胡桃楸胚性愈伤组织诱导与体细胞胚胎发生

胡桃楸是东北东部山地阔叶红松林的重要组成树种。因其被大量采伐,资源日趋枯竭。体细胞胚胎发生是快速繁殖和人工种子研制的基础,对遗传改良有重要意义。为探讨不同外植体、植物生长调节物质种类及配比对胡桃楸培养物的影响,建立了胡桃楸体胚发生及再生植株体系。结果表明:合子胚为外植体时最易形成胚性愈伤组织,外植体最佳取材时期为5～6月。胡桃楸胚性愈伤组织最适诱导为MS+1.0mg·mL-12,4-D+0.5mg·mL-16-BA;体细胞胚的诱导、发育和分化的适宜的培养基为附加蔗糖60g.L-1、水解酪蛋白700mg·mL-1时不添加任何生长调节物质的MS培养基。     

芍药花药愈伤组织诱导及体细胞胚发生

以芍药(Paeonia lactiflora)品种粉玉奴花药为外植体,研究不同浓度2,4-D对愈伤组织诱导、体胚发生及植株再生的影响,采用组织细胞学方法观察愈伤组织以及体细胞胚发育过程,采用根尖染色体法鉴定再生植株倍性。结果表明,芍药花药愈伤组织诱导的最适培养基为MS+1 mg·L–1 2,4-D+1 mg·L–1 N...     

巴西橡胶树未受精胚珠培养时愈伤组织与胚状体的起源(简报)

THEORIGINOFCALLUSANDEMBRYOIDINCULTUREDUNFERTILIZEDOVULESOFHEVEABRASILIENSISYangXiaoqua(DepartmentofFallScience,SouthChinaUniversityofTechnolop,Guangzhou510641)FuJiarui(DepartmentofBiology,ZhongshanUniversity,Guangzhou510275)迄今为止,利用未受精胚珠高体培养诱导木本植物形成单倍体植株的仅有杨树及巴西橡胶树两例[1-3],但均缺乏详细的胚胎学观察资料,胚状体的起源不甚清楚。在某些草本植物中,起源问题已有详细的研究。例如向日葵未受精胚珠离体培养时,胚状体起源于未受精的卵…     

海边香豌豆胚性愈伤组织的诱导和体细胞胚发生

将生长１４ｄ的海边香豌豆（Ｌａｔｈｙｒｕｓ ｍａｒｉｔｉｍｕｓ（Ｌ．）Ｂｉｇｅｌ）无菌苗下胚轴切成０．５ｃｍ左右的片段,置于含有１ｍｇ／Ｌ２,４－Ｄ,０．５ｍｇ／Ｌ ＢＡ和０．５％ＮａＣｌ的ＭＳ培养基中,２８ｄ后诱导出胚性愈伤组织。将其转入含有适当浓度２,４－Ｄ的ＭＳ培养基上,又２８ｄ后可得到大量球形胚和心形胚以及极少量鱼雷胚和子叶胚。诱导体细胞胚适合的２,４－Ｄ浓度为０．５ｍｇ／Ｌ。较高浓度的２     

金花茶花药愈伤组织的体细胞减数分裂

金花茶的小孢子单核期花药,经培养的继代培养６个月后的愈伤组织中,发现有少量体细胞进行减数分裂。在减数第一和第二次分裂中,同源染色体的配对和分离基本正常,最后形成四分体。该愈伤组织经石革切片和压片观察,发现其主要由大量的液化细胞和贮藏细胞所组成,此外,还有少部分分生细胞。没有发现进一步的分化。其染色体数目,２ｎ＝３０者占７１．７％,其余则为非整倍体。     

红江橙体胚发生及影响因素的研究

红江橙花后４周的幼果,直径约１ｃｍ左右,这时期的胚珠最适于胚性愈伤组织的诱导。以ＭＴ为基本培养基,加上适当浓度的ＩＡＡ、ＢＡ和ＭＥ可显著提高胚性愈伤组织诱导率。体胚发生,以ＭＴ＋ＩＡＡ０．１ｍｇ１－１＋ＢＡ（ＺＴ）１ｍｇ１－１培养基较好,能诱导产生正常体胚,且频率较高。胚性愈伤组织继代次数对体胚发生也有一定的影响,继代６次以内,胚性愈伤组织具有旺盛产生体胚能力;继代至第９次时,产生体胚的能力明显下降;至第１２代时,不能产生胚状体。成熟胚转换成小植株,以ＭＴ＋ＧＡ２ｍｇ１－１＋ＮＡＡ０．１ｍｇ１－１培养基成苗率最高。     

小麦远缘杂种幼胚胚状体的发生,发育及低温对愈伤组织分化能力…

通过普通小麦与滨麦、簇毛麦及山羊草属７个种杂交幼胚培养,获得８个体细胞胚性无性系（８个组合１０个胚）及大量试管苗。愈伤组织及胚性愈伤组织诱导率分别为６５．７９％和２６．３２％。形态学及细胞学鉴定结果,均为真杂种。不同染色体组及同一染色体组不同基因型的幼胚,在组织培养中有明显差异。非部体细胞具有遗传的全能性,但当染色体数目严重偏离双单倍体数目的,其全能性即丧失。胚状体的发育具有与合子胚极相似的典型结     

石刁柏愈伤组织形态发生能力及器官发生的研究

石刁柏愈伤组织可分为4种类型。淡绿色、紧实、块状的愈伤组织(A)为典型的器官发生型愈伤组织,根和芽分化率高;绿白色、紧实、瘤状的愈伤组织(B)形态发生能力低;淡黄色、松散、颗粒状的愈伤组织(C)为典型的胚胎发生型愈伤组织,胚状体分化率高;而黄褐色、较松散、团块状的愈伤组织(D)无形态发生能力。器官原基起源于愈伤组织中具单极性的分生细胞团。芽的发生多为外起源,亦有内起源;根的发生多为内起源,亦有外起源。     

金花茶花药愈伤组织的体细胞减数分裂

金花茶(Camellia petelotii)的小孢子单核期花药,经培养和继代培养6个月后的愈伤组织中,发现有少量体细胞进行减数分裂。在减数第一和第二次分裂中,同源染色体的配对和分离基本正常,最后形成四分体。该愈伤组织经石蜡切片和压片观察,发现其主要由大量的液化细胞和贮藏细胞所组成,此外,还有少部分分生细胞。没有发现进一步的分化。其染色体数目,2n=30者占71.7%其余则为非整倍体。     

碳氮源对花榈木胚性愈伤组织诱导、发育及有机物积累的影响

为探讨花榈木体胚发生过程中不同碳氮源处理对胚性愈伤组织诱导、发育和有机物积累的影响,并筛选出有利于花榈木体胚发生的碳氮源,优化体胚发生体系,该研究以成熟胚为外植体,通过单因素试验分析3种碳源、4种蔗糖浓度和6种氮源处理下胚性愈伤组织诱导、发育和有机物积累的差异。结果表明：(1)蔗糖中胚性愈伤组织诱导率显著高于葡萄糖和麦芽糖,但其体胚诱导率、体胚分化率、胚性愈伤组织可溶性糖、淀粉和可溶性蛋白含量差异不显著。(2)随着蔗糖浓度的升高,胚性愈伤组织、体细胞胚(体胚)诱导率、体胚分化率、胚性愈伤组织重量和可溶性蛋白含量呈先升高后降低的趋势,均以添加30 g·L^-1蔗糖最高,而胚性愈伤组织可溶性糖和淀粉含量呈增加的趋势。(3)在6种氮源处理中,胚性愈伤组织诱导率以添加500 mg·L^-1谷氨酰胺的处理最高,体胚诱导率则以添加谷氨酰胺和水解酪蛋白的处理较高,但不同氮源处理间体胚分化率无差异;添加有机氮源的处理其胚性愈伤组织可溶性蛋白含量显著高于无氮源处理。总之,不同的碳氮源通过影响花榈木胚性愈伤组织的诱导、发育和有机物的积累,从而影响其体胚诱导率,但对体...     

AgNO_3对颠茄毛状根生物碱及关键酶基因表达的影响

为了研究不同浓度AgNO_3对颠茄毛状根生长过程中托品烷类生物碱及影响其合成关键酶基因表达的影响,该研究使用五种不同浓度的AgNO_3处理黑暗培养12 d的颠茄毛状根,2 d后收集毛状根并测定其鲜、干质量、托品烷类生物碱的含量、部分生理指标(MDA、Pro、可溶性糖、可溶性蛋白)、关键酶基因(pmt、trI、h6h)表达量。结果表明:AgNO_3虽然抑制了颠茄毛状根的生长,但却促进了托品烷类生物碱的积累,与对照相比,50、100、150μmol·L~(-1)处理均显著性地提高了托品烷类生物碱的产量。同时在150μmol·L~(-1)处理下,毛状根代谢途径中MDA与对照相比均具有显著性的提高,脯氨酸含量在150μmol·L~(-1)下也有了显著性提高,达到了5.92μg·g~(-1)FM,是对照的2.91倍。可溶性糖与可溶性蛋白含量在150μmol·L~(-1)浓度下处理时其含量分别是对照的1.55倍和1.67倍。托品烷类生物碱合成过程中关键酶基因(pmt、trI、h6h)的表达量在不同浓度AgNO_3处理下均有不同程度的提高。由此可以推断,AgNO_3在150μmol·L~(-1)处理下,可能通过调控脯氨酸、可溶性蛋白、可溶性糖这几种初级代谢产物或某几种关键酶基因的表达来影响颠茄毛状根托品烷类的合成。     

Initiation of gametophytic callus and somatic embryogenesis in Laminaria japonica (Phaeophyta) exposed to mutagenic agents

Zoospores of Laminaria at the stage of zoospore germination fixed to glass slides were irradiated by γ-rays in doses of 50, 100, or 250 Gy; or treated with colchicine at a concentration of 4 × 10^?5% for 5 days. The cultivation was conducted in vessels with seawater at a temperature of 12°N and illumination of 4000 lux for one month. Once a day, from day 22 to day 30, the temperature was reduced to 0°N for 12 h. As a result, in experimental samples gametophytes appeared that did not form gametangia; these appeared by the third day of cultivation, as plaques up to 2 cm in diameter (1–2 plaques per slide). In the same culture we found structures (1–2 per slide) consisting of strictly radially arranged rows of somatic cells attached to the slides. Later, these disks transformed into cones up to 0.5 cm in diameter. We recorded the development of a single-layered sporophyte of Laminaria arising from the center of such a cone.     

Long-term somatic embryogenesis and maturation of somatic embryos in Hevea brasiliensis

A high frequency of secondary embryogenesis was induced from isolated early cotyledonary-stage somatic embryos of Hevea brasiliensis. A long-term embryogenic line was established by the use of recurrent embryogenesis and maintained for 3 years on hormone-free medium by the transfer of selected proembryogenic masses every 10 days.

The addition of 234 mM sucrose as stress with sucrose and 10⁻⁵ M abscisic acid (ABA) to the culture medium enhanced the maturation of somatic embryos. Under these culture conditions, the embryo population was composed of 45% globular, 18% oblong and 37% torpedo-stage embryos. These somatic embryos had well-formed tissue structure, a well-defined epidermis, protein storage bodies, and a high accumulation of starch. The triglyceride content was five times as high in the torpedo-stage embryos that developed on medium supplemented with 234 mM sucrose and 10⁻⁵ M ABA as in embryos obtained on basal medium with 58 mM sucrose.     

速生湿地松良种胚性愈伤组织诱导与增殖

为使速生湿地松良种快速大规模繁殖,对其胚性愈伤组织进行诱导和增殖优化研究.该文以1代湿地松种子园中10个速生湿地松优良无性系(基因型)的未成熟合子胚为外植体,系统研究基因型、合子胚发育阶段、基本培养基、植物生长调节剂种类和浓度等不同因子对胚性愈伤组织诱导效率的影响,探讨胚性愈伤组织的增殖条件.结果表明:基因型、合子胚发...     

柑橘愈伤组织生长速度与体细胞胚胎发生的关系

为了探讨柑橘愈伤组织不能再生的原因,试图寻找柑橘愈伤组织生长速度与其体细胞胚胎发生之间的关系,对7种柑橘类型的29种基因型的愈伤组织的生长速度进行了测定,并对愈伤组织生长速度与体细胞胚胎发生之间的相关性进行了统计分析。结果表明,柑橘愈伤组织生长速度与体细胞胚胎发生之间的相关系数为r=-0.3683。由此推断在这两者之间还存在其它影响因素。     

Organogenesis and somatic embryogenesis from callus cultures in Muscari armeniacum Leichtl. ex Bak.

Summary Establishment of fast-growing, highly regenerable callus cultures was examined in Muscari armeniacum Leichtl. ex Bak. in order to develop an efficient genetic transformation system. High-frequency callus formation was obtained from leaf explants of cv. Blue Pearl on media containing 2,4-dichlorophenoxyacetic acid (2,4-D), α-naphthaleneacetic acid (NAA) or 4-amino-3,5,6-trichloropicolinic acid (picloram, PIC). Fast-growing, yellowish nodular callus lines and white friable callus lines containing a few somatic embryos were established on initiation medium supplemented with 4.5 μM 2,4-D and with 54 μM NAA, respectively. The yellowish nodular calluses vigorously produced shoot buds after transfer to media containing 0.44–44 μM 6-benzyladenine (BA), whereas the white friable calluses produced numerous somatic embryos upon transfer to plant growth regulator-free (PGR-F) medium. Histological observation of shoot buds and somatic embryos indicated that the former consisted of an apparent shoot meristem and several leaf primordia, and the latter had two distinct meristematic regions, corresponding to shoot and root meristems. Both shoot buds and somatic embryos developed into complete plantlets on PGR-F medium. Regenerated plants showed no observable morphological alterations. High proliferation and regeneration ability of these calluses, were maintained for over 2 yr.     

Histology of early somatic embryogenesis inHevea brasiliensis: The importance of the timing of subculturing

Somatic embryos ofHevea brasiliensis can be obtained by culturing thin sections of inner tegument of seed on two successive different media, MH1 and MH3. Histological study showed that in calli cultured on non-renewed medium MH1 for 40 days, the embryogenesis process initiated on the 20th day did not produce results owing to early degeneration of the cells involved in the embryogenic pathway. However, typical embryogenic cells formed when medium MH1 was renewed once during the first phase of culture (between day 20 and day 30). Proembryos developed when the calli were subcultured on medium MH3 10–15 days later. Embryogenic cells did not form when there was frequent renewal of medium MH1 or early subculturing on MH3 after less than 40 days of culture on MH1. Methodical histological monitoring of the development of embryogenic quality of calli thus made it possible to define the optimum culture sequences for the embryogenesis process and which are favourable for regular obtaining of proembryos.     

Nodular somatic embryogenesis and frond regeneration in duckweed,Lemna gibba G3

Duckweed(Lemna gibba) is a useful model system for elucidating plant development, but the techniques needed for regenerating fronds from calli are not yet well established. This study examined the effects of auxin, sucrose, and gelling agents on callus and frond formation inL. gibba G3. After three weeks of culturing on a solid medium, two types of calli were observed: watery, pale-green, and undifferentiated; or white, compact calli that were organized into nodules and which resembled somatic embryogenie calli. Homogeneous callus lines were produced through selective subculture. To induce nodular calli, auxin (2,4-D) was absolutely required, with an effective concentration of 5 to 20 μM; induction was found to be possible with up to a maximum concentration of 4.4%. The calli were then maintained on a medium with a reduced 2,4-D concentration (1 μM), and were transferred every three weeks. Optimal callus induction and growth were obtained by using 3% sucrose with a combination of 0.15% Gelrite and 0.4% agar. Fronds, however, could be regenerated only on distilled water solidified with a combination of 0.4% agar and 0.15% Gelrite. On this medium, 87% of the callus expiants regenerated into fronds after four weeks of culture. These new fronds were morphologically normal but small, approximately 15 to 20% of the size of stock fronds. Continued culture of these fronds in an SH medium produced normal duckweeds, and histological examination of the cultures revealed several distinct types of callus nodules. Nonetheless, because zygotic embryogenesis inL. gibba does not produce distinct bipolar structures, the developmental pathway of frond regeneration from these nodular cultures remains unknown.