中。     

金丝小枣改接冬枣后的栽培技术

冬枣大面积开发不足 1 0年 ,但发展速度特快 ,无棣县从 1 996年开始 ,经过 5年已发展到 5533ｈｍ2 。由于重栽轻管 ,普遍存在着产量低、质量差的问题 ,嫁接 3年的冬枣树产量不足 4ｋｇ。为探讨改接后的栽培技术 ,我们从 1 997年至 2 0 0 0年进行了本项试验。1　试验园基本情况1 997年春 ,在无棣县水湾镇北齐村以 3年生金丝小枣为砧树改接冬枣 ,面积 3.3ｈｍ2 。嫁接当年成活率99%。枣园株行距 3ｍ× 4ｍ ,土壤 ｐＨ值 7.0～ 7.5,在 0～ 4 0ｃｍ土层中有机质含量为 1 .31 %。当地年平均气温 1 2 .1℃ ,无霜期 2 0 5天 ,年平均降水量 598.3ｍ…     

恩施李家河白柚嫩枝扦插生根研究

以湖北恩施名优柚品种李家河白柚当年生枝条为试验材料,选择5种常用生长激素试剂不同浓度对插穗生根进行研究,结果表明:采用GGR7浓度为100mg/ml效果处理插穗生根效果最佳,根总长达241.7cm,根重达2.9g。     

黄花菜花莛剪截促芽扦插育苗试验

利用塑料大棚和露地黄花菜采摘后的花莛,采用剪段、促芽、短截3种不同扦插育苗方式,在田园土加河砂、田园土加草木灰2种基质中进行扦插育苗试验。结果表明,塑料大棚黄花菜花莛剪截促芽扦插育苗是最佳扦插育苗方式。     

冬枣研究进展

冬枣又名冻枣、雁来红、苹果枣、冰糖枣,是目前公认的鲜食优质栽培品种[1],主要分布于山东省的滨州、德州、聊城、东营和河北省的沧州、黄骅、衡水等地区.近10年来,发表的论文多为介绍性文章[2～4],研究集中在生物学特性、栽培技术、保鲜等方面,而对冬枣的起源、演变、种质资源、性状的遗传变异等方面的研究均少有报导.     

枣嫩枝扦插生根试验

以中枣1号为试材,用不同浓度的国繁2号为生根剂,研究了珍珠岩、蛭石、珍珠岩 蛭石 河沙、河沙对枣嫩枝扦插生根的影响.结果表明,用1 000 mg/L～2 000 mg/L生根剂处理插穗,然后扦插在珍珠岩 蛭石 河沙(1:1:1)混合基质中生根效果较好,平均生根数达24根以上,生根率为100 %,根长为6.2 cm以上.     

枣的引种试验初报

2004年引进鲁北冬枣、苹果枣、大雪枣和鸡蛋枣进行栽培试验.结果表明,4个枣品种在浙江西南山区均能正常生长.其中大雪枣和鸡蛋枣结果早,产量高,但果实品质欠佳,经济效益较低;而鲁北冬枣和苹果枣比大雪枣和鸡蛋枣晚1年结果,但果实品质佳,市场价位高,经济效益好,且比原产地早上市10～15天,初步认为有良好的发展前景.     

Development of an in-vitro rooting bioassay using juvenile-phase stem cuttings of Persea americana Mill.

Summary

A rooting test was developed with shoot cuttings taken from aseptically germinated avocado seed. The rooting required treatments in two steps: (1) three days in a medium containing indole-3-butyric acid (IBA) (25 mg l^?1) and (2) four to eight weeks in an auxin-free medium. Rooting was accomplished with both media containing 0.3× strength Murashige and Skoog salts, 3% sucrose, 0.4 mg l^?1 thiamine hydrochloride, 100 mg l^?1 i-inositol, and 0.8% ‘TC’ agar. The auxin-free medium also contained 1 gl^?1 activated charcoal.