Application of nurse culture for plant regeneration from protoplasts of Lilium japonicum thunb

Summary The regeneration of lily protoplasts isolated from suspension cells of Lilium japonicum was achieved by using the nurse culture method. The protoplasts divided only under the nurse culture application. The divided protoplasts grew into colonies and developed into visible calluses on a medium containing picloram. After the calluses were transferred to a hormone-free medium, plantlets formed from them. The highest frequency of plant regeneration was obtained on a medium containing 1 μM gibberellin 4 (GA₄). The cleaved amplified polymorphie sequences (CAPS) method was used to confirm that the regenerants were not plants that had escaped from nurse cells. We were able to transplant the plantlets to soil in pots without acclimatization, and they showed normal growth.     

Plant Regeneration of Protoplasts of Trifolium lupinaster L. from Cell Suspension Cultures

paper deals with regeneration of protoplasts in cell suspension cultures of hypocothl from Trifolium lupinaster L. on the SL2 basal medium with BA 0.1 mg/L and picloram 0.06 mg/L for 3--4 month,s. The protopiasts were isolated from suspensions cells subcultured for 3 days and were recuhured in modified liguid medium 8p. The first division of the regenerated cell occurred 3 days after being cultured in medium Bp. Small calli could be seen with naked eyes by one month. The calli when grew up to 2 mm long, were transferred in succession differentiation medium A and B for organ differentiation. The differentiated shoots formed their roots on 1/2 MS supplamented with NAA 1.0mg/L and then grew into plantlets.     

A procedure for regenerating Japonica and Indica varieties of rice from protoplasts

Fertile rice plants have been regenerated from protoplasts of two japonica rice varieties (Radon and Baldo) using a protocol initially developed for plant regeneration from protoplasts of an indica rice. Embryogenic calli were developed from immature embryos of Radon and Baldo rice on a callus induction medium, and then used to establish cell suspensions. Protoplasts were isolated from the cell suspensions, and cultured on a Millipore filter placed on a Kao/agarose medium that contained cell clusters from suspensions of IR52 or IR45. The protoplasts grew vigorously on Kao medium and developed into embryogenic calli within two to three weeks. Somatic embryo development occurred during a subsequent transfer of the calli to an LS medium for two to three weeks. The calli were then transferred to MS or N6 plant regeneration medium, and within one to three weeks, plants regenerated from 21 to 32% of the Radon calli, and 33 to 35% of the Baldo calli. Based upon these results and the previous success in regenerating an indica variety from protoplasts, this procedure has great promise for regenerating a range of rice varieties, and probably for regeneration of other monocotyledonous plants from protoplasts     

籼稻原生质体培养和植株再生

用籼稻IR52、IR8和IR45的幼花序和幼胚愈伤组织在LS培养基建立了稳定的悬浮培养物。悬浮系的建立经历三个阶段:褐变期,长根期,成熟期。建立了适合籼稻原生质体生长的Y8培养基,其植板率显著高于KPR和PCM培养基。悬浮细胞系间差异明显,只有部份系可以提供有分裂能力的原生质体或具看护活性。以上三个品种的原生质体均分裂良好,但只有IR52和IR8分化出苗,其中IR52分化率1.25%,得再生植株50余株,移至田间生长结实正常。     

In Vitro Induction of Haploid Plantlets from Unpollinated Young Ovaries of Lily and Its Embryo logical Observations

Unpollinated young ovaries of lily (Lilium davidii var. willmottiae (Wilson) Roffill) were inoculated on modified MS medium and N6 medium. Ovary cultures were incubated at 25–28℃, and illuminated with a fluorescent light of about 800–1200 Lux. Cultured ovaries gradually became thicker and longer after 10 days. The calli (about 6–12 mm in size) were produced after 40 days. The calli were then transferred to the differentiation medium. After 50 days, regeneration plantlets were formed. Embryoids were directly produced from some ovaries, which then developed into plantlets. Observation of chromosome number of regeneration plants shows: 65.71% regeneration plants are haploid plants, 34.29% are diploid. Embryological observation of ovary culture shows that haploid plants are from megaspore tetrad, while diploid plants are probably from nucellus cell.     

High growth rate and regeneration capacity of hypocotyl protoplasts in some Brassicaceae

Protoplasts isolated from 4-day-old hypocotyls of various species of Brassica (Brassica napus, B. campestris and B. oleracea ) produced callus with high efficiency in media containing casein hydrolysate and high concentrations of the auxin 2,4-D (4.5 μM). Cell division began after 24 h and 60% of the cells had divided after 48 h. In contrast, protoplasts isolated from stem and mesophyll of plants grown in vitro or in the greenhouse began to divide after a delay of 3–5 days. In these cases 40–50% of the cells had divided after 5 days as compared to 70% for hypocotyl protoplasts. To obtain a high frequency of regeneration, rapidly growing calli were transferred to media having a high cytokinin:auxin ratio as early as possible, usually 3 weeks after protoplast isolation. The average regeneration frequency for calli obtained from mesophyll protoplasts was 50%, while as many as 70% of the calli derived from hypocotyl protoplasts of B. napus regenerated plantlets on a medium containing zeatin (9.1 μM) and IAA (0.6 μM). On the same medium regeneration of Brassica oleracea was obtained. A low percentage of calli (1%) from Brassica campestris formed shoots when cultured on a combination of zeatin (4.6 μM), BA (4.4 μM) and IAA (0.6 μM).     

Regeneration Of Plantlets from Solanum nigrum L. Mesophyll Protoplasts

Using the “EA3-867” cellulase prepared in our laboratory, viable mesophyll protoplasts were isolated from Solanum nigrum L. The protoplasts grew and divided when cultivated in banging drops and thin liquid layer of NT medium, and calli formed. After transfering the calli on Dudits and MS solid medium (both supplemented with zeatin 1 mg/L, NAA 0.5 mg/L), regenerated plantlets had been obtained. The effects of different inositol amounts in NT medium on the growth of protoplasts were compared. The percentage of 1st and 2nd cell division after 5–8 days culture and the number of cell clusters increased in NT medium containing 250 mg/L inositol.     

Somatic Embryogenesis and Cytological Variation in Protoplast Culture of Levisticum officinale Koch

Protoplasts were isolated from spongy calli in a well growing state. Protoplasts were induced to undergo sustained divisions and to form colonies in the liquid C81V medium supplemented with 2,4-D and kinetin. When protoplast derived colonies were transferred onto agarsolidified medium, the spongy, white calli developed. After being subcultured on N6 medium plus 6BA and IBA, the light-yellow, granular embryogenic calli emerged on the protoplast regenerated callus surface. A large number of plantlets were obtained on MS medium with NAA and IBA via somatic embryogenesis Cytological observation on the donor calli used for protoplast isolation and plantlets regenerated from protoplasts were carried out. Remarkable variation of nucleus morphology and chromosome numbers were observed in donor calli. However, the cytological abnormalities in plantlets regenerated from protoplasts were comparatively less seen. The reason are discussed.     

Mesophyll protoplast culture of sweet potato (Ipomoea batatas L.)

Mesophyll protoplasts of sweet potato (Ipomoea batatas L.) were readilyisolated by soaking chopped leaf tissue in distilled water for 16 h prior to enzymatic digestion. Isolated mesophyll protoplasts began to divide three days after start of culture in liquid modified N₆ medium and and formed colonies after 30 days of culture. The colonies transferred to solid medium grew rapidly and differentiated into calli. Some of the calli transplanted onto regeneration medium produced roots.     

Tissue Culture of Lily Filament and Its Cytological Observations

Anthers with the filament of lily （Lilium davidii var. Willmottiae (Wilson) Roffill） were planted on modified MS medium. Filament cultures were incubated at 25℃± 1℃, and illuminated with a fluorescent light of about 800–1200 lux. Cultured filaments were initially short in length, but gradually became thicker and elongater after 20 days. After 30 days, the calli (about 2 mm in size) were produced. The calli were then transferred to the differentiation medium. After 20 days, the bulblets were developed from the calli, and the regeneration plants were formed after 40 days for tetraploid induction, plantlets were treated by aqueous solution of colchicine. A preliminary ploidy analysis of the root tip cells of these treated plants indicated that it was predominantly tetraploid (4n=48) Of 56 mitotic figures examined, 19 were tetraploid, 10 were diploid and 27 were aneuploid. The intercellular migrating chromatin substance appeared in the calli were also observed.     

甘蓝型油菜与芝麻菜体的细胞杂交

为拓宽油菜育种的基因资源库, 改良油菜品种, 以甘蓝型油菜(Brassica napus)花油3号下胚轴和芝麻菜(Eruca sativa)下胚轴为材料分离制备原生质体; 然后采用PEG-高Ca2+-高pH法进行原生质体融合, 当PEG浓度为35%, 原生质体融合密度为5×105个/mL时, 融合25 min时, 融合率可达18.2%。融合后在培养密度为1×105个/mL时, 以附加1.0 mg/L 2,4-D +0.5 mg/L 6-BA+0.5 mg/L NAA+ 200 mg/L肌醇+300 mg/L水解酪蛋白的改良的KM8p为融合体培养基, 以0.1 mol/L 蔗糖+0.2 mol/L葡萄糖+0.2 mol/L甘露醇作渗透稳定剂进行液体浅层培养, 效果较好, 愈伤组织再生率最高为6.8%。将融合体再生的小愈伤组织转移至培养基(B5无机盐+0.087 mol/L蔗糖+0.2 mg/L 2, 4-D+0.5 mg/L NAA+0.2 mg/L 6-BA+ 0.5% Agar, pH 5.8)上增殖培养, 待愈伤组织长至直径为3~5 mm时, 及时将其转至分化培养基(MS无机盐+0.087 mol/L 蔗糖+0.1 mg/L IAA+0.8 mg/L 6-BA+0.8% Agar, pH 5.8)中诱导不定芽再生, 芽分化率为35.7%。当不定芽长为2~3 cm时, 将其切下转入附加0.5 mg/L IBA+0.2 mg/L 6-BA的1/2MS生根培养基中诱导生根, 14 d左右即可形成再生植株, 生根率可达88%。同时, 以紫外线(60 μW/cm2)照射芝麻菜原生质体, 进行不对称融合, 照射2 min的获得了愈伤组织和再生植株, 照射4 min的只获得愈伤组织, 而照射5 min以上的没有获得愈伤组织, 但其愈伤组织再生、增殖及植株再生均不如对称融合。从细胞学鉴定的21块杂种愈伤组织上再生出16株杂种植株。     

欧当归原生质体培养中体细胞胚胎发生和细胞学变化

从继代培养的欧当归(Levisticum officinale Koch)愈伤组织分离的原生质体在 C81V培养基中培养,得到了较高频率的持续分裂。形成的细胞团转移到固体培养基上后,发展成了白色松软型的愈伤组织。将其转移到附加6-苄氨基嘌呤和吲哚丁酸的 N6培养基上继续培养了2—3个月后,表面出现了浅黄色、颗粒状的胚性愈伤组织。后者在附加吲嗓丁酸和萘乙酸的 MS 培养基上培养,可通过体细胞胚胎发生途径分化出大量小植株。对供体愈伤组织和原生质体再生植株进行了细胞学观察。     

Plant Regeneration from Sainfoin(Onobrychis viciaefolia)Protoplasts Derived from Cell Suspensions of Hypocotyl

The protoplasts were isolated from cell suspension cultures of hypocotyl (Onobrychis viciaefolia) cullured continuously for 3–4 months, and were cultured in modified Wguid Ⅴ- KM medium. The first division of the regenerated cell occurred after 24 h. culture. Small calli could be seen with naked eyes in 4 weeks. The calli which were propagated to 2–4 mm long in diameter in the (Ⅳ) medium were transferred onto differentiation medium and shoots appeared after 2–3 weeks. The differentiated shoots formed their roots on 1/2 MS supplamented with NAA 1.0mg/1 and grew into plantlets.     

甘蓝型油菜与芝麻菜体的细胞杂交

为拓宽油菜育种的基因资源库, 改良油菜品种, 以甘蓝型油菜(Brassica napus)花油3号下胚轴和芝麻菜(Eruca sativa)下胚轴为材料分离制备原生质体; 然后采用PEG-高Ca2+-高pH法进行原生质体融合, 当PEG浓度为35%, 原生质体融合密度为5×105个/mL时, 融合25 min时, 融合率可达18.2%。融合后在培养密度为1×105个/mL时, 以附加1.0 mg/L 2,4-D +0.5 mg/L 6-BA+0.5 mg/L NAA+ 200 mg/L肌醇+300 mg/L水解酪蛋白的改良的KM8p为融合体培养基, 以0.1 mol/L 蔗糖+0.2 mol/L葡萄糖+0.2 mol/L甘露醇作渗透稳定剂进行液体浅层培养, 效果较好, 愈伤组织再生率最高为6.8%。将融合体再生的小愈伤组织转移至培养基(B5无机盐+0.087 mol/L蔗糖+0.2 mg/L 2, 4-D+0.5 mg/L NAA+0.2 mg/L 6-BA+ 0.5% Agar, pH 5.8)上增殖培养, 待愈伤组织长至直径为3~5 mm时, 及时将其转至分化培养基(MS无机盐+0.087 mol/L 蔗糖+0.1 mg/L IAA+0.8 mg/L 6-BA+0.8% Agar, pH 5.8)中诱导不定芽再生, 芽分化率为35.7%。当不定芽长为2~3 cm时, 将其切下转入附加0.5 mg/L IBA+0.2 mg/L 6-BA的1/2MS生根培养基中诱导生根, 14 d左右即可形成再生植株, 生根率可达88%。同时, 以紫外线(60 μW/cm2)照射芝麻菜原生质体, 进行不对称融合, 照射2 min的获得了愈伤组织和再生植株, 照射4 min的只获得愈伤组织, 而照射5 min以上的没有获得愈伤组织, 但其愈伤组织再生、增殖及植株再生均不如对称融合。从细胞学鉴定的21块杂种愈伤组织上再生出16株杂种植株。     

Plant regeneration from protoplasts isolated from suspension cultures of leek (Allium ampeloprasum L.)

A procedure is described for the regeneration of plants from protoplasts of tetraploid leek (Allium ampeloprasum L.), 2n = 4x =32. Regeneration-competent protoplasts could only be obtained from an embryogenic suspension culture that was initiated with friable, embryogenic callus derived from immature embryos. The generally low plating efficiency could be increased by embedding the protoplasts in Ca-alginate, compared to culturing the protoplasts in liquid or agarose-solidified medium. A minimum plating density of 2 × 10⁵ pps/ml was required to obtain microcalli. Upon transfer of the protoplast-derived calli on agarose-solidified BDS medium, morphologically different callus types proliferated. After transfer to regeneration medium, compact or friable calli with an embryogenic appearance produced somatic embryos and plantlets at a frequency of up to 80%. Calli that had been classified as heterogeneous also regenerated shoots, but mainly via organogenesis, at a frequency of 46%. After transfer of shoots to half strength MS medium, healthy, well-rooted plants were obtained, that were successfully transferred to soil. All plants contained the tetraploid DNA level.     

Mesophyll Protoplast Culture and Plant Regeneration of Oriental Planetree (Platanus orientalis)

Large populations of mesophyll protoplasts were released from the leaves of 1.5–2 month old sterile seedlings, with a high protoplast yield (3.7× 10 6g-1FW) after protoplast purification. The purified protoplasts were cultured in a modified K8p liquid medium supplemented with 0.5 mg/L 2,4-D, 1 mg/L NAA and 0.5 mg/L BA. Higher density (1× 106/ml) in the initial culture of protoplasts is favourable to the division of cultured mesophyll protoplasts of this woody species among the densities tested. The protoplasts started to divide after 6 days of culture, and achieved 26.8% division frequency by 14 days. Sustained divisions resulted in mass production of cell colonies and small calli in 8 weeks. The calli further grew to 2–3mm on the gelrite-solidified K8 medium supplemented with 0.2 mg/L NAA aud 0.5 mg/L BA. Then, they were transferred onto the MSB proliferation medium with 0.1 mg/L NAA and 0.25 mg/L BA, where compact and cream-coloured calli were formed. Shoot formation was initiated on MSB differentiation medium coraming 0.5 mg/L IAA, 1 mg/L each of BA and ZT. It was observed that the frequency of shoot formation was about 28.7%. Whole plantlets were regenerated upon transferring 3 cm shoots to 1/2MS medium with 0.5mg/L IBA and 0.1mg/L BA, from which they were already transplanted into pots and grew well in the phytotron of Shanghai Institute of Plant Physiology.     

Regeneration of whole plants from protoplasts isolated from tissue-cultured shoot primordia of garlic (Allium sativum L.)

Protoplasts derived from tissue-cultured shoot primordia of garlic (Allium sativum L.) initiated successive cell divisions within 4 days and formed small individual calli (0.2mm in diameter) after 5 weeks of culture on Gamborg's B5 medium supplemented with 0.1% casein hydrolysate, 1mg/1 1-naphthaleneacetic acid and 1mg/1 6-benzylaminopurine. Plating efficiency was roughly 5% at the density of 1x10⁴ protoplasts/ml of medium. Adventitious buds developed from the calli during subsequent subculture on Gamborg's B5 medium supplemented with 40mg/l adenine and 10% coconut milk. When transferred to the same medium without supplements, these buds grew into shoots and rooted. The regenerated garlic plantlets were successfully transferred to the greenhouse and grew into whole plants.     

Somatic embryogenesis and plant regeneration from immature seed-derived calli of rugosa rose (Rosa rugosa Thunb.)

A procedure for plant regeneration from immature seed-derived calli of rugosa rose (Rosa rugosa Thunb.) via somatic embryogenesis is described. Embryogenic calli were initiated from immature seeds 2–3 weeks after anthesis on Murashige and Skoog (MS) medium without growth regulators. Induced calli had a white, friable and nodular appearance with several proembryos. These calli were subcultured at 20-day intervals on MS medium containing 0.1–0.2 M galactose on which they grew rapidly; but somatic embryogenesis was inhibited. Somatic embryos were again induced from the subcultured calli after transferring to MS medium containing 0.1 M M fructose or sucrose but lacking growth regulators. After transferring these embryos (1–2 mm) to MS medium containing 0.1 M sorbitol, 3% of them germinated and grew into plantlets which showed sustained growth on the MS medium containing only 0.1 M sorbitol as the sole carbon source.     

骆驼刺发根农杆菌转化系的原生质体培养和植株再生

从发根农杆菌A4转化的荒漠植物—璐驼刺毛状根愈伤组织中分离的原生质体培养的结果表明,酶解新转代7～10d的淡黄色松软愈伤组织,可获得大量有活力的原生质体。原生质体在附加有1．5mg．L-1 2,4．D、0．2mg．L-1 6．BA、0．3m01．L-1甘露醇、2％（W/V）蔗糖和500mg·L-1水解酪蛋白的DPD培养基中进行液体浅层培养可持续分裂。培养基的最适渗透压为（450±3）mOsm·kg-1,原生质体的最适植板密度为4×10^5个．mL-1。制备原生质体的愈伤组织以低温（4℃）预处理后,原生质体的产率和分裂频率均提高,分裂频率最高可达50％。原生质体分裂形成的愈伤组织转移在附加1-2mg．L-1 6-BA（或KT）和0．2mg·L-1NAA的MS培养基上培养后,可以分化并获得再生植株。纸电泳检测表明,原生质体再生的愈伤组织和分化植株仍然含有毛状根转化系的特异产物——冠瘿碱。     

Plant Regeneration from Protoplasts of Suspension Cells of Saposhnilkovia divaricata (Turcz.) Schischk

Embryogenic calli were produced from the segments of the young roots, hypocotyls or petioles of test-tube seedlings on MS agar medium containing 1 mg/1 2,4-D. When shaken in the MS liquid medium, the calli formed cell suspension with many embryogenic cell clumps.Using the enzyme mixture: Onozuka R-10 1.5%+MacerozymeR-10 0.3%+Snailase 0.5%+CaCl2 5 mmol/l + Mannitol 0.6 mol/1 (pH=5.8), protoplasts were obtained from the cell clumps which had been subcultured for three to' seven days. When cultivated, the protoplasts grew and began to divide after four days, and formed cell clumps about l—2 mm within fifty days. Protoplast-derived calli were formed from the cell clumps on the MS agar medium with 0.5 mg/l 2,4-D. When transferred onto the MS agar medium containing 0.1 mg/1 6-BA or 0.1 mg/1 2,4-D and 0.5 mg/1 6-BA, the calli differentiated into embryoids. On the MS agar medium without phytohormone, the embryoids grew into plantlets.