Callus induction from protocorm-like body segments and plant regeneration in Cymbidium (Orchidaceae)

Summary

Embryogenic callus induction and plant regeneration in Cymbidium Great Flower ‘Rainbow Drop’ were examined. Longitudinally bisected segments of protocorm-like bodies (PLBs) formed calli within about one month on modified Vacin and Went medium (1949) supplemented with 1-naphthaleneacetic acid (NAA) or 2,4- dichlorophenoxyacetic acid (2,4-D) alone or in combination with N-phenyl-N’-l, 2, 3-thiadiazol-5-yl urea (TDZ).The combination of 0.5 mg l^–1 NAA and 0.1 mg l^–1 TDZ was found to be the most effective for callus induction. The calli grew well when subcultured every four weeks on the same medium. The calli easily formed PLBs after being transferred to media without plant growth regulators. Healthy plantlets without any phenotypic abnormality were obtained from callus-derived PLBs.     

Rapid in vitro propagation of Dendrobium hybrids through direct shoot formation from foliar explants,and protocorm-like bodies

In vitro propagation protocol for Dendrobium hybrids Sonia 17 and 28, two highly priced commercial cut flower cultivars through direct organogenesis from in vitro derived foliar explants was established. Rapid clonal propagation was achieved by subsequent induction of protocorm-like bodies (PLBs) and its conversion to shoots. No significant differences were observed in the induction of direct shoots, shoot multiplication, PLBs formation and subsequent shoot development and rooting of shoots between the two cultivars. Leaf explants from flower stalk node derived shoots cultured on half-strength Murashige and Skoog (MS) medium supplemented with 44.4 μM N⁶-benzyladenine (BA) developed more than seven shoots per explant. The isolated shoots transferred onto the same medium induced more than eight PLBs from the base within 60 days, which upon transferral to fresh medium having the same level of BA facilitated rapid proliferation. More than 200 PLBs were yielded from fifth subculture. Half-strength MS medium containing 6.97 μM kinetin (Kn) facilitated conversion of more than 90% PLBs to shoots. PLBs exhibited proliferation without decline up to the 15th subculture. Half-strength MS medium with 2 g l⁻¹ activated charcoal was the best for in vitro rooting. Plantlets of the hybrids exhibited more than 80% ex vitro establishment.     

High frequency of protocorm like bodies (PLBs) induction and plant regeneration from protocorm and leaf sections of Aerides crispum

An efficient and reproducible method for the large-scale propagation of Aerides crispum L. using protocorm and leaf sections has been developed. Protocorm and leaf sections were cultured on Murashige and Skoog (MS) medium supplemented with cytokinins [N⁶-benzyl adenine (BA), thidiazuron (TDZ), and kinetin (KN), 0.5, 1.0, 2.0 and 5.0 μM], auxins [α-naphthaleneacetic acid (NAA), indole-3-acetic acid (IAA), 0.5, 1.0, 2.0 and 5.0 μM] and coconut liquid endosperm (CW: 5, 10 and 15%). The explants developed protocorm like bodies (PLBs) within 5–8 weeks on the growth medium. BA supplemented medium was found best for the induction of PLBs and an optimum of 49.1 and 22.0 PLBs developed from protocorm and leaf sections on medium supplemented with 1 and 2 μM BA, respectively. Upon subculture on basal MS medium, the PLBs differentiated plantlets within 6–8 weeks. The resulting plantlets were successfully transferred to potting mixture and 85% of plantlets survived after green house transplantation. This simple protocol will be useful for large-scale propagation of A. crispum L.     

Production of protocorm-like bodies with bioreactor and regeneration in vitro of Oncidium ‘Sugar Sweet’

To produce mass propagules of Oncidium ‘Sugar Sweet’, we tested the feasibility of producing protocorm-like bodies (PLBs) using 5 l balloon type air-lift bioreactors, and selected an optimal culture medium for shooting and rooting in vitro. The results showed that liquid bioreactor cultures were more efficient for PLBs proliferation when compared to solid- and liquid-agitated flask cultures. The maximum PLBs biomass (326.3 g per bioreactor, FW) was obtained in the immersion bioreactor culture, with the growth ratio reaching 10.9 after 50 days of culture. This was obviously higher than the ebb and flood bioreactor culture. During bioreactor culture, sucrose and electric conductivity (EC) in the culture medium were negatively correlated with PLBs growth; the highest PLBs fresh and dry biomass was obtained 40 days after culture. An inoculation density of 20 g (FW) was optimal for PLBs growth in a 3 l working volume of 5 l bioreactor. Furthermore, MS medium supplemented with 2.0 mg l⁻¹ BA for shooting and 0.5 mg l⁻¹ IBA for rooting was optimal during in vitro culture, the plantlets were successfully established in the potting substrate.     

蕙兰CfAOC基因的克隆及表达分析

以野生蕙兰为试材,利用分子手段解析CfAOC(allene oxide cyclase,丙二烯氧化物环化酶)在蕙兰花香合成途径中的作用,同时为揭示蕙兰花香合成的分子机制提供理论依据。结果表明:分别以蕙兰基因组DNA和cDNA为模板PCR扩增出CfAOC基因的全长序列和CDS序列,比较发现CfAOC基因由3个外显子和2个内含子构成,亚细胞定位预测该蛋白位于叶绿体中,氨基酸序列分析显示该基因编码的蛋白含有保守的丙二烯氧化物环化酶结构域,进化树结果也表明CfAOC与其它植物的AOC同源性较高,都参与茉莉酸及其衍生物的合成代谢。CfAOC基因的时空特异性表达分析发现该基因在蕙兰盛花期时的花中表达量最高,暗示该基因可能与蕙兰花香合成有关。     

PP333对墨兰生长发育和叶片结构的影响

以不同浓度ＰＰ３３３溶液喷施墨兰２－４次，１０００ｍｇ／ｋｇＰＰ３３３处理可使墨兰叶片短、宽且厚、叶色浓绿，有光泽，叶较挺直，新芽多，单株花数多，从而改善观花赏叶价值。     

黄瓜在贮藏期间生理生化特性变化分析

为了探讨不同耐贮性黄瓜在室温贮藏条件下各项指标的变化特点,以耐贮黄瓜品种宁运3号和不耐贮黄瓜品种南抗1号为试验材料,于采后3、5、7、10、13 d,分别对其果实硬度、失重率、皮色指数、丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性和呼吸速率等指标进行了测定。结果发现,从采后3 d至采后13 d:(1)宁运3号果实硬度仅下降了15.73%,南抗1号降幅达32.74%;(2)宁运3号失重率增加到2.49%,而南抗1号增加至6.17%;(3)宁运3号MDA含量提高了80.15%,南抗1号提高了102.88%;(4)贮藏1周后,宁运3号的SOD活性仍比南抗1号高出84.20%,而呼吸速率却低38.29%。随着贮藏时间的延长,大部分生理生化指标两者间差异显著。     

温度对芋贮藏效果的影响

芋 (ColocasiaesculentaSchott.)为原产于热带、亚热带的球茎类作物 ,以膨大的球茎为食用器官 ,富含淀粉。芋的耐贮性好 ,收获后可贮藏到翌春 5月。芋在贮藏过程中 ,常出现失水干瘪、空心、褐变等问题 ,这些不良变化均与贮藏条件有关。笔者在不同温度下贮藏芋 ,对其内含物变化进行了分析 ,以期为芋的贮藏提供理论依据。1　材料与方法1.1　材料　采用江浙一带主栽的红梗芋和白梗芋为材料 ,这两个品种均属于子芋型。1.2　方法　红梗芋与白梗芋于 2 0 0 0年 10月 15日采自浙江大学华家池菜圃 ,选择大小一致的芋头清洗、风干 ,装入 0 .0 2mm厚…     

The physiology of Cymbidium plantlets cultured in vitro under conditions of high carbon dioxide and low photosynthetic photon flux density

Summary

Cymbidium plantlets were grown in vitro under conditions of high CO₂ and low photosynthetic photon flux density using the Miracle Packt culture system. Shoots and roots of plantlets showed differential growth characteristics. Shoot growth was not different in plantlets cultured under CO₂-enriched (CDE) and non-enriched (NCDE) conditions. Root growth was promoted in plantlets cultured under CDE in the presence or absence of 2% sucrose (S) with rockwool (R) as the supporting material. Growth was poor in plantlets cultured in 1% agar. Root growth was best in plantlets cultured under CDE R+S. Sucrose is still an important component for root growth under CDE conditions even though CO₂ can be used as an alternative carbon source. Photosynthetic measurements (CO₂ uptake and total Rubisco activity) showed the presence of active and operational photosynthetic machinery in plantlets cultured under CDE and NCDE conditions. The apparent lack of photoautotrophy (as evident from the lack of starch grains in chloroplasts) in plantlets cultured under NCDE conditions is not the result of a lesser potential for photoautotrophy; rather it is a consequence of sub-optimal CO₂ concentrations within the culture vessels.     

砂梨采后生理及贮藏技术研究

简述砂梨果实采后呼吸、乙烯等主要生理特性,综述国内外预冷、CA气调贮藏、冷藏及1-MCP保鲜剂等贮藏技术对砂梨保鲜效果的研究进展.     

灵武长枣贮藏保鲜试验

以灵武长枣鲜枣为贮藏试材．采用PE打孔保鲜袋＋气调剂包装的鲜枣贮藏效果好；采前喷布0．2％氯化钙溶液的鲜枣耐贮藏；贮前用鲜枣专用保鲜剂浸泡．能明显降低贮藏中枣果的霉烂率；随着色度的增加贮藏好果率降低；早成熟的枣不耐贮藏，9月下旬至10月上旬采收的果实贮藏效果好。     

Enhanced micropropagation of Dendrobium huoshanense C.Z. Tang et S.J. Cheng through protocorm-like bodies: The effects of cytokinins,carbohydrate sources and cold pretreatment

The effects of cytokinins, carbohydrate sources and cold pretreatment on the conversion of protocorm-like bodies (PLBs) to shoots were investigated for the enhancement of micropropagation of Dendrobium huoshanense C.Z. Tang et S.J. Cheng, an endangered medicinal plant in China. The effects of cytokinins and carbohydrate sources on the conversion of PLBs to shoots depended on their types and concentrations. The best results in terms of shoot development from PLBs occurred on 1/2 MS medium supplemented with 20 μM kinetin and 10 g l⁻¹ maltose. Cold pretreatment at 10 °C for 1–2 weeks significantly enhanced the conversion of PLBs to shoots, and over 1300 shoots were obtained from one gram of PLBs after 3 months of culture. The developed shoots were rooted on growth regulator-free MS medium supplemented with 8 g/l banana paste to give complete plantlets, which were successfully acclimatized with a survival rate of approximately 65%. The results indicate that a suitable cold pretreatment (10 °C for 1 week) followed by the use of 20 μM kinetin and 10 g/l maltose in 1/2 MS medium would produce a large number of shoots from PLBs for plantlet regeneration of D. huoshanense.     

黄皮耐贮性与果皮超微结构的研究

以大鸡心、小鸡心、圆种3个黄皮品种为材料,探讨了常温(28～33℃)贮藏3个黄皮品种耐贮性与果皮超微结构的差异。结果表明,圆种黄皮最耐贮藏,小鸡心次之,大鸡心耐贮性最差。经扫描电镜观察,黄皮外表皮薄,只有2～3层细胞构成。外表皮结构疏松,外表面有小裂隙,外被一层均匀的蜡质,密布表皮毛和气孔,果实分泌物中有结晶状物。新鲜采收黄皮果皮中即有病原微生物潜伏,随贮藏时间延长,黄皮果外表皮病原物大量繁殖,表皮毛与蜡质层脱落,气孔也逐渐闭合。3个品种黄皮外表皮的其它特征,如表面皱折大小与数量、表皮毛和气孔的密度、形状和大小等有明显差异。     

枣的耐藏性及其生物学特性研究

对１４个枣的鲜食、制蜜品种的耐藏性进行了比较研究，结果表明：早熟脆枣，灵宝圆枣、油福水枣、合阳玲玲枣比较耐藏；枣果实耐藏性与呼吸速率呈显著负相关，与失水速率呈显著正相关。果实呼吸速率，失水速率、果肉细胞大小和果肉比重是影响耐藏性的主要因子。     

魔芋多糖和竹叶汁对绿竹笋保鲜效果的研究

以易变质的绿竹笋为试材，通过天然产物魔芋多糖和竹叶中的有效成分对绿竹笋进行涂膜处理，并在3℃低温下贮存。结果表明：经涂膜的绿竹笋，其失重率，老化程度大大低于未经涂膜的。涂膜的绿竹笋在低温下贮存至第20天时，其木质纤维化程度低，有效地阻绿竹笋的老化变质，延长了贮藏期，且外观品质良好。     

Improvements in somatic embryogenesis protocol in Feijoa (Acca sellowiana (Berg) Burret): Induction,conversion and synthetic seeds

Pineapple guava (Acca sellowiana) syn. Feijoa sellowiana, a Brazilian indigenous Myrtaceae is under domestication in South Brazil. Previous works showed that this species is responsive to somatic embryogenesis and recalcitrant to conventional methods of clonal propagation. In the present work it was evaluated the role of components of culture medium in the induction and development of somatic embryos. The technology of synthetic seeds was also evaluated. Zygotic embryos were inoculated in LPm medium supplemented with 8 mM glutamic acid and 8 mM l-glutamine, 2,4-dichlophenoxiacetic acid (20 μM) and myo-inositol. For conversion of somatic embryos and synthetic seeds it was tested the effect of 6-benzylaminopurine and gibberellic acid combined or not with activated charcoal. The highest values for embryogenetic induction (100%) and number of somatic embryos/explant (113) were observed in the LPm medium supplemented with Glu (8 mM), and 2,4-D. The culture medium supplemented with BA (0.5 μM) and GA₃ (1 μM) and activated charcoal (1.5 g L⁻¹) enhanced the conversion of somatic embryos to plantlets. Pre-germinated somatic embryos encapsulated in sodium alginate with BA (0.5 μM) and GA₃ (1 μM) developed radicles. The use of synthetic seed was a requisite for the survival of plantlets.     

贮藏期对资丘木瓜药材质量的影响

以资丘木瓜药材为试材,将采收后的资丘木瓜果实进行晒制干燥,封装贮藏在阴凉干燥处,研究了不同贮藏时间对资丘木瓜含水量、齐墩果酸、熊果酸含量的影响。结果表明:随着贮藏时间的增加,资丘木瓜药材中含水量从9.10%上升到14.60%,贮藏期在18个月内,资丘木瓜中齐墩果酸、熊果酸含量以及二者之和基本保持稳定,而18个月后含量开始下降,并且低于药典中的含量。该试验研究资丘木瓜商品药材0~30个月贮藏期的含水量、有效成分含量的变化,发现较长贮藏期引起药材质量下降,以期为资丘木瓜的生产管理和质量标准的制定提供科学依据。     

Antioxidant Bioactive Compounds and Spoilage Microorganisms of Wax Apple (Syzygium samarangense) during Room Temperature Storage

Postharvest deterioration of wax apple leads to unacceptable appearances, physical and quality losses that raise serious concerns commercially. Bioactive compounds of wax apple and spoilage microorganisms were studied at room temperature storage (23 ± 1 °C). Antioxidant activity and total phenolic content increased up to a maximum of 1.56 mg AAE/100 g and 88.37 mg GAE/100 g, while prolonged storage resulted in 70.0% and 33.6% loss, respectively. Further, 80% loss in vitamin C content was observed from an initial value of 21.63 mg AAE/100 g during storage. Bacterial isolates of Enterobacter sakazakii, Klebsiella pneumoniae, Klebsiella planticola, Pantoea agglomerans, Chromobacterium violaceum, and Streptomyces roseochromogenus with microbial load of 1.19 * 10⁸ CFU/g fresh weight, and fungal isolates of Penicillium purpurogenum, Mucor hiemalis, Aspergillus niger, Aspergillus fumigatus, and Candida tropicalis with a total load of 5.64 * 10⁷ CFU/g fresh weight were identified as spoilage organisms. Bacterial isolates of Klebsiella pneumoniae was the most prevalent at 47.78%, occurring 21 times, while Penicillium purpurogenum was the most prevalent fungi, occurring 5 times at 38.46%. Results have significant implications on measures to preserve quality of wax apples during storage by adoption of advanced postharvest handling and processing approaches.     

莲藕贮藏中褐变度及多酚氧化酶活性的初步研究

研究了不同温度、不同莲藕状态、不同褐变抑制剂处理对莲藕褐变度及多酚氧化酶活性的影响。实验结果表明，低温、节藕、抗坏血酸（０．２５％）＋柠檬酸（０．２％）和ＮａＨＳＯ３（０．０５％）＋柠檬酸（０．２％），莲藕褐变最轻。多酚氧化酶活性随时间的延长而减弱     

不同品种(系)梨贮藏过程果实失重率与果皮叶绿素、蜡质含量的变化

以香梨、‘早酥’梨及其11个杂交后代为材料,在冷库和室温条件下贮藏,研究贮藏过程梨果实失重率与果皮蜡质、叶绿素含量的变化规律。结果表明:冷库和室温条件下贮藏,果实失重率、烂果率呈上升趋势,品种(系)间差异较大,冷库贮藏果实失重率和烂果率明显低于室温下贮藏;果皮叶绿素含量呈下降趋势,冷库贮藏果实的果皮叶绿素含量明显高于室温贮藏;不同贮藏条件不同品种(系)果皮蜡质含量的峰值出现时间不同,冷库贮藏的蜡质含量明显高于室内贮藏。冷库贮藏效果好。