以叶盘为外植体的白桦的再生

从不同的激素组成(BA, K T, 2, 4~D, NAA, GA₃)、基本培养基(MS, WP)、外植体放置的方向性进行了实验, 建立了以白桦叶盘为外植体的再生系统。当叶盘向轴面朝下放置在培养基上时, 三周后, 从叶盘边缘生出不定芽。不定芽的诱导率为64%, 平均每片叶盘可生出6 个不定芽。叶盘再生系统的建立为白桦的遗传转化提供了前提。     

亚麻植株的再生及诱导因素的研究

亚麻根、下胚轴、茎和叶外植体在适宜培养基上可产生愈伤组织和不定芽。愈伤组织在分化培养基上产生幼芽。在生根培养基上小苗生根长大。组织细胞学观察表明,下胚轴表皮、皮层和韧皮部细胞都能产生小分生细胞团,后者形成不定芽和愈伤组织。愈伤组织边缘区域分化芽原基,内部产生大量的分生组织结节和维管组织结节。根原基起源于维管组织结节的形成层状细胞。不同器官外植体再生植株的潜力不同,对诱导条件的反应有差别,其中茎和下胚轴切段易兼生不定芽和愈伤组织,再生植株频率高。外源激素、基本培养基和损伤刺激明显影响植株再生。     

甘蓝型油菜下胚轴和带柄子叶再生体系研究

以甘蓝型油菜野油19号的下胚轴和带柄子叶为外植体,研究其下胚轴和带柄子叶在不同浓度激素配比下的分化率及再生频率的变化。该品系的油菜下胚轴和带柄子叶在1.5 mg/L的2,4-D中预培养4 d后,转入分化培养基中,其愈伤组织形成早,发生快,再生频率和分化频率均较高。其中,下胚轴转入MS+3 mg/L 6-BA+0.1 mg/L NAA培养基中的分化率和再生频率最高,再生频率达到86.67%;带柄子叶外植体的再生频率要比下胚轴的再生频率低,在MS+4 mg/L 6-BA+0.3 mg/L NAA的分化培养基中芽的再生频率为46.67%。本研究初步建立了甘蓝型油菜野油19号的高频率再生体系。     

紫苏不同外植体的培养及再生

探讨了紫苏（Perilla frutescens）不同外植体在不同激素的不同浓度及组合培养基中的培养及再生情况,建立了紫苏的高效快捷再生体系。结果表明：（1）再生率由高到低依次是茎尖、真叶、子叶和下胚轴;（2）茎尖无论有无激素处理,再生率都在85%以上,添加合适的激素可提高增殖系数。真叶在MS＋TDZ 0.05 mg/L～0.1 mg/L范围处理下再生率均达70%左右。子叶最适激素组合为MS＋KT 1.0 mg/L＋IAA 1.0 mg/L,再生率22.22%。下胚轴最适激素组合为MS＋6-BA 1.0 mg/L＋IAA 1.0 mg/L,再生率14.61%;（3）再生苗在1/2 MS中生根良好,生根率达86.67%,平均根长7.36 cm;（4）真叶外植体可形成叶簇,并可反复诱导不定芽发生,增殖能力强,培养周期短,是最理想的外植体。     

西瓜的组织培养和植株再生

为了进行抗病毒基因工程在西瓜育种上应用的研究,我们首先开展了西瓜快繁技术的摸索工作。以京欣1号西瓜的子叶、下胚轴、花药为外植体诱导愈伤组织及植株的再生。将外植体培养在 MS 基本培养基附加不同量及不同组合的2,4-D、BA、KT、NAA 的 PH5.8的培     

6-BA、NAA和2,4-D不同配比对荠菜愈伤组织诱导、生长及植株再生的影响

以野生荠菜[Capsella bursa-pastoris （L.） Medic]无菌苗为试材,选取下胚轴、子叶、真叶和叶柄作为外植体,研究了不同外植体的出愈情况,不同植物生长调节剂及配比对愈伤组织诱导、继代及植株再生的影响。结果表明：（1）下胚轴作为外植体出愈情况最好,继代后生长快;（2）下胚轴愈伤组织的最适植株再生培养基为MS＋2～3mg·L-16-BA＋0.2~0.6mg·L-1NAA;（3）愈伤组织培养阶段的2,4-D浓度对其植株再生能力有影响。     

观赏羽衣甘蓝高频再生体系的建立

观赏羽衣甘蓝是一种赏食兼用的耐冻优良景观植物.为了通过基因工程手段赋予其抗虫性,并进一步提高其低温耐受性,获得新的抗性种质,本研究以优良育种品系为试材,详细探讨了影响离体培养不定芽再生的因素,建立了高效再生体系.以8份不同类型羽衣甘蓝基因型的带柄子叶、子叶、下胚轴为外植体,研究了不同基因型、不同外植体、不同的培养基激素浓度配比及添加AgNO3对不定芽诱导的影响.结果表明:无论基因型及使用的培养基,带柄子叶均为最佳外植体;不同的基因型、不同外植体其最佳的芽诱导培养基不同;筛选出两份材料,其带柄子叶分别在L6(MS+6-BA 1.0 mg/L+NAA 0.1mg/L)及L3(MS+6-BA 1.5 mg/L)培养基中不定芽诱导率为100%,下胚轴诱导率最高也能达88.33%;培养基中添加4 mg/L AgNO3不利于羽衣甘蓝的不定芽诱导;再生株生根以MS+NAA 0.1 mg/L效果好,生根率可达100%.     

连翘试管植株的诱导

植物名称:连翘(Forsythia Suspensa)。材料类别:子叶、苗端、下胚轴。取成熟的连翘种子,进行常规消毒后,接种于不加激素的MS培养基上。当苗高1.5—2cm时,在无菌条件下切取子叶、苗端、下胚轴分别接种。培养条件:以MS培养基为基本培养基,添加不同的激素,组成不同激素水平的培养基进行试验。在室温(17—23℃)黑暗条件下诱导愈伤组织,在26℃左右,每日光照10—12小时(光强为2000     

大白菜下胚轴离体不定芽高效再生体系的研究

以大白菜的下胚轴为外植体,比较了不同浓度TDZ和6-BA两种细胞分裂素与不同浓度NAA相配合的培养基上不定芽再生的差异,并利用筛选出的高效再生培养基研究外植体苗龄、切段来源、接种方式以及品种对不定芽再生的影响。结果表明:与6-BA相比,TDZ对诱导下胚轴不定芽再生更有效,在M S+TDZ 0.3 m g.L-1+NAA0.5 m g.L-1+A gNO35 m g.L-1的培养基上,下胚轴不定芽再生频率高达87.8%,平均每下胚轴再生不定芽数也达到15.1个;3~5 d苗龄之间的下胚轴不定芽再生能力无显著差异,再生频率均达到80%以上,此后随着苗龄的增加,不定芽分化频率快速下降,苗龄为7 d时再生频率只有51.1%;下胚轴不同切段不定芽再生能力由强到弱表现为:上部切段>中部切段>下部切段;以正插(形态学下端插入培养基)方式接种的外植体不定芽再生能力显著大于反插(形态学上端插入培养基)和平放的;不同品种大白菜下胚轴的不定芽再生能力有一定差异。     

棉花高频体细胞胚胎发生及再生体系建立

棉花的体细胞胚胎发生率低,限制了转基因棉花的发展。为了扩大可再生棉花的基因型,发展新疆优质棉花的特点,以新疆的主要栽培品种新陆早33为材料,以下胚轴为外植体,使用葡萄糖,麦芽糖作为主要碳源,用Phytagel固化,对不同激素的浓度组合和培养条件进行探索,对棉花胚性愈伤的诱导到体细胞胚胎的发生阶段进行优化,体细胞胚胎成熟以后进行萌发培养可以获得正常的植株。通过试验证明,有利于棉花的愈伤组织生长的激素浓度为KT 0.1 mg/L,2,4-D 0.1 mg/L,下胚轴的中部诱导愈伤形态最好。体细胞胚胎发生阶段以KT,IBA组合,以低盐培养基进行子叶胚的成苗,建立了再生体系。     

长白山不同海拔白桦幼苗移栽至同一生境的光合及反射光谱特性

环境是影响植物生理性状的主要因素之一,通过改变植物的生长环境来研究植物生理性状的改变是目前研究植物生理生态的热点,而高海拔地区多样的环境为研究物种适应环境变化提供了良好的实验条件。本研究通过移栽的技术手段,将分布在海拔750 m、海拔1200 m和海拔1400 m的3~5年生白桦幼苗移植到海拔750 m相同的林下环境条件下,将3种白桦移栽幼苗和野生白桦幼苗的光响应参数、光谱反射率以及光谱反射指数进行对比研究,分析移栽初期和移栽一年后植物生理性状的异同,探索白桦幼苗迁入新环境的适应性。研究结果表明:移栽初期,通过对比不同海拔来源的白桦移栽幼苗彼此之间各项生理性状以及与原海拔野生白桦幼苗的生理性状发现,包括最大净光合速率(A_(max))、气孔导度(G_s)、胞间CO_2浓度(C_i)在内的生理性状差异显著(P0.05),幼苗光谱反射指数差异性显著(P0.05)。经过一年的适应,不同海拔来源的白桦幼苗与移栽地海拔750 m野生白桦幼苗的生理性状之间差异不显著(P0.05),幼苗光谱反射指数差异性不显著(P0.05),而与原海拔野生幼苗生理性状之间差异显著(P0.05),幼苗光谱反射指数差异显著(P0.05)。在移栽初期,移栽幼苗的各项生理指标已经因环境的改变而发生变化,但仍保留原海拔野生幼苗的生理特性;移栽一年后,移栽幼苗逐渐适应环境,其相关生理性状发生改变,并趋同于移栽地野生白桦幼苗的生理性状。对比一个生长季前后白桦移栽幼苗生理性状的变化可以发现,白桦作为先锋种植物,在新迁入环境后具有良好的环境适应性,能通过调整生理性状适应新环境。研究对幼苗在林下的演替以及森林的更新具有借鉴意义。     

THE MOVEMENT OF IAA-C14 IN THE HYPOCOTYL OF PHASEOLUS VULGARIS

The amount of IAA-C¹⁴ transported basipetally through excised hypocotyl sections was strongly affected by the pH of the donor blocks, less so by the pH of the receivers. The effect of donor pH was mostly on uptake. The small amount of acropetal movement was not noticeably affected by pH. Sucrose added to the donor resulted in increased basipetal transport. The time-course of C¹⁴ movement into basal receivers followed a linear course from 1.5 to 3 hr as expected, but there was no net loss from the donors until after 30-45 min. The usual type of velocity calculation, which assumes uptake starting from zero time, would therefore be lower than the true value. Basipetal transport through segments cut from various positions in the hypocotyl and from seedlings of various ages was maximal in 6-8-day-old hypocotyl segments cut 25-30 mm below the cotyledons. Acropetal movement was minimal at all positions of all ages tested.     

In vitro morphogenetic response and distribution of endogenous plant hormones in hypocotyl segments of snapdragon (Antirrhinum majus L.)

Snapdragon seedlings, 20 mm in length, were cut into 5 segments from the cotyledon to the root, which were cultured in vitro on hormone-free MS medium. Adventitious shoot formation was highest in the basal hypocotyl segments with stimulation by the addition of BA. Endogenous cytokinins were higher in the basal hypocotyl segments than in the two upper hypocotyl segments, whereas auxin content was higher in the two upper than in the basal hypocotyl segments. Ratios of cytokinins to auxin were also the highest in the basal hypocotyl segment. A general principle in in vitro culture that a high concentration of cytokinin and a low concentration of auxin promotes the induction of shoot morphogenesis was confirmed from measurements of endogenous growth regulator concentrations.     

白桦、落叶松不同器官水浸液对种子萌发和播种苗生长的种间化感作用

研究了白桦的根、枝、叶,落叶松的根、枝、叶和皮不同浓度水浸液(5.0、12.5、25.0、50.0和100.0 mg·mL-1)对另一树种种子萌发和当年生播种苗生长的化感作用.结果表明:落叶松不同器官水浸液(根5.0 mg·mL-1除外)处理均抑制白桦种子的萌发,其平均发芽率为:对照(75％)＞根(66％)＞皮(59％)＞枝(58％)＞叶(54％),随浓度增加,根、枝水浸液的抑制作用增强,而叶、皮水浸液的抑制作用减弱.落叶松各器官水浸液对白桦胚根和胚轴生长具有较强的抑制作用,且以100.0 mg·mL-1浓度的叶水浸液抑制作用最强,胚根和胚轴长分别降低38％和55％(P＜0.05).落叶松枝、叶水浸液处理对白桦播种苗的苗高、地径及生物量有一定的促进作用,根、皮水浸液则具有抑制作用.白桦各器官水浸液能促进落叶松种子的萌发,根和枝的水浸液促进胚轴生长,叶的水浸液抑制胚轴生长,50.0和100.0 mg·mL-1浓度的叶水浸液处理的种子胚轴分别较对照降低27％和28％(P＜0.05).其对落叶松播种苗生长的影响以促进作用为主,5.0 mg·mL-1浓度的白桦叶水浸液处理的落叶松苗高、地径、生物量分别较对照高54％、60％和100％ (P＜0.05).白桦与落叶松之间存在明显的化感作用,混交可能对林木生长产生一定的促进作用.     

Compensation among root classes in Phaseolus vulgaris L.

The activity of soil pathogens, competition for assimilates, and the changing availability of below-ground resources make root systems subject to a continuous and dynamic process of formation and loss of both fine and coarse roots. As hypocotyl borne roots appear later than other root classes, they may serve to functionally replace basal and primary roots lost to biotic and abiotic stress. Using common bean (Phaseolus vulgaris L.), we conducted experiments in solution and solid media culture with treatments involving the removal of part of the root system (basal, hypocotyl borne or primary roots), phosphorus availability, and depth of seeding to test the hypothesis that there are compensation mechanisms among basal, hypocotyl borne and primary roots to cope with the loss of part of the root system. The root system was highly plastic in response to root excision, which resulted in the maintenance of below-ground biomass accumulation. In most cases, this compensation among root classes was enough to maintain plant performance in both phosphorus sufficient and phosphorus stressed plants. Removal of a specific root class induced an increase in the growth of the remaining root classes. All root classes, but especially the primary root, contributed to the compensation mechanism in some way. Primary roots represented around 10% of the root system in control plants and this proportion increased dramatically (up to 50%) when other root classes were removed. In contrast, negligible compensatory re-growth was observed following removal of the primary root. Greater planting depth increased the production of hypocotyl borne roots at the expense of basal roots. The proportion of hypocotyl borne roots increased from 25% of the whole root system when seeds were placed at a depth of 2 cm to 30% when they were placed at 5 cm and to 38% when placed at 8 cm, with corresponding decreases in the proportion represented by basal roots. The common feature of our observations is the innate ability of the root system for its own regeneration. Total root biomass maintained strict allometric relationships with total shoot biomass in all treatments. Re-stabilization of root to shoot balance after partial root loss is governed by overall plant size following allometric relationships similar to undisturbed plants. However, the pattern of this root regeneration was not uniform since the way the three root classes compensated each other after the removal of any one of them varied among the different growth media and phosphorus supply conditions. The resulting changes in root architecture could have functional significance for soil resource acquisition.     

An improved and reliable chili pepper (Capsicum annuum L.) plant regeneration method

In this work we report a new method forin vitro chili pepper (Capsicum annuum L.) plant regeneration based on shoot formation from wounded hypocotyls. Chili pepper seeds were surface sterilized and germinated on agar (0.8%) at 25 ± 2°C in the dark. Five factors that may influence shoot regeneration were studied: age of seedlings, hypocotyl wounding site, time elapsed between wounding the hypocotyls and decapitation of seedlings, culture media and cultivars. In order to study the influence of the first three factors on shoot regeneration, the apical, middle or basal hypocotyl regions of seedlings of cv. Mulato Bajio at different stages of development (9, 15, 16, 21 and 28 d old) were wounded with a syringe needle, and the seedlings were cultured on MS semisolid medium without growth regulators at 25 ± 2°C under a 16/8 h light/dark photoperiod (daylight fluorescent lamps; 35 mol m-² s-^-1) until decapitation. The seedlings were decapitated (3 mm below the cotyledons) at different times after wounding (0, 2, 4, 10, 12 and 14 d), and each explant was evaluated for bud and shoot formation ( 5 mm in length) at the wounded site after 30 d of incubation. In general, seedlings at the stage of curved hypocotyl (9 d old) wounded in the apical region of hypocotyl were the best explants for shoot regeneration when inoculated on culture medium without growth regulators. Decapitation after wounding also influenced the shoot regeneration efficiency, with 10–14 d being the best period. Up to 90% shoot regeneration in cv. Mulato Bajio was obtained under these conditions. Statistically significant differences were observed for shoot formation among 21 cultivars tested. Regeneration of whole plants was achieved by rooting the shoots with indole-3-butyric acid pulses of 60 mg L^–1 for 3 h and then subculturing on MS medium without growth regulators.     

皱叶甘蓝的原生质体培养与植株再生

皱叶甘蓝(Brassica oleracea L. var. subauda)“SA61”(SV)的叶及下胚轴分离的原生质体在 MS_1(修改的MS)培养基上细胞壁再生和分裂启动较快。叶原生质体在 DPD_1(修改的 DPD)培养基上获得了最高的分裂率和植板率;下胚轴原生质体在MS_1上获得最佳的培养效果。叶原生质体培养3—4天后见到一次分裂;下胚轴原生质体在48小时左右即可发生一次分裂。原生质体培养 20—30天后形成肉眼可见的微愈伤颗粒,40天左右即可达1mm大小。在7种不同培养基上增殖微愈伤组织,MB_2、MB_3表现了优良的效果。在MS_2培养基上的芽分化效果最为理想。在不加任何激素的MS培养基上诱导生根,2周后得到再生植株。     

人脐带间充质干细胞分离培养方法的研究

目的探讨人脐带间充质干细胞(MSCs)体外分离培养的最佳方法。方法无菌条件下采集早产儿(不足37周)和足月儿的脐带,分离MSCs,比较胎龄、脐带新鲜程度、分离方法和不同培养基对脐带MSCs原代培养过程的影响,通过免疫荧光法检测脐带MSCs表面标记物的表达情况,观察脐带MSCs的生物学特性。结果足月分娩,新鲜脐带,采用组织块平铺法和MesencultTM培养基,脐带MSCs原代培养成功率较高。相同条件下,早产儿脐带MSCs原代培养成功率低于足月分娩脐带。人脐带MSCs高表达CD44、CD90和CD29。结论筛选出一种人脐带MSCs体外分离培养的最佳方法。     

A highly efficient in vitro plant regeneration system and Agrobacterium-mediated transformation in Plumbago zeylanica

Plumbago zeylanica is a unique model for studying flowering plant gametogenesis, heterospermy, and preferential fertilization, yet understanding the control of related molecular mechanisms is impossible without efficient and reproducible regeneration and stable genetic transformation. We found three key factors for enhancing successful regeneration: (1) tissue source of explants, (2) combination and concentration of growth regulators, and (3) culture conditions. The highest frequency of shoot regeneration was achieved using hypocotyl segments cultured on MS basal medium supplemented with BA 2.0 mg/l, NAA 0.75 mg/l, adenine 50 mg/l and 10% (v/v) coconut milk under subdued light at 25±2°C; under these conditions, each hypocotyl segment produced over 30 shoots, arising primarily through direct organogenesis after 3 weeks of culture. Regenerated shoots rooted easily on half-strength basal MS medium and were successfully established in the greenhouse. Using this tissue culture protocol, reporter gene GUS under the constitutive CaMV 35S promoter was introduced into P. zeylanica cells of petiole, cotyledon and hypocotyl with A. tumefaciens strains AGL1 and LBA4404. Transient expression was observed in all recipient tissues. Stable transgenic calli originating from petiole were obtained.