苹果组织培养中的玻璃苗问题（简报）

苹果茎尖接种在NH_4~+和NO_3~-浓度比不同的培养基上,第二代均出现玻璃苗。在浓度比较低的培养基上,绿茎的玻璃苗率和病情指数较小,浓度比高的培养基上发生的玻璃苗转接到较低比值的培养基上后,玻璃苗症状减轻,并有少量转为正常苗。一定范围内降低培养基中氨态氮的比例利于防止或减轻玻璃苗发生。     

香椿的组织培养和玻璃苗的防止

１植物名称香椿（Ｔｏｏｎａｓｉｎｅｎｓｉｓ）。２材料类别（１）种子发芽３～５ｄ后的下胚轴及带少许下胚轴的子叶;（２）当年生半木质化的腋芽茎段。３培养条件芽诱导及增殖培养,以ＭＳ为基本培养基,蔗糖３０ｇ·Ｌ~（－１）,琼脂０．５％,附加激素（单位ｍｇ·Ｌ~（－１））：（１）６－ＢＡ０．２;（２）６－ＢＡ０．２、ＧＡ_３２．０;（３）ＩＡＡ０．１、６ＢＡ０．２;（４）ＺＴ０．２、ＧＡ_３２．０。诱导生根培养基为１／ＺＭＳ或仅含ＭＳ有机质（铁盐减半）,附加１．０ｍｇ·Ｌ~（－１）ＩＢＡ、１５ｇ·Ｌ~（－１）…     

麝香石竹玻璃苗与正常苗的生理特性差异

诱导麝香石竹茎段外植体产生不定芽的分化,所得到的正常苗与玻璃苗的生理特性明显有差异。表现在玻璃苗的鲜重、干重、粗纤维和叶绿素含量与正常苗相比显著降低;玻璃苗的可溶性糖含量增加38％,而蔗糖含量下降63%,束缚水含量显著增高,自由水含量明显降低;玻璃苗的淀粉酶总活性也明显升高,碱性和中性区过氧化物酶同工酶活性显著提高而酸性区的同工酶活性有所下降。然而,玻璃苗和正常苗形成时的芽分化频率以及伸长生长量之间无明显区别。结果表明,麝香石竹试管苗的玻璃化可能是在碳水化合物代谢、氮代谢和水分存在状况等发生生理异常的情况下在芽分化启动后的生长过程中发生的,而不是在芽分化启动时已经决定的。     

秋水仙素结合组织培养技术诱导大葱多倍体的研究

该文研究了秋水仙素不同浓度不同时间处理大葱愈伤组织的诱导效果,发现随着处理时间和浓度的增加,愈伤组织死亡率增加,多倍体细胞诱导率在一定范围内随处理时间和浓度增加升高,但浓度超过一定量诱导率则相反,以0.06%的秋水仙素处理72h多倍体细胞诱导率最佳,且不对愈伤组织产生严重伤害,获得的变异材料与正常二倍体相比,其叶片变粗,生长迟缓,气孔器变大,经鉴定为多倍体。     

棉花组织培养中异常苗的发生与转化

研究了棉花 (Gossypium hirsutum L.)组织培养中异常苗发生的类型、规律、影响因素及转化为正常苗的途径及技术。结果表明 ,在棉花组织培养中异常苗发生的频率极高 ,且形式多样 ,大体可分为生长点异常苗、叶片异常苗、胚轴异常苗、联体苗、丛生叶苗、单叶苗、玻璃化苗、白化苗、褐化苗和重新愈伤化苗等 1 0类。其中生长点异常苗和叶片异常苗最为常见。影响异常苗形成的因素很多 ,其中主要有外植体种类、培养基组成、培养方式和培养时间。有的异常苗来源于畸形胚 ,有的异常苗由正常苗转化而来。在合适的条件下异常苗可转化为正常苗 ,但不同培养基对异常苗转化为正常苗的影响不同 ,且不同基因型的异常苗转化为正常苗的能力也有差别。此外 ,从外界调控机制与棉花培养细胞的内在发育机制的相互作用方面讨论了造成棉花组织培养异常苗发生的原因 ;并讨论了降低异常苗产生频率的技术途径和异常苗存在对棉花组织培养的影响     

翅果油树脱毒试管苗的组织培养技术研究

对翅果油树的无菌苗培养、愈伤组织诱导、继代愈伤组织诱导和生根诱导、褐化现象及预防等进行了研究。结果表明：种子无菌培养的最佳培养基为1／2MS;继代愈伤组织诱导的最佳培养基为N2(MS BA0．5 NAA0．02)、N4(MS BA0．5 NAA0.04);植物激素类型及浓度配比是生根诱导的关键,NAA、GA、IBA为必需激素类型;用多种途径避免和预防了实验过程中的褐化现象,降低了褐化率;建立了翅果油树组织培养高效再生植株的实验体系。     

红龙果的组织培养和嫁接成苗

1　植物名称　红龙果 (Ｈｙｌｏｃｅｒｅｕｓｕｎｄａｔｕｓ)。2　材料类别　嫩茎节。3　培养条件　 (1 )芽诱导培养基 :ＭＳ 6 ＢＡ 5ｍｇ·Ｌ- 1 (单位下同 ) ＮＡＡ 0 2 ;(2 )生根培养基 :1 /2ＭＳ ＩＢＡ 2 1 %活性炭。以上培养基均含 3 %蔗糖、0 5 1 %卡拉胶 ,ｐＨ 5 8,培养温度 (2 5± 2 )℃ ,光照1 2ｈ·ｄ- 1 ,光照度 2 0 0 0ｌｘ。4　生长与分化情况4.1　无菌材料的获得　将红龙果嫩茎节用棉花蘸少许肥皂水刷洗 ,在流水下冲洗干净 ,无菌条件下切成数段 (每段 3～ 4ｃｍ长 ) ,用 70 %的酒精消毒 3 0ｓ,再用 0 1 %升汞溶液消…     

组织培养中畸形胚状体及超度含水态苗的研究

畸形胚状和超度含水态苗是组织培养中常见的2种形态、生理异常现象,由于其难以发育成苗或很难移栽成活而严重影响组织培养的成功率。概述了这2种畸形现象的的形态特征及防止方法等,并讨论了应进一步研究的问题。     

新疆香梨脱毒苗的组织培养快速繁殖技术研究

香梨(PyrussinkiangensisYü)是新疆重要的经济果树,其试管苗微繁与一般梨属植物一样,容易玻璃化,生根率及移栽成活率均较低,亟待解决(赵剑和杨文杰1998;王革献等2003;Kadota和Niimi2003)。为此,本文就此问题作了一些探讨。培养基中以单位植株诱导形成侧芽的个数计算;展叶数以试管苗叶片完全展开、扁平为标志。得到如下结果:1.增殖方式1主要是通过提高腋芽的分化个数来增殖的,增殖效率较高,但玻璃化严重,以带侧芽茎段培养时的腋芽分化,虽然增殖效率相对较低,但玻璃苗率为0,茎尖枯死也不多,且试管苗展叶良好,即在保证一定增殖效率的情况下…     

矮牵牛组织培养及变异苗的RAPD分析

探索了矮牵牛组织培养的配方,对组培过程中产生的表型变异植株进行了DNA水平的分析。并对矮牵牛叶片组织培养及产生变异的影响因素等进行探讨。     

Construction of SSR-based chromosome map in bunching onion (Allium fistulosum)

We have constructed a linkage map of bunching onion (Allium fistulosum L., 2n = 16) using an F(2) population of 225 plants. The map consists of 17 linkage groups with 212 bunching onion SSR markers and 42 bulb onion (A. cepa L.) SSR, InDel, CAPS or dCAPS markers, covering 2,069 cM. This is the first report of a linkage map mainly based on SSR markers in the genus Allium. With the 103 anchor markers [81 bunching onion SSRs, 11 bulb onion SSRs and 11 bulb onion non-SSRs (1 InDel, 9 CAPSs and 1 dCAPS)] whose chromosome assignments were identified in A. cepa and/or A. fistulosum, via the use of several kinds of Allium alien addition lines, 16 of the 17 linkage groups were connected to the 8 basic chromosomes of A. cepa.     

QTL analysis for pseudostem pungency in bunching onion (Allium fistulosum)

Low pungency is one of the most important agronomic traits in bunching onion (Allium fistulosum L.). Although the degree of pungency can be evaluated indirectly using a colorimetric test for pyruvic acid, DNA markers linked to low-pungency quantitative trait loci (QTLs) are still desired. In this study, we evaluated pungency in the bunching onion pseudostem through six trials conducted over 3?years using an F _2:3 population. QTL analysis based on the genetic linkage map revealed that the major pungency QTL was located within a 24.2-cM interval on Chr. 2a. The low-pungency parent-derived allele at AFAT04B03, a simple sequence repeat locus linked to the pungency QTL, was rare among commercial bunching onion cultivars. In addition, individuals homozygous for the low-pungency parent-derived allele at AFAT04B03 were significantly less pungent than those that were homozygous or heterozygous. Thus, these findings suggest that AFAT04B03 is an effective selection marker for low pungency in bunching onion breeding.     

Studies on the uptake of trivalent and hexavelent chromium by onion (Allium cepa)

Abstract

Experiments were conducted to examine the uptake and translocation of root-absorbed trivalent and hexavalent state of chromium in the onion plant (Allium cepa) grown in soil and sand culture. Chromium content in plant tissues increased with increasing amount of added chromium. Distribution of chromium in the plant in general, found to be in the order: root>>bulb>shoot. Higher uptake in the plants grown in sand from both the sources of chromium was observed as compared with the corresponding values for soil culture. Morphological and growth effects of the treatments of different oxidation state of chromium indicated that higher doses of Cr(VI) [150 and 300 μg mL^?1] were more toxic to the onion plants compared to equivalent doses of Cr(III).     

Long-term multiplication of onion (Allium cepa L.) by cyclic shoot regeneration in vitro

We succeeded in cultivating onion plants in vitro with a high potential for shoot regeneration. The apex must be destroyed or injured to obtain axillary buds. This capacity was restricted to the abaxial base of the youngest sheaths. It was shown necessary to restore plant individuality before further proliferation; this process constituted one cycle. For successive regeneration each cycle was composed of three steps: shoot proliferation in the presence of a cytokinin, shoot individualization and plant development in the absence of growth regulators. Effect of growth regulators on the physiological status of onion plants cultured in vitro is discussed.Abbreviations BA 6-benzyladenine - NAA naphthaleneacetic acid     

Alterations in leaf photosynthetic electron transport in Welsh onion (Allium fistulosum L.) under different light intensity and soil water conditions

• Welsh onions (Allium fistulosum L.) are often affected by stressful environments, such as high light and drought, during summer cultivation, which hinders their growth.
• We used CO₂ assimilation, OJIP transient and MR curves to analyse the photosynthetic characteristics of Welsh onion.
• The results showed that single high light stress caused a decrease in the net photosynthesis rate through stomatal limitation, while the single drought treatment and the combined stress induced nonstomatal limitation. F_O and F_J increased, F_m decreased, and a distinct K‐phase was induced. High light and drought stress blocked MR transients, leading to a gradual decrease in V_PSI and V_PSII‐PSI.
• In general, photosynthesis of Welsh onion was inhibited by high light and drought, which destroyed the receptor and donor side of PSII and reduced electron transport capacity of PSII and PSI.

     

Isolation of allicepin, a novel antifungal peptide from onion (Allium cepa) bulbs.

From the bulbs of the onion Allium cepa, a novel antifungal peptide distinct from the antimicrobial peptide previously reported from onion seeds was isolated. The antifungal peptide, designated allicepin, was purified with a procedure that involved aqueous extraction, ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel and FPLC-gel filtration on Superdex 75. Allicepin was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel. The molecular weight of allicepin was estimated to be 10 K by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration on Superdex 75. Allicepin exerted an inhibitory activity on mycelial growth in several fungal species including Botrytis cinerea, Fusarium oxysporum, Mycosphaerella arachidicola and Physalospora piricola.     

In vitro shoot proliferation and plant regeneration from kurrat (Allium ampeloprasum var. kurrat) seedlings

Shoots were produced from kurrat seedling and mature plant explants cultured in Murashige and Skoog medium (MS) alone or supplemented with 4.4 M benzyladenine (BA). Shoots were also produced from explants through a two-step procedure. Regenerated shoots were induced to form roots on MS medium with 5 g I^-1 activated charcoal. Plants were successfully established in soil.Abbreviations AC activated charcoal - BA benzyladenine - MS Murashige & Skoog's (1962) medium - 2,4-d 2,4-dichlorophenoxyacetic acid