Direct Adventitious Shoot Formation from Apical Shoot Explants of Euphorbia tirucalli

The induction of adventitious buds from apical shoot explants of Euphorbia tirucalli was studied. On average, 10.5 adventitious buds were efficiently induced in a ring on the segment from one apical explant on MS (Murashige and Skoog) medium supplemented with 0.5 mg l⁻¹ thidiazuron and 0.5 mg l⁻¹ benzylaminopurine. The adventitious buds could develop into adventitious shoots during subsequent cultures on hormone-free MS medium. For rooting, shoot clumps were cultured on half-strength MS medium containing 0.2 mg l⁻¹ α-naphthaleneacetic acid or indole-3-butyric acid. All the rooted plants survived establishment in soil within 2 months.     

Thidiazuron Induced Multiple Shoot Formation in Chickpea (Cicer arietinum L)

Thidiazuron (TDZ), a substituted urea with cytokinin-like activity stimulated shoot proliferation in chickpea (Cicer arietinum L). Embryonic axis with half portion of both cotyledons was more responsive explant, producing ～22 shootslexplant at 1.0 µM TDZ concentration but higher concentration of TDZ (5.0 µM) reduced both the shoot proliferation and growth. An incubation time of 12 h at 1.0 µM TDZ was sufficient for induction of multiple shoot formation.TD2 induced high frequency of shoot formation as compared to BAP and also minor salts of MS medium played an important role in increasing the number of shoots. Roots could be induced in these shoots in MS medium supplemented with 0.5 µM IBA.     

Multiple Shoot Regeneration from Immature Embryo Explants of Papaya

A simple and rapid method for multiple shoot formation in vitro from immature embryo axis explants of Carica papaya L. cvs. Honey Dew, Washington and Co2 is described. Multiple shoot regeneration was achieved by culture of the explants on modified Murashige and Skoog (MS) medium supplemented either with thidiazuron (TDZ; 0.45–22.7 μM) or a combination of benzylaminopurine (BAP; 0.2 – 8.84 μM) and naphthalene acetic acid (NAA; 0.5 – 2.64 μM). Highest frequency of shoot regeneration occurred on medium supplemented either with 2.25 μM TDZ or a combination of BAP (4.4 μM) and NAA (0.5 μM). Composition of the basal media influenced the frequency of multiple shoot initiation. Stunted shoots regenerated at 4.5 μM and higher concentrations of TDZ. Such shoots could, however, be elongated by transfer to medium containing 5.7 μM GA₃. Rooting of the regenerated shoots was achieved in presence of indolebutyric acid (IBA; 4.92 – 19.68 μM), however, least response was in presence of 14.7 μM IBA. Rooted plants were hardened and transferred to pots. This revised version was published online in July 2006 with corrections to the Cover Date.     

Multiple Shoot Induction from Cotyledonary Node Explants of Terminalia chebula

A protocol for multiple shoot induction from cotyledonary node explants of Terminalia chebula Retz. has been developed. Germination frequency of embryos (up to 100 %) was obtained on Murashige and Skoog (MS) medium supplemented with 0.5 mg dm^–3 gibberellic acid (GA₃). Maximum number of shoots (6.4 shoots per cotyledonary node) was obtained on half-strength MS + 0.3 mg dm^–3 GA₃+ 1.0 mg dm^–3 indole-3-butyric acid (IBA) + 10.0 mg dm^–3 benzylaminopurine (BAP) after 4 weeks of culture. When the cotyledonary nodes along with the axillary shoot buds were allowed to grow in the same medium upto 19.2 shoots were obtained after 8 – 9 weeks. Best rooting (100 %, 5.5 roots per shoot) was observed when shoots were excised and transferred to half-strength MS medium containing 1.0 mg dm^–3 IBA + 1 % mannitol and 1.5 % sucrose. Survival of rooted plants in vivo was low (35 – 40 %) when they were directly transferred to soil in glasshouse. However, transfer to soil with MS nutrients and 1.0 mg dm^–3 IBA in culture room for a minimum duration of 2 weeks increased the survival percentage of plants to 100 %.     

Chlorophyll Formation in Excised Roots of Cucumber and Pea

The effects of red and blue light on the formation of chlorophyll in excised roots of cucumber and pea was investigated and compared with previously reported experiments on wheat roots. All three kinds of roots are similar in that in continuous red light no or very little chlorophyll is formed. and in blue light a considerable amount of chlorophyll is produced. Roots of cucumber and pea differ from those of wheat, in that red light is ineffective (or nearly so) even when combined with blue.     

Thidiazuron Induced Multiple Shoot Induction and Plant Regeneration from Cotyledonary Explants of Mulberry

A rapid micropropagation protocol through induced multiple shoots from the cotyledonary explant of mulberry (Morus alba L) is described. The highest number of shoots (20.3) was obtained when explants from 14-d-old embryos were cultured on Murashige and Skoog (MS) medium supplemented with 7 μM thidiazuron for 45 d. Of the three cultivars used, cv. S-36 was the best followed by cv. K-2 and S-1. The shoots were transferred to MS medium supplemented with 5 μM 6-benzylaminopurine for elongation. The elongated shoots were rooted on half strength MS medium containing 1 – 7 μM indole 3-butyric acid or 1-naphthalene acetic acid. The rooted plants were transplanted to soil with 90 % success. The emerged shoot primordia probably initiated from the pre-existing meristems since the shoot bud show definite vascular connection to the major vascular tissue. This revised version was published online in July 2006 with corrections to the Cover Date.     

从长寿花嫩叶直接诱导体细胞胚和出芽

1　植物名称　长寿花 (Kalanchoeblossfeldiana) ,又名寿星花、矮生伽蓝菜。2　材料类别　盆栽植物的嫩叶片。3　培养条件　基本培养基为MS。诱导培养基 :( 1 )MS +NAA 1 .0mg·L- 1 (单位下同 ) + 6 BA1 .0 ;( 2 )MS +NAA 1 .0 ;( 3)MS + 6 BA 1 .0。生根培养基为 :( 4 ) 1 /2MS不加任何生长调节剂。以上培养基含 2 %蔗糖、0 .6%琼脂 ,pH 5 .8。培养温度( 2 5± 2 )℃。4　生长与分化情况　嫩叶外植体经 70 %酒精消毒 1 5s和 0 .1 %升汞消毒 8min后 ,以无菌水清洗。切成 1cm× 1cm大小的切段 ,接种于诱导培养基上培养。嫩叶外植…     

从多花野牡丹和野牡丹花柄直接诱导出芽

1植物名称多花野牡丹(Melastoma affine)和野牡丹(M.candidum). 2材料类别野外生长并处于开花期的花柄和幼嫩叶片. 3培养条件 MS基本培养基,含2%蔗糖、0.6%琼脂,pH 5.4.诱导培养基:(1)MS NAA 1.0 mg·L-1(单位下同) 6-BA 1.0,(2)MS 6-BA 1.0,(3)MS NAA 1.0;芽的生长增殖培养基:(4)MS NAA 0.5 6-BA 3.0;生根培养基:(5)MS IBA 0.1.培养温度(27±3)℃,光照度1100lx,光照时间10 h·d-1.4生长与分化情况嫩叶外植体先以洗洁精刷洗干净后,以0.1%升汞消毒8 min,并以无菌水清洗,切成2～3段放在诱导培养基上暗培养.花柄外植体经0.1%升汞消毒10 min后,以无菌水清洗.剥去花柄表面的粗糙皮层,然后将其切成0.3 cm长的切段,接种于诱导培养基上暗培养.     

Multiple Shoot Regeneration from Young Shoots of Kenaf (Hibiscus cannabinus)

A method was developed to initiate multiple shoots from the young shoot of kenaf. Young shoots along with the cotyledons were excised from ten-day old aseptically germinated seeds and pre-cultured for two weeks in Murashige and Skoog (MS) medium supplemented with benzyl adenine (BA) or a combination of BA and kinetin. After two weeks in culture, elongated shoots were excised above the cotyledonary nodes and cultured on fresh medium of the same composition. Multiple shoots were initiated within eight weeks. The number of shoots varied among cultivars. The highest number of shoots (11/explant) occured in cultivar Tainung 2 (T2) cultured in MS medium supplemented with 8.8 μM BA. Concentrations of BA higher than 8.8 μM had a negative effect on the number of shoots. Furthermore, callus growth was initiated from which morphologically abnormal shoots were induced. Kinetin had a significant effect only on cultivar Everglades 41 (E41). Shoot elongation and rooting were obtained simultaneously in half strength MS basal medium with no plant growth regulators. About 98% of the rooted plants were grown to maturity under greenhouse conditions. This method was successful with all four genotypes tested. However, significant genotypic variations were observed among the genotypes.     

Abscisic Acid in Prunus Trees: Isolation and the Effect on Growth of Excised Shoot Tissue

The abscisic acid content of the mature shoot tissue of vigorous Prunus avium, medium sized Prunus cerasus and dwarfing Prunus cerasus self (S) was estimated by spectropolarimetry and gas chromatography. There is no correlation between the levels of ABA found in the tissue and the dwarfing potential of the trees investigated. However, Prunus arium stem tissue shows the lowest sensitivity to ABA, whereas the explants of normal and dwarfing Prunus cerasus exhibit a stronger inhibition.     

Direct Primary Somatic Embryogenesis and Shoot Formation from Immature Leaves of Manihot esculenta

Primary somatic embryogenesis and shoot organogenesis in vitro could be directly induced from immature leaves of cassava ( Manihot esculenta Crantz) with higher concentration ( 10 to 80 mg/L) of NAA. Compared with 4 mg/L 2,4-D on the induction and regeneration system, NAA showed some advantageous characteristics, that is, NAA could direcfiy induce both primary somatic embryogenesis and shoot organogenesis, whereas 2,4-D could only induce somatic embryogenesis. NAA induced somatic embryogenesis much quicker, producing visible somatic embryos within 9 to 13 days and shoot (tips) within 10 to 14 days, than 2,4-D, which would induce visible somatic embryos after 15 days. Plant regeneration from the NAA-induced somatic embryos was as high as 48%, but was only 4.1% from that of 2,4-D. The test also showed that primary somatic embryogenesis or shoot organogenesis could be induced directly from immature leaves in 12 out of 16 cassava varieties.     

Growth Capacity of Embryo Axes Excised from Dormant and Germinating Horse Chestnut Seeds and Their Response to Exogenous Abscisic Acid

In embryo axes excised from mature horse chestnut (Aesculus hippocastanum L.) seeds, both freshly-fallen and subjected to cold stratification, the ability for growth was studied. While excised axes were kept on water at 28°C for 3 days, their fresh weight and length increased, the polypeptide composition of soluble proteins changed, the content of some heat-stable polypeptides decreased, and the capacity for protein synthesis in vivo retained. All these processes were similar to those in the axes of intact seeds during stratification until radicle protrusion. Growth of excised axes accelerated with the increasing duration of stratification. Cycloheximide (50 mg/l) and -amanitin (7 mg/l) inhibited axis growth, but an inhibitor of ABA synthesis fluridone (5 mg/l) and a natural cytokinin dihydrozeatin (10^–5 M) did not influence the growth rate. The growth capacity of axes excised from dormant and germinating horse chestnut seeds indicates the absence of dormancy in the axes of mature seeds. ABA (10^–5 M) suppressed completely the growth of axes detached from seeds experiencing cold stratification but still not germinating, although protein synthesis was not inhibited. The axes excised from the seeds after radicle emergence were insensitive to ABA and grew actively in its presence. ABA-induced growth inhibition might be related to the suppressed synthesis of minor polypeptides required for growth or to the activated synthesis of some growth-retarding proteins. The conclusion was drawn that the excised axes could be used as a model for studying the processes preceding visible germination of recalcitrant seeds.     

The Structure of an Arabinogalactan Isolated from Bamboo Shoot

It was found that azide bound to alcohol oxidase non-covalently and caused a color change from yellow to red. Alcohol oxidase was purified with a high yield from methanol-limited chemostat-grown cells of Candida boidinii S2 as an enzyme-azide complex by a simple procedure. That is, a cell-free extract was prepared from cells treated with a cationic detergent, Cation M2, and alcohol oxidase amounted to more than 80% of the soluble protein. Inactivation of the enzyme by H₂O₂ and aldehydes was decreased in the complex. The results were discussed as to the production of various aldehydes with the yeast cells.     

In Vitro Culture of Subanguina picridis in Acroptilon repens Callus,Excised Roots,and Shoot Tissues

The knapweed nematode Subanguina picridis is a foliar parasite that is of interest as a biological weed control agent of Russian knapweed. Attempts were made to culture the nematode in callus, excised roots and in shoots derived from roots of Russian knapweed. In callus tissues, the nematode developed from second-stage juvenile to adult but failed to reproduce; it developed only to the fourth stage in excised roots. However, S. picridis was successfully cultured in vitro in shoots derived from roots. The nematode induced galls on the leaves, petioles, and shoot apices and developed and reproduced inside the galls. Gibberellic acid increased the development rate of the nematode and promoted the formation of males. This is the first gnotobiotic culture of a nematode used for biological weed control.     

竹笋采后木质化与多酚氧化酶，过氧化物酶和苯丙氨酸解氨酶活性的关系（简报）

竹笋采后10d内,PPO,POD和PAL活性呈迅速上升趋势,之后缓慢下降,木质素含量在采后10d内迅速增加,随后缓慢增加,1℃和10℃之间的PPO,POD和PAL活性的差异都达显著水平（P＜0．05）,木质素含量的差异达极显著水平（P＜0．01）。     

Carbohydrate Availability and Shoot Formation in Tobacco Callus Cultures

Tobacco callus grown on a shoot-forming medium containing sorbitol or no carbon source survived, but did not produce shoots. Transfer of tissue from a sucrose medium to carbohydrate-deficient media and vice versa suggested that the growth of the tissue was a function of a total period in contact with available carbohydrate. Both starch and free sugars in the tissue were utilized during shoot initiation. Furthermore, it appeared that the continuous availability of carbohydrate was required for shoot primordium growth and/or their development into leafy vegetative shoots in dark-grown cultures.